+----------------------------------+--------+-----+-------------------+
| ![](media/image1.w               |        | **A |                   |
| mf){width="0.3576388888888889in" |        | dvi |                   |
| height="0.33958333333333335in"}  |        | sor |                   |
|                                  |        | y** |                   |
| U.S. Department                  |        |     |                   |
|                                  |        | **C |                   |
| of Transportation                |        | irc |                   |
|                                  |        | ula |                   |
| **Federal Aviation**             |        | r** |                   |
|                                  |        |     |                   |
| **Administration**               |        |     |                   |
+----------------------------------+--------+-----+-------------------+
| **Subject:** MAINTENANCE OF      | **D    |     | **AC No:**        |
| AIRPORT VISUAL AID FACILITIES    | ate:** |     | 150/5340-26A      |
|                                  | 4/     |     |                   |
|                                  | 4/2005 |     | **Change:**       |
|                                  |        |     |                   |
|                                  | **Ini  |     |                   |
|                                  | tiated |     |                   |
|                                  | by:**  |     |                   |
|                                  | A      |     |                   |
|                                  | AS-100 |     |                   |
+----------------------------------+--------+-----+-------------------+

**1. PURPOSE.** This Advisory Circular (AC) provides recommended
guidelines for maintenance of airport visual aid facilities.

**2. APPLICABILITY.** The standards and practices contained in this AC
are recommended by the Federal Aviation Administration (FAA) for use by
airports in the maintenance of airport owned lighted visual aid
facilities.

**3. CANCELLATION.** AC 150/5340-26 Maintenance of Airport Visual Aid
Facilities, dated August 26, 1982, is cancelled.

**4. PRINCIPAL CHANGES.**

a.  Safety procedures and potential hazards from series circuits have
    been expanded and clarified.

b.  Maintenance management has been updated and expanded to cover use of
    Original Equipment Manufacturer Parts.

c.  Electrical test equipment has been updated to provide information on
    current types of testing equipment.

d.  Preventive maintenance has been revised to include procedures for
    more recently designed light fixtures and
    requirements/recommendations for photometric testing of runway
    lighting systems.

e.  Added sections on airfield lighted guidance signs, Precision
    Approach Path Indicator (PAPI) and airport lighting control and
    monitoring systems (ALCMS).

f.  Deleted section on marking of paved areas on airports.

g.  Expanded section on troubleshooting of airport lighting series
    circuits.

h.  Added maintenance tolerances in Appendix A for elevated and
    in-pavement runway guard lights, stop bar lights, CAT III taxiway
    centerline lighting and PAPI.

![](media/image2.png){width="2.5541666666666667in"
height="0.5923611111111111in"}

DAVID L. BENNETT

Director of Airport Safety and Standards

**Intentionally Left Blank**

TABLE OF CONTENTS

[CHAPTER 1. INTRODUCTION. 1](#chapter-1.-introduction.)

[1.0 GENERAL. 1](#general.)

[1.1 SCOPE. 1](#scope.)

[CHAPTER 2. SAFETY. 3](#chapter-2.-safety.)

[2.0 GENERAL. 3](#general.-1)

[2.1 COMMON CAUSES OF ACCIDENTS. 3](#common-causes-of-accidents.)

[2.2 SAFETY PROCEDURES AND GUIDELINES.
3](#safety-procedures-and-guidelines.)

[2.3 ELECTRICAL HAZARDS OF SERIES LIGHTING CIRCUITS.
3](#electrical-hazards-of-series-lighting-circuits.)

[2.4 SAFETY PRACTICES. 5](#safety-practices.)

[2.5 SAFETY BOARDS. 6](#safety-boards.)

[2.6 SAFETY CHECKLIST. 7](#safety-checklist.)

[2.7 SAFETY EQUIPMENT IN VEHICLES. 7](#safety-equipment-in-vehicles.)

[2.8 ELECTRIC SHOCK. 7](#electric-shock.)

[2.9 SAFETY TRAINING. 8](#safety-training.)

[2.10 SAFETY WARNING SIGNS/DANGER TAGS.
8](#safety-warning-signsdanger-tags.)

[2.11 GROUNDING AND BONDING. 9](#grounding-and-bonding.)

[2.12 CONFINED SPACES. 9](#confined-spaces.)

[2.13 LIGHTNING. 9](#lightning.)

[2.14 TOXIC AGENTS. 10](#toxic-agents.)

[2.15 FIRE EXTINGUISHERS. 11](#fire-extinguishers.)

[2.16 FIRST AID. 13](#first-aid.)

[CHAPTER 3. MAINTENANCE MANAGEMENT.
15](#chapter-3.-maintenance-management.)

[3.0 MAINTENANCE PHILOSOPHY. 15](#maintenance-philosophy.)

[3.1 MAINTENANCE SCHEDULE. 15](#maintenance-schedule.)

[3.2 MAINTENANCE RECORDS. 15](#maintenance-records.)

[3.3 PREVENTIVE MAINTENANCE PROGRAM.
16](#preventive-maintenance-program.)

[3.4 RECORD RETENTION. 17](#record-retention.)

[3.5 REFERENCE LIBRARY. 17](#reference-library.)

[3.6 SPARE PART PROVISIONING. 17](#spare-part-provisioning.)

[CHAPTER 4. TEST EQUIPMENT. 21](#chapter-4.-test-equipment.)

[4.0 INTRODUCTION. 21](#introduction.)

[4.1 TYPES OF EQUIPMENT AND USAGE. 21](#types-of-equipment-and-usage.)

[CHAPTER 5. PREVENTIVE MAINTENANCE.
27](#chapter-5.-preventive-maintenance.)

[5.0 GENERAL. 27](#general.-2)

[5.1 AIRPORT LIGHTING VAULT. 27](#airport-lighting-vault.)

[5.2 CONSTANT CURRENT REGULATORS (CCRs).
32](#constant-current-regulators-ccrs.)

[5.3 LIGHT FIXTURE AND BASE MAINTENANCE.
36](#__RefHeading___Toc100190761)

[5.4 ILLUMINATED RUNWAY AND TAXIWAY GUIDANCE SIGNS.
46](#illuminated-runway-and-taxiway-guidance-signs.)

[5.5 ROTATING BEACONS. 46](#rotating-beacons.)

[5.6 LIGHTED WIND CONE ASSEMBLIES. 49](#lighted-wind-cone-assemblies.)

[5.7 PRECISION APPROACH PATH INDICATOR (PAPI) SYSTEM.
51](#precision-approach-path-indicator-papi-system.)

[5.8 VISUAL APPROACH SLOPE INDICATOR (VASI).
54](#visual-approach-slope-indicator-vasi.)

[5.9 RUNWAY END IDENTIFIER LIGHTS (REILs).
56](#runway-end-identifier-lights-reils.)

[5.10 MEDIUM APPROACH LIGHTING SYSTEM (MALS, MALSF, MALSR).
60](#medium-approach-lighting-system-mals-malsf-malsr.)

[5.11 HAZARD BEACONS AND OBSTRUCTION LIGHTS.
62](#hazard-beacons-and-obstruction-lights.)

[5.12 AIRPORT LIGHTING CONTROL AND MONITORING SYSTEMS (ALCMS).
64](#airport-lighting-control-and-monitoring-systems-alcms.)

[5.13 STANDBY AND EMERGENCY POWER SYSTEMS.
65](#standby-and-emergency-power-systems.)

[CHAPTER 6. TROUBLESHOOTING PROCEDURES FOR SERIES LIGHTING CIRCUITS.
71](#chapter-6.-troubleshooting-procedures-for-series-lighting-circuits.)

[6.0 INITIAL FAULT INVESTIGATION. 71](#initial-fault-investigation.)

[6.1 LOCATING GROUND FAULTS IN THE FIELD.
72](#locating-ground-faults-in-the-field.)

[6.2 LOCATING OPEN CIRCUIT FAULTS. 73](#locating-open-circuit-faults.)

[6.3 INTERCONNECTED CIRCUIT FAULTS. 74](#interconnected-circuit-faults.)

[6.4 INTENTIONAL GROUND TEST. 74](#intentional-ground-test.)

[6.5 GROUNDED OUTPUT TEST FOR LOCATING OPEN CIRCUITS.
76](#grounded-output-test-for-locating-open-circuits.)

[6.6 USING HEAT SENSING EQUIPMENT TO LOCATE GROUND FAULTS.
76](#using-heat-sensing-equipment-to-locate-ground-faults.)

[6.7 USING CABLE FAULT LOCATING EQUIPMENT TO LOCATE GROUND FAULTS.
77](#using-cable-fault-locating-equipment-to-locate-ground-faults.)

[APPENDIX A. STANDARDS AND TOLERANCES.
89](#appendix-a.-standards-and-tolerances.)

# CHAPTER 1. INTRODUCTION.

## 1.0 GENERAL.

This Advisory Circular (AC) provides guidance for the recommended
minimum maintenance practices to be used in the maintenance of airport
visual aid facilities. Use this circular in conjunction with information
available in instruction books, equipment manuals, handbooks and other
ACs. Since the function of such facilities is to assist in the safe and
efficient movement of aircraft during landing, takeoff and taxiing
maneuvers, it is essential that a high degree of operating reliability
be maintained. To achieve this, it is necessary to establish and
maintain an effective preventive maintenance program. This AC provides
suggestions on establishing such a program but, due to the varying
complexities of airports and facilities provided, such a program must be
tailored to suit each individual airport's particular needs. Since
corrective and preventive maintenance procedures for specific equipment
are adequately covered in manuals supplied with the equipment, this AC
addresses maintenance topics of a more general nature.

## 1.1 SCOPE.

This AC provides system maintenance information for establishing a
preventive maintenance program for airport visual aid facilities. The
information provided covers the following systems:

-   Airport lighting vault and series lighting circuits

-   Constant current regulators

-   Runway and taxiway elevated edge lighting systems

-   Runway and taxiway in-pavement lighting systems

-   Runway guard lights and stop bar lights

-   Illuminated runway and taxiway signs

-   Rotating beacons

-   Lighted wind cone assemblies

-   Precision Approach Path Indicator (PAPI) system

-   Visual Approach Slope Indicator (VASI)

-   Runway End Identifier Lights (REIL) and Omni directional Approach
    Light System (ODALS)

-   Medium Intensity Approach Light System (MALS, MALS/F, MALS/R)

-   Hazard beacons and obstruction lights

-   Control systems

-   Standby engine generator systems

In addition to these equipment topics, this circular also covers
recommended safety practices and suggested troubleshooting procedures
for airport series lighting circuits.

**Intentionally Left Blank**

# CHAPTER 2. SAFETY.

## 2.0 GENERAL.

This chapter contains information that will aid airport owners/operators
in establishing an effective safety program. Safety is the
responsibility of each individual, regardless of position. Safety must
be practiced daily in every maintenance activity that is performed.
Local operational procedures and OSHA requirements should also be
followed. The safety program established at each airport should include
preventive safety precautions used when servicing the equipment and
first-aid procedures for use in the event of an injury.

## 2.1 COMMON CAUSES OF ACCIDENTS.

Some common causes of accidents are listed below:

a.  Working on equipment without adequate coordination with equipment
    users.

b.  Working on equipment without sufficient experience on that
    equipment.

c.  Failure to follow instructions in equipment manuals.

d.  Failure to follow safety precautions.

e.  Failure to properly lock out equipment.

f.  Using unsafe equipment.

g.  Becoming lax due to working in a familiar environment.

h.  Poor housekeeping of work areas.

i.  Working at unsafe speeds.

The number one cause of accidents is working at unsafe speeds. This is
often the main contributing factor in failing to follow proper safety
guidelines in all the other causes outlined in the list above. The
perception that there is not enough time to take proper safety
precautions or think through the proper procedures has the potential for
causing an accident. Even in emergency repair situations, care must be
taken to make the time to follow proper safety procedures to avoid
injury or death.

## 2.2 SAFETY PROCEDURES AND GUIDELINES.

Most visual aids are exposed to weather and moisture and may develop
electrical shock hazards through damage from lightning or insulation
deterioration from exposure. Begin maintenance procedures only after a
visual inspection has been made for possible hazards. Due to the danger
of lightning, lighted navigational aids should not be serviced during
periods of local thunderstorm activity. Develop and implement a set of
action plans to follow in the event of an accident occurring. Ensure
that positive responsive actions take place within moments of accident
notification by establishing and having in place a known set of
predetermined responses. Precious seconds are saved getting medical
assistance to those in need when action plans are in place. Rehearse and
review action plans regularly.

## 2.3 ELECTRICAL HAZARDS OF SERIES LIGHTING CIRCUITS.

Airport lighting circuits, by their nature, are very dangerous. This is
especially true for the uninformed electrician with little or no
experience working on constant current series circuits. Airport lighting
circuits can operate at potentials of several thousand volts depending
on the size of the regulator driving the circuit and the load.

**2.3.1** There are three basic rules to remember when working on and
around airport lighting circuits:

1.  **[ALWAYS]{.underline}** assume that the circuit is energized until
    you have proven otherwise. **[ALWAYS]{.underline}** check for
    current before disconnecting the series circuit connector, removing
    the S1 cutout, or opening the primary series circuit by any other
    means. Make it a required practice to check the circuit with an
    ammeter prior to breaking the connection -- **[NO
    EXCEPTIONS.]{.underline}** Never attempt to measure voltage in a
    series lighting circuit using ordinary volt meters. An inductive
    voltage measuring device (sometimes referred to as a "ticker") such
    as is described in chapter 4 may be used to detect the presence of
    induced voltage on a series lighting cable after checking for the
    presence of current. Always use a true RMS clamp-on type ammeter to
    verify if the circuit is energized. **[ALWAYS]{.underline}** check
    the operation of the test equipment on a known live circuit before
    and after measurements are taken.

2.  **[NEVER]{.underline}** under any circumstances break a live series
    circuit. The voltage generated in the circuit can reach levels many
    times normal before the regulator's open circuit protection can shut
    it down. As long as a current flow can be maintained, even if it is
    through [you]{.underline}, the regulator will continue to operate.
    This is one of the reasons that series circuits can be so hazardous
    to work around. By their nature, there is no personnel protection
    provided such as might be found on parallel interior wiring.

3.  **[NEVER]{.underline}** enter a manhole with energized conductors
    and never handle cables or transformers in light base cans while
    there is current present. Cables or connectors can have cracked
    insulation where it is not visible or may be deteriorated and fall
    apart, exposing you to circuit conductors.

**2.3.2 Induced Voltages.**

Series circuits are typically run from the transformer vault in duct
banks where the wires are lying parallel to each other in close
proximity. Voltages may be induced in an otherwise un-energized
conductor and may be a hazard when troubleshooting and testing. Circuits
that have a load that varies due to flashing action of runway guard
lights or REIL strobes are particularly prone to induce voltages in
other conductors due to the pulsing characteristics of the voltage and
current in these circuits. Always check for induced voltages before
handling an airfield lighting series circuit conductor.

**2.3.3 Re-lamping.**

The most common lighting maintenance task on the airfield is re-lamping
of runway and taxiway lighting fixtures. Depending on the type of
fixture, this may be accomplished in the field or, as in the case of
most inset lights, the entire fixture is removed, replaced, and brought
to the maintenance shop for refurbishing. The greatest unseen danger to
you is re-lamping or removing the fixture with the circuit energized.
This has always been a common practice by airport electricians for
convenience and the dangers are often overlooked. There are two primary
hazards associated with this practice. The first occurs when an
isolation transformer has a primary to secondary short in the windings.
Remember that even though these are referred to as
[isolation]{.underline} transformers, they were not designed for
personnel protection. They are merely designed to isolate the secondary
from the primary circuit to allow the circuit to continue to operate
with a lamp burned out. A transformer with a primary to secondary short
may not cause a circuit malfunction and could therefore remain unnoticed
in normal operation with a live primary. This exposes you to the full
voltage present on the primary circuit and can be especially dangerous
if another short is present on the primary circuit. When that happens,
you can become the path to ground for the full primary current, a
circumstance which is almost always fatal. This condition is especially
dangerous when working with inset lights and removing them from the
light base can while the circuit is energized. As soon as the fixture is
unbolted and lifted from the can, you become the path to ground. Some
have tried to alleviate this hazard by attaching a ground wire from the
bottom of the light fixture to a grounding lug on the inside of the can.
However, you cannot know if the wire is truly connected until you remove
the fixture, at which time it is too late.

The second hazard encountered when re-lamping an energized light fixture
is from the open circuit voltage present at the secondary of the
transformer. The open circuit voltage present on the secondary of the
transformer is proportional to the size of the transformer. The
open-circuit secondary voltage on a 300 watt transformer is
approximately 110 volts. Moreover, depending on the materials used in
the design of the isolation transformer and the type of regulator
powering the circuit, relatively high voltage peaks can be generated.
Once again, the larger the transformer, the higher the peaks with as
much as 200 volts being generated in some circumstances. The duration of
this peak varies inversely with the size of the transformer (i.e. larger
transformers have shorter durative spikes). Because of their size and
duration, the peak voltages can create an unsafe condition for
maintenance personnel. Therefore, we recommend that you perform
re-lamping of the series lighting circuits with the circuits
de-energized, especially during the re-lamping of fixtures with exposed
contacts. If this is not practical, wear appropriate insulating gloves
with leather gauntlets during re-lamping procedures.

A final hazard that is present when re-lamping any type of fixture,
whether in the field or at the maintenance shop, is the danger of cuts
from broken lamps. Many times when an airfield lamp fails, the glass
envelope becomes cracked or brittle and can break during the removal
process. Always wear leather gloves when removing lamps to prevent your
hands from being cut in the event of a lamp shattering.

## 2.4 SAFETY PRACTICES.

When you perform maintenance on airport visual aids, use the following
safety practices:

a.  Ensure that workers are trained and familiar with electrical safety.

b.  Strictly observe safety rules.

c.  Ensure that commercial test equipment is Underwriters Laboratory
    (UL) approved and rated for the voltage under test or for the
    application.

d.  Prior to beginning any maintenance work on airport lighting
    circuits, coordinate the work schedule with the tower, facility
    manager, or airport operations personnel. Make sure circuits will
    not be energized during maintenance by observing strict lock-out
    tag-out procedures for the equipment and obtain authorization for
    local control if equipment is normally operated from a remote
    control point.

e.  Where maintenance work is to be accomplished on a high-voltage
    circuit, assign at least two electricians, with at least one having
    a thorough knowledge of the layout of all airport high-voltage
    circuits.

f.  Because performing maintenance on many lighted visual aids requires
    workers to traverse the active airfield, all workers shall be fully
    knowledgeable of air traffic control and radio communication
    procedures. Workers shall be fully familiar with airport runway and
    taxiway layout to avoid any possibility of runway incursions. All
    air traffic control instructions shall be read back to the
    controller and if the worker has any question regarding the
    instructions of the controller, the worker shall ask the controller
    to repeat the message. All vehicles operated within the aircraft
    operations area shall be properly marked and lighted per FAA AC
    150/5210-5, Painting, Marking and Lighting of Vehicles Used on an
    Airport.

If you are the observer electrician, your duties include:

a.  Keeping other personnel not involved in the work clear of the
    equipment.

b.  Being familiar with power disconnects and immediately disconnecting
    the power source in case of emergency.

c.  Being qualified in first-aid and prepared to render emergency care
    if necessary. You should bear in mind that prevention of an
    electrical accident is of primary importance even though first-aid
    treatment is available.

d.  Observing the work being done to detect and warn against unsafe
    practices.

**2.4.1 Personal Safety Precautions.**

Every electrician should adopt the following common sense safety
precautions as standard procedure:

a.  Know the location of main power disconnect devices.

b.  Know how to summon medical aid.

c.  De-energize circuits by removing necessary fuses using properly
    insulated fuse pullers or by turning off and locking out circuit
    breakers or other disconnecting means. Consult circuit diagrams to
    identify all fuses, breakers or disconnects involved. Remember that
    removal of a fuse does not remove the voltage from the "hot" fuse
    clip. Discharge all capacitors.

d.  Do not depend on interlocks to remove power or on indicating lights
    to signal that power is off. Verify that power is off by using a
    voltmeter and/or ammeter on the component after opening the power
    switch. Verify operation of voltmeter (or ammeter) on known live
    circuit before and after measurements are taken.

e.  Insulate your feet by standing on a dry rubber mat. Remember,
    however, that contact with the grounded equipment cabinet could
    nullify this protection.

f.  Stay clear of terminals, leads, or components that carry voltages of
    any magnitude. Also, avoid contact with components that are
    grounded, including the frame.

g.  Shut down and de-energize the equipment when it is necessary to
    reach into the equipment in locations where rapid and direct
    withdrawal of the hand is not possible. In any case, only one hand
    should be exposed, with the other hand kept away from contact with
    voltages or ground.

h.  Be certain that there is no power applied to a circuit when making a
    continuity or resistance check (the meter will be damaged and you
    could be injured).

i.  Ground test equipment to the equipment under test unless otherwise
    specified in instruction manuals.

j.  Place a warning sign, such as "DANGER - DO NOT USE OR OPERATE," at
    the main switch or circuit breaker, and provide a lockout for the
    circuit on which you will be working. Follow direction of local
    facility lock-out tag-out procedures manual.

k.  Do not wear jewelry, wristwatches, or rings while working with
    electrical equipment.

l.  Keep clothing, hands, and feet dry if at all possible.

m.  Use the correct tool (screwdriver, alignment tool, etc.) for doing
    the job.

n.  Never use toxic or flammable solvents for cleaning purposes.

o.  Where air pressure is required for cleaning, use a low-pressure (30
    psi or less) air source. Eye protection (goggles or face mask) is
    necessary when using compressed air for cleaning.

p.  Wear goggles and safety shoes when around high voltage.

q.  Do not take anything for granted when working with inexperienced
    help.

## 2.5 SAFETY BOARDS.

Locate a plywood board for posting safety procedures and a pegboard for
mounting safety equipment in the airport lighting vault, switchgear
rooms, engine generator rooms, and other appropriate locations. In
addition, provide a telephone for emergency use as well as regular
communications use. Recommended safety procedures and safety items to be
included on or adjacent to safety boards are as follows:

a.  Accident and fire procedures.

b.  Emergency telephone numbers, such as doctor, hospital, rescue squad,
    fire department, airport operations, police and Air Traffic Control
    Tower (ATCT).

c.  Resuscitation instructions.

d.  Resuscitation equipment (Resuscitube or equivalent).

e.  First-aid kit.

f.  High-voltage disconnect (hot) stick.

g.  Non-conductive body rescue hook.

h.  Rubber gloves rated for maximum voltage present with leather gloves
    and protective storage bag.

i.  Insulated fuse puller.

j.  Non-metallic flashlight

k.  Grounding stick.

l.  Safety posters and bulletins.

m.  Portable non-conductive warning signs with non-conductive hangers.

n.  Fire extinguisher of proper type rating for electrical fires.

o.  Emergency eyewash station if not provided elsewhere in building.

p.  Automatic External Defibrillator

**2.5.1 Safety Board Inspection.**

Inspect the equipment located on the safety board as indicated below:

a.  Test rubber gloves in accordance with ASTM D120, Specification for
    Insulated Rubber Gloves. ASTM specifications may be obtained from
    the American Society for Testing and Materials, 1916 Race Street,
    Philadelphia, PA 19103.

b.  Testing may be performed by private testing labs, utility companies,
    and large military and Federal establishments.

c.  Gloves should be proof-tested at the following intervals:

-   In daily use -- 30 days.

-   Infrequently used -- 180 days.

d.  Visually inspect hot sticks for paint smears, carbon paths, dirt
    smears, etc., and clean them, if required, prior to use. Re-surface
    and test hot sticks that cannot be cleaned and/or have significant
    surface-coating ruptures.

**NOTE:** *Wear certified rubber gloves (ASTM D120) and protective
leather gauntlets whenever hot sticks are used.*

## 2.6 SAFETY CHECKLIST.

Complete a safety inspection on a monthly basis to ensure that the
safety boards contain all required items and that test equipment is in a
safe operating condition. Retain the completed checklist on file for at
least one year.

## 2.7 SAFETY EQUIPMENT IN VEHICLES.

All vehicles operated on the airfield should have a properly sized fire
extinguisher and first aid kit. Equip all vehicles and/or personnel with
radio communication to be available to summon help in an emergency. Mark
and register all vehicles appropriately. Equip all vehicles with a
lighted warning beacon and a copy of current Airport (ATC) Procedures
and Ground Vehicle Guide to Airport, Signs and Markings.

## 2.8 ELECTRIC SHOCK.

An electric shock is the passing of an electric current through a
person. The amount of damage depends on the amount of voltage and
current to which the person is subjected.

a.  Voltages between 200 and 1000 volts at commercial powerline
    frequencies are particularly harmful since, under these conditions,
    heart muscle spasm and paralysis of the respiratory center occur in
    combination. However, lower voltages can also prove fatal, as
    evidenced by records of deaths caused by 32 volt farm lighting
    systems. The body response to current is a follows:

-   5 to 15 mA stimulates the muscles

-   15 to 19mA can paralyze the muscles and nerves through which it
    flows

-   25 mA and above may produce permanent damage to nerve tissues and
    blood vessels

-   70 mA and above may be fatal.

b.  The injurious effects suffered during electric shock depend upon the
    path of the current through the body. The current path will take the
    most direct route through the body from the two points of contact.
    For this reason, any current path which involves the heart or the
    brain is particularly dangerous. Therefore, keeping one hand clear
    of the equipment will eliminate the possibility of a current path
    from arm to arm.

## 2.9 SAFETY TRAINING. {#safety-training. .unnumbered}

Establish a safety training course and present to all employees. Present
follow-up training on a periodic basis to ensure that employees are
safety motivated. Include first aid and CPR (Cardio-Pulmonary
Resuscitation) training in the safety training course. The safety course
shall include driver safety training and proper procedures on contacting
local emergency, police, and fire agencies.

## 2.10 SAFETY WARNING SIGNS/DANGER TAGS. {#safety-warning-signsdanger-tags. .unnumbered}

The following discusses the use of warning signs on high voltage
equipment.

**2.10.1 "Danger -- High Voltage" Sign.**

Permanently place "DANGER -- HIGH VOLTAGE" signs on all fixed electrical
equipment where potentials of 500 volts or more terminal-to-ground are
exposed. Place signs in a conspicuous location, usually on the outside
of the equipment.

![](media/image3.wmf){width="2.798611111111111in"
height="2.0590277777777777in"}

**Figure 2-1 "Danger -- High Voltage" Sign**

**2.10.2 Lock-Out/Tag-Out and Danger Tags.**

Each airport electrical maintenance department should have a written
lock-out/tag-out procedure. Equipment or circuits should never be worked
on unless locked out and tagged by the person performing the work. Never
trust anyone but yourself. Have your partner check behind you to make
sure the proper equipment is turned off. The lock-out tag should only be
removed by the person who signed it except in some circumstances when
verbal permission has been granted to another person or when the worker
who signed the tag is on vacation, etc. Never rely on the tower
controllers to assure electrical safety. The controllers in the tower
are relieved periodically and the next person may not know of the work
that is going on. Always take whatever time is necessary to make sure
that the circuit or equipment you are working on is safe. One of the
primary reasons for accidents is when workers get in too great a hurry
and don't take proper precautions and follow proper safety procedures.
The other main reason is when the electrician lets his/her guard down
because they are working in a familiar environment and becomes negligent
about safety procedures.

![](media/image4.wmf){width="2.488888888888889in"
height="2.654861111111111in"}

**Figure 2-2 Danger Tag**

**2.10.3 Locks and Padlocks.**

Use built-in locks on switchgear and disconnecting switches whenever the
equipment is tagged, and return the keys to the supervisor responsible
for their control. Padlocks need not be used if it is decided that use
and control of such locks would be difficult because of the type of
switchgear and its location. However, use padlocks with "DANGER" tags
when equipment or electrical lines remain out of service or when
electrical work has been discontinued until a later date. When outside
contractors are involved, each contractor should attach and control tags
and locks independently.

## 2.11 GROUNDING AND BONDING. {#grounding-and-bonding. .unnumbered}

Never remove, alter, or attempt to repair conductors or conduit systems
providing grounding or electrical bonding for any electrical equipment
until all power is removed from equipment. Warn all personnel of the
ungrounded/unbonded condition of the equipment. Display appropriate
warning signs, such as danger tags, to warn personnel of the possible
hazards.

## 2.12 CONFINED SPACES. {#confined-spaces. .unnumbered}

Be sure to have a plan in place for dealing with confined spaces that
conforms to OSHA standards. Make sure to test the air quality and use an
approved blower to ventilate any confined spaces before entering. This
includes any unventilated space especially manholes and storage tanks.
Remember that gases produced by rotting materials, both vegetable and
animal, will displace oxygen. These materials can be commonly found in
airport lighting manholes. When working in manholes and storage tanks
with vertical access, personnel must wear proper Class II or Class III
harnesses and be connected to a rescue tripod-mounted winch mounted
above the entrance. Use forced air blowers with flexible ducts to
provide fresh air to confined spaces. Keep vehicles away from air
intakes for blowers. Vehicle exhaust can quickly contaminate the quality
of the forced air.

## 2.13 LIGHTNING. {#lightning. .unnumbered}

When personnel are subjected to direct lightning strikes, the results
are nearly always fatal. Although extraordinary escapes from direct
strikes have been reported, the shock is so great that survival is rare.
The major portion of lightning casualties arises from secondary effects,
such as side flashes and induced charges.

**NOTE: *IF ADMINISTERED IN TIME,*** ***FIRST-AID TREATMENT, ESPECIALLY
ARTIFICIAL RESPIRATION OR CARDIO-PULMONARY RESUSCITATION MAY PREVENT
DEATH FROM ANY DIRECT CHARGES.***

Observe the following rules for personal safety, if possible, during any
thunderstorm:

a.  Remain indoors unless absolutely unavoidable. Remember, when on the
    airfield [YOU]{.underline} are the tallest object and therefore
    vulnerable to lightning strikes. Stay within a dry area of a
    building, preferably away from all metal objects.

b.  If there is a choice of shelter, select the type of shelter in the
    following order:

-   Large metal or metal-frame building

-   Dwellings or other buildings which are protected against lightning

-   Vehicles

-   Large unprotected buildings.

c.  If remaining out-of-doors is unavoidable, keep away from the
    following:

-   Small sheds and shelters in an exposed location; in particular, any
    that house power equipment.

-   Wire fences, antennas, supporting structures, or lines; whether
    telephone, electric, or otherwise.

-   Hilltops and wide-open spaces.

-   Isolated trees.

## 2.14 TOXIC AGENTS. {#toxic-agents. .unnumbered}

Toxic agents are poisonous substances that can cause injury by contact
or injection. Substances termed "caustic" or "corrosive" cause the flesh
to be eaten away on contact; the results of contact with these agents
range from minor skin irritations to severe burns. There are materials
that are toxic only if they are taken internally. Toxic agents also
exist as a gaseous vapor and may be injurious immediately or over a long
period of time. There are also a few substances used in electric
equipment that are basically non-toxic agents, but under certain
conditions can become highly toxic.

**2.14.1 Carbon Tetrachloride.**

Never use carbon tetrachloride. Contact with liquid carbon tetrachloride
destroys the natural oils of the skin, producing a whitish appearance on
skin surfaces that are exposed. Continuous skin exposure may cause skin
eruptions. Carbon tetrachloride fumes are highly toxic.

**2.14.2 Trichloroethylene.**

This agent, used principally as a degreasing solvent, is a narcotic and
anesthetic material. Organic injury rarely results from overexposure,
but repeated overexposure can cause anemia and liver damage.

**2.14.3 Battery Acids.**

The most common battery acid is sulphuric acid. Sulphuric acid is a
corrosive toxic agent; repeated or prolonged inhalation of its fumes can
cause inflammation of the upper respiratory tract, leading to chronic
bronchitis. Loss of consciousness with severe damage to the lungs may
result from inhalation of concentrated vapors when the sulphuric acid is
hot. The acid, in a highly concentrated form prior to adding water for
battery use, acts as a powerful caustic, destroying skin and other
tissue. This destruction appears as severe burns, and such exposure may
be accompanied by shock and collapse. The fumes from highly concentrated
sulphuric acid cause coughing and irritation of the eyes; prolonged
exposure may produce chemical pneumonitis.

Batteries and battery acid also produce hydrogen gas, a by-product of
the charging process. Hydrogen gas is highly flammable and can react
explosively in conjunction with a spark or flame.

All locations where lead-acid batteries are used or housed should have,
as a minimum, an emergency eyewash station installed. If water is not
readily available, portable emergency eyewash stations consisting of a
wall mountable water bottle should be made readily available.

## 2.15 FIRE EXTINGUISHERS. {#fire-extinguishers. .unnumbered}

Conveniently locate fire extinguishers of the proper type (see Paragraph
2.15.4), and in good working condition, near all high-voltage equipment.

**2.15.1 A Brief Introduction to Fire Extinguishers and Fire Types.**

When used properly, portable fire extinguishers can save lives and
property by putting out a small fire or containing it until the fire
department arrives.

Portable fire extinguishers, however, are not designed to fight large or
spreading fires. Even for small fires, they are useful only under
certain conditions:

-   The operator must know how to use the extinguisher. There is no time
    to read directions during an emergency.

-   The extinguisher must be within easy reach and in working order,
    fully charged.

-   The operator must have a clear escape route that will not be blocked
    by fire.

-   The extinguisher must match the type of fire being fought.
    Extinguishers that contain water are unsuitable for use on grease
    and electrical fires.

-   The extinguisher must be large enough to put out the fire. Many
    portable extinguishers discharge completely in as few as 8 to 10
    seconds.

**2.15.2 How to Use Portable Fire Extinguishers.**

Remember the PASS system:

**P**...Pull the Pin

**A**...Aim the extinguisher nozzle at the base of the flames

**S**...Squeeze trigger while holding the extinguisher upright

**S**...Sweep the extinguisher from side to side

ALWAYS make sure the fire department is called and inspects the fire
site, even if you think you have extinguished the fire!

**2.15.3 Should You Try to Fight the Fire?**

Before you begin to fight a fire:

-   Make sure everyone has left or is leaving the building

-   Make sure the fire department has been called

-   Make sure the fire is confined to a small area and is not spreading

-   Make sure you have an unobstructed escape route to which the fire
    will not spread

-   Make sure you have read the instructions and know how to use the
    extinguisher.

**It is reckless to fight a fire in any other circumstances. Instead,
leave immediately and close off the area.**

**2.15.4 Class of Fire Extinguishers.**

Fire extinguishers are divided into four categories, based on different
types of fires. Each fire extinguisher also has a numerical rating that
serves as a guide for the amount of fire the extinguisher can handle.
The higher the number, the more fire-fighting power. The following is a
quick guide to help choose the right type of extinguisher:

-   **Class A** extinguishers are for ordinary combustible materials
    such as paper, wood, cardboard, and most plastics. The numerical
    rating on these types of extinguishers indicates the amount of water
    it holds and the amount of fire it can extinguish.

-   **Class B** fires involve flammable or combustible liquids such as
    gasoline, kerosene, grease and oil. The numerical rating for Class B
    extinguishers indicates the approximate number of square feet of
    fire it can extinguish.

-   **Class C** fires involve electrical equipment, such as appliances,
    wiring, circuit breakers and outlets. Never use water to extinguish
    Class C fires -- the risk of electrical shock is far too great!
    Class C extinguishers do not have a numerical rating. The C
    classification means the extinguishing agent is non-conductive.

-   **Class D** fire extinguishers are commonly found in a chemical
    laboratory. They are for fires that involve combustible metals, such
    as magnesium, titanium, potassium and sodium. These types of
    extinguishers also have no numerical rating, nor are they given a
    multi-purpose rating -- they are designed to Class D fires only.

Some fires may involve a combination of these classifications.

**2.15.5 Most Common Types of Fire Extinguishers.**

-   **Water extinguishers** or air-pressurized water (APW) extinguishers
    are suitable for **Class A fires only. [Never use a water
    extinguisher on grease fires, electrical fires or Class D fires --
    the flames will spread and make the fire bigger!]{.underline}**
    Water extinguishers are filled with water and pressurized with
    oxygen. Again -- water extinguishers can be very dangerous in the
    wrong type of situation. Fight the fire only if you are certain it
    contains ordinary combustible materials.

-   **Dry chemical extinguishers** come in a variety of types and are
    suitable for a combination of **Class A, B and C fires.** These are
    filled with foam or powder and pressurized with nitrogen.

a.  **BC** - This is the regular type of dry chemical extinguisher. It
    is filled with sodium bicarbonate or potassium bicarbonate. The BC
    variety leaves a mildly corrosive residue which must be cleaned
    immediately to prevent any damage to materials.

b.  **ABC** -- This is the multipurpose dry chemical extinguisher. The
    ABC type is filled with monoammonium phosphate, a yellow powder that
    leaves a sticky residue that may be damaging to electrical
    appliances such as a computer.

Dry chemical extinguishers have an advantage over CO^2^ extinguishers
since they leave a non-flammable substance on the extinguished material,
reducing the likelihood of re-ignition.

-   **Carbon Dioxide (CO^2^) extinguishers** are used for **Class B and
    C fires.** CO^2^ extinguishers contain carbon dioxide, a
    non-flammable gas, and are highly pressurized. The pressure is so
    great that it is not uncommon for bits of dry ice to shoot out the
    nozzle. They don't work very well on Class A fires because they may
    not be able to displace enough oxygen to put the fire out, causing
    it to re-ignite.

CO^2^ extinguishers have an advantage over dry chemical extinguishers
since they don't leave a harmful residue -- a good choice for an
electrical fire on a computer or other electronic device.

**It is vital to know what type of extinguisher you are using. Using the
wrong type of extinguisher for the wrong type of fire can be
life-threatening.**

## 2.16 FIRST AID.

First aid is what to do before the doctor comes. It is never a
substitute for the medical help. The maintenance technician should take
the lifesaving measures necessary in emergencies, but avoid doing harm.
Many first-aid measures are quite simple and do not require
"split-second speed" in their application. Haste without knowing what
one is doing can be worse than doing nothing at all. At other times,
immediate action is essential to save a life or prevent serious
complications; this action can only be taken by someone who is on the
scene when minutes are vital. Learn about first aid before emergencies
happen. Be prepared to give help safely and beneficially when necessary.
Contact the American Red Cross to provide refresher first-aid courses to
maintenance personnel to keep them proficient.

**Intentionally Left Blank**

# CHAPTER 3. MAINTENANCE MANAGEMENT.

## 3.0 MAINTENANCE PHILOSOPHY.

The purpose of the maintenance management system is to ensure the
maximum availability of any given system at a minimum cost in man-hours
or funds. "Availability" and "costs" are relative terms; they must be
interpreted for each airport. For example, a CAT I runway may still be
considered operational with 15% of the edge lights out, while a PAPI
system may be unserviceable with more than one lamp out per box. By the
same reasoning, the cost of maintaining a spare regulator may be
considered cost prohibitive, while stocking replacements for 10% of the
runway edge lights may be considered a normal practice. In addition,
operational factors are a major consideration in determining what
maintenance is required. Airports with heavy traffic may require more
frequent maintenance servicing than those used only by light traffic.
The maintenance operations include maintenance planning, preventive
maintenance inspection, visual inspection, repair, installation,
calibration, and unscheduled maintenance procedures. Maintenance
procedures, including the work order and documentation required, may
vary between airports. The purpose of this document is to provide the
minimum maintenance procedures required for safe and efficient movement
of aircraft during takeoff, landing, and taxiing operations.

Regardless of the actual maintenance routines decided upon, the
following elements are essential to any controlled maintenance program.
The maintenance procedures in this AC are considered minimum guidelines:

a.  Document the service checks that comprise the maintenance program.

b.  Record the performance of each maintenance action, scheduled or
    unscheduled.

c.  Document repairs and troubleshooting performed on each piece of
    equipment and the results of those actions as well as the symptoms
    related to the malfunction. This allows for more rapid
    troubleshooting of similar problems at a later date.

## 3.1 MAINTENANCE SCHEDULE.

Documenting the maintenance schedule by spelling out each item of
routine maintenance is beneficial in several ways:

a.  It allows planned allocation of man-hours to the maintenance
    function.

b.  It helps to establish spare part stock levels.

c.  It identifies the necessary maintenance routines to new employees,
    decreasing training time needed for system familiarization.

d.  It identifies the scope of the maintenance task in terms of
    man-hours and material requirements.

## 3.2 MAINTENANCE RECORDS.

Maintenance records are an important part of an effective maintenance
management system; they provide a service history of each piece of
equipment, ensure regular maintenance without duplication of effort, and
provide a data base for statistical analysis of lighting system
performance. Without records, knowledge gained from regular inspections
will not be retained, and preventive maintenance will be difficult. An
effective records system should allow for the recording and retrieval of
information with a minimum of effort. The records system should compile
data that will document the effectiveness of the maintenance program. By
checking the records, a manager should be able to determine whether a
particular maintenance task is being done too frequently or not often
enough. By such a trial-and-error process, a maintenance program
uniquely tailored to the facility can be developed.

## 3.3 PREVENTIVE MAINTENANCE PROGRAM.

Reliable functioning of airport lighted visual aids is essential to
airport safety, capacity, and operation especially for low visibility
operations. Therefore, it is essential that a preventive maintenance
program be established to ensure reliable service and proper equipment
operation. Properly scheduled inspections, testing, and calibrations are
essential to the proper functioning of these systems. Airport lighting
systems are designed to be dependable and may continue to operate for
long periods of time even if maintenance is neglected. Eventually a
failure will occur and, if the failure occurs at a critical time, safety
may be jeopardized. Lighted visual aid maintenance should receive high
priority to prevent equipment failure, false signals, and deterioration
of the system.

**3.3.1 Installation and Material.**

The first element in a preventive maintenance program is high quality,
properly installed equipment. Preventive maintenance is difficult on
equipment that has been installed haphazardly without consideration of
maintenance requirements. When such conditions exist, they should be
brought to the attention of the proper authority and corrected rather
than trying to establish a preventive maintenance program to compensate
for the condition.

Consult the electrical maintenance supervisor at an airport prior to and
during the design of any installation of new or additional visual aid
systems. By so doing, the airport can avoid costly problems during and
after construction. Consideration should also be given to the method of
selection and training of any contractor personnel involved in the
installation of airfield lighting products. The need for specialized
training for airport maintenance electricians applies to the contractor
personnel also.

**3.3.2 Personnel.**

The second element in a preventive maintenance program is trained
experienced personnel. Maintenance personnel should have a thorough
knowledge of the equipment, should have experience with high voltage,
and should be able to make careful inspections and necessary repairs.
Special training is available and may be desirable, as most
well-qualified electricians can be trained on-the-job if suitable
supervision and instruction are provided. Considerable experience with
the equipment and its operation is desirable. These individuals should
be present, or on-call, during the operating hours of the airport to
correct any deficiencies that may develop. In short, airport visual aid
maintenance personnel should be specialists in the field.

**3.3.3 Tools and Test Equipment.**

The third element in a preventive maintenance program is the tools and
test equipment required to perform the maintenance. This includes
specialized tools and test equipment, adequate working space, adequate
storage space, spare parts, and applicable technical manuals.

**3.3.4 Preventive Maintenance Inspection Program.**

The fourth element in a preventive maintenance program is an effective
preventive maintenance inspection schedule for each visual aid. This
schedule should also include all cable systems. The preventive
maintenance inspection (PMI) schedule is the foundation for the
successful maintenance of the equipment. If the PMI is performed
properly and at the scheduled time, it will ensure top system
performance and will minimize unscheduled interruptions and breakdowns.
Review of the inspection records, checks, tests, and repairs provides a
constant awareness of the equipment condition and gives maintenance
personnel advanced warning of impending trouble.

**3.3.5 Preventive Maintenance Inspection Schedule.**

Scheduled inspections and tests are those accomplished on specific types
of equipment on a periodic basis. The schedule may be based either on
calendar or on hourly-use increments. The PMI schedules, based upon
recommendations from the manufacturers and users of the equipment, are
considered to be the typical requirements to keep the equipment in good
condition. Adjust the frequency of a particular PMI after experience is
gained under local operating conditions.

## 3.4 RECORD RETENTION.

There is no set period of time that maintenance records should be kept,
but in keeping within the goals mentioned above, a period of twice the
longest period recorded would appear to be the minimum (i.e., 2 years in
the case of annual maintenance action). Records of daily inspection
will, of course, lose their significance much sooner, probably within a
month. It should be noted however, that maintenance records should be
retained permanently, if possible, as situations may develop years later
in which those records can prove invaluable.

## 3.5 REFERENCE LIBRARY.

Establish a reference library to maintain a master copy of all Equipment
Technical Manuals (ETMs), ACs, as-built drawings, and other useful
technical data. The electrical supervisor should establish and maintain
responsibility for maintaining the technical reference library and
ensure that technical manuals and drawings are kept up to date and not
lost or damaged.

**3.5.1 Equipment Technical Manuals (ETMs).**

ETMs and other manufacturer's literature form an important part of the
reference library. Obtain two copies of all technical manuals and
related manufacturer's literature. Retain a master copy in the reference
library, and provide a separate copy for the shop. In addition, keep a
copy of each equipment manual at the equipment location. This
facilitates troubleshooting and repairs without the necessity of
traveling back to the shop location to retrieve the manual. Do not
remove the master copy of the technical manual from the reference
library as it can easily become misplaced or lost. In the event the shop
copy is lost, make another photocopy of the technical manual from the
reference library instead of releasing the master copy.

**3.5.2 Advisory Circulars.**

Important reference information on installation, design tolerances, and
operation of visual aid equipment may be found in FAA ACs. Include a
copy of the ACs covering the equipment at the facility, along with a
copy of this AC, in the reference library.

**3.5.3 Other Technical Data.**

Other reference information that is occasionally useful should also be
added to the library. This might include local electrical codes,
engineer's handbooks, test equipment manuals, and other general
information publications.

**3.5.4 As-Built Drawings.**

Maintain the master copy of all as-built (record) drawings as part of
the reference library. Incorporate modifications to any equipment into
the drawings as soon as the modification is completed. Give a copy of
the "as-built" lighting plan, showing the location of all cable runs,
runway lights, etc., and including the wiring diagrams for the lighting,
engine generator, and the visual aid system, to the field technicians as
a working copy. Install or identify test points at appropriate locations
in the field circuitry and record locations of these test points on the
"as-built" drawings. Immediately update any notations regarding test
points or discrepancies in the drawings made in the field on the master
set in the reference library.

## 3.6 SPARE PART PROVISIONING.

This paragraph contains guidelines on how to establish a stock of spare
parts to be used for quick repair of lighting equipment that fails
unexpectedly. The purpose of a spare parts system is to have the
necessary part on hand when a piece of equipment fails; this will
minimize the time the system is out of operation. However, the greater
the number of spare parts stored, the greater the inventory costs. The
optimum spare part system balances the cost of system downtime (lost
operation, tenant inconvenience, safety, etc.) with the cost of
purchasing and storing spare parts. A small airport with few operations
may suffer little inconvenience with the loss of their lighting system
and may, therefore, choose to stock few spare parts. A large airport may
rely heavily on its lighting system for low visibility operations and
would, therefore, require a substantial quantity of spare parts. In the
case of a large airport, the funds lost by the tenants due to
interrupted operations and the impact on the safety and security of the
traveling public must also be taken into consideration. A malfunction at
a major airport can have a far reaching effect on the national airspace
system. When establishing a spare parts inventory, two questions must be
answered:

(1) What parts should be stocked?

(2) How many of each part?

When new construction occurs or a project is funded for replacement of
existing systems, fund and include a quantity of spare parts (fixtures,
lamps, fuses, relays and spare CCR control boards, etc.) in the
equipment furnished by the contractor. This gives the maintenance
department a built-in stock of spare parts and lessens the time required
to procure parts for the new equipment. This is especially true if the
equipment being installed is different from what is currently in use.

**3.6.1 Choosing Spare Parts.**

To answer the two questions posed above, several factors must be
considered, including failure rate, part availability, and effect of the
part failure.

**3.6.2 Failure Rate.**

The failure rate (or replacement rate) is the product of the expected
life of an item and the number of items in the system. For instance, if
a lamp is expected to last six months, and we have 100 lamps in the
system, then an average of 100 lamps will be replaced every six months
or approximately four per week. Accurate records of parts used over time
will help immensely in determining a failure rate.

**3.6.3 Part Availability.**

Part availability refers to the time it takes to secure a replacement
part. This usually means procurement lead time. If a part can be readily
procured from shelf stock of a local supplier, it might not be necessary
to add the part to the spare parts inventory; as it could be purchased
when needed or the number of spare parts in the inventory could be
reduced. However, if there is a six-week lead time required by the
supplier, then stock six times the weekly failure rate (24 lamps in the
example above). Spare parts for constant current regulators and other
special equipment fall into this category. For instance, a replacement
printed circuit board or other assembly typically has a six to twelve
week lead time and unless a spare regulator is maintained for emergency
use, the loss of a circuit could have a serious effect on airport
operations. There are methods of obtaining parts which may reduce the
effect of a long lead time. These include substitution (the use of a
functionally equivalent part from another manufacturer), cannibalization
(replacing one of a pair of adjacent failed lamps by "borrowing" a lamp
from elsewhere in the system), and temporary fixes (such as the use of
portable lights in place of the fixed light installation) while awaiting
corrective maintenance. It should be noted, however, that these
solutions should be considered only as an emergency measure and that
proper spare parts provisioning will eliminate the need for such
techniques.

**3.6.4 Effect of the Failure.**

The effect of the failure of a particular spare part depends on how
important the part is to the equipment it is installed in, and how vital
the equipment is to airport operations. The failure of a lamp in an edge
light would not lead to any system downtime, but the failure of a
circuit board in a constant current regulator would cause the loss of
the entire lighting circuit that it powers. The equipment manufacturer
will give guidance on recommended spare parts. As experience is gained
with the system, other parts may be added or deleted from the inventory.
The impact of a part's failure should be considered when building a
spare parts inventory.

**3.6.5 Part Identification.**

An important part of maintaining a spare parts inventory is accurately
cataloging the parts on hand by manufacturer's part number. This is
important to ensure that the correct part is used in a broken piece of
equipment; many optical parts are visually similar but vary
significantly in performance. The use of the manufacturer's part number
is also vital when reordering; if a part is ordered by its generic name,
the manufacturer may send a later version of the part which is
incompatible with the existing system. It is extremely important to
maintain manufacturer's data which reflects your equipment, describing
the type, model number, and serial number details.

**3.6.6 Use of Original Equipment Manufacturer (OEM) Part.**

The use of non-OEM parts or lamps in FAA approved equipment is strongly
discouraged. The FAA has strict specifications for approval of all
airport lighting equipment and use of non-OEM parts or lamps in such
equipment or systems can render the equipment to be functionally non-FAA
approved. This could possibly lead to serious liability consequences in
case of an aircraft incident at an airport following these practices. In
the case of runway and taxiway lighting fixtures, the use of a generic,
non-approved lamp can render the photometric output of the fixture out
of specification with disastrous results in light output and,
consequently, safety of low visibility operations.

**Intentionally Left Blank**

# CHAPTER 4. TEST EQUIPMENT.

## 4.0 INTRODUCTION.

An average electrician may have little day-to-day use for anything more
than a voltmeter; however, when maintaining airport lighting series
circuits, the equipment needs become more demanding. An airport
electrician needs to be able to perform many tasks involving
troubleshooting and calibration that are typically out of the norm for
the average wireman. Series circuits operate at potentially high
voltages and are prone to develop shorts and opens that require an
advanced knowledge of the use of ohmmeters and insulation resistance
testers (meggers) to properly trace the problem and get the lighting
circuits back up and operating in a minimum of time. There is also a
need for current measurements at relatively low currents (\<20 amps)
that require highly accurate and calibrated equipment. A small change in
the output current in a series circuit can have a large effect on light
output and lamp life. At maximum output of 6.6 amps at the lamp, a
current change (increase or decrease) of 1% can change the light output
of the lamp by as much as 5%. That same 1% change (increase) can result
in a 20% decrease in lamp life. It is therefore obvious from these facts
that accurate test equipment and proper knowledge of its usage are vital
to the maintenance of the airfield lighting system. Due to the
non-sinusoidal output waveform of many constant current regulators, it
is imperative to verify the accuracy of all current measuring devices.
Evaluate all equipment used for the calibration of regulators and have
the equipment calibrated for the values to be measured (2.8 -- 20 amps)
by a certified calibration lab.

For maintenance purposes it is therefore recommended that every airport
acquire at least a volt-ohm-meter, an insulation tester and an accurate
true RMS measuring clamp-on AC ammeter or true RMS digital multimeter
with an accurate clamp-on ammeter probe. These units are useful for
various maintenance routines and are necessary for troubleshooting and
calibration of constant current regulators and series lighting circuits.

## 4.1 TYPES OF EQUIPMENT AND USAGE.

**4.1.1 Volt-Ohm-Milliammeter (VOM).**

An analog VOM is a highly versatile piece of test instrument that is
capable of measuring AC/DC voltages, resistance, and low values of DC
current. The better quality units offer reasonable accuracy and
ruggedness and are useful for making a large variety of measurements.
The most common use of this instrument is for making resistance
measurements on series circuits for the purpose of troubleshooting when
a fault has occurred. An analog VOM is useful because of its ability to
show fluctuating trends and rates and the ease with which it offers a
go, no-go check when rapid troubleshooting is required. An analog VOM
does have limitations however. Its relatively low-input impedance and
susceptibility to interference make it unsuitable for some measurements,
especially when dealing with electronic circuits or when working in an
environment with RF (radio frequency) energy present. Also it must be
remembered that a typical VOM should not be used for making current
measurements in an airfield lighting series circuit because it does not
possess the ability to make true RMS, high accuracy measurements.

**4.1.1.1 [Safety.]{.underline}**

Safety must always be considered when using a VOM. Know the voltage
levels and shock hazards related to all equipment to be tested. Be sure
that the VOM has been tested and calibrated. Inspect and calibrate
portable test instruments at least once a year. Check the condition of
the VOM test leads before making any measurement. General
recommendations for specific uses of a VOM are contained in the
manufacturer's manual supplied with the equipment.

1.  [High-voltage measurements]{.underline}. Never try to take direct
    voltage measurements on power distribution circuits rated over 600
    volts. Measurement of high voltage is accomplished by installing
    properly rated instrument transformers and meters.

2.  [Switch settings]{.underline}. When making voltage measurements on
    power and control circuits, be sure that the meter selector and
    range switches are in the correct position for the circuit under
    test before applying test leads to the circuit conductors. To
    prevent damage to the meter movement, always use a range that
    ensures less than full-scale deflection of the pointer. A 1/3 to
    mid-scale deflection of the pointer assures the most accurate
    readings.

3.  [Case insulation]{.underline}. Do not hold the VOM in the hand while
    taking the reading. Support the instrument on a flat surface. If
    holding the VOM is unavoidable, do not rely upon the insulation of
    the case.

**4.1.2 Digital Multimeter (DMM).**

A digital multimeter is another piece of essential test equipment for
the airport electrician's toolbox. This versatile instrument can deliver
high accuracy and, through the use of various accessories, the ability
to make a wide range of measurements. The best advice when purchasing
this or any type of test equipment is to buy the best you can possibly
afford. Always make sure that the DMM you use is a [true
RMS]{.underline} type and that the accessories are of the highest
accuracy (see Paragraph 4.1.5).

A DMM with a good quality amp-clamp accessory is a good combination for
measuring the output current of constant current regulators. It is
sometimes difficult to know whether the instrument you are using is
accurate or not. Even though the DMM is rated as a true RMS instrument
and has a high rated accuracy, the accessories may not be as accurate.
Ensure that the accuracy of the DMM and all accessories are checked and
calibrated annually by a certified calibration lab for the ranges to be
measured. In the case of airport lighting series circuits, 2.8 to 20
amps is the range for verifying proper calibration.

All safety precautions listed for VOMs also apply to DMMs.

**4.1.3 Insulation Resistance Tester (MegOhmMeter).**

The insulation resistance tester or megohmmeter is a necessary tool for
maintaining and troubleshooting underground airport lighting cables.
Insulation resistance testers come in a variety of styles from the
traditional hand-crank models to battery and AC mains powered versions.
These instruments are used for testing the insulation
resistance-to-ground of underground cables; for testing insulation
resistance between conductors; and for testing resistance-to-ground or
between windings of transformers, motors, regulators, etc. The battery
powered models are the most prevalent and come in all shapes and sizes
in both analog and digital readout. Most of the digital models have an
analog bar graph to supplement the digital reading. Another
consideration in selecting an insulation resistance tester is the output
voltage. Some battery and line powered units now have selectable output
voltages that can range as high as 5000 volts DC. As a minimum, select
an insulation resistance tester with an output of 1000 volts DC. If
possible, consider using a unit with higher maximum voltage output as
this lends more possibilities of finding high resistance faults and more
closely approximates the rated voltage of the cables and transformers.
However, note that testing old cables in questionable condition and/or
circuits that have been operating at much lower voltages may suffer
damage from testing at voltages over 1000 volts. Exercise caution when
testing older circuits for the first time.

**4.1.3.1 Safety.**

1.  When preparing to make an insulation resistance test, first make a
    complete safety check. Make sure that equipment to be tested is
    disconnected from all power sources. Open all safety switches and
    lock out other control equipment so that the equipment cannot be
    accidentally energized.

2.  If neutral or ground conductors must be disconnected, make sure they
    are not carrying current and that, when disconnected, no other
    equipment will lack protection.

3.  Observe the voltage rating of the tester and take suitable
    precautions.

4.  Large equipment and cable usually have sufficient capacitance to
    store a dangerous amount of energy from the test current. After
    taking resistance readings and before handling the test leads, allow
    any energy stored in the equipment to discharge by leaving the
    tester connected for at least 30 seconds before touching the leads.
    Many new testers will automatically discharge the equipment under
    test and give the user a visual or audible indication when it is
    safe to remove the test leads. Consult the equipment manual for
    information on manufacturer's instructions.

5.  Do not use the tester in an explosive atmosphere. An explosion may
    result if slight sparking is encountered when attaching or removing
    test leads, or as a result of arcing through or over defective
    insulation.

**4.1.4 Underground Cable/Fault Locators.**

A cable locator is an indispensable tool for quickly locating airport
lighting cable and ducts. A cable locator normally consists of a
transmitter which is either directly, or indirectly by means of an
inductive coupler, attached to an underground cable and a receiver which
is used to pick up the transmitted signal to follow the path of the
cable. These devices are very handy for locating the path of a conductor
while troubleshooting cables in PVC conduit and are even more necessary
when dealing with direct buried cables. Whenever work on the airport
requires digging of any kind it is necessary to utilize a locator to
prevent inadvertent cutting of cables. Most of the receivers also
incorporate the ability to locate 60 Hz AC cables without the necessity
of applying a signal or tone to the conductor. If the airport circuits
are supplied by direct-buried conductors or have direct-buried control
cables, it is advisable to purchase a locator which also has the
capability of locating ground faults. It should be noted, however, that
faults in cables installed in conduit cannot be located using these
devices. Cable locators that include fault-finding capability are
normally equipped with an A-frame probe that is used with the receiver
to determine the direction of a fault between the conductor or shield to
ground.

**4.1.4.1 Safety.**

When using a direct connection to the conductor to be located or tested,
always exercise care to ensure that the circuit supplying the conductor
has been de-energized and locked out, and tagged.

**4.1.5 Clamp-on Ammeter.**

The stand-alone clamp-on ammeter is useful for measuring AC and
sometimes DC current. Most of the modern instruments of this type are
provided with plug-in leads to permit the instrument to be used as a
voltmeter or as an ohmmeter. Ensure that the unit is a true-RMS type so
as to deal properly with the sometimes distorted waveform output of some
constant current regulators. Also the same warnings apply to these
devices as to the DMM/clamp-on combination when it comes to accuracy of
the instrument. Since most of these devices are rated to measure current
far in excess of what you need to measure on airport lighting circuits,
their accuracy at the low end of the measurement scale may be in
question. Clamp-on devices having an accuracy of + or -- 2 % or better
should be used if at all possible as a small change in current can
produce a large change in lamp light output. It may be beneficial to
have a registered calibration laboratory check the instrument and
calibrate it to the lower amp range.

**4.1.5.1 Safety.**

A clamp-on ammeter reduces operator exposure to high voltage. However,
the operator must observe normal safety precautions to prevent coming in
contact with exposed conductors when taking current readings.

**4.1.6 AC Proximity Voltage Tester.**

These small non-contact testers, sometimes referred to as "tickers," can
be handy for detecting voltage present in insulated cables. Depending on
the model, they may have a wide measurement range. They should not,
however, be used to determine if an airfield lighting series circuit is
energized (4.1.6.1). The reason for this is because of the behavior of
voltage in a series circuit. The voltage is reduced by the various
voltage drops (loads) present in the circuit until at some point near
the middle of the circuit there is no measurable voltage although
current flow is still present. Breaking the circuit at that point or at
any point in the live series circuit can result in injury or death. See
Paragraph 2.3.1.

**4.1.6.1 Safety.**

Do not rely on these units as the only instrument used to protect
oneself from coming into contact with energized conductors. A good
quality clamp-on ammeter device is the only safe way to check for an
energized series lighting conductor. After checking for the presence of
current with a clamp-on ammeter, an inductive proximity voltage
measuring device may be used to detect the presence of induced voltage.
Also, as with all test instruments used for measuring voltage or
current, make sure that you test the device on a known live circuit
before and after making any measurement of this kind.

**4.1.7 Time Domain Reflectometer.**

The Time Domain Reflectometer (TDR) was once a very expensive laboratory
quality instrument used for testing control and coax cable systems. Now
however, these instruments have evolved into less expensive hand-held
units capable of pinpointing the location of opens or faults in long
runs of twisted pair control cables. If your facility is using long runs
of telephone type twisted pair cables for control of airfield lighting
equipment from a remote control tower location, it may be useful to
invest in one of these devices for troubleshooting purposes. The TDR
applies a signal to the cable pair in question and can give readout in
feet indicating the distance to the cable fault as well as a visual
display of the cable run. This can save many hours of troubleshooting
when trying to find a bad splice in a long run of control cable. The
newest models have settings for testing power cables, data cables, coax
cables, as well as telephone and control cables. Some of these units are
capable of measuring cable lengths of up to 48,000 ft.

A similar device is the Optical Time Domain Reflectometer which is used
to perform similar tests on optical fiber cable. With the advent of
computerized control systems employing fiber optic networks for control
of airfield lighting systems, the ability to troubleshoot these cable
systems is becoming necessary. At the time of this writing, these
instruments are still extremely high in price and probably not a
justifiable expense to the average airport maintenance department. In
most cases it may be more economical to employ outside contractors to
perform any troubleshooting and repairs on fiber optic cable systems.

**4.1.7.1 Safety.**

As with other measurement devices that require direct connections to
conductors, be sure to exercise a proper safety check to verify that the
conductor or circuit under test has been de-energized and is locked-out
and tagged.

**4.1.8 Tone and Probe Tracing Sets.**

Normally used by technicians employed in the telephone industry, these
devices can be a great addition to the airfield electrician's toolbox.
The kits are inexpensive and can be used for many purposes at an airport
to identify individual conductors whether in a control cable or
individual power cables in a manhole or vault. The simple transmitter is
connected directly to any un-energized conductor and injects a tone on
the conductor that can be heard by using an inductive probe.

**4.1.8.1 Safety.**

As with other measurement devices that require direct connections to
conductors, be sure to exercise a proper safety check to verify that the
conductor or circuit under test has been de-energized and is locked-out
and tagged.

**4.1.9 Infrared Thermometer.**

Infrared thermometers are hand-held devices that can give a direct
temperature readout of any surface from several feet away. They can be
aimed at the target via a laser target sight. In addition to identifying
loose connections in panelboards, these instruments may be used for
troubleshooting of ground faults in airfield lighting circuits. By
measuring the temperature of different light bases on the runway or
taxiway and comparing the temperature differential between light bases,
it is possible to find the location of a ground fault if the cable and
transformer assembly have been arcing and burning inside a light base.

**4.1.9.1 Safety.**

Since the use of an infrared thermometer requires no contact with the
surface of the object to be measured, these devices are generally very
safe to use. Follow manufacturer's instructions and avoid direct eye
exposure to the laser sighting beam.

**4.1.10 Portable Oil Dielectric Tester.**

Most older constant regulators are oil filled for cooling. The oil acts
as an insulator and therefore must be maintained. Dirt, sludge, and
other contaminants will reduce the dielectric strength of the insulating
oil causing a potential for failure of the transformer. Sample and test
the oil as indicated in Paragraph 5.2.5. A portable oil tester may be a
justifiable expense if the airport maintains a large number of
oil-cooled regulators. Some of these test apparatus may include
accessories for testing of rubber "hot" gloves. As an alternative,
samples may be sent out to a testing lab or local electric utility for
testing.

**4.1.10.1 Safety.**

Portable oil dielectric testers utilize high voltages up to 30 kV and
extreme care must be taken operating this equipment. Always follow all
manufacturer's operation and safety instructions.

**4.1.11 Ground Rod Resistance Tester.**

Ground rod resistance testers come in several styles and are necessary
for checking and maintaining the effectiveness of grounding systems and
counterpoise systems at the airport. These testers measure the
resistance between the grounding system and the earth ground. Some of
the newer models are simple clamp-on units capable of giving the
resistance-to-ground of ground rods or grounding conductors by measuring
the ground leakage current without disconnecting the grounding conductor
under test. Follow manufacturer's instructions closely to obtain an
accurate ground resistance reading, thus avoiding a false, lower than
actual resistance-to-ground measurement that can result from incorrect
use. The grounding system in question may be used for beacon towers,
lighting vaults, engine generators, and for other lighted visual aids,
or it may be a counterpoise system for underground cables. The maximum
acceptable ground resistance is 25 ohms. It is preferable that the
resistance be 10 ohms or less. In many locations, the water table is
gradually falling. In these cases, the ground electrode systems that
were effective when initially installed are no longer effective. This
emphasizes the importance of a continuous program to periodically check
the grounding system. It is not sufficient to check the grounding system
only at the time of installation.

**4.1.11.1 Safety.**

A grounding system is a very important integral safety feature in
airport lighting systems. To be effective, the grounding system must
have a very low resistance-to-ground. The higher the inherent resistance
of the grounding system, the greater the voltage that can build up on a
grounded chassis or frame. When this built-up voltage discharges through
a person, injury or death may result. For this reason, check the
effectiveness of the grounding system regularly.

**4.1.12 Mobile Photometric Measurement System.**

Maintain the light output of runway lighting systems within specified
limits to provide effective visual cues to the pilot while landing in
low visibility conditions. Clean or service the lights when the
brightness of the fixture is less than 70% of the minimum output
required when operated at full intensity, per values listed for that
fixture in AC 150/5345-46, Specification for Runway and Taxiway Light
Fixtures. A fixture degraded below this is ineffective for high
background brightness, low visibility conditions and should be targeted
for maintenance. See Appendix A, Standards and Tolerances, Table 8.

In the past, *in situ* photometric measurements were only possible using
a hand held spot meter. This method has proven to be very ineffective
and can only detect gross differences between lights and cannot account
for alignment errors. Now, however, mobile systems are available which
can test individual fixtures within a lighting system at high speed and
with a high degree of accuracy. Some of these systems can produce
individual iso-candela diagrams of individual lights to aid in
troubleshooting and maintenance as well as indicate misaligned fixtures.
Some systems can also provide GPS coordinates for each light on the
runway to aid in locating deficient fixtures for cleaning or repair.
Equipment used for photometric measurements must be of the highest
quality and be proven capable of high accuracy and repeatability to
avoid the collection of erroneous data.

# CHAPTER 5. PREVENTIVE MAINTENANCE.

## 5.0 GENERAL.

This chapter discusses the preventive maintenance program for the visual
aid facilities and equipment. It contains a Preventive Maintenance
Inspection (PMI) schedule for each major item of equipment with
step-by-step instructions for performing the PMI. The PMIs establish a
recommended routine which may be altered to suit local conditions.
General troubleshooting procedures for airport lighting systems are
contained in Chapter 6. Corrective maintenance procedures for specific
equipment will be found in the manufacturer\'s operating and maintenance
instructions and are not included in this AC.

## 5.1 AIRPORT LIGHTING VAULT.

To perform the PMIs, as shown in Table 5.2, proceed as follows:

**5.1.1 [Daily Checks]{.underline}**.

Check the operation of all controls. If the airport is equipped with a
computer control system that allows control and monitoring from the
maintenance shop or other remote location, verify the proper operation
of all controls from that location.

**5.1.2 [Weekly Checks]{.underline}.**

\(1\) [Cleanliness]{.underline}. Check the general cleanliness of the
vault. Sweep out the vault regularly. Keep it free from dust, dirt,
sand, spider webs, insect nests, etc.

\(2\) [Moisture]{.underline}. Check for any collection of moisture. If
there is a drain in the floor, make sure that it is operating properly.
Mop up moisture from the floor.

\(3\) [Screens]{.underline}. Check screens on all ventilators. Repair or
replace, as necessary, to keep out wasps and other nest-building
insects. Check operation of ventilation fans and thermostat controls. If
vault is equipped with air conditioning, check for proper operation of
system and thermostat control in warm weather months.

\(4\) [Storage]{.underline}. Check vault for improper use as a
storeroom. Avoid storing spare parts, rags, etc., near the high-voltage
equipment. If the vault has an attached room, use this room for storing
spare lamps, fuses, rags, spare parts, etc.

**5.1.3 [Monthly Checks]{.underline}.**

**5.1.3.1 Insulation-Resistance Test.**

Performing regular preventive maintenance checks on airfield lighting
circuits is absolutely necessary for reliable operation of the system.
Because of the potential of operating at very high voltages, the
components of the series circuit are extremely susceptible to failure.

Perform insulation resistance tests on all airfield circuits on a
monthly basis as a minimum. If the airport has circuits that fail
regularly due to age or other reasons, consider weekly checks. Many
potential failures can be found during daylight hours before they become
a problem by making weekly PM insulation resistance checks a habit. Keep
records in the regulator vault with the circuit identified as well as
the date and results of the test. Provide space for notes as to special
conditions such as weather conditions at the time of the test, recent
lightning activity and to note failure locations and causes when found.
A sample form is shown in Figure 5-1.

Insulation resistance test sets can be purchased that are operated by
hand-crank, batteries, or on 120 volt AC supply. The battery operated
sets are the most versatile. Hand-crank units are the least accurate as
the operation of the instrument can vary significantly between
operators. Take care in selecting a test set and potential output
voltages. As a minimum, the test set should have an output of 1000 volts
DC. Test sets with outputs of 2500 VDC to 5000 VDC are also available
and are superior at detecting high resistance faults. It should be
noted, however, that when testing older circuits, especially circuits
that normally operate at lower voltages, use of a 5000 VDC tester may
show a fault in an otherwise undetected weak spot in a cable or
transformer. It is therefore advisable, when testing at voltages higher
than 1000 VDC, to be prepared to make immediate repairs if necessary.

When performing insulation resistance tests for preventive maintenance,
it is necessary to be consistent in the way the tests are carried out
from one session to the next. Test results may vary due to a number of
circumstances. For instance, the test should be administered for the
same length of time each time it is performed and at the same test
voltage so that the results may be accurately compared.

A very important consideration when performing insulation resistance
tests is the time required for the reading of insulation resistance to
reach a maximum. The primary cause of delay in reaching full charge is
known as the dielectric absorption effect. It may be a matter of several
minutes before this is completed and for the reading to reach an
absolute maximum. It is best to establish a minimum time for conducting
the tests based on experience.

For short time readings of insulation resistance, operate the instrument
for a definite length of time, either 30 seconds to 1 minute, and read
at the end of that time. Make future tests with the same length of
operating time.

Other variables such as moisture, weather, and time of day may affect
the readings. Readings should ideally be taken after circuits have been
de-energized for several hours. Readings may appear higher immediately
after operating the circuit. This is a sign of deteriorating insulation
in transformers and possibly cable that is allowing moisture to enter.
Operating the circuits raises the temperature and drives moisture from
the insulation resulting in an artificially higher reading.

There is no ideal value for insulation resistance readings on series
circuits due to factors such as circuit length, age, etc. The best rule
here is to base this decision on past experience with your own facility.
Each circuit may be different based on age, manufacturer of cable and
equipment, installation methods (direct buried or installed in conduit),
local weather conditions, and amount of moisture normally present in the
system. The decision of when to consider a circuit failing and in need
of preventive maintenance repairs may vary from one circuit to another
at the same facility. Generally speaking, any circuit that measures less
than 1 megohm is certainly destined for rapid failure. The time it takes
for a circuit to fail is affected by the output voltage of the
regulator, type of fault and presence of moisture at the location of the
fault. The larger the circuit size in kW, the higher the output voltage
and hence, the more the condition of the insulation becomes critical.
The important information is the deterioration of the resistance values
from month to month and year to year. The resistance value inevitably
declines over the service life of the circuit; a 10-20 percent decline
per year may be considered normal. A yearly decline of 50 percent (4
percent monthly) or greater indicates the existence of a problem (such
as a high resistance ground) or serious deterioration of the circuit
insulation. In this instance the maintenance supervisor should consider
performing troubleshooting to locate the problem (Chapter 6). A table
for typical existing circuit loop resistance is shown in Table 5-1.

It should also be noted that the insulation resistance that is required
for new installations will have a great effect on the ability of the
maintenance staff to maintain the series lighting circuits after
installation and acceptance. With newer cable installations being more
frequently installed in conduit and base cans as opposed to direct
burial, initial resistance values up to and in excess of 500 megohms are
normally achievable and should be required.

  ----------------------------------- -----------------------------------
  Circuit Length in Feet              Suggested minimum resistance to
                                      ground in megohms

  10,000 or less                      50

  10,000 to 20,000                    40

  20,000 or more                      30
  ----------------------------------- -----------------------------------

**Table 5-1. Suggested Resistance Values for Maintenance**

**5.1.3.2 Input Voltage.**

Measure the input voltage to the vault. Take this measurement at various
times of the day and/or night since the demand on the commercial power
network varies throughout the day. Record the input voltage of each
phase for future reference. If it is out of tolerance, contact the power
company and have them correct the problem.

**AIRPORT LIGHTING CIRCUIT INSULATION RESISTANCE TEST RECORD**

**VAULT OR SUBSTATION \#
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

**CIRCUIT IDENTIFICATION
\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_**

  ---------- ---------- ------------------------------------------ --------------
  **DATE**   **OHMS**   **WEATHER CONDITIONS AND COMMENTS**        **INITIALS**

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   

                                                                   
  ---------- ---------- ------------------------------------------ --------------

**Figure 5-1. Sample Insulation Resistance Record**

**5.1.4** **[Semi-annual Checks.]{.underline}**

**5.1.4.1** **Ground Resistance.**

Perform a ground-resistance measurement for each item of equipment using
a ground resistance tester. Record the readings and compare with
previous readings to discover deterioration in the grounding system. The
lower the resistance value, the better; a value of 5 to 10 ohms is
desirable. If the resistance is greater than 25 ohms, immediate action
must be taken to lower the resistance.

**5.1.4.2 Primary High-Voltage Buses and Ground Buses.**

Check the high-voltage bus installation with particular attention to the
condition of the insulators, supports, and electrical connections. Keep
the bus insulators wiped free of dust or any other deposits. Check the
ground bus carefully throughout its entire length. If the bus or any
ground connection to the bus is broken, make immediate repairs.
De-energize the system before cleaning or repairing the bus.

**5.1.4.3 Relays.**

Inspect the protective relay, circuit selector switches, and auxiliary
relay panels when servicing the vault equipment. Check the operation of
these devices, clean the contacts, adjust release springs, and check
contact arms and dash pots. Replace all unserviceable parts.

**5.1.4.4 Oil Fuse Cutouts.**

Check operation and electrical connections of the oil fuse cutouts.
Check the contacts and check the oil level. Add oil when necessary. If
fuses with replaceable links have failed, replace them with fuse links
especially manufactured for this purpose. If the oil fuse cutouts have a
manual operating lever, check the operation of the locking arrangement.
Be sure the manual operating handle is locked in the "OFF" position
before servicing vault equipment that is being supplied through the oil
fuse cutout.

**5.1.4.5 Oil Switches.**

Check the operation of the oil switches. Be sure that the moveable
handle on the oil switch, which has three positions, "MANUAL OFF,"
"MANUAL ON," and "AUTOMATIC," is in the "AUTOMATIC" position at all
times. This allows the switch to be remotely controlled. Check the
contacts and oil level and service when necessary.

**5.1.4.6 Power Transfer Switches.**

Check operation of power transfer switches. Check contacts for dirt or
corrosion.

**5.1.4.7 Control Panel or Computer Control Equipment.**

In some cases, an auxiliary control panel is installed in the vault, or
a computer controlled system is installed along with a monitor interface
that may provide control capabilities from the vault. In such cases,
carefully check the operation of all parts of the panel. Clean all
contacts and make sure all electrical connections are in good condition.
Clean the interior of the panel carefully. If computer-controlled,
inspect and clean all air filters associated with the cooling fans for
the computers and uninterruptible power supply units if so equipped.

**5.1.4.8 Photoelectric Time Switch.**

If a photoelectric time switch is installed, maintain according to the
manufacturer's instructions. Check light levels with a photographic
light meter to ensure that the control turns on and off at the proper
ambient light levels.

**5.1.4.9 Astronomic Time Switch.**

If this switch is installed, service according to the manufacturer's
instruction book. Inspect the operation, check clock for proper time,
clean motor commutator and main switch contacts, and check all
electrical connections. Since this is a precision instrument, the
manufacturer or an authorized service representative should make
repairs.

**5.1.4.10 Radio-Control of Airport Lighting.**

Check the operation of radio-controlled airport lighting by keying a
portable transmitter and observing the actuation of the switching
mechanism. If a fault is detected, follow the manufacturer's
recommendation for repair or replacement.

**5.1.4.11 Lightning Arresters.**

Check the lightning arresters for burning, scorching, or other signs of
failure. Inspect lightning arresters for damage after each lightning
storm in the area.

**5.1.4.12 Miscellaneous.**

Inspect all miscellaneous vault items, such as circuit breakers,
terminal blocks, potheads, vault lights, switches, etc. Make sure they
are clean and all connections are tight. Inspect all safety board
equipment and fire extinguishers.

**5.1.5 [Annual Checks.]{.underline}**

**5.1.5.1 Dielectric Checks.**

Perform dielectric tests on oil in oil-filled equipment such as circuit
breakers, regulators, and transformers as described in Paragraph 5.2.

**5.1.5.2 Paint.**

Check the condition of the paint on the equipment and vault. Repaint as
necessary.

**5.1.6 [Recommended Vault Procedures.]{.underline}**

**5.1.6.1 Airport Plan.**

Permanently post an airport plan in the vault to aid in testing and
troubleshooting the field circuit loops. This airport plan (preferably
behind glass) shows the field layout, marked with the location of all
lights, cable runs, cable splices, and lighted visual aid equipment.
Name and telephone number(s) of person(s) responsible for electrical
maintenance for the airport should be located adjacent to the airport
plan.

**5.1.6.2 Schematic Diagram.**

Display up-to-date diagrams of all power and control circuits in the
vault. Display both a schematic diagram, which is a symbolic depiction
of the logic of the circuit, and a wiring diagram, which is a detailed
layout showing all wires and connections.

**5.1.6.3 Vault Security.**

Lock the vault, except during maintenance, to keep unauthorized
personnel out. Contact with the high-voltage buses in an airport
lighting vault is nearly always fatal. Allow only authorized personnel,
experienced in the hazards of high voltage, in the vault.

**5.1.6.4 High-Voltage Warning Signs.**

Prominently display high-voltage warning signs, as described in
Paragraph 2.10, at appropriate locations.

**5.1.6.5 Safety Board.**

Install safety boards, as described Paragraph 2.5, in the vault.

+---------------------------------------------------+---+---+---+---+---+---+
| **Maintenance Requirement**                       | * | * | * | * | * | * |
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|                                                   | Y |   | Y | Y | Y | H |
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|                                                   | * |   | * | * | * | * |
+---------------------------------------------------+---+---+---+---+---+---+
| 1\. Check control operation                       | X |   |   |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 2\. Check general cleanliness                     |   | X |   |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 3\. Check for moisture                            |   | X |   |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 4\. Check ventilator screens or air conditioner   |   | X |   |   |   |   |
| controls                                          |   |   |   |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 5\. Inspect safety boards, safety equipment and   |   |   | X |   |   |   |
| fire extinguishers                                |   |   |   |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 6\. Check insulation resistance of all field      |   |   | X |   |   |   |
| circuits\*                                        |   |   |   |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 7\. Check input voltage to vault                  |   |   |   | X |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 8\. Check ground resistance                       |   |   |   | X |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 9\. Inspect and clean buses                       |   |   |   | X |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 10\. Check relay operation                        |   |   |   | X |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 11\. Check oil fuse cutouts                       |   |   |   | X |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 12\. Check oil switches                           |   |   |   | X |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 13\. Operate power transfer switches              |   |   | X |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 14\. Check control panel or computer control      |   |   |   | X |   |   |
| equipment                                         |   |   |   |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 15\. Check photoelectric switch                   |   |   |   | X |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 16\. Check astronomic time switch                 |   |   |   | X |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 17\. Check radio control of lighting equipment    |   |   | X |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 18\. Check lightning arrestors                    |   |   |   | X |   | X |
+---------------------------------------------------+---+---+---+---+---+---+
| 19\. Inspect miscellaneous electrical equipment   |   |   |   | X |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 20\. Test oil dielectric strength in transformers |   |   |   |   | X |   |
| and regulators                                    |   |   |   |   |   |   |
+---------------------------------------------------+---+---+---+---+---+---+
| 21\. Paint equipment as necessary                 |   |   |   |   | X | X |
+---------------------------------------------------+---+---+---+---+---+---+

> \* Weekly insulation resistance tests may be necessary for older
> circuits.

**Table 5-2. Preventive Maintenance Inspection Schedule for Airport
Lighting Vaults**

## 5.2 CONSTANT CURRENT REGULATORS (CCRs).

Constant current regulators come in two basic types, air cooled and
liquid filled. The two basic types of regulators can be further
classified as either magnetic or electronic. Magnetic types typically
utilize either a resonant circuit or a saturable reactor principle. In a
resonant network circuit, the current output is proportional to the
input voltage and therefore any change in input voltage will cause a
corresponding change in output current. Most resonant network regulators
are only manufactured in sizes less than 10 kW. We recommend that
manufacturer's literature on the operation, theory of operation, and
recommended maintenance procedures for the particular regulator(s) being
used be obtained and kept on hand in the vault and maintenance office
for reference.

Most constant current regulators manufactured today are reliable and
reasonably trouble-free. However, do not be lulled into complacency when
considering preventive maintenance of these vital components in the
airport lighting electrical system. A regulator failure without a spare
backup regulator or spare parts on hand can shut down a vital runway or
taxiway indefinitely.

Many times otherwise conscientious electricians have been surprised by a
sudden failure or caught without spare parts for a piece of equipment.
Unlike other elements in the electrical system that use commonly
available parts, when a failure occurs of a component in a CCR, it is
most likely an entire PC board that will have to be replaced and
manufacturers may not have parts readily available. As a minimum, keep
one type of each board and critical component such as silicon controlled
rectifiers (SCRs) on hand for each type and size of CCR in use at the
airport. This task has been made easier by some manufacturers as they
make CCRs that use common control boards and components regardless of
size, style, or type.

**5.2.1 [Daily Checks.]{.underline}**

1.  Check all control equipment for proper operation. Check remote
    control operation on each brightness step. This has been made easier
    at many airports due to the upgrade to computer controlled systems
    with an interface terminal at the maintenance shop office. Before
    the end of each shift, the supervisor can energize the airport
    lighting systems and monitor the CCRs for proper operation.

**5.2.2 [Weekly Checks.]{.underline}**

1.  Pay a visit to each electrical vault or substation at least once a
    week to check for cleanliness and general condition. We recommend
    making the visit while the circuits are in operation so as to notice
    any unusual noises or smells that could lead to discovering a
    problem with one of the CCRs. If the airport has a weekly schedule
    of performing insulation tests on field circuits or testing
    emergency generators, test and inspect the CCRs at this same time.

**5.2.3 [Monthly Checks.]{.underline}**

1.  Check and record input voltage and current. If the voltage is not
    within + or -- 5% of the design voltage, notify the power company to
    correct the input voltage.

2.  Check and record the output current of each CCR on each brightness
    step. Compare the values with the tolerances listed in Tables 5-3 &
    5-4. Make sure you are using a [high accuracy true RMS
    ammeter]{.underline} when making these measurements. If any are
    found to be out of tolerance, adjust CCR per manufacturer's
    instructions.

**5.2.4 [Semi-annual Checks.]{.underline}**

1.  If it is suspected that a circuit may be overloaded, a measurement
    of the output load may be made at this time. Evidence of overloading
    could be overheating, failure to produce rated current (6.6 or 20 A)
    at maximum brightness setting, or erratic behavior when operated
    with a transient load such as runway guard lights or runway end
    identifier lights (REILs).

    **!!CAUTION!!**

    **[MEASUREMENTS OF THE OUTPUT LOAD OF A CCR REQUIRE TAKING VOLTAGE
    MEASUREMENTS AT THE LOAD OUTPUT TERMINALS OF THE CCR. A CCR CAN
    DEVELOP AS MUCH AS 4545 VOLTS IN THE CASE OF A FULLY LOADED 30 kW
    CCR. NEVER ATTEMPT TO MEASURE THE VOLTAGE ACROSS THE OUTPUT OF A
    REGULATOR WITHOUT A LOAD CONNECTED. IN OPEN CIRCUITED CONDITIONS,
    THE VOLTAGE CAN REACH EXTREMELY HIGH VALUES BEFORE OPEN-CIRCUIT SHUT
    DOWN OF THE REGULATOR OCCURS. ONLY QUALIFIED ELECTRICIANS EXERCISING
    EXTREME CAUTION AND USING THE CORRECT INSTRUMENTS AND SAFETY
    PRECAUTIONS SHOULD ATTEMPT THESE MEASUREMENTS.]{.underline}**

    Measure voltage across the output of the CCR using a potential
    transformer having a ratio of 40:1 and a primary voltage rating of
    at least 4800 volts. Use a high accuracy true-RMS digital multimeter
    or power analyzer to measure the output of the potential
    transformer. Alternatively, many newer control and monitoring
    systems have provision for constant monitoring of output voltage,
    current and circuit load. Before measuring output load, it is
    imperative that a check be made to ensure that all the lamps are
    operating in the circuit. Open secondary windings on series
    transformers impose an inductive load on the regulator which can
    result in erratic behavior of the regulator and inaccurate
    measurements. Measure the output voltage across the output terminals
    with the normal load connected and the regulator operating at the
    highest brightness step. Multiply the output current (normally 6.6
    or 20 A) by the voltage measured across the output of the regulator
    to obtain the approximate load (i.e. 4545 volts x 6.6 amps = 30Kw).
    This is a close approximation that assumes that the regulator is
    operating at a high power factor. Assure that the load value does
    not exceed the given kW rating of the regulator.

2.  Visually inspect the regulator for any signs of loose connections or
    overheating. Be aware that many of the connections that should be
    inspected are not visible by merely opening the front access panel
    on the regulator. De-energize and lock out power to the regulator
    and remove the top, sides, or back panels depending on the type of
    CCR to access and inspect the connections. Pay special attention to
    line and load connections where high current is present and also
    inspect connections on capacitors closely. Look for any signs of
    discoloring that would indicate overheating and a loose connection
    and physically test any and all connections for tightness.

**5.2.5 [Annual Checks.]{.underline}**

1.  For regulators that are oil filled, make a dielectric strength test
    of the oil. Take at least a 1-pint sample of oil from the oil
    sampling or drain valve at the base of the regulator tank. Sediments
    may have settled to the bottom of the tank that could contaminate
    the sample. If such sediments are observed in the sample, take
    another sample to try to obtain a sample that is free of sediment or
    if possible, remove a sample from the top of the regulator tank. It
    is also very important to make sure that a clean vessel is used to
    obtain and store the sample so as not to contaminate it. An oil
    dielectric tester, as described in Chapter 4, may be used or if no
    facilities are available for making dielectric tests, contact the
    nearest power company equipped to perform these tests. If the oil is
    dirty or black, this is usually a sign of a major electrical problem
    within the tank which will require major work. If the oil dielectric
    strength is low, it should be replaced or filtered and dried to
    restore its dielectric strength. Wash out sludge deposits on the
    core and coil assembly and in the tank with clean dry oil. Models
    with an internal primary switch will tend to collect more sludge due
    to arcing under oil. Fill with oil to the proper level with the type
    oil approved by the regulator manufacturer. Dielectric strength (kV)
    for new oil should be 30kV+. A normal range for oil being tested
    should be 26-30 with 22 kV as the minimum acceptable level.

2.  Perform a short circuit test as follows:

    Turn off power to the regulator. Short the output terminals using
    No. 10 AWG wire (or larger) across the output terminals. Turn on the
    regulator and advance intensity through each step. Read the output
    current on each step using an accurate true RMS ammeter. The output
    current should be within the tolerances shown in Tables 5-3 & 5-4.

3.  If the current output is not within limits, check the voltage input
    to the regulator. It should be within +/-5 percent of rated input
    voltage. Be sure the correct voltage tap is used (on dry-type
    transformers). Turn off the regulator and lock out and tag out the
    input supply. Disconnect the short and reconnect output cables.
    Compare the short circuit values with those obtained from the
    monthly output current readings. If necessary, adjust output current
    according to the manufacturer's equipment maintenance manual.

4.  Perform an open circuit test as follows:

    Perform this test only on those regulators with open circuit
    protective devices. Turn off power to the regulator and lock out the
    primary supply circuit. Disconnect cables from output terminals.
    Turn on power to the regulator. Advance the brightness selector
    switch to any step. The open-circuit protective device should
    automatically operate within two seconds to turn off the regulator.
    Turn off the selector switch. Reset the open-circuit protective
    device. If the test is satisfactory, turn off regulator power and
    lock out primary supply and reconnect the output cables. Re-energize
    primary power to the regulator and set selector switch for automatic
    (remote) operation.

5.  Perform an over-current test:

> If the regulator is equipped with over-current protection, follow the
> manufacturer's recommendations and procedures as outlined in the
> regulator manual for performing an over-current test.

**[Standard FAA CCR Output Currents vs. Allowable Range, Per FAA AC
150/5345-10E]{.underline}**

+--------------------+---------------------------+--------------------+
| Output Step        | Nominal Output            | Allowable Range    |
+--------------------+---------------------------+--------------------+
| > 3                | > 6.6 amps                | > 6.40-6.70        |
+--------------------+---------------------------+--------------------+
| > 2                | > 5.5 amps                | > 5.33-5.67        |
+--------------------+---------------------------+--------------------+
| > 1                | > 4.8 amps                | > 4.66-4.94        |
+--------------------+---------------------------+--------------------+

**Table 5-3. 3-Step CCR Output Tolerances**

+-------------+-------------+-------------+-------------+-------------+
| Output Step | Output      | Allowable   | Output      | Allowable   |
|             |             |             |             |             |
|             | 6.6 A       | Range       | 20 A        | Range       |
|             | Regulator   |             | Regulator   |             |
+-------------+-------------+-------------+-------------+-------------+
| > 5         | 6.6 amps    | 6.40-6.70   | 20.0 amps   | 19.40-20.30 |
+-------------+-------------+-------------+-------------+-------------+
| > 4         | 5.2 amps    | 5.04-5.36   | 15.8 amps   | 15.33-16.27 |
+-------------+-------------+-------------+-------------+-------------+
| > 3         | 4.1 amps    | 3.98-4.22   | 12.4 amps   | 12.03-12.77 |
+-------------+-------------+-------------+-------------+-------------+
| > 2         | 3.4 amps    | 3.30-3.50   | 10.3 amps   | 9.99-10.61  |
+-------------+-------------+-------------+-------------+-------------+
| > 1         | 2.8 amps    | 2.72-2.88   | 8.5 amps    | 8.24-8.76   |
+-------------+-------------+-------------+-------------+-------------+

**Table 5-4. 5-Step CCR Output Tolerances**

+------------------------------------------------+---+---+---+---+---+---+
| Maintenance Requirement                        | D | W | M | S | A | U |
|                                                |   |   |   |   |   |   |
|                                                | A | K | T | M | N | N |
|                                                |   |   |   |   |   |   |
|                                                | I | L | H | A | N | S |
|                                                |   |   |   |   |   |   |
|                                                | L | Y | L | N | L | C |
|                                                |   |   |   |   |   |   |
|                                                | Y |   | Y | L | Y | H |
|                                                |   |   |   |   |   |   |
|                                                |   |   |   | Y |   |   |
+------------------------------------------------+---+---+---+---+---+---+
| 1\. Check control circuits on all brightness   | X |   |   |   |   |   |
| steps                                          |   |   |   |   |   |   |
+------------------------------------------------+---+---+---+---+---+---+
| 2\. Check condition and operation of regulator |   | X |   |   |   |   |
+------------------------------------------------+---+---+---+---+---+---+
| 3\. Check input voltage and current            |   |   | X |   |   |   |
+------------------------------------------------+---+---+---+---+---+---+
| 4\. Check output current on each brightness    |   |   | X |   |   |   |
| step                                           |   |   |   |   |   |   |
+------------------------------------------------+---+---+---+---+---+---+
| 5\. Check output load on regulator if needed   |   |   |   | X |   |   |
+------------------------------------------------+---+---+---+---+---+---+
| 6\. Check relays, wiring and insulation        |   |   |   | X |   |   |
+------------------------------------------------+---+---+---+---+---+---+
| 7\. Check dielectric strength of cooling oil   |   |   |   |   | X |   |
| (if used)                                      |   |   |   |   |   |   |
+------------------------------------------------+---+---+---+---+---+---+
| 8\. Perform a short-circuit test               |   |   |   |   | X |   |
+------------------------------------------------+---+---+---+---+---+---+
| 9\. Perform an open-circuit test (only on      |   |   |   |   | X |   |
| regulators with open circuit protection.       |   |   |   |   |   |   |
+------------------------------------------------+---+---+---+---+---+---+
| 10\. Clean rust spots and repaint as           |   |   |   |   |   | X |
| necessary.                                     |   |   |   |   |   |   |
+------------------------------------------------+---+---+---+---+---+---+

**Table 5-5. Preventive Maintenance Inspection Schedule for Constant
Current Regulators**

## 5.3 LIGHT FIXTURE AND BASE MAINTENANCE.

**5.3.1 [Introduction.]{.underline}**

Airport lighting fixtures for runway and taxiway use are divided into
two broad categories: elevated and in-pavement. The maintenance
requirements for each of these types are quite different. In-pavement
lights generally require more maintenance than elevated lights to
provide consistent performance and uniformity of light output. Elevated
runway edge lights require more care in alignment so that the light
output is aimed properly to meet photometric requirements. Several
factors, however, are common to both types of fixtures. Dirt and other
contaminants, particularly rubber on in-pavement lights, reduce light
output and require periodic cleaning of the glassware or lens to assure
optimum performance. Bases also require maintenance attention on a
regular basis to ensure the integrity of the fixture/base assembly.

**5.3.2 [Runway and Taxiway Elevated Edge Lighting
Systems.]{.underline}**

Elevated lights, particularly taxiway lights, generally require less
maintenance attention than the in-pavement lights such as runway
centerline and touchdown zone lights. Taxiway edge lights normally only
require periodic re-lamping. However, they are probably the most likely
candidates for other types of damage on the airfield. Aircraft and
ground vehicles, snow plows and mowers seem to have a particular
affinity for running over elevated taxiway edge lights. It is for this
reason that many airports are using in-pavement taxiway edge lights more
frequently in areas of high traffic or frequent damage. The primary
problems and hazards associated with the repair of elevated lights, when
they have been run over or damaged, is from the glass and bare
electrical conductors that may be exposed. Be sure to take proper safety
precautions when handling these items (i.e. proper gloves and other
safety equipment). Glass from broken taxiway globes is extremely sharp
and poses a hazard both to the maintenance electrician and also as a
significant Foreign Object Damage (FOD) hazard for aircraft. Probably
the single biggest problem with repairing damaged elevated taxiway or
runway lights is the removal of the existing frangible coupling. Reduce
this problem by applying a coating of anti-seize compound or aluminum
anti-oxidant to the threads before installing a new coupling.

Runway edge lights and threshold lights require more maintenance than
taxiway lights. Runway edge lights may require periodic cleaning to
remove dirt, mud, bird droppings, etc. The lenses of elevated runway
edge lights can also become pitted and sand-blasted from jet blast and
require replacement. When re-lamping or repairing runway edge lights,
care must be taken to make sure that all lenses and filters are in their
proper orientation and that the fixture itself is in the proper
orientation relative to the runway. Most elevated runway edge light
globes have an arrow on top that must be aimed perpendicular to the
runway centerline. The beams of runway edge lights are aimed toward the
runway centerline at 3.5 degrees. The beam is also aimed up 4 degrees
from horizontal. Proper orientation of the fixture is necessary for this
toe-in and required photometric output to be maintained. When re-lamping
any type of fixture, always check the lamp before installing to make
sure that it is the correct type and wattage. Many lamps look alike.
Never re-lamp fixtures with the circuit energized. Hazards associated
with this practice are covered in Chapter 2 of this document. Also,
never use any lamp other than the lamp approved by the original
equipment manufacturer of the fixture. Failure to do so may affect
photometric output of the fixture and cause the fixture assembly to no
longer meet FAA requirements.

**5.3.2.1** **[Preventive Maintenance Inspection
Procedures.]{.underline}**

To perform the PMIs contained in Table 5-6, proceed as follows:

**5.3.2.2 [Daily Checks.]{.underline}**

1.  Perform a visual inspection of the system at twilight or night each
    day. This inspection consists of a driving patrol to visually check
    for dimly burning bulbs, burned-out lamps, and fixtures out of
    alignment. Record the locations of such fixtures and make
    corrections as soon as possible. Replace dimly burning lamps and
    burned-out lamps when the system is deactivated.

2.  Check lenses for cleanliness and clean as required.

**5.3.2.3 [Monthly Checks.]{.underline}**

1.  Check the orientation of all lenses. Make this check by viewing the
    lights at night or by performing testing as outlined in (2.) below.
    Misaligned light units will appear dimmer or brighter than those
    that are properly aligned. The lenses may get out of adjustment when
    replacing lamps or when mowers and other vehicles strike the
    elevated lights.

2.  Intensity Checks / Photometric Testing. Test equipment is now
    available to allow for the rapid and accurate testing of the output
    of both in-pavement and elevated runway lighting fixtures (Paragraph
    4.1.12). In regards to elevated lighting, this type of testing
    primarily applies to high intensity runway edge lighting (HIRL).
    Regular photometric measurements are the only practical way of
    determining if the lights are emitting the specified amount of light
    and for determining misalignment errors. By the use of regular
    photometric measurements, maintenance of lighting fixtures may be
    targeted only where needed thereby saving resources and time while
    allowing the airport to be assured of meeting light output
    specifications, especially necessary in low-visibility conditions.
    Necessary frequency of photometric measurements will vary from
    facility to facility and from runway to runway depending upon the
    amount of traffic and age of the fixtures (see table 5-6). After
    some experience has been gained, the interval may be adjusted to
    operational needs. The frequency of measurement for a precision
    approach runway should be based on traffic density, the local
    pollution level, the reliability of the installed equipment and the
    continuous assessment of the results of the in-field measurements
    but in any case should not be less than twice a year. Photometric
    testing should be performed:

> \(a\) Before cleaning, re-lamping, or realignment to establish whether
> maintenance is necessary, and
>
> \(b\) After cleaning, realignment or repair, to check the
> effectiveness of the maintenance action. High intensity elevated
> runway edge lights that exhibit light output below 70% of the minimum
> light output required when operated at maximum intensity per AC
> 150/5345-46, Specification for Runway and Taxiway Light Fixtures,
> should be targeted for maintenance. Any light with measured output
> less than 70% of the minimum light output required per AC 150/5345-46
> is ineffective for high background brightness, low visibility
> conditions. See Appendix A, Standards and Tolerances, Table 8.

3.  Straighten, level, and align all lighting units that have been
    knocked out of alignment.

4.  Check lamp sockets for cleanliness and good electrical connections.
    If moisture is present, replace the fixture gasket.

5.  Inspect and clean the weep hole in the frangible coupling of
    stake-mounted lights.

**5.3.2.4 [Semi-annual Checks.]{.underline}**

1.  Check the ground elevation around lighting fixtures. The frangible
    point should be approximately 1 inch (2.5 cm) above the ground
    elevation. Grade around the fixture where necessary to maintain this
    fixture/grade relationship. Also, maintain the elevation of all
    lights the same height above the runway/taxiway pavement edge. Check
    the elevation more frequently during times of frequent freeze/thaw
    cycles. The height of the lights should not exceed 14 inches (35 cm)
    when located within 5 feet (1.5 m) of the runway or taxiway edge. In
    snow regions, where the lights are located beyond 5 feet (1.5 m)
    from the runway or taxiway edge, the lights may be raised 2 inches
    (5 cm) for each foot beyond the 5 foot (1.5 m) point. At the 10 foot
    (3 m) position, the lights may have a maximum height of 30 inches
    (75 cm). The increase in height is permitted only if any overhanging
    part of an aircraft expected to use the runway or taxiway could
    clear the light by at least 6 inches (15 cm) when the plane's main
    landing gear is located on any part of the runway or taxiway.

2.  Check light bases and housings for evidence of moisture penetration.
    Check gaskets, seals, and clamps for deterioration and damage. Check
    the torque of light base cover bolts.

3.  Check fixtures, bases, and housing for corrosion, rust and peeling
    paint.

**5.3.2.5 [Annual Checks.]{.underline}**

1.  Check each light fixture carefully for cracking, corrosion, or
    shorts.

2.  Clean the contacts and ensure that lamp fits firmly into receptacle.

3.  Check condition of all connections.

4.  Check all gaskets on a leaky light unit and replace with new rubber
    gaskets.

**5.3.2.6 [Unscheduled Maintenance.]{.underline}**

Remove snow from around the lighting fixtures as soon as possible after
a snowfall so the light fixtures are not obscured. If heavy snowfalls
are predicted, plant red flags or sticks of sufficient length adjacent
to the edge lights to mark their location. The flags will facilitate
snow removal and will lessen the damage to fixtures by snow removal
equipment.

**5.3.3 [Maintenance Procedures.]{.underline}**

The following paragraphs discuss general maintenance procedures for the
runway and taxiway units that are not functioning:

**5.3.3.1** **[Lamp Replacement.]{.underline}**

With the lights operating, make a visual check to positively identify
the lighting unit or units that are not functioning.

**CAUTION:**

**De-energize the circuit and lock out the circuit or regulator so that
the circuit**

**cannot be energized from the remote lighting panel or other means
before starting**

**work on the lights. Remove S-1 switch cutouts if present.**

1.  Turn off the lights and lock out circuits. Install safety warning
    signs at appropriate locations.

2.  With the replacement lamp at hand, open up the fixture and remove
    the old lamp.

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(a) Examine the old lamp to confirm the source of failure.

(b) Compare the identification markings on the old and replacement lamps
    to verify that the replacement lamp is the correct type.

(c) Inspect the lamp socket, connections, and wire insulation.

(d) Check the light unit and base for evidence of leakage or
    condensation and remove any water present.

(e) Replace fused film disc cutout, if used.

(f) Install new lamps, ensuring that the lamp face is clean and free of
    oils, fingerprints, etc. Use a clean, dry, soft cloth and never
    touch the lamp with unprotected fingers.

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```
3.  Check filters, when used, for cracking or misalignment and replace
    or adjust as required.

4.  Clean all reflectors, globes, filters, and covers as required. When
    hood or shield is used, check adjustment.

5.  When closing the light, confirm that the gaskets are positioned for
    proper sealing. Tighten all screws, clamps, and fasteners.

6.  Check frangible couplings for cracks.

7.  Check the horizontal and vertical alignment of the lights for proper
    adjustment.

8.  When all outages have been corrected, energize the circuit and make
    a visual check of the repaired units for proper operation. Record
    the repairs.

**5.3.3.2 Spare Unit Replacement.**

In some instances, it may be more convenient to fix defective edge
lights by replacing the entire light with a spare unit. This will
minimize the runway downtime and allow troubleshooting and refurbishment
of the defective light at a more convenient location. Spare unit
replacement is very convenient for repairing lights struck by lightning
or vehicles.

**5.3.3.3 Film Disc Cutouts.**

Some of the older installations use fused film disc cutouts to bypass
failed lamps. Some circuits that have more than one light on the
secondary side of each isolating transformer use them to bypass a
burned-out lamp and keep the other lamps on the transformer operating.
When replacing lamps in these lights, also replace the film disc cutout.
Use the disc cutout of proper type and size. The film disc is located
within the light enclosure and is installed between spring-loaded
terminals.

**5.3.3.4 Inspection.**

When replacing the lamp, inspect the light thoroughly for other damage.
Check for water in bases or lights, cracked and chipped glassware,
defective or incorrectly positioned gaskets, loose connections, cracked
or deteriorated insulation, and misalignment of lights or shields.

**5.3.3.5 Cleaning.**

When changing lamps, clean the light fixture inside and outside, as
required. Light surfaces must be kept clean to transmit light
satisfactorily. In establishing a cleaning program, first consider the
sources of the dirt problem. Many airfield lights are located at or near
ground level and are subject to blowing dirt or dust, rain spattering,
jet exhaust residue, bird droppings, corrosion, and heat and static
attraction of dirt. In some cases, submersion or exposure to water may
be a problem. Cleaning procedures will vary depending on the cause of
the problem and its effect on the system. Cleaning problems may often be
reduced by preventive measures.

**5.3.3.6 Cleaning Schedule.**

The cleaning schedule will vary at each location depending on such
factors as environment, geographical location, and the types of lighting
units. Clean each light thoroughly at least once a year. Regular
photometric measurements may indicate a need for a more aggressive
cleaning schedule.

**5.3.3.7 Cleaning Procedures.**

Wash glassware, reflectors, lenses, filters, lamps, and all optical
surfaces. Washing may increase the light output by as much as 15 percent
more than wiping with a dry cloth.

(a) Do not use strong alkaline or acid agents for cleaning.

(b) Do not use solutions that leave a film on the surface.

(c) Remove the unit when possible and clean in the shop.

(d) For reflectors or other optical surfaces that cannot be removed for
    cleaning, use alcohol or other cleaning agents that do not require
    rinsing or leave a residue.

**5.3.3.8 Moisture.**

(a) **Water and Condensation.** Water is the most common cause of
    problems in airfield lighting fixtures. In bases, water may cause
    grounding of the lamp or circuit; in the optical assembly it may
    submerge optical components, cause corrosion and deterioration, form
    condensation on optical surfaces, and accelerate the accumulation of
    dirt on optical surfaces. Preventing water from entering bases is
    very difficult. The alternate heating and cooling of the lights can
    create a strong "breathing" effect, especially when the base is
    located in saturated ground. The water may also enter through
    conduits, along the conductor or the cable, through gaskets and
    seals, through damaged glassware, or through fine holes in the walls
    of the bases.

(b) **Protection From and Removal of Water.** The immediate problem of
    water in lights and bases is removal and prevention of reentry. In
    the light bases, the accumulated water can usually be drained or
    pumped out. Drain holes should be drilled or cleaned out if already
    present. Gaskets, seals, and clamps that may admit water should be
    checked. Chipped, cracked, or broken glassware should be replaced.
    If water cannot be eliminated from light bases, ensure all
    electrical connections and insulation are watertight and above the
    waterline. New conduit and base installations should be designed to
    drain and have a separate drainage system installed at low elevation
    points in the system.

    1.  Before installing the cover plate, blow out cover bolt holes to
        make certain that fastening bolts are not anchored in sand or
        debris that prevents the cover from being torqued sufficiently
        on the gasket. Make sure the bolt holes have serviceable threads
        and that the gasket is in good condition and properly placed to
        minimize the possibility of moisture entry around their threads.

    2.  The base flange bolts should be drawn down in opposite pairs
        until all are tightened to the recommended torque. Avoid
        excessive torque.

    3.  Strikes and Blast Damage. Light units damaged by strikes from
        aircraft or vehicles, or by propeller or jet blasts, should be
        repaired or replaced immediately. Areas where this damage recurs
        should be checked frequently. A careful check should be made
        following damage of this type because the attaching cable may
        also be damaged. At locations where damage is frequent due to
        vehicular traffic, consider replacing elevated lights with
        approved in-pavement types.

(c) **Repair and Replacement.** When possible, replace the entire
    damaged unit. Simple repairs usually consist of the following:

    1.  Remove the broken frangible coupling from the base cover.

    2.  Connect the new light to the secondary connector.

    3.  Install a new light on a new frangible coupling.

    4.  Check for correct alignment; align as required.

(d) **Frangible Coupling Replacement.** Frangible couplings are used
    primarily to reduce damage to aircraft in case of a strike. They
    provide an intentional weak point and aid in preventing damage to
    other components. An open-end wrench, pipe wrench, cold chisel, and
    punch and hammer are usually sufficient to remove and install
    frangible couplings.

+----------------------------------------------+---+---+---+---+---+---+
| **MAINTENANCE REQUIREMENT**                  | * | * | * | * | * | * |
|                                              | * | * | * | * | * | * |
|                                              | D | W | M | S | A | U |
|                                              | * | * | * | * | * | * |
|                                              | * | * | * | * | * | * |
|                                              |   |   |   |   |   |   |
|                                              | * | * | * | * | * | * |
|                                              | * | * | * | * | * | * |
|                                              | A | K | T | M | N | N |
|                                              | * | * | * | * | * | * |
|                                              | * | * | * | * | * | * |
|                                              |   |   |   |   |   |   |
|                                              | * | * | * | * | * | * |
|                                              | * | * | * | * | * | * |
|                                              | I | L | H | A | N | S |
|                                              | * | * | * | * | * | * |
|                                              | * | * | * | * | * | * |
|                                              |   |   |   |   |   |   |
|                                              | * | * | * | * | * | * |
|                                              | * | * | * | * | * | * |
|                                              | L | Y | L | N | L | C |
|                                              | * | * | * | * | * | * |
|                                              | * | * | * | * | * | * |
|                                              |   |   |   |   |   |   |
|                                              | * |   | * | * | * | * |
|                                              | * |   | * | * | * | * |
|                                              | Y |   | Y | Y | Y | H |
|                                              | * |   | * | * | * | * |
|                                              | * |   | * | * | * | * |
+----------------------------------------------+---+---+---+---+---+---+
| 1\. Inspect for outages; repair as necessary | X |   |   |   |   |   |
+----------------------------------------------+---+---+---+---+---+---+
| 2\. Check cleanliness of lenses              | X |   |   |   |   |   |
+----------------------------------------------+---+---+---+---+---+---+
| 3\. Perform photometric testing (HIRL) and   |   |   | X |   |   | X |
| check light alignment and orientation        |   |   |   |   |   |   |
+----------------------------------------------+---+---+---+---+---+---+
| 4\. Re-align lights as needed                |   |   | X |   |   | X |
+----------------------------------------------+---+---+---+---+---+---+
| 5\. Clean fixtures and sockets               |   |   |   |   |   | X |
+----------------------------------------------+---+---+---+---+---+---+
| 6\. Check light elevation                    |   |   |   | X |   |   |
+----------------------------------------------+---+---+---+---+---+---+
| 7\. Check for moisture in lights             |   |   |   | X |   |   |
+----------------------------------------------+---+---+---+---+---+---+
| 8\. Inspect fixture for rust, deterioration  |   |   |   |   | X |   |
+----------------------------------------------+---+---+---+---+---+---+
| 9\. Check lamp fitting and clean contacts    |   |   |   |   | X |   |
+----------------------------------------------+---+---+---+---+---+---+
| 10\. Check gaskets                           |   |   |   |   | X |   |
+----------------------------------------------+---+---+---+---+---+---+
| 11\. Remove snow and/or vegetation from      |   |   |   |   |   | X |
| around lights                                |   |   |   |   |   |   |
+----------------------------------------------+---+---+---+---+---+---+

**Table 5-6. Preventive Maintenance Inspection Schedule for Runway and
Taxiway Elevated Edge Lights.**

**5.3.4 [Runway and Taxiway In-pavement Lighting Systems.]{.underline}**

In-pavement or inset lights require more maintenance than elevated
lights. Rubber deposits on the lens are the main cause of poor
performance for fixtures installed in the runway. Jet fuel, deicing
fluid, and other contaminants can also collect on the lens and
deteriorate the light output, even on lights installed in taxiways.

When maintenance other than simple cleaning is required, the only way to
ensure that in-pavement fixtures are properly maintained is to remove
them from the runway or taxiway and replace with a refurbished unit. A
quantity of spare fixtures equal to 10% of the installed quantity should
be maintained for each type of fixture for this purpose. Many airports
that have a large number of in-pavement lights have either built or
modified trailers or vehicles to allow for fast, efficient removal and
replacement of in-pavement fixtures. These dedicated lighting
maintenance vehicles or trailers can be equipped with generators, air
compressors, and proper tools to perform almost any task. Then the
fixture may be removed and brought to the maintenance shop where it is
disassembled and properly refurbished. Equipment is also now available
to perform photometric testing in the maintenance shop to verify that a
refurbished fixture is performing to specifications prior to being
reinstalled in the runway or taxiway.

The main enemy of inset lights is water intrusion. More recently
designed lighting fixtures have a much improved ability to keep water
out of the optical assembly. Improved gasket materials and designs have
drastically reduced the amount of maintenance required. When dealing
with fixtures where water intrusion has become a problem, the first step
is to determine where the water is entering the fixture. This can be in
one of several places; the o-ring gasket sealing the fixture assembly,
the gasket or sealing material around the lens, or the seal around the
entrance point for the electrical conductors feeding the fixture. The
best way to determine where the problem lies is to construct a testing
jig by using a spare fixture. The method will vary depending on the type
of fixture and the manufacturer. Aim to construct a method of
pressurizing the fixture with air while submersing it in water. Five to
ten pounds of air pressure is usually sufficient. The area with the bad
seal will show up by the trail of air bubbles exiting the fixture. Care
must be taken to regulate the pressure used to test the fixture because
if too much pressure is applied, the lens can be blown out. NEVER apply
air pressure to the fixture before submersing it in water as this could
present a hazard if one of the lenses is blown out of the fixture. Some
newer fixture designs come from the factory with an air valve stem
attached to the bottom of the fixture. This fitting is used at the
factory to pressure test the fixture during final assembly and can be
used for maintenance also. Consult the manufacturer of fixture for
recommended air pressure settings. Once the area of the leak is
determined, the cause can be found and corrected. On older fixture
designs, the lens may be sealed into the fixture using RTV sealant. If
replacing this type of lens, be sure to use the appropriate sealant and
primer as recommended by the fixture manufacturer. Usually a Dow Corning
RTV 106, high temperature silicone sealant is used. Most new fixture
designs employ a lens with a replaceable gasket. This greatly improves
the time and effort required to replace the lens. Inset light lenses
should be replaced when they have become scratched or pitted.

When re-lamping either elevated or inset fixtures, do not to touch the
glass of the lamp with the bare hands. Oils found in the skin will cause
hot-spots on the lamp and lead to premature failure. When installing a
new lamp, be sure that the correct orientation is kept. Some lamps have
arrows to indicate positioning in the holder. Improper lamp positioning
can result in improper or reduced photometric output of the fixture.
When reassembling an inset fixture, follow all manufacturer's
instructions. Remove rust and other deposits from the inside surfaces of
the fixture by using an abrasive blasting cabinet with the proper
abrasive. Glass beads or material such as ground walnut shells work well
and, as long as proper care is taken, they will not harm the lens or
wiring of the fixture. Do not use abrasive materials on reflector
assemblies in the fixture. Reassemble the fixture after checking or
replacing the gaskets or O-rings. A light coating of silicone grease is
sometimes recommended for the O-rings.

When reinstalling the fixture, check the condition of o-ring gaskets
installed on the flange ring (if supplied) and replace if necessary.
Lubricate O-rings with a small amount of silicone grease. Make sure that
new screws or bolts and lock washers are used to reinstall the fixture
and tighten to the specified torque with a calibrated torque wrench.
Remove and replace any broken bolts. Failure to do so can result in all
the bolts breaking under the impact of a landing aircraft. Develop a
systematic plan for checking the torque of inset fixtures on a regular
basis, particularly on the runway.

**5.3.4.1 [Preventive Maintenance Inspection Procedures.]{.underline}**

Because in-pavement lights are installed in the aircraft traffic area
and are run over by aircraft, they are high maintenance items that
require frequent attention to maintain specified performance.
Additionally, their location below ground level makes them prone to
water infiltration; this also requires frequent attention. These
problems should be remembered when performing the PMIs contained in
Table 5-7 and described below.

**5.3.4.1.1 [Daily Checks.]{.underline}**

A driving patrol should be made daily at twilight. The inspector should
look for burned-out or dimly burning lamps and record their location.

**5.3.4.1.2 [Weekly Check]{.underline}**[s**.**]{.underline}

A field electrician should inspect and service any lights reported as
defective in the daily inspections. The preferred service method is to
replace the in-pavement light unit with a spare and take the defective
unit back to the shop for repair. The lighting circuit must be
deactivated, locked-out and tagged-out before any maintenance is
attempted on the lights. The following defects may be the cause of the
malfunction:

(a) **[No light]{.underline}**

    1.  The fixture should be removed and replaced with a refurbished
        unit and brought to the maintenance shop for relamping and
        refurbishing.

    2.  Electrical Failure. If the replacement light also fails to
        operate or a string of lights fail, the problem is probably in
        the series circuit. Troubleshooting procedures are contained in
        Chapter 6.

(b) **[Dim light]{.underline}**

    1.  Dirty Light. The exposed optical surface of the in-pavement
        light gets dirty from exposure to aircraft traffic and weather.
        Clean the lights periodically, as described in Paragraph
        5.3.4.1.7-2. This can also be a sign of a weak lamp and cause
        for fixture replacement.

    2.  Light Aiming. Shallow-base in-pavement light fixtures are often
        twisted out of alignment by aircraft landing or turning.
        Visually check any dimly burning lights to see if they are
        merely misaligned.

    3.  Water in the Fixture. Examine the lens for standing water or
        condensation behind the lens. If water is present, remove and
        service the fixture.

**5.3.4.1.3 [Monthly Checks]{.underline}.**

Until a regular maintenance schedule is established, it may be necessary
to perform the checks below on a monthly or even weekly basis at busy
facilities. After some experience has been gained, the interval may be
adjusted to meet operational needs. The frequency of measurement of
lights for a precision approach runway should be based on traffic
density, the local pollution level, the reliability of the installed
equipment and the continuous assessment of the results of the in-field
measurements but in any case should not be less than twice a year.

(a) **Cleaning.** Due to their position at ground level, in-pavement
    lights require frequent cleaning to maintain their specified
    performance. The frequency with which the lights must be cleaned
    depends on the light's location, weather conditions, and number of
    airport operations. Both rubber deposits and runway de-icing fluids
    have been shown to have an extremely detrimental effect on light
    output. Clean the lights when the light output of the fixture is
    less than 70 percent of the minimum required output when operated at
    maximum intensity per AC 150/5345-46, Specification for Runway and
    Taxiway Light Fixtures. A fixture degraded below this is ineffective
    for high background brightness, low visibility conditions.

(b) **Intensity Checks/Photometric Testing.** Test equipment is now
    available to allow for the rapid and accurate testing of the light
    output of both in-pavement and elevated runway lighting fixtures
    (Paragraph 4.1.12). Regular photometric measurements are the only
    practical way of determining if the lights are emitting the
    specified amount of light and for determining misalignment errors.
    By the use of regular photometric measurements, maintenance of
    runway lighting fixtures may be targeted only where needed thereby
    saving resources and time while allowing the airport to be assured
    of meeting light output specifications, especially in low-visibility
    conditions. This aids in providing a consistent lighting pattern to
    provide the pilot with the best possible, non-ambiguous visual cues
    when landing. Necessary frequency of photometric measurements will
    vary from facility to facility and from runway to runway depending
    on amount of traffic and age of fixtures. After experience has been
    gained with the measurement equipment, inspection schedules may be
    determined or modified. Due to the susceptibility of runway
    centerline lights to accumulate rubber deposits on the lens, weekly
    checks may be necessary. This is especially true for CAT II and CAT
    III runways where low-visibility operations are conducted. Any
    in-pavement runway light exhibiting a light output of less than 70%
    of the minimum output required when operated at maximum intensity
    per AC 150/5345-46, Specification for Runway and Taxiway Light
    Fixtures, is ineffective for high background brightness, low
    visibility conditions and should be targeted for cleaning or
    maintenance. Photometric testing should be performed:

    1.  Before cleaning or re-lamping, to establish what maintenance is
        necessary, and

    2.  After cleaning, or other maintenance actions, to track the
        effectiveness of the maintenance and determine the extent of
        degradation of the optical assembly. Lights that continue to
        exhibit output minimum levels should be scheduled for removal
        and servicing. See Appendix A, Standards and Tolerances,
        Table 8.

**5.3.4.1.4 [Bi-Monthly Checks.]{.underline}**

(a) **Bolt Torque.** The torque of the bolts attaching the light to its
    base should be checked. The impact of aircraft wheels can loosen
    mounting bolts and cause misalignment or fixture damage; this is
    particularly troublesome in the touchdown zone.

**5.3.4.1.5 [Semi-annual Checks.]{.underline}**

Check the shallow base installations for the presence of water. Any
water should be removed and the base should be sealed to prevent its
reentry. This check should be conducted more frequently in winter months
since freezing may cause damage to the fixture by shearing the fixture
hold-down bolts or rupturing the base. Having a dry light base is the
exception rather than the rule. Water in light bases is very common,
resulting from the miles of conduit that leak and slowly fill the system
with water. To avoid water freezing in bases, place ETHA-foam (also
known as closed cell foam) disks that are 2 inches thick by 8 inches
diameter in the bases to displace the water. This prevents ice damage to
the base, fixture, and transformer by allowing any remaining water to
crush the ETHA-foam disks.

**5.3.4.1.6 [Unscheduled Maintenance.]{.underline}**

Remove snow from around the lighting fixtures as soon as possible after
a snowfall to prevent obscuring the light fixtures. Exercise extra care
to prevent striking the lighting fixtures with snowplow blades. After
snow removal operations, inspect all lighting fixtures and replace any
damaged light assemblies. Whenever snowplows must traverse over
in-pavement light fixtures, they should be traveling at less than 5
miles per hour or should lift the blades clear of the fixture. Rubber
and plastic snowplow blades that are especially suited to plowing wet or
slushy snow are available; rotary brooms are also recommended. If snow
removal is a frequent winter job, high-strength steel light fixtures may
be specified to better withstand the impact of snow plowing. Check
wireways in saw kerfs. If wires are floating out, reinstall using wedges
for anchoring wires. Space wedges 2 feet (60 cm) on center. Seal
wireways using P-606 sealer.

+-----------------------------------------------+---+---+---+---+---+---+---+
| **MAINTENANCE REQUIREMENT**                   | * | * | * | * | * | * | * |
|                                               | * | * | * | * | * | * | * |
|                                               | D | W | M | B | S | A | U |
|                                               | * | * | * | * | * | * | * |
|                                               | * | * | * | * | * | * | * |
|                                               |   |   |   |   |   |   |   |
|                                               | * | * | * | * | * | * | * |
|                                               | * | * | * | * | * | * | * |
|                                               | A | K | T | I | M | N | N |
|                                               | * | * | * | * | * | * | * |
|                                               | * | * | * | * | * | * | * |
|                                               |   |   |   |   |   |   |   |
|                                               | * | * | * | * | * | * | * |
|                                               | * | * | * | * | * | * | * |
|                                               | I | L | H | M | A | N | S |
|                                               | * | * | * | * | * | * | * |
|                                               | * | * | * | * | * | * | * |
|                                               |   |   |   |   |   |   |   |
|                                               | * | * | * | * | * | * | * |
|                                               | * | * | * | * | * | * | * |
|                                               | L | Y | L | H | N | L | C |
|                                               | * | * | * | * | * | * | * |
|                                               | * | * | * | * | * | * | * |
|                                               |   |   |   |   |   |   |   |
|                                               | * |   | * | * | * | * | * |
|                                               | * |   | * | * | * | * | * |
|                                               | Y |   | Y | Y | Y | Y | H |
|                                               | * |   | * | * | * | * | * |
|                                               | * |   | * | * | * | * | * |
+-----------------------------------------------+---+---+---+---+---+---+---+
| 1\. Check for burned-out lamps or dimly       | X |   |   |   |   |   |   |
| burning lights                                |   |   |   |   |   |   |   |
+-----------------------------------------------+---+---+---+---+---+---+---+
| 2\. Replace defective lights with refurbished |   | X |   |   |   |   |   |
| units                                         |   |   |   |   |   |   |   |
+-----------------------------------------------+---+---+---+---+---+---+---+
| 3\. Clean lights with dirty lenses            |   |   | X |   |   |   | X |
+-----------------------------------------------+---+---+---+---+---+---+---+
| 4\. Perform photometric testing of runway     |   |   | X |   |   |   | X |
| lighting systems                              |   |   |   |   |   |   |   |
+-----------------------------------------------+---+---+---+---+---+---+---+
| 5\. Check torque of mounting bolts            |   |   |   | X |   |   |   |
+-----------------------------------------------+---+---+---+---+---+---+---+
| 6\. Check for water in shallow light bases    |   |   |   |   | X |   |   |
+-----------------------------------------------+---+---+---+---+---+---+---+
| 7\. Remove snow from around fixtures          |   |   |   |   |   |   | X |
+-----------------------------------------------+---+---+---+---+---+---+---+
| 8\. Check wires in saw kerfs                  |   |   |   |   |   |   | X |
+-----------------------------------------------+---+---+---+---+---+---+---+

**Table 5-7. Preventive Maintenance Schedule for In-pavement Runway and
Taxiway Lighting**

**5.3.4.1.7 Maintenance Procedures.**

Servicing in-pavement lighting should be scheduled to cause the minimum
disruption to normal airport operations. For this reason, it is
recommended that a number of spare fixtures be kept for installation in
place of defective fixtures. The number of spare fixtures should be
about 10 percent of the total number of each type of in pavement lights
in use. By replacing the defective light with a spare unit, minimum time
is spent on the runway; the defective light may be repaired in the shop.
The procedures below give a generalized approach to repair; for more
specific information about a particular light, consult the
manufacturer's instruction book.

(a) **Light Removal**. The light fixture must be removed for relamping
    or base inspection. When removing the fixture for base inspection,
    be careful not to damage the connections to the isolation
    transformers. In cold weather, ice or snow may obstruct the bolt
    heads and make fixture removal difficult. Some facilities have
    constructed a wooden box, slightly larger than the fixture and a few
    inches tall. The box has an electric heating element inside and an
    open bottom. When it is necessary to remove a frozen fixture, place
    the box over it and connect the heating element to a power source
    (usually a generator on the back of a truck). When the box heats the
    fixture enough to melt the ice, removal may be easily accomplished.

(b) **Cleaning.** Several different techniques are available for
    cleaning the exterior glassware of inset lights. Some techniques
    require special equipment and are suited to large scale operations
    and require runway access with the light installed, while other
    techniques are more suited to bench cleaning of a light. The
    maintenance supervisor should select the method best adapted to the
    facility. Remember that not all techniques may be used with all
    lights; the manufacturer's recommendations contained in the
    instruction book are the final authority.

    1.  [Manual]{.underline}. Commercially available cleaning detergents
        and pads can be used for removal of deposits from the lighting
        fixture lens unless prohibited by the manufacturer. Do not use
        abrasive materials such as sandpaper or emery cloth because they
        will scratch the glass. Solvents are available that will clean
        the lens, but the solvent must be left on for a period of time
        to dissolve the deposit. The solvent used must be compatible
        with the lens sealing material. Commercial automotive paint
        rubbing or polishing compounds have been used successfully but
        care must be taken to not damage the lens when using abrasive
        cleaners. While manual techniques are well suited for bench
        cleaning of lights, they are very time consuming for cleaning
        lights when installed in pavement.

    2.  [Blasting with Ground Shells]{.underline}. Unless not
        recommended by the light fixture manual the cleaning can be done
        by using 20/30 grade, clean, ground walnut or pecan shells and
        clean, dry compressed air or nitrogen (nozzle pressure 85 psi).
        Figure 5-2 shows a typical example of how to clean the lighting
        fixture with shells.

-   An average time of 10 seconds is required for cleaning the external
    surface of the lens.

-   The average usage of ground walnut shells is 0.6 pound (0.25 kg) per
    fixture.

-   The cleaning system shown is not available as an assembled unit;
    however, a commercially available air compressor with controls and
    gauges, a sandblaster unit, and abrasive resistant hoses may be
    used.

-   After removal of the deposit from the lens, the fixture's light
    channel should be cleaned of shells with a blast of air, and the
    remaining dust wiped off with a clean cloth.

    ![](media/image5.wmf)

    **Figure 5-2. Cleaning Runway Centerline and Touchdown Zone
    Lights.**

(c) **Light Aiming.** The in-pavement lights are aimed as part of the
    installation procedure. For lights installed on the tops of
    transformer housings, the aiming is fixed and nonadjustable. For
    lights installed on glue-in bases, the aiming may come out of
    alignment due to twisting of the light bases. The runway centerline
    lights should be aligned to within 2 degrees of a line parallel to
    the runway centerline. When reinstalling the base, use an adhesive
    compatible with the type of pavement. P-606 sealer has compounds
    that are compatible with both concrete and asphalt pavements; be
    sure to choose the correct mixture. If mobile photometric testing
    equipment is not available, the aiming of in-pavement lights may be
    checked by turning the lights on during foggy weather. The fog makes
    the lightbeam visible, and it is easy to tell if a light is properly
    oriented in such conditions. For touchdown zone lights, the light
    beam is offset 4 degrees toward the runway centerline. The aiming of
    touchdown zone lights may be judged by viewing the barrettes on
    either side of the runway while standing on the centerline. When
    viewing the barrettes on either side of the runway from some
    distance, any light appearing dimmer or brighter than the lights
    next to it may be improperly aimed and should be checked.

(d) **Light Cleaning and Sealing.** In-pavement lights gradually get
    dirty internally, and the internal optical surfaces should be
    cleaned when the light is disassembled for relamping or maintenance.
    Sandblasting equipment using glass beads may be used to clean rubber
    deposits off the casting after all removable parts have been taken
    off. Use a cleaning solution that does not leave a residue after
    drying. When re-lamping a light, be careful to handle the lamp only
    by the leads; fingerprints on the glass assembly will shorten lamp
    life. Mount lamps in brackets according to manufacturer's
    recommendations; using the wrong lamp or mounting it improperly can
    drastically reduce the light output of the fixture. When
    reassembling the light, replace all gaskets and O-rings exposed
    during the relamping process. Examine the optical prism to make sure
    that the sealer around the edges is in good shape. Replace the
    optical prism if it is cracked, scratched, or badly pitted.

(e) **Reinstallation.** If reinstalling a light fixture in a "dry
    system" (a conduit system without drains which depends on gaskets
    under the fixtures to keep out water), when mounting an in pavement
    unit on its base, care must be used to be sure that a watertight
    seal is obtained. Be sure the gasket and its mating surface are free
    of sand or grit; this is a common fault in servicing that allows
    moisture to enter. Graphite compound or gasket cement may be used on
    the gasket surfaces to ensure a watertight seal. When installing an
    in-pavement light in a "wet system" (a conduit system that employs
    drains at low points) the fixture is typically mounted directly on
    the base without a gasket. With either system, a supply of
    compressed air should be used to blow any sand or dirt out of bolt
    holes and mating surfaces to assure proper fit and bolt torque.
    Securely tighten all fixtures to the manufacturer's specified
    torque.

(f) **Photometric Measurements.** Photometric measurement of in-pavement
    lights is the most direct way of determining if they are emitting
    the specified amount of light. See Paragraph 5.3.4.1.3.-2.

## 5.4 ILLUMINATED RUNWAY AND TAXIWAY GUIDANCE SIGNS.

**5.4.1 [Cleaning.]{.underline}**

Most signs require minimal maintenance aside from lamp replacement.
However, with the intrusion of dust, dirt and water it is necessary to
inspect and clean the interior of signs periodically to ensure proper
light output. Mice and other rodents are known to set up house-keeping
in signs. Frequently, this results in damage to wires and other
components and the presence of grass, trash and other bedding material.
For these reasons, inspect and clean airfield guidance signs at least
twice a year.

**5.4.2 [Lamp Replacement.]{.underline}**

As with all airport lighting systems, re-lamping should be accomplished
with the sign de-energized to prevent the possibility of electric shock.
This has been made an easier task by the addition of switches on signs
to disconnect the power. The act of re-lamping has also been made easier
and quicker by designs of both incandescent and fluorescent types that
allow re-lamping without the use of tools.

**5.4.3 [Current Check.]{.underline}**

At least twice a year, the current through the lamp circuit should be
checked to verify that it is correct for the sign in question. If not
correct for all steps, make current adjustments on the sign internal
regulator board or if a Style 5 sign, check the circuit CCR to make sure
it is operating at 5.5A.

## 5.5 ROTATING BEACONS.

**5.5.1 [Rotating Beacon Maintenance.]{.underline}**

Many of the older high intensity 36-inch and 24-inch beacons have been
refurbished and converted from incandescent lamps to metal halide lamps.
Most new beacons use metal halide lamps. The metal halide lamps have the
advantage of longer life making the requirement for an automatic lamp
changer unnecessary. While this has greatly reduced the amount of
maintenance formerly needed to keep the lamp changer assembly in good
operation, it has not reduced the amount of attention that should be
placed on beacon maintenance. Metal halide lamps have a 20,000 hour
rated life expectancy and should be replaced every 2 ½ years. The
standard MVR400/U lamps produce 36,000 lumens of light. The old
incandescent 1000 watt lamps produced 22,000 lumens of light. The metal
halide lamps will burn down to around 22,000 lumens of light after 2 ½
years of service at which time they should be replaced with a new lamp.
In the case of the L-801 medium intensity beacons fitted with a 175 watt
metal halide lamp, the lamps should be changed every 1 ½ to 2 years.

One other difference in beacons that are fitted with metal halide lamps
rather than incandescent is that the lamp takes 4-5 minutes to reach
complete brightness. This fact should be pointed out to controllers and
operations personnel. If the beacon has been on and is shut off during
operation, it will take 12-15 minutes for the lamp to cool off and
re-fire.

**5.5.2 [Preventive Maintenance Inspections.]{.underline}**

**5.5.2.1 [Daily Checks.]{.underline}**

(a) Check the operation of the beacon. Verify dusk to dawn operation and
    operation of controls, either via photoelectric cell or manual.

(b) Count the revolutions per minute (rpm) of the beacon: should be
    either 6 or 12 rpm ± 1 rpm, depending on the type. Check for proper
    color and flash sequence.

(c) Check telltale indicator lamp (if equipped) to see if it is
    illuminated. If it is illuminated, it indicates that the beacon is
    operating on the reserve lamp (if equipped). The burned-out lamp
    should be replaced immediately.

**5.5.2.2 [Bi-Monthly Checks.]{.underline}**

(a) **Lamp Changer (if equipped).** Check the operation of the lamp
    changer. De-energize the beacon circuit and remove the operating
    lamp from its receptacle. Energize the beacon circuit and observe
    that the beacon changes to the reserve lamp. De-energize the beacon
    circuit and re-install the lamp previously removed.

(b) **Slip Rings (if equipped).** Check the condition of the slip rings
    and brushes. Clean the slip rings and brushes per manufacturer's
    instructions. If sparking or pitting has occurred, smooth rings
    according to manufacturer's instructions. Avoid sanding as this
    produces a raw copper surface which shortens brush life. If the slip
    rings are deeply pitted, replace or have them turned down. Replace
    worn out brushes.

(c) **Clutch.** Test the clutch torque by hooking a spring scale in one
    of the handles on the side of the housing. The clutch should slip
    between 8 to 10 pounds or per manufacturer's instructions.

(d) **Lens Retainer.** Check the clamps or screws that secure the beacon
    lens (or cover) in place to be sure they are tight and the lens is
    properly seated.

(e) **Telltale Light.** Check the telltale light for a burned out lamp.
    Clean glassware if necessary.

(f) **Relays.** Check the operation of the relay and clean relay
    contacts if they are pitted or show evidence of poor contact.
    Replace relay if points are badly pitted.

(g) **Glassware.** Clean and polish all glassware, both inside and
    outside, using a type of non-abrasive cleaner that will not scratch
    the lens.

**5.5.2.3 [Semi-annual Checks.]{.underline}**

(a) **Input Voltage.** Check the input voltage and record the reading.
    It should be within 5 percent of the rated lamp voltage. Voltage
    levels higher than a lamp's nominal rating will prematurely reduce
    the lamp's life proportionally to the increased voltage. Conversely,
    voltage levels lower than a lamp's nominal rating will reduce the
    lamp's light output proportionally to the reduced voltage. Make the
    measurement at the beacon lamp terminals, with all field equipment
    energized, so the voltage reading will reflect operating conditions.
    Beacon lamps are very sensitive to voltage changes. A drop of 10
    percent will reduce the light output by 31 percent while a rise of
    10 percent will shorten the lamp life 72 percent.

(b) **Lamp Focus and Beam Elevation.** Verify that beacon beam is
    narrow, well defined and projects horizontally. Check that the
    elevation setting has not slipped. Normal elevation setting for FAA
    beacons is 3½ degrees. Beam elevation can normally be adjusted by
    lowering the lamp mounting position to elevate the beam or raising
    the lamp position to lower the beam.

(c) **Lubrication.** Beacons with a grease fitting on the vertical main
    shaft should be lubricated twice a year under ordinary operation or
    as directed by the manufacturer. Motors supplied with oil cups
    should be lubricated at the same time with SAE 20 oil. If there are
    no cups, the motor has sealed bearings and requires no lubrication.
    Ring gears should have a small amount of grease applied per
    manufacturer's recommendation. **Caution: Using an excessive amount
    of grease will result in its dropping down upon the slip rings and
    causing poor contact and arcing.**

(d) **Drive Belt (if equipped).** Check condition and tension of drive
    belt and adjust or replace if necessary.

(e) **Lightning Protection System.** Check the lightning rod connection
    for tightness and check the condition of the down conductor for
    corrosion or damage. Check and record the ground resistance. Compare
    the reading with the previous ground resistance checks. Reading must
    be less than 25 ohms. If the reading exceeds 25 ohms, immediate
    action must be taken to correct the grounding problem.

**5.5.2.4 [Annual Checks.]{.underline}**

(a) **Base Level**. Check the level of the beacon in four directions.
    Make corrections as necessary.

(b) **Gears.** Clean the old grease from the gears. When installing new
    grease, observe the caution statement above.

(c) **Wiring.** Inspect all wiring, electrical connections and relays
    for abrasions, breaks and loose connections. Check terminal lugs for
    tight electrical connection. Inspect conduit for loose supports and
    connections. Replace broken brackets.

(d) **Weatherproofing and gaskets.** Check the condition of the
    weather-proofing and gaskets. Replace gaskets when cracked or
    deteriorated. Before installing new gaskets, clean the gasket
    channels and seats thoroughly. When it is necessary to secure the
    gasket with rubber cement, coat both the gasket and seat with
    appropriate cement and permitted to dry until tacky before the
    gasket is positioned.

+--------------------------------------------------+---+---+---+---+---+---+---+
| **Maintenance Requirement**                      | * | * | * | * | * | * | * |
|                                                  | * | * | * | * | * | * | * |
|                                                  | D | W | M | B | Q | S | A |
|                                                  | * | * | * | * | T | M | N |
|                                                  | * | * | * | * | R | A | N |
|                                                  |   |   |   |   | L | N | L |
|                                                  | * | * | * | * | Y | Y | Y |
|                                                  | * | * | * | * | * | * | * |
|                                                  | A | K | T | I | * | * | * |
|                                                  | * | * | * | * |   |   |   |
|                                                  | * | * | * | * |   |   |   |
|                                                  |   |   |   |   |   |   |   |
|                                                  | * | * | * | * |   |   |   |
|                                                  | * | * | * | * |   |   |   |
|                                                  | I | L | H | M |   |   |   |
|                                                  | * | * | * | * |   |   |   |
|                                                  | * | * | * | * |   |   |   |
|                                                  |   |   |   |   |   |   |   |
|                                                  | * | * | * | * |   |   |   |
|                                                  | * | * | * | * |   |   |   |
|                                                  | L | Y | L | H |   |   |   |
|                                                  | * | * | * | * |   |   |   |
|                                                  | * | * | * | * |   |   |   |
|                                                  |   |   |   |   |   |   |   |
|                                                  | * |   | * | * |   |   |   |
|                                                  | * |   | * | * |   |   |   |
|                                                  | Y |   | Y | Y |   |   |   |
|                                                  | * |   | * | * |   |   |   |
|                                                  | * |   | * | * |   |   |   |
+==================================================+===+===+===+===+===+===+===+
| 1\. Check for beacon operation and proper color  | X |   |   |   |   |   |   |
| sequence.                                        |   |   |   |   |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 2\. Count rpm of beacon.                         | X |   |   |   |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 3\. Check telltale indicator lamp for reserve    | X |   |   |   |   |   |   |
| lamp status.                                     |   |   |   |   |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 4\. Check operation of the lamp-changer.         |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 5\. Check slip rings and brushes.                |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 6\. Test the clutch torque.                      |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 7\. Check lens retainers.                        |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 8\. Check telltale indicator lamp.               |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 9\. Check operation of relays.                   |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 10\. Clean and polish glassware.                 |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 11\. Check and record input voltage.             |   |   |   |   |   | X |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 12\. Check lamp focus and beam elevation.        |   |   |   |   |   | X |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 13\. Lubricate main shaft, motor, ring gear, and |   |   |   |   |   | X |   |
| padlocks.                                        |   |   |   |   |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 14\. Check operation of electrical switches and  |   |   |   |   |   | X |   |
| contacts.                                        |   |   |   |   |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 15\. Check lightning arresters and grounding     |   |   |   |   |   | X |   |
| system.                                          |   |   |   |   |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 16\. Check power meter.                          |   |   |   |   |   | X |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 17\. Check level of base.                        |   |   |   |   |   |   | X |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 18\. Clean and re-grease gears.                  |   |   |   |   |   |   | X |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 19\. Inspect wiring, lugs, and conduit.          |   |   |   |   |   |   | X |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 20\. Check weatherproofing and gaskets.          |   |   |   |   |   |   | X |
+--------------------------------------------------+---+---+---+---+---+---+---+

**Table 5-8. Preventive Maintenance Schedule for Rotating Beacons**

## 5.6 LIGHTED WIND CONE ASSEMBLIES.

**5.6.1 [Preventive Maintenance Inspections.]{.underline}**

**5.6.1.1 [Daily Checks.]{.underline}**

(a) Visually check to see that all the lights are burning properly each
    night. If the lamps burn dimly, the voltage is probably too low. If
    the lamps burn out too frequently, the voltage is probably too high.
    The voltage should be 120 volts ± 5 percent volts AC or as defined
    in the manufacturer's specifications. Many of these supplemental
    wind cones are fed from the runway edge light series circuit via a
    power adapter and consequently, the voltage to the lamps and the
    brightness of the lamps may vary slightly with a change in runway
    light intensity.

(b) If a photocell is used, cover it and verify that the lights turn on.

**5.6.1.2 [Monthly Checks.]{.underline}**

(a) Check the cone assembly to see that it swings freely throughout the
    360 degree travel.

(b) Check the condition of the wind cone fabric. The fabric of the cone
    should be carefully examined at close range. The fabric should be
    completely replaced when it is badly worn, rotted, soiled, or faded
    in color.

(c) Check to make sure that the movement of the wind cone is not impeded
    by vegetation.

**5.6.1.3 [Bi-monthly Checks.]{.underline}**

(a) All the lamps may be replaced after 80 percent of the rated life and
    prior to 90 percent of the rated lamp life. However, if daily
    operational checks are being made, this may not be necessary but it
    would be advisable to change all of the lamps at the same time to
    prevent recurring maintenance visits.

(b) The globes should be cleaned when replacing the lamps.

**5.6.1.4 [Semi-annual Checks.]{.underline}**

(a) Check the bearings to see if they need lubricating. An application
    of light grease should be sufficient. In areas exposed to extreme
    dust, clean the bearings and repack with light grease. In freezing
    weather, the grease becomes very viscous and action of the wind cone
    in light winds will often become sluggish. During such weather, it
    may be necessary to completely clean the bearings or grease and
    lubricate them with light oil.

(b) Take an insulation reading on the underground feeder if wired from a
    parallel source and record the results. Compare results to previous
    readings to look for signs of insulation deterioration. If powered
    from a power adapter connected to a series lighting circuit, check
    the voltage at each output step of the series circuit to make sure
    the power adapter is still functioning within manufacturer's
    parameters.

**5.6.1.6 [Annual Check.]{.underline}**

(a) Check the assembly base securing bolts for tightness. Tighten as
    required.

(b) Check the wiring at the hinged area or check the slip ring
    connections if internally lighted. If frayed, loose, or pitted,
    repair or replace.

(c) Check the ground system for loose connections.

(d) Test the resistance of the grounding system. It should measure 25
    ohms to ground or less.

(e) Check the condition of the paint on the wind cone structure. Touch
    up or repaint as required.

  ------------------------------------------------------------------------------------------------------------------------------------
  **Maintenance Requirement**                       **DAILY**   **WKLY**   **MTHLY**   **BIMHY**   **SMANY**   **ANNLY**   **UNSCH**
  ------------------------------------------------- ----------- ---------- ----------- ----------- ----------- ----------- -----------
  1\. Check lamp operation.                         X                                                                      

  2\. Check photocell operation.                    X                                                                      

  3\. Check for freedom of motion of wind cone                             X                                               
  frame.                                                                                                                   

  4\. Check condition of wind cone fabric.                                 X                                               

  5\. Check lamp age for scheduled replacement.                                        X                                   

  6\. Clean glassware.                                                                 X                                   

  7\. Check paint on segmented circle.                                                 X                                   

  8\. Clean and grease bearings.                                                                   X                       

  9\. Read insulation resistance.                                                                  X                       

  10\. Check mounting bolts.                                                                                   X           

  11\. Check wiring at hinge.                                                                                  X           

  12\. Check grounding system resistance.                                                                      X           

  13\. Check paint on wind cone structure.                                                                     X           

  14\. Remove vegetation and check condition at                                                                            X
  foundation.                                                                                                              
  ------------------------------------------------------------------------------------------------------------------------------------

**Table 5-9. Preventive Maintenance Schedule for Lighted Wind Cones.**

## 5.7 PRECISION APPROACH PATH INDICATOR (PAPI) SYSTEM.

**5.7.1 [Preventive Maintenance Inspection Procedures.]{.underline}**

A typical layout of the PAPI system is shown in Figure 5.3.

**5.7.1.1 [Daily Checks]{.underline}.**

Confirm all lamps are burning and are of equal brightness. Adequate
spare lamps should be available to permit a complete replacement of all
lamps in the system. Spare bypass fuses, if used, should also be
stocked. Lamps should be replaced immediately if they burn out or become
darkened. If the PAPI uses bypass fuses, never replace a lamp until the
associated fuse is checked.

**5.7.1.2 [Monthly Checks.]{.underline}**

1.  Check operation of controls. Check photocell brightness control and
    runway light circuit interlock (if used), radio control (if used),
    and/or remote control switch.

2.  Check for damage by mowers, snowplows, etc.

3.  Clean lamps and filters.

4.  Visually check mechanical parts for cleanliness, burned wires or
    connections, cracked insulators, lamps or filters, etc.

5.  Check if the lightning arresters and/or surge suppressors are
    scorched or show other signs of being burned out, and replace as
    necessary. Also, check after electrical storms.

6.  Check the lamp boxes and adapter units for damage or debris from
    water, mice, wasps, bird nests, spider webs, etc., and clean or
    repair as needed.

7.  Check for burrows or other signs of rodent activity in vicinity of
    cables; take steps to discourage their presence to minimize
    likelihood of cable damage.

8.  If an adapter unit is used, read and record the output current and
    the input voltage to the adapter unit.

9.  Check the horizontal and lateral alignment of the light boxes, and
    check the aiming (vertical angle) with the PAPI aiming instrument.
    Record the angle setting and the date in a maintenance log. It is
    particularly important to check aiming frequently whenever the soil
    freezes or thaws or has a change in moisture content (especially
    clay soils).

10. Check leveling and operating of tilt switch - if applicable.

**5.7.1.3 [Quarterly Checks.]{.underline}**

Check the obstacle-free approach plane for clearance from tree growth,
new towers, pole lines, or other obstacles. The obstacle free plane is 4
miles long and extends 10 degrees on either side of the runway
centerline.

**5.7.1.4 [Semi-annual Checks.]{.underline}**

1.  Check insulation resistance of underground cables and record the
    results.

2.  Check resistance of the grounding system and record the results.

![](media/image6.wmf){width="5.998611111111111in"
height="4.847222222222222in"}

**Figure 5-3. PAPI Configuration.**

  -------------------------------------------------------------------------------------------------------------------------------------
  **Maintenance Requirement**                        **DAILY**   **WKLY**   **MTHLY**   **QTRLY**   **SMANY**   **ANNLY**   **UNSCH**
  -------------------------------------------------- ----------- ---------- ----------- ----------- ----------- ----------- -----------
  1\. Check lamps for operation.                     X                                                                      

  2\. Check operation of controls.                                          X                                               

  3\. Check for damage by service vehicles or                               X                                               
  aircraft.                                                                                                                 

  4\. Clean lamps and filters.                                              X                                               

  5\. Check mechanical parts for damage.                                    X                                               

  6\. Check lightning arresters.                                            X                                               

  7\. Check for water damage or insect infestation.                         X                                               

  8\. Check for presence of rodents.                                        X                                               

  9\. Record output current and input voltage of                            X                                               
  adapter (if used).                                                                                                        

  10\. Check alignment and aiming of light boxes.                           X                                               

  11\. Check leveling and operation of tilt switch.                         X                                               

  12\. Check integrity of obstacle-free approach                                        X                                   
  plane.                                                                                                                    

  13\. Check insulation resistance of underground                                                   X                       
  cables.                                                                                                                   

  14\. Check resistance of grounding system.                                                        X                       
  -------------------------------------------------------------------------------------------------------------------------------------

**Table 5-10. Preventive Maintenance Schedule for PAPI (Precision
Approach Path Indicator).**

**5.7.2 [Maintenance Procedures.]{.underline}**

**5.7.2.1 [Adjustment of the Vertical Aiming]{.underline}.**

This adjustment is performed by using a clinometer. Clinometers are
normally supplied with the PAPI or may be purchased from the PAPI
manufacturer. Handle these precision instruments carefully. Make sure
the aiming device is the one supplied with the PAPI light units.

1.  Check the manufacturer's manual (supplied with the units) for the
    procedures used to check each PAPI unit for proper aiming angle.
    Follow the procedures recommended for using the manufacturer's
    leveling device.

2.  Stand in front of the PAPI units (approximately 50 feet away) and
    check that the light changes color simultaneously along the whole
    width of each unit. If not, horizontal leveling was not done
    properly, the red filters are out of position, or the box is warped.

3.  Check the tilt switch on all units (where provided) by placing the
    small level on the marked top surface of the tilt switch and
    adjusting the tilt switch if necessary. If the tilt switch shuts off
    the power when it is level, the tilt switch should be replaced. The
    main switch may have to be toggled off and on to reset tilt switch
    circuit. For tolerances, refer to the manufacturer's installation
    manual.

**5.7.2.2 [Check of Adapter Unit Current Output]{.underline}.**

1.  With system on, adjust day current to 6.4 to 6.6 amperes.

2.  Cover photocell with a heavy glove or other dark material, wait for
    time delay to de-energize, and read current. If the system has a
    night adjustment, set current to 4.8 to 5.0 amperes.

3.  Remove covering from photocell. The lights should switch back to day
    brightness after a short time delay (15 seconds to 1 minute).

## 5.8 VISUAL APPROACH SLOPE INDICATOR (VASI).

Some facilities have VASI systems which are currently being replaced
with PAPI systems. The procedures in Table 5-10 are applicable, for the
most part, for VASI as well. Check the manufacturer's maintenance manual
for unique procedures applicable for the system installed, as most are
old and replacement parts are not always available.

**5.8.1** **[Preventive Maintenance Inspection
Procedures]{.underline}**.

To perform the PMIs contained in Table 5-11, proceed as follows:

**5.8.1.1 [Daily Checks.]{.underline}**

Check that all lamps are burning and are of equal brightness. Adequate
spare lamps should be available to permit a complete replacement of all
lamps in the system. Spare bypass (grasshopper) fuses, if used, should
also be stocked. Lamps should be replaced immediately if they burn out
or become darkened. If the VASI uses bypass fuses, never replace a lamp
until the associated fuse is checked.

**5.8.1.2 [Monthly Checks.]{.underline}**

1.  Check operation of controls. Check photocell brightness control and
    runway light circuit interlock (if used), radio control (if used),
    and/or remote control switch.

2.  Check for damage by mowers, snowplows, etc.

3.  Clean lamps and filters.

4.  Visually check mechanical parts for cleanliness, burned wires or
    connections, cracked insulators, lamps or filters, etc.

5.  Check if lightning arresters and/or surge suppressors are scorched
    or show other signs of being burned out and replace as necessary.
    Also, check after electrical storms.

6.  Check for damage or debris from water, mice, wasps, bird nests,
    spider webs, etc., in lamp boxes and adapter units and clean or
    repair as needed.

7.  Check for burrows or other signs of rodent activity in vicinity of
    cables; take steps to discourage their presence to minimize
    likelihood of cable damage.

8.  If an adapter unit is used, read and record the output current and
    the input voltage to the adapter unit

9.  Check the horizontal and lateral alignment of the light boxes, and
    check the aiming (vertical angle) with the VASI aiming bar. Record
    the angle setting and the date in a maintenance log. It is
    particularly important to check aiming frequently whenever the soil
    freezes or thaws or has a change in moisture content (especially
    clay soils).

10. Check leveling and operation of tilt switch (used in VASI-2 and some
    VASI-4 installations).

**5.8.1.3 [Quarterly Checks.]{.underline}**

Check the obstacle-free approach plane for clearance from tree growth,
new towers, pole lines, or other obstacles. The obstacle free plane
starts at the first VASI light bar and extends over the approach area at
an angle one degree lower than that of the first VASI bar. The obstacle
free plane is 4 miles long and extends 10 degrees on either side of the
runway centerline.

**5.8.1.4 [Semi-annual Checks.]{.underline}**

1.  Check insulation resistance of underground cables and record the
    results.

2.  Check resistance of the grounding system and record the results.

**5.8.2 [Maintenance Procedures.]{.underline}**

**5.8.2.1 [Adjustment of the Vertical Aiming.]{.underline}**

This is normally done with an aiming bar, calibration bar, and small
(machinist\'s) level. Handle these precision instruments carefully. Make
sure the aiming bar is the one supplied with the VASI light units. The
following steps should be followed each time the VASI is checked.

1.  Place the calibration bar on a rigid surface that is approximately
    level, such as a concrete floor or a table or counter that is
    sitting on a concrete floor. Most wooden floors will deflect enough
    under one person\'s weight to make it impossible to level accurately
    the calibration bar.

2.  Place the small level on the calibration bar and level it with the
    adjustable feet, both in the linear and transverse directions.

3.  Turn the small level 180 degrees to check for centering of the
    bubble. If it does not check when reversed, adjust the small level
    so that the bubble will remain centered when the small level is
    reversed.

4.  Place the aiming bar on the calibration bar and check that its
    spirit level remains centered in the 0-degree, 3-degree, and
    6-degree positions and settings. Adjust spirit level if necessary to
    center the bubble. If the bubble cannot be centered at each of the
    three angles, the aiming bar should be replaced.

5.  Place the instruments in the carrying case for transporting out to
    the VASI boxes.

6.  Place the small level on the bottom center of the aperture (light
    slot) at the front of the box and level the box transversely with
    the two front adjusting (mounting) screws.

7.  Set the proper angle on the aiming bar (usually 2½ degrees for light
    bar No. 1, closest to runway end, and 3 degrees for light bar No. 2)
    and insert through the aperture so the end of the aiming bar rests
    on the transition bar.

8.  With aiming bar in line with left-hand lamp, adjust left rear
    adjusting screw. Move the aiming bar to the right side of box and
    adjust right rear screw. Repeat for left and right side until bubble
    is centered at each position.

9.  Recheck transverse leveling, and recheck longitudinal leveling with
    the aiming bar in center of light box.

10. Stand in front of the VASI box (approximately 50 feet away) and
    check that the light changes color simultaneously along with the
    whole width of the unit. If not, either the leveling was not done
    properly, the box is warped, or the transition bar is not in its
    proper place.

11. Check the tilt switch on all VASI-2 systems and VASI-4 systems
    (where provided) by placing the small level on the marked top
    surface of the tilt switch and adjusting the tilt switch if
    necessary. If the tilt switch shuts off the power when it is level,
    the tilt switch should be replaced. The main switch may have to be
    turned off, and back on, to reset tilt switch circuit.

**5.8.2.2 [Check of Adapter Unit Current Output]{.underline}**.

1.  With system on, adjust day current to 6.4 to 6.6 amperes.

2.  Cover photocell with a heavy glove or other dark material, wait for
    time delay to de-energize, and read current. If the VASI has a night
    adjustment, set current to 4.8 to 5.0 amperes.

3.  Remove covering from photocell. The lights should switch back to day
    brightness after a short time delay (15 seconds to 1 minute).

+--------------------------------------------------------+---+---+---+---+
| **MAINTENANCE REQUIREMENT**                            | * | * | * | * |
|                                                        | * | * | * | * |
|                                                        | D | M | Q | S |
|                                                        | * | * | * | * |
|                                                        | * | * | * | * |
|                                                        |   |   |   |   |
|                                                        | * | * | * | * |
|                                                        | * | * | * | * |
|                                                        | A | T | R | M |
|                                                        | * | * | * | * |
|                                                        | * | * | * | * |
|                                                        |   |   |   |   |
|                                                        | * | * | * | * |
|                                                        | * | * | * | * |
|                                                        | I | H | T | A |
|                                                        | * | * | * | * |
|                                                        | * | * | * | * |
|                                                        |   |   |   |   |
|                                                        | * | * | * | * |
|                                                        | * | * | * | * |
|                                                        | L | L | L | N |
|                                                        | * | * | * | * |
|                                                        | * | * | * | * |
|                                                        |   |   |   |   |
|                                                        | * | * | * | * |
|                                                        | * | * | * | * |
|                                                        | Y | Y | Y | Y |
|                                                        | * | * | * | * |
|                                                        | * | * | * | * |
+--------------------------------------------------------+---+---+---+---+
| 1\. Check lamps for operation                          | X |   |   |   |
+--------------------------------------------------------+---+---+---+---+
| 2\. Check operation of controls                        |   | X |   |   |
+--------------------------------------------------------+---+---+---+---+
| 3\. Check for damage by vehicles or aircraft           |   | X |   |   |
+--------------------------------------------------------+---+---+---+---+
| 4\. Clean lamps and filters                            |   | X |   |   |
+--------------------------------------------------------+---+---+---+---+
| 5\. Check mechanical parts for damage                  |   | X |   |   |
+--------------------------------------------------------+---+---+---+---+
| 6\. Check lightning arrester                           |   | X |   |   |
+--------------------------------------------------------+---+---+---+---+
| 7\. Check for water damage or insect infestation       |   | X |   |   |
+--------------------------------------------------------+---+---+---+---+
| 8\. Check for presence of rodents                      |   | X |   |   |
+--------------------------------------------------------+---+---+---+---+
| 9\. Record output current and input voltage of adapter |   | X |   |   |
| (if used)                                              |   |   |   |   |
+--------------------------------------------------------+---+---+---+---+
| 10\. Check alignment and aiming of light boxes         |   | X |   |   |
+--------------------------------------------------------+---+---+---+---+
| 11\. Check leveling and operation of tilt switch       |   | X |   |   |
+--------------------------------------------------------+---+---+---+---+
| 12\. Check integrity of obstacle-free approach plane   |   |   | X |   |
+--------------------------------------------------------+---+---+---+---+
| 13\. Check insulation resistance of underground cables |   |   | X |   |
+--------------------------------------------------------+---+---+---+---+
| 14\. Check resistance of grounding systems             |   |   |   | X |
+--------------------------------------------------------+---+---+---+---+

**Table 5-11. Preventive Maintenance Schedule for VASI (Visual Approach
Slope Indicator)**

## 5.9 RUNWAY END IDENTIFIER LIGHTS (REILs).

**5.9.1 [Preventive Maintenance Inspection Procedures.]{.underline}**

A typical layout of the REIL System is shown in Figure 5-4. To perform
the PMIs contained in Table 5-12, proceed as follows:

**5.9.1.1 [Daily Checks.]{.underline}**

1.  Check that lamps are operating and are flashing in proper sequence.

**5.9.1.2 [Bi-monthly Checks.]{.underline}**

1.  Check the controls for proper operation. Observe operation on each
    intensity step.

2.  Check cleanliness of optical surfaces, both interior and exterior.

3.  Check for damage or misaligned lights.

4.  Check interlock device on door of each cabinet. Verify that shutdown
    occurs when each door is opened.

5.  Check for vegetation or other obstruction around lights.

**5.9.1.3 [Semi-annual Checks.]{.underline}**

1.  Check the interior of control panel and flasher cabinets for
    cleanliness and moisture.

2.  Check electrical contacts and connections to ensure tightness.

3.  Check and adjust alignment and elevation of light units. For
    omnidirectional units, check only the elevation. For unidirectional
    REILs, check alignment and elevation using the following tools:

```{=html}
<!-- -->
```
(a) A plywood triangle cut to angles of 15 degrees, 80 degrees, and 85
    degrees.

(b) A 4-inch line level.

```{=html}
<!-- -->
```
4.  The procedure to align the unidirectional REIL is as follows:

```{=html}
<!-- -->
```
(a) To check the 15-degree toe-out, hold the triangle horizontally
    against the face with the 15-degree angle pointed toward the other
    light unit. By aligning the outside edge of the triangle to point at
    the opposite light unit, 15-degree toe-out is achieved.

(b) To attain the 10-degree vertical aiming, the 80-degree angle is
    placed against the flat portion of the REIL face with the 15-degree
    point-down. When the line level shows the upper edge of the triangle
    level, the REIL is 10 degrees up from the horizontal (see Figure
    5.5).

```{=html}
<!-- -->
```
5.  Check baffles if used on REIL. Where baffles are installed, the
    light units should be aimed at an angle of 3 degrees vertical and 10
    degrees toed out. The louvers should be sloped down 10 degrees
    toward the runway and down 5 degrees toward the approaching
    aircraft. The louvers should be painted black to lower the reflected
    light.

**5.9.1.4 [Annual Checks.]{.underline}**

1.  Make a careful inspection of all power distribution equipment and
    protective devices at terminal pole and lights.

2.  Check insulation resistance of power cables.

3.  Check the ground resistance at the terminal pole and each light
    fixture.

4.  Service timer motor and contacts (if used).

5.  Repaint as required.

![](media/image7.wmf){width="6.500694444444444in"
height="7.896527777777778in"}

**Figure 5-4. REIL Layout.**

![](media/image8.wmf){width="6.4847222222222225in" height="4.76875in"}

**Figure 5-5. REIL Aiming**

+--------------------------------------------------+---+---+---+---+---+---+---+
| **Maintenance Requirement**                      | * | * | * | * | * | * | * |
|                                                  | * | * | * | * | * | * | * |
|                                                  | D | W | M | B | S | A | U |
|                                                  | A | K | T | I | M | N | N |
|                                                  | I | L | H | M | A | N | S |
|                                                  | L | Y | L | H | N | L | C |
|                                                  | Y | * | Y | Y | Y | Y | H |
|                                                  | * | * | * | * | * | * | * |
|                                                  | * |   | * | * | * | * | * |
+==================================================+===+===+===+===+===+===+===+
| 1\. Check operation of lamps.                    | X |   |   |   |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 2\. Check the operation of controls.             |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 3\. Check cleanliness of optical system.         |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 4\. Check for mechanical damage or misaligned    |   |   |   | X |   |   |   |
| parts.                                           |   |   |   |   |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 5\. Check operation of interlocks.               |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 6\. Check for vegetation around lights.          |   |   |   | X |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 7\. Check cabinets for cleanliness and moisture. |   |   |   |   | X |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 8\. Check electrical connections.                |   |   |   |   | X |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 9\. Check alignment and elevation of             |   |   |   |   | X |   |   |
| unidirectional REIL.                             |   |   |   |   |   |   |   |
|                                                  |   |   |   |   |   |   |   |
| > Check only elevation of omnidirectional units. |   |   |   |   |   |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 10\. Realign unidirectional REILs, as required.  |   |   |   |   | X |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 11\. Check baffles on REIL (if used).            |   |   |   |   | X |   |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 12\. Check power distribution equipment.         |   |   |   |   |   | X |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 13 Check insulation resistance of cable.         |   |   |   |   |   | X |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 14\. Check resistance of grounding systems.      |   |   |   |   |   | X |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 15\. Service timer motor and contacts (if used). |   |   |   |   |   | X |   |
+--------------------------------------------------+---+---+---+---+---+---+---+
| 16\. Check need for painting.                    |   |   |   |   |   | X |   |
+--------------------------------------------------+---+---+---+---+---+---+---+

**Table 5-12. Preventive Maintenance Schedule for REIL (Runway End
Identifier Lights)**

## 5.10 MEDIUM APPROACH LIGHTING SYSTEM (MALS, MALSF, MALSR).

**5.10.1 [Preventive Maintenance Inspection Procedures.]{.underline}**

A typical layout of the MALSR System is shown in Figure 5-6. To perform
PMIs contained in Table 5-13, proceed as follows:

**5.10.1.1 [Daily Check.]{.underline}**

1.  Check and record burned-out lamps.

**5.10.1.2 [Weekly Checks.]{.underline}**

1.  Request tower personnel to turn on the system and cycle through each
    brightness step from the remote control panel. If the system is
    equipped with air-to-ground radio control, check each brightness
    step for proper operation. During the sequence, the maintenance
    technician should be in a position to observe the system operation.

2.  Replace burned-out lamps as necessary to meet the criteria in
    Appendix A, Table 2.

3.  Check the exterior optical surface of all lights. Clean as required.

![](media/image9.wmf){width="5.41875in" height="4.501388888888889in"}

**Figure 5-6. MALSR Configuration**

  -------------------------------------------------------------------------------------------------------------------------------------
  **Maintenance Requirement**                        **DAILY**   **MKLY**   **MTHLY**   **BIMHY**   **SMANY**   **ANNLY**   **UNSCH**
  -------------------------------------------------- ----------- ---------- ----------- ----------- ----------- ----------- -----------
  1 Check for burned-out lamps.                      X                                                                      

  2\. Check system operation.                                    X                                                          

  3\. Replace burned-out lamps.                                  X                                                          

  4\. Check in pavement lights for cleanliness.                  X                                                          

  5\. Record input and output voltages of control                           X                                               
  cabinet.                                                                                                                  

  6\. Clear any vegetation obstructing the lights.                          X                                               

  7\. Check angle of elevation of lights.                                                           X                       

  8\. Check structures for integrity.                                                               X                       

  9\. Check approach area for new obstructions.                                                     X                       

  10\. Check photoelectric controls (if used).                                                      X                       

  11\. Check electrical distribution equipment.                                                                 X           

  12\. Check insulation resistance of cable.                                                                    X           

  13\. Check fuse holders, breakers, and contacts.                                                              X           
  -------------------------------------------------------------------------------------------------------------------------------------

**Table 5-13. Preventive Maintenance Schedule for MALSR (Medium
Intensity Approach Light System with Runway Alignment Lights)**

**5.10.1.3 [Monthly Checks.]{.underline}**

1.  Record the input and output voltages of the control cabinet and
    compare with previous readings to ascertain the rate of
    deterioration of the system.

2.  Clear vegetation or obstructions from the front of all lights to
    ensure adequate visibility. Approved chemicals can be used to help
    control the growth of vegetation around the lights.

**5.10.1.4 [Semi-annual Checks.]{.underline}**

1.  Check light fixtures for alignment. The elevation angle settings of
    the lamps differ at each light bar station. These angles should be
    permanently displayed at each station to facilitate maintenance.

2.  Check structures carefully for hidden corrosion. Special attention
    should be paid to wood-to-wood, wood-to-steel, wood-to-earth, and
    steel-to-earth contacts.

3.  Check the approach area for new structures or for growth of
    vegetation which may violate the approach clearance criteria. A
    clear line-of-sight is required from any point on a plane 1/2 degree
    below the glide slope extending 250 feet (75 m) from each side of
    centerline for a distance up to 1,600 feet (500 m) in advance of the
    outermost lights in the system. If objects block a view of the
    lights and cannot be removed, refer the problem to appropriate
    airport authorities.

4.  If used, check and adjust the photoelectric controls. Use a
    photometer to verify the photoelectric control is adjusted to turn
    the lights on at a North sky light intensity level of 35 footcandles
    and turn off at 58 footcandles. If the unit is properly adjusted,
    the system will operate on the high brightness position on a
    relatively clear day from approximately 1/2 hour before sunset to
    1/2 hour after sunrise. Also, check the orientation of the
    photoelectric cell. The cell should be oriented by aiming at the
    North sky at or slightly above the northern horizon. If adjustments
    are required, refer to the applicable manufacturer's instruction
    book for detailed adjustment procedures.

**5.10.1.5 [Annual Checks.]{.underline}**

1.  Check pole-top-mounted or termination switches.

2.  Check all main power and control cable insulation resistance. Record
    reading on the insulation resistance form. Compare the current
    reading with previous readings to determine if cables are
    deteriorating.

3.  Check fuse holders, breakers, and contacts. Contacts in the control
    cabinet should be carefully inspected. If the contacts are badly
    worn, they should be replaced. Do not file or burnish contacts.
    Discoloration of contacts or some roughness due to normal arcing is
    not harmful. The contacts should be wiped to remove the dust. Blown
    fuses should be replaced with the correct size and type. Do not
    assume that the old fuse is the correct size and type.

**5.10.1.6 [Unscheduled Maintenance.]{.underline}**

Consideration should be given to group changing of all PAR 38, 150-watt
lamps after 1800 hours of operation on maximum brightness, recorded on
an elapsed time meter.

## 5.11 HAZARD BEACONS AND OBSTRUCTION LIGHTS.

**5.11.1 [Preventive Maintenance Inspection Procedures.]{.underline}**

To perform the PMIs contained in Table 5-14, proceed as follows:

**5.11.2 [Daily Checks.]{.underline}**

Verify that all hazard beacons and obstruction lights are burning each
night. Replace burned-out lamps.

**5.11.3 [Monthly Checks.]{.underline}**

1.  For flashing hazard beacons, count the number of flashes of the
    hazard beacon over a full 2-minute period. The flashing rate may
    range from 20 to 40 per minute; the beacon "OFF" time should be
    about half the "ON" time.

2.  Check the operation of the photocell or other automatic control
    devices.

**5.11.4 [Semi-annual Checks.]{.underline}**

Test the insulation resistance of feeder cables and ground resistance of
the grounding system.

**5.11.5 [Annual Checks.]{.underline}**

1.  Check the condition of the wire, insulation, splices, switches,
    connections, and fuses. Check the fuse size (should not be more than
    120 percent of rated load). The fuse holder should be tight with
    clean, uncorroded contacts. Check the wiring for loose connections
    and the insulation for breaks or fraying. Check switches for loose,
    burned, or misaligned contacts.

2.  Check the lamp voltage at the lamp socket and record the voltage.
    Compare the voltage with the previous reading. If the voltage
    reading is more than 10 percent different from the nominal value,
    determine the cause and correct the problem. If a booster
    transformer is used, check the input and output voltage levels.

3.  Check gaskets and seals for leaks. Adequate weatherproofing is
    necessary for the protection of lights. All gaskets should be
    renewed when cracked or deteriorated. Before installing a new
    gasket, thoroughly clean the gasket channel to make the gasket seat
    properly. When it is necessary to secure the gasket with rubber
    cement, coat both gasket and seal with cement and permit to dry
    until tacky before the gasket is placed in position.

4.  Visually check the lightning-protection system. Check all
    connections for tightness and continuity. Check lightning arresters
    for cracked or broken porcelain and for missing mounting brackets.
    Repair as required.

5.  Check the power company meter. The meter should be checked for
    creeping under no-load conditions. If it is creeping with the light
    off, carefully check for grounds. If none are found, notify the
    power company to correct the problem. Check the leads for tightness
    and keep the meter surface clean.

6.  When the obstruction lights are mounted on disconnect hangers and
    are equipped with lowering devices, wire guides, and pulleys, all
    fittings, supports, and cables should be cleaned and lubricated. The
    contact surfaces of the electrical disconnect should be cleaned.

7.  The duplex obstruction lights should be serviced as described above.
    In addition, if a changeover relay is used, it should be cleaned and
    the relay housing gasket should be kept in good condition. Replace
    all missing cover screws to prevent water, moisture, and dust from
    entering the relay enclosure. Only one light in the double
    obstruction light is energized when a transfer relay is used. Upon
    failure of the first lamp, the relay should transfer power to the
    second or standby lamp. The relay is mounted in the fixture base. A
    pilot lamp is normally provided across the standby lamp to provide a
    remote indication that one lamp has burned out. Check the operation
    of this remote lamp.

8.  The beacon should be cleaned and reconditioned yearly or when a lamp
    is replaced. Follow the procedures below:

```{=html}
<!-- -->
```
(a) Clean and polish the globes and lenses using a glass cleaner or
    ammonia and water. Wipe the globes dry before reassembling. Remove
    dust and dirt from grooves. A stenciling brush or a small paint
    brush is especially useful for this purpose. Remove all paint spots
    and streaks from along the edge of glass.

(b) Using a brush or cloth, clean the dirt and dust from fixture and
    open all drain holes. Check the condition of sockets. Look for
    burned or galled screw bases, loose connections, and frayed or
    broken insulation.

(c) Check the load contactor for pitted, burned, or misaligned contacts.
    Ensure that the armature moves freely and that the spring tension is
    sufficient to pull the armature away from the coil when
    de-energized.

**5.11.6 [Unscheduled Maintenance.]{.underline}**

Change the lamp when the burning time has attained 80 percent and not
more than 95 percent of its rated life. Make certain that the correct
lamp is installed. Allow the new lamp to burn for a few minutes to make
certain that the lamp is not defective.

  -----------------------------------------------------------------------------------------------------------------------------------
  **Maintenance Requirement**                      **DAILY**   **WKLY**   **MTHLY**   **BIMHY**   **SMANY**   **ANNLY**   **UNSCH**
  ------------------------------------------------ ----------- ---------- ----------- ----------- ----------- ----------- -----------
  1\. Check operation of lamps.                    X                                                                      

  2\. Check flash rate of hazard beacons.                                 X                                               

  3\. Check operation of photocell.                                       X                                               

  4\. Check insulation resistance and ground                                                      X                       
  resistance.                                                                                                             

  5\. Check wire and connections.                                                                             X           

  6\. Check voltage at lamp socket.                                                                           X           

  7\. Check weatherproofing of the fixture.                                                                   X           

  8\. Check lightning protection system.                                                                      X           

  9\. Check power meter.                                                                                                  

  10\. Service lowering device and other                                                                      X           
  supporting hardware.                                                                                                    

  11\. Check changeover relay in dual fixture.                                                                X           

  12\. Clean and recondition beacon.                                                                          X           

  13\. Install new lamp after 80 percent of rated                                                                         X
  life.                                                                                                                   
  -----------------------------------------------------------------------------------------------------------------------------------

**Table 5-14. Preventive Maintenance Inspection Schedule for Hazard
Beacons and Obstruction Lights**

## 5.12 AIRPORT LIGHTING CONTROL AND MONITORING SYSTEMS (ALCMS).

**5.12.1 [Maintenance.]{.underline}**

While the maintenance of computer based control and monitoring systems
is beyond the scope of this document, there are certain basic provisions
of the control system that may be addressed, particularly at the time of
installation. These provisions will make the task of maintaining these
systems ultimately easier for the maintenance staff.

**5.12.2 [Maintenance Training.]{.underline}**

When installing a new system, the control system designer should specify
the amount and length of training classes required for the electrical
maintenance and other airport personnel (i.e. Operations). All persons
who may be called upon to troubleshoot or maintain the system should be
properly trained. The training material should be reviewed at a minimum
once per year. Training classes for maintenance personnel should be
limited to a maximum of 4-6 people per class in order to insure hands-on
training. The key to successful training is the availability of
well-written comprehensive manuals from the manufacturer that assume
that maintenance personnel do not retain a day-to-day knowledge of key
maintenance procedures. Today's control systems are fairly
maintenance-free and the maintenance person does not get to use his or
her expertise on a daily basis. The maintenance manual and training
should, at a minimum, include the following subjects.

a.  System block diagram -- Theory of Operation

b.  System drawing package - System assemblies and wiring diagrams

c.  Touch screen operation

d.  Maintenance of HMI interface

e.  Overall system maintenance

f.  Hands-on troubleshooting

g.  Procedure in transferring control from Air Traffic Controllers (ATC)
    to maintenance personnel and return to ATC.

h.  Control system power-up and power-down sequences

i.  Failsafe scenarios and what to do during failsafe operation

j.  System reporting capabilities

k.  Control and monitoring capabilities

**5.12.3 [Technical Support.]{.underline}**

It is very important that the airport maintenance people have adequate
technical support from the system manufacturer. This support is not just
needed during the warranty period but for the years after that. It is in
the best interest of the airport to always have back-up support
available. This support should include the following:

a.  Technical phone assistance

b.  Technical support telephone line available 7 days a week, 24 hours a
    day, 365 days a year

c.  On-site technical field service as required

**5.12.4 [Maintenance Manuals.]{.underline}**

The ALCMS manufacturer shall have supplied the necessary copies of the
operation and maintenance manuals that are hard-covered and suitable for
the daily operation and maintenance of the system. The manuals should
include operational overview, system theory of operation, and graphical
user interface screen operation

**5.12.5 [FAA ATC Manuals.]{.underline}**

The airport should possess the ALCMS manufacturer's operation manuals
for the Air Traffic Controllers (ATC) that are hard-covered and suitable
for daily operation of the system. At a minimum, the manuals shall
include Touch screen operation (human machine interface) and Touch
screen maintenance (i.e. calibration).

**5.12.6 [As-Installed Drawing Package.]{.underline}**

The airport should possess a complete set of As-Installed drawings from
the ALCMS manufacturer. The As-Installed drawings should reflect the
final installation design of the ALCMS including System Block Diagram
(1-line drawings), System External Wiring Diagrams, Assembly Drawings,
and Assembly Wiring Diagrams.

## 5.13 STANDBY AND EMERGENCY POWER SYSTEMS.

**5.13.1 [General Engine Maintenance Notes.]{.underline}**

The following are some general and miscellaneous maintenance inspections
for emergency generator systems.

**5.13.2 [Engine and Generator Mounts.]{.underline}**

Check engine and generator mounting bolts and the condition of the
mounting pads every 1000 hours or annually (whichever comes first) and
tighten or repair as required.

**5.13.3 [Load Test.]{.underline}**

Start and exercise the generator set under load on a monthly basis (per
NFPA recommendations). When exercising the generator set, load should be
at least 35% of nameplate rating. Operate the generator at that load or
higher until coolant temperature becomes stable. This will evaporate any
moisture that may have condensed in the crankcase and prevent
wet-stacking. Load test all standby generators at 100% rated load for 4
hours once each year to eliminate carbon buildup in the cylinders and as
a means of indicating any potential problems with the unit. If the
airport does not possess load bank equipment suitable for performing
this test, contact the local supplier of the generator equipment to
supply the load testing service.

**5.13.4 [Cooling System.]{.underline}**

Change coolant system antifreeze annually; however, coolant with
manufacturer recommended supplemental inhibitors may be operated up to
two years or 4000 hours, whichever comes first.

Inspect coolant system hoses at least every 500-600 hours for signs of
deterioration and replace if necessary.

Inspect the water pump drain hole for plugging every 500-600 hours and
clean out if necessary.

Replace the bearings in the fan hub assembly with new bearings at major
engine overhaul.

Check drive belts daily for prime power applications and monthly for
standby applications. Adjust as required. At this time, inspect belts
for splits, cracks, and glazing and replace as required.

**5.13.5 [Turbocharger, Exhaust Connections.]{.underline}**

Visually inspect the mountings, intake and exhaust ducting, and
connections for leaks daily. Check the oil inlet and outlet lines for
leaks or restrictions to oil flow. Check for unusual noise or vibration
and, if excessive, stop the engine and do not operate until the cause is
determined.

Check the exhaust manifold retaining nuts, exhaust flange clamp, and
other manifold connections for leakage and tighten, if necessary. Check
heat-insulating exhaust system, turbo-charger, and turbocharger riser
blankets for damage daily. Replace torn, matted, crushed, oil-soaked, or
otherwise damaged insulation blankets immediately.

**5.13.6 [Battery.]{.underline}**

Check the hydrometer "eye" of maintenance-free batteries for charge. If
lead-acid or low maintenance batteries are used, check the specific
gravity of each cell every 150 hours. This check may also be made each
time a weekly inspection is made prior to starting the generator. Check
more frequently in warm weather due to more rapid loss of water through
evaporation. Maintain the electrolyte level according to the battery
manufacturer's recommendations, but do not overfill. Overfilling can
cause poor performance or early failure. Keep the terminal side of the
battery clean. When necessary, wash with a solution of baking soda and
water. Rinse with fresh water. Do not allow the soda solution to enter
the cells. Inspect the cables, clamps, and hold-down brackets regularly.
Clean and re-apply a light coating of petroleum jelly when needed.
Replace corroded or damaged parts. Keep batteries fully charged. Replace
any battery that fails to hold a charge. By checking each battery cell
with a hydrometer, a weak cell can be detected and the battery replaced
before a failure occurs. Periodically check battery connections for
corrosion and tightness. If necessary, remove connections and wire brush
corrosion from terminals and cable ends. Replace damaged wiring. Replace
batteries every two years to assure proper operation.

**5.13.7 [Air Cleaners.]{.underline}**

A clogged air cleaner element will cause excessive intake restriction
and a reduced air supply to the engine. This in turn can result in high
operating temperatures, increased fuel consumption, inefficient engine
operation, and engine malfunction or damage. Replace dry type air
cleaner elements, if used, with new elements after one year of service.
Inspect the entire air system for leaks. Look especially for air inlet
piping or boots that are loose and for loose or damaged clamps.

**5.13.8 [Lubricating Oil and Filters.]{.underline}**

Check the oil level weekly for standby or daily for prime power
generator sets, with the engine stopped. If necessary, add sufficient
oil to raise the level to the proper mark on the dipstick. All diesel
engines are designed to use some oil, so the periodic addition of oil is
normal. Lubricating oil filters should be changed whenever the engine
oil is changed, normally a minimum of once a year or every 150 hours of
operation for standby units. Under normal operation, note oil pressure
each time the engine is started as well as during load test.

**5.13.9 [Fuel Lines, Flexible Hoses.]{.underline}**

Check hoses as part of the pre-start inspection. Examine hoses for
leaks, and check all fittings, clamps, and ties carefully. Make sure
that hoses are not resting on or touching shafts, coupling, heated
surfaces including exhaust manifolds, any sharp edges, or other
obviously hazardous areas. Since all machinery vibrates and moves to a
certain extent, clamps and ties can fatigue with age. To ensure
continued proper support, inspect fasteners frequently and tighten or
replace them as required. Examine leaks immediately to determine if
fittings have loosened or cracked or if hoses have ruptured or worn
through. Take corrective action immediately. Hoses have a finite service
life. With this in mind, thoroughly inspect all hoses at least every 500
operating hours and/or annually. Look for cover damage and/or
indications of twisted, worn, crimped, brittle, cracked, or leaking
lines. Hoses with their outer cover worn through or with damaged metal
reinforcement should be considered unfit for further service.

**5.13.10 [Electrical Generator Maintenance Notes.]{.underline}**

Dirt, heat, moisture, and vibration are common enemies of a generator.
Keeping the generator clean and dry, maintaining proper alignment of the
generator and its prime mover, and preventing overloads will result in
efficient operation and long life. Protect generators that are outdoors
from the elements by suitable houses or enclosures. Dirt and dust will
conduct electricity between points of different electrical potential.
Moisture will aggravate the problem further. Insulation system failure
can result if corrective action is not taken. The condition of the
insulation system can be tested by measuring the insulation resistance.
Accumulations of dust and dirt not only contribute to insulation
breakdown, but they can also increase temperature by restricting
ventilation and by blocking the dissipation of heat. It should also be
noted that the presence of rodents such as mice around the generator
enclosure can be a cause for premature failure. Mice have been known to
enter the generator housing through a missing or damaged screen and chew
through windings causing a short circuit and failure.

**5.13.11 [Preventive Maintenance Inspection Procedures.]{.underline}**

**5.13.11.1 [Weekly Checks.]{.underline}**

1.  Before starting the engine, check the following:

-   Battery water level.

-   Specific gravity of battery electrolyte (check all battery cells)

-   Immersion heater operation

-   Engine oil level.

-   Governor oil level if equipped with hydraulic/mechanical governor.

-   Engine generator coolant level.

-   Fuel level in main storage tank.

-   Battery trickle-charge current

> NOTE: *If necessary to add oil, water, or fuel, record amount. Do not
> operate diesel engines without load as it results in fouling the
> cylinders and injectors.*

2.  Load-test the engine generator for 1 hour. Turn on the airport
    lights and visual aids before beginning the test. Load on generator
    should be at least 35% of generator rated load.

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(a) Start the generator by one of the two methods below. Alternate the
    method of starting the generator on successive load tests.

    1.  Start the generator by using the remote control in the tower or
        other remote location. If there is no remote control, use the
        controls in the vault located on the emergency transfer switch.

    2.  Start the engine by simulating a power failure. This may be done
        by switching off incoming commercial power. This procedure
        should be used only after coordination with the tower, flight
        service station, or other authority in charge of air traffic
        control.

        a.  Record the time for engine generator to start and transfer
            switch to operate.

        b.  Check for normal operation of controls.

        c.  Take a reading of the following after engine generator has
            operated for 15 minutes under load:

            Output voltage Phase: 1\_\_\_\_\_ 2 \_\_\_\_\_ 3 \_\_\_\_\_

            Output current Phase: 1 \_\_\_\_\_ 2 \_\_\_\_\_ 3 \_\_\_\_\_

            Output frequency \_\_\_\_\_\_\_\_\_

            Engine oil pressure \_\_\_\_\_\_\_

            Coolant temperature \_\_\_\_\_\_

        d.  Check room ventilation louvers for freedom of operation and
            manual and automatic operation of fan.

        e.  For starting method (1), reset control switch from "run" to
            "automatic." After the set time delay, normally 15 minutes,
            the transfer switch should operate and transfer the load
            back to commercial power. Check time for load transfer and
            check time for engine to shut down after programmed engine
            "cool down" cycle, normally 5 minutes.

        f.  For starting method (2), turn the commercial power back on,
            and measure the delay from the resumption of commercial
            power until transfer of load to commercial power. Then
            measure the delay from load transfer until shutoff of the
            engine.

    3.  Clean the engine generator set, its accessories, control
        compartments, and do necessary housekeeping of the immediate
        area.

**5.13.11.2 [Quarterly Checks and Annual Checks.]{.underline}**

1.  Perform checks and record readings same as those noted on weekly
    checks.

2.  In addition to the weekly checks, perform the checks listed in Table
    5-15.

**5.13.11.3 [Bi-annual Checks.]{.underline}**

1.  Perform all checks covered in Table 5-15.

2.  Drain and flush engine-cooling system after operating the engine
    under load for 1 hour.

3.  Remove covers and inspect generator bearings for wear and condition
    of lubrication.

4.  Replace batteries.

  ----------------------------------------------------- ----------- ----------
  **Engine -- Lubricating System**                      Quarterly   Annually

  1\. Check for leaks                                   X           X

  2\. Check engine oil level and pressure               X           X

  3\. Check hydraulic/mechanical governor oil level     X           X

  4\. Change engine oil and filters every 150 hours of              X
  operation or                                                      

  5\. Change hydraulic/mechanical governor oil                      X

  **Engine -- Cooling System**                                      

  1\. Check for leaks                                   X           X

  2\. Check radiator for air restriction                X           X

  3\. Check operation of coolant heater                 X           X

  4\. Check hoses and connections                       X           X

  5\. Check coolant level and temperature               X           X

  6\. Check belt condition and tension                  X           X

  7\. Check heat exchanger corrosive water treatment    X           X
  plugs (if equipped)                                               

  8\. Check motor operated louvers                      X           X

  9\. Check radiator duct work and fan shroud           X           X

  10\. Check antifreeze and additive concentration                  X

  11\. Check fan hub, drive pulley & water pump                     X

  12\. Change coolant filter (if equipped)                          X

  13\. Check thermostat and radiator cap                            X

  **Engine -- Air Intake System**                                   

  1\. Check for leaks                                   X           X

  2\. Check air cleaner restriction                     X           X

  3\. Check all piping connections                      X           X

  4\. Clean air cleaner element and housing             X           

  5\. Change air filter element                                     X

  6\. Clean crankcase breather element                              X

  **Engine -- Fuel System**                                         

  1\. Check for leaks                                   X           X

  2\. Check governor control linkage                    X           X

  3\. Check fuel lines & connections                    X           X

  4\. Drain sediment from day tank                      X           X

  5\. Drain water separators                            X           X

  6\. Check day tank fuel level                                     X

  7\. Check fuel transfer pump                                      X

  8\. Check diesel engine primer pump                               X

  9\. Change fuel filters                                           X

  10\. Change day tank supply filter (or clean)                     X

  11\. Change water separator filter (if equipped)                  X

  12\. Check float tank breather element (if equipped)              X

  13\. Check fuel tanks for contamination                           X
  ----------------------------------------------------- ----------- ----------

**Table 5-15. Quarterly and Annual Preventive Maintenance Checklist for
Standby Generator Sets**

  ---------------------------------------------------- ----------- ----------
  **Engine -- Exhaust System**                         Quarterly   Annually

  1\. Check for leaks                                  X           X

  2\. Check exhaust restriction                        X           X

  3\. Drain exhaust condensation trap (if equipped)    X           X

  4\. Torque exhaust manifold & turbocharger cap                   X
  screws                                                           

  5\. Torque exhaust flange bolts                                  X

  **Electrical System**                                            

  1\. Check battery -- charging system                 X           X

  2\. Check battery -- electrolyte level               X           X

  3\. Check engine safety controls, alarms and wiring  X           X

  4\. Check battery connections and terminals          X           X

  5\. Check engine starting motor cranking current                 X

  **Engine Related Systems**                                       

  1\. Check for vibration & metal cracks               X           X

  2\. Check engine mounting hardware and tighten                   X

  3\. Check fuel injector pump & injector timing                   X

  4\. Check engine for dirt/debris and clean vent                  X
  screens                                                          

  5\. Grease fan pillow block bearing (if equipped)                X

  **Main Generator**                                               

  1\. Check air inlet & outlet restrictions            X           X

  2\. Grease generator bearing (if equipped)                       X

  3\. Clean generator per manufacturer's instructions              X

  4\. Perform 4 hour full load test                                X

  **Switchgear**                                                   

  1\. Check operation of transfer switch and timing    X           X
  relays                                                           

  2\. Inspect transfer switch contacts for pitting or  X           X
  arcing                                                           

                                                                   
  ---------------------------------------------------- ----------- ----------

**Table 5-15. Quarterly and Annual Preventive Maintenance Checklist
(continued)**

# CHAPTER 6. TROUBLESHOOTING PROCEDURES FOR SERIES LIGHTING CIRCUITS.

## 6.0 INITIAL FAULT INVESTIGATION.

**SAFETY:**

a\. Troubleshooting tests contained in this chapter may involve voltages
that are dangerous. Safety precautions must be exercised for the
protection of personnel and property (see Paragraph 2.3, Electrical
Hazards of Series Lighting Circuits).

b\. Personnel performing the testing and troubleshooting procedures must
be experienced in high-voltage techniques and must be adequately
supervised. All maintenance personnel should be thoroughly trained in
emergency procedures for treatment of electrical shock.

Series circuits are subject to two primary types of malfunctions, shorts
to ground or opens. Keep in mind that an airfield lighting series
circuit powered by a constant current regulator is an ungrounded
circuit. Therefore, the circuit and CCR will function normally with one
ground on the circuit. It is only when two or more grounds appear and a
"short circuit" path is created that the current begins to flow through
the earth, around the lighting load, and a section of lights appears
out. In the case of an open in the primary field circuit, no current can
flow and the entire circuit goes out.

Constant current regulators larger than 10kW are required to have open
circuit protection that will shut the CCR down within two seconds after
current flow has been interrupted. Most manufacturers, however, provide
this protection on all their CCRs. When in doubt, check your CCR's
operating manual. Open circuits can exist in conjunction with grounds
and if the CCR can develop enough voltage to overcome whatever
resistance exists in the circuit, it will establish current flow and
continue operating.

In most instances, we learn of a malfunctioning lighting circuit from a
report made by the control tower or through an operations report.
Sometimes it is noticed by an electrician making a routine daily runway
inspection or light check. Either way, the complaint may consist of a
section of lights out or an entire circuit not functioning. The first
step in an initial fault investigation is to make a quick visual
inspection of the affected lighting on the airfield. This will provide
information as to whether an entire circuit is out or just a portion of
the lighting on a specific circuit is affected. This gives an
electrician a good idea as to the possible cause of the malfunction. If
an entire circuit is out, the problem could be an open circuit in the
field wiring or a malfunctioning CCR. If only a portion of the lights on
a circuit is out, the problem is most likely due to a short to ground at
each end of the affected section. Keep in mind that if the malfunction
is due to a short to ground in the field circuit, the longer the circuit
remains energized, the more damage will result at the location of the
ground faults due to arcing.

In the vault, once the exact malfunctioning circuit has been determined,
the regulator supplying the circuit can be located. Turn the regulator
local control to the "OFF" position and shut down and lock out the power
supply to the regulator. If a standard Style S1 cutout is present,
disconnect the S1 and separate the blades of the cutout switch on the
field side of the switch. This will allow you to check both the
continuity and insulation resistance in the field circuit. After
separating the ends of the field circuit by either separating the blades
of the S1 or disconnecting at least one end of the field circuit from
the regulator, prepare to take a measurement for continuity in the
circuit.

If using a volt-ohm-meter (VOM), the first step is to set the meter to
the R x 1 scale and "zero" the meter (if using a digital multimeter,
these steps are not necessary). This is accomplished by setting the
meter to the desired scale (R x 1 in this case) and touching the two
meter leads together. Make sure the leads are plugged into the correct
sockets in the meter (on most VOMs, this is the + and common sockets)
and adjust the "zero ohms" knob until the meter needle is at the zero
point (usually on the right side of the meter scale). After this
adjustment has been made, take a reading of the resistance in the field
circuit by checking between the two separated conductors of the field
circuit. If no continuity can be read in the circuit, check for a short
to ground in each side of the circuit and then proceed to Section 6.2,
"Locating Open Circuit Faults." If the circuit shows continuity (a
measurable amount of resistance) normally between 20 to 70 ohms, the
circuit is not open. If a much higher resistance is measured (1000 ohms
+), then a high resistance open circuit fault has occurred. Many times
this is indicative of a transformer with a faulty primary winding that
has not completely burned open yet. It could also be due to a cut cable
which has both ends in contact with the earth.

If the resistance in the circuit checks normal, proceed to check the
resistance to ground from each end of the circuit to ground. If any
resistance can be read to ground with the meter set at R x 1, then one
or more low resistance shorts to ground exist and troubleshooting
procedures are moved to the field (see Section 6.1). If the meter reads
no continuity (no meter movement) when the circuit is checked to ground,
set the meter for the R x 100 and R x 10,000 scales respectively and,
after zeroing the meter, check for a short to ground on these two
scales. Remember that the positive (red) lead should always be connected
to the circuit or conductor under test and the negative (black) lead
should be connected to ground. Also be aware that on the R x 10,000
scale, merely touching the meter leads with your fingers will produce a
reading. Most ground faults serious enough to cause the lights to go out
will be reading less than 1000 ohms to ground, usually less than 100
ohms to ground and will be easily indicated on the R x 1 scale. If no
ground fault is detected on the circuit with the VOM or DMM, use an
insulation resistance tester to test the circuit. Insulation resistance
testers operate at much higher voltages, 500 to 5000 volts, and are more
useful in locating a high resistance ground fault.

If no problems are detected in the field circuit, the next step is to
try to energize the CCR using the manual control on the front of the
CCR. After reconnecting the field circuit to the CCR, or reinstalling
the S1 and turning the primary power back on to the regulator, begin by
putting the switch in the step 1 position and note if the CCR comes on.
If it does not, the problem may be as simple as a tripped breaker or
blown fuse and you should proceed to check for proper input voltage to
the CCR. If the CCR energizes for about 2 seconds and then shuts off,
the fault is likely a malfunction of the open circuit or over current
protection circuitry in the CCR. If the field circuit appears normal,
disconnect and lock out the primary power source to the CCR and perform
a short circuit test by shorting the output of the regulator with a #10
or larger wire, and test the operation of the regulator again. If the
regulator still shuts off after a few seconds, there is an internal
problem with the regulator or its controls. Consult the operation and
maintenance manual for the CCR for specific troubleshooting
instructions.

If the CCR remains on and appears to be operating normally on the lowest
brightness setting, continue switching the CCR up through the brightness
steps while noting the increase in current output on the meter until the
maximum brightness is reached, either step 3 or step 5 depending on the
style of the regulator. If the regulator has a normal output on the
lower steps, but the output is low on the highest step, the regulator
may be overloaded or there may be too much inductance in the field
circuit. Perform a short circuit test of the regulator by turning the
regulator off and disconnecting and locking out the primary power to the
regulator. Then connect a #10 wire across the output and re-energize the
regulator. If the regulator operates normally with the output shorted,
this would indicate an overload is present in the field circuit. If
there have been no additional loads added to the field circuit, check
for burnt out lamps or otherwise open secondary connections on the field
transformers. Newer regulators are required to withstand up to 30%
open-circuited isolation transformers. Older regulators may only
tolerate 10%. When a large number of open-circuited transformers exist
on the output of a regulator, it increases the inductive loading on the
regulator and will cause the regulator to act strangely and many times
appear overloaded. One cause of this condition may be a lightning strike
that has blown out a large number of lamps in the circuit.

## 6.1 LOCATING GROUND FAULTS IN THE FIELD.

Once it has been established that the circuit is shorted to ground, the
troubleshooting procedures can be moved to the field. Keep in mind that
if there is a section of lights out on the circuit, there will ALWAYS be
at least two shorts or ground faults in the circuit. At this time the
circuit may be energized and a visual inspection can be made to try to
locate the faults. If the circuit is a simple loop configuration, a
visual inspection can sometimes be an effective means to find the
problem. It is best to have someone at the vault with a radio so that as
soon as the good to bad transition areas in the circuit are located,
word can be sent to the vault to shut off the regulator and lock it out
so that repairs can be made. Drive the circuit looking for any section
of lights that are out or appear to be extremely dim and mark this area
by putting a surveyor's flag or a paint mark at the locations of the
last light burning and the first light out as shown in Figure 6-2. After
the circuit has been de-energized and locked-out, check the lights at
each end of these "transition areas" for burned transformers,
connectors, etc. Always remember that there will be at least two shorts
in the circuit and both must be repaired. In some instances, especially
in the case of direct buried cables or when the circuit has been
energized for a long period of time while ground faults are present,
more than two shorts to ground may have occurred.

The best method for finding ground faults after the initial visual
inspection has been made is to locate them using the VOM. Leave the ends
of the circuit separated at the vault and suspend the ends of the cables
in free air if disconnected from the S1 or other connection. Refer to
as-built plans if available to locate the center of the circuit and
break the circuit at that point by disconnecting the cable at one side
of the transformer. (See Figures 6‑3a & 6‑3b). Take a reading to ground
in both directions from this point and determine which way the fault is
located. It is entirely possible that the meter may indicate a fault in
both directions from this point or only in one direction as there may be
two or more faults in the same section of cable. Leaving this connection
open (if possible), proceed to a point in the circuit approximately
halfway between the midpoint and the vault in the direction of the fault
and break the circuit again. As before, take a reading on the circuit in
each direction to determine the location of the fault. Continue until
each fault is located and corrected.

During the course of troubleshooting, you may find that when you remove
a transformer from the can or the ground that the fault seems to
disappear. When this happens the fault is located at that transformer;
normally you can visually see the burned transformer. However, in the
case of an internal primary to secondary short in the transformer, there
may not be anything readily apparent. Look at the fixture attached to
the transformer and check to see if the socket or secondary plug is
burned. This is usually a good sign of a primary to secondary short. A
short of this nature can be confirmed by touching one lead of the VOM to
one of the primary leads of the transformer and touching the other to
one of the sockets on the secondary connector. If the transformer is
shorted, continuity will be indicated on the meter. Sometimes checking
between one of the primary connectors and the outside body of the
transformer will indicate a transformer with a significant leak to
ground. This can be performed with an insulation resistance tester for
better results. If checking the insulation integrity of transformers,
you can also submerge the transformer in a bucket of water and connect
the positive lead of the Megger to one of the primary leads and the
negative lead to a bare wire dropped into the bucket. If any leakage is
shown, the transformer is suspect or bad depending on the reading.
Reasonably new transformers should read over 1000 megohms, with readings
decreasing with age.

## 6.2 LOCATING OPEN CIRCUIT FAULTS.

Open circuits can be successfully located using similar tactics as those
used for locating short circuits or ground faults. If the circuit
appears to be grounded in conjunction with an open, the troubleshooting
procedure used for finding ground faults may be used since the open and
ground will likely be located at the same place. Many times a cable will
burn in two if left operating after a short to ground has developed. If
the initial fault investigation has revealed an open in the field
circuit and the circuit does not appear to be grounded, de-energize the
regulator and lock out the regulator power supply and proceed to the
field and locate the approximate center of the circuit.

***Tip: Any time an open circuit is indicated, the first question to ask
is: "Has anyone been doing any excavating in the vicinity of the
airfield?" If so, go out and look for a pile of fresh dirt and you will
likely find your problem.***

For this type of troubleshooting where you are looking for continuity,
it is helpful to have the ends of the circuit connected together at the
vault via the S1 cutout or some other means \-\-- see Figure 6-5. That
way, when the problem is corrected, it can be verified by being able to
read a loop from any point in the circuit. Proceed to the approximate
midpoint of the circuit and disconnect the circuit at the transformer
and ground the circuit in both directions. Check for continuity to
ground at another point in the circuit by disconnecting the transformer.
If the circuit is connected together at the vault and you have only one
open in the circuit, you should read continuity in one direction but not
the other back to the grounded midpoint of the circuit. When the
grounded conductor is identified, have someone at the midpoint
connection make and break the connection to ground in one direction and
then the other until you have established which section of the circuit
is open. Then proceed to a point halfway between your present location
and the grounded midpoint in the section of the cable that is open and
take another reading. If this time you can read to ground in the
direction of the midpoint of the circuit, then you know that the open is
behind you or between you and the last point you tested. By moving the
intentional ground point and looking for continuity in each section of
the circuit, the open(s) can be quickly located. See Figure 6-5 for
details.

## 6.3 INTERCONNECTED CIRCUIT FAULTS.

It is common for airfields with multiple circuits to experience
interconnecting faults. There are two main types of interconnecting
faults. The first occurs when two or more circuits contain grounds
and/or opens in a manner that electrically connects the circuits
together. The second type occurs when two or more circuits do not
contain any faults, but they become capacitively coupled together.

When multiple circuits contain faults that connect them together, a
section of primary cable is common to all circuits involved. (See
Figures 6-6 & 6-7.) Multiple ground faults are the most common cause of
this problem. A continuity check between the suspected circuits will
confirm if they are electrically connected. To troubleshoot this
condition, disconnect and isolate the output leads of regulator "B,"
then locate the circuit fault on regulator "A" circuit. This will
usually locate the common fault area of both circuits.

A capacitive coupling fault occurs when two or more series circuits run
parallel and in close proximity to each other. This situation becomes a
problem if the circuits have monitors on them because the induced
currents can simulate field faults. A continuity check between the
suspect circuits confirms they are not electrically connected together.
To correct a capacitive coupling fault, simply swap the output leads of
one of the regulators involved. This will cancel the capacitive coupling
effect.

**[!!Warning!!]{.underline}**

**[The troubleshooting methods and procedures outlined in the following
paragraphs involve dangerous voltages and should only be attempted by
qualified personnel using appropriate safety procedures. Also, while
sometimes helpful or necessary, be aware that these methods are by their
nature "destructive testing" and if performed indiscriminately can
result in more damage occurring in the field circuit.]{.underline}**

*The following troubleshooting methods are best described as
"destructive testing." These methods can be used when either time
constraints or difficulty testing using an ohm meter or insulation
resistance tester makes traditional troubleshooting impractical. One
such instance might be in the case of direct buried circuits where
traditional troubleshooting is difficult and time consuming due to
having to dig up each connection to perform testing. Another case when
this type of troubleshooting might be considered is when a runway
circuit is out of service, and time is of the essence due to disrupting
air traffic operations at your facility. These methods do require that
the circuit have a significantly low resistance to ground at the point
of the fault, preferably less than 1000 ohms to ground, the less the
better. It should also be noted that small regulators (10kW or less) may
not develop sufficient voltage to be effective.*

## 6.4 INTENTIONAL GROUND TEST.

**6.4.1** The Intentional Ground Test is another method used to find a
single ground fault. (See Figures 6-8a & 6-8b.) If an insulation
resistance test indicates a ground in the circuit, but a visual
inspection is inconclusive, this test method will help locate the
problem.

First, shut off and lock out the regulator. Next, label the two
regulator output leads "1" and "2." Connect a 45-watt isolation
transformer and light fixture between regulator output "1" and ground as
shown in Figure 6-8a. The ground resistance of the test connection must
be very small. Next, energize the regulator. Keep away from the test
setup. If the test lamp illuminates, there is at least one ground fault
on the circuit. The brighter the test lamp glows, the lower the
resistance of the ground fault(s). With the regulator energized, conduct
a visual inspection of the circuit.

**6.4.2** If there is a section of dim or out light fixtures, a ground
fault exists between the last light operating properly and the first dim
or out light. Mark this area.

**6.4.3** If all the lights are dim or out, the ground fault is between
output "2" and the first light fixture on that side of the circuit.

**6.4.4** If all the lights appear to be OK, the ground fault is between
output "1" and the first light fixture on that side of the circuit.

**6.4.5** De-energize and lock out the regulator. Switch the test
transformer/light assembly from output "1" to output "2" (See Figure
6-8b). Energize the regulator. The test lamp should illuminate. Conduct
a visual inspection of the circuit.

**6.4.6** If there is a section of dim or out light fixtures, and the
location of the "good to bad" lights is in the same spot as marked in
Paragraph 6.4.2, the circuit has a single ground fault at that location.
(The transition area is the same, but the lights that were on in
Paragraph 6.4.2 should now be off, and the lights that were off in
Paragraph 6.4.2 should now be on.) De-energize and lock out the
regulator. Check the connector kits, cable splices, etc., between the
two adjacent light fixtures of the marked area and repair or replace
suspected faults as necessary. At this point a VOM or insulation
resistance tester may be used to verify faulty transformers, etc. Once
the single ground fault is cleared, the test lamp will not illuminate
when the regulator is energized. Remember, stay away from the primary
cable while the regulator is on.

**6.4.7** If there is a section of dim or out light fixtures and the
location of the "good to bad" lights is [not]{.underline} in the same
spot as marked in Paragraph 6.4.2, there are at least two ground faults
on the circuit. Mark this new transition area. De-energize and lock out
the regulator. Check the connector kits, cable, transformer, etc.,
between the two adjacent light fixtures of the newly marked area and
repair or replace suspected faults as necessary. As each fault is
cleared, energize the regulator and perform a visual inspection of the
circuit. Keep away from the energized primary cable and always lock out
the regulator when handling the cable. The "good to bad" transition area
should move toward the spot marked in Paragraph 6.4.2. Continue
troubleshooting the faults in this manner until the last ground is
repaired and the test lamp does not illuminate when the regulator is
energized.

**6.4.8** If all the lights appear to be operating correctly, the ground
is between output "2" and the first light on that side of the circuit.
(The same as found in Paragraph 6.4.3.) De-energize and lock out the
regulator. Work from the light fixture towards output "2." Check the
cable, connector kits, splices, etc., and repair or replace suspected
faults as necessary. The ground fault has been fixed when the test lamp
does not illuminate when the regulator is energized.

**6.4.9** If all the lights are dim or out, the ground fault is between
output "1" and the first light fixture on that side of the circuit (the
same as found in Paragraph 6.4.4). De-energize and lock out the
regulator. Work from the light fixture towards output "1." Check the
cable, connector kits, splices, etc., and repair or replace suspected
faults as necessary. The ground fault has been fixed when the light
fixtures operate properly and the test lamp does not illuminate when the
regulator is energized. Remove the fault marker(s) from the field.

**6.4.10** If a Megger is not available, the intentional ground test can
be modified to become a valuable preventive maintenance tool. (See
Figure 6-9.) Connect the transformer/light assembly to the regulator
output through an S-1 cutout, as shown in Figure 6-9. When the S-1
handle is removed, the intentional ground is connected to the circuit.
Once a month, shut off the regulator and pull the S-1 handle out.
Energize the regulator to the high step and observe the test lamp. If
the circuit has developed a ground fault, the lamp will illuminate. The
lower the resistance of the fault, the brighter the lamp will glow. The
main advantage of performing this check regularly is that a single
ground fault can be detected and located easily, before multiple faults
affect the visual appearance of the circuit. The general rule of thumb
is, if the test lamp glows, the ground needs to be located and repaired.
Add this procedure to your preventive maintenance routine and you will
always stay one step ahead of grounding troubles.

## 6.5 GROUNDED OUTPUT TEST FOR LOCATING OPEN CIRCUITS.

**6.5.1** The grounded output test is similar to the intentional ground
test used to locate ground faults (Paragraph 6.4). In order for this
test to work, the open fault needs to be grounded. (See Figure 6-10.) If
the open is not grounded or the ground resistance of the fault is too
great, this method may only work with large kW rated regulators. Make
sure the regulator is off. Refer to Figure 6-10a & b. Mark the regulator
leads "1" and "2." Remove lead "1" from the regulator. Cap or tape the
bare end of lead "1." Make sure it does not touch anything, and stay
away from it when the regulator is energized. Next, connect the
regulator output terminal, from which "1" was removed, to earth ground.
Once again, the ground resistance of this connection must be as low as
possible. Energize the regulator to the highest step. Stay away from the
test connection to ground.

**6.5.2** If the regulator trips off on open circuit protection, do not
attempt to energize the regulator a second time. Either the regulator is
too small or the ground resistance of the fault is too large. In most
cases, 4 and 7.5 kW regulators do not have enough power to drive a
grounded output test that has any ground resistance at the fault
location. Ideally, the best regulator to use would be a 30kW for 6.6 amp
circuits, and a 70 kW for 20 amp circuits. If possible, connect the
circuit to the largest regulator in the vault and try again. If the
circuit cannot be turned on, troubleshoot the open fault with the ohm
meter/megohm test. (See Paragraph 6.2.)

**6.5.3** If the regulator stays on and is registering output current,
the open circuit fault can be found using the grounded output test. It
is common for the regulator output current to fluctuate with this test
set up. This condition will not damage the regulator, but continue to
operate the regulator only long enough to locate the fault. Once the
fault is cleared, the regulator should return to normal operation. With
the regulator energized, conduct a visual inspection of the field
circuit. There should be a section of lighted fixtures and a section of
out fixtures. Mark the "good to bad" transition area. The open fault
will be between the last light fixture operating and the first
non-illuminated fixture. If all the lights are on, the open is between
output "1" and the first fixture on that side of the circuit. If all the
lights are out, the open is between output "2" and the first fixture on
that side of the circuit. De-energize and lock out the regulator.

**6.5.4** Remove the ground connection from the regulator output
terminal. Reconnect lead "1" to the regulator output terminal. Next,
remove lead "2" from the regulator. Cap or tape the bare end of lead
"2," making sure it does not touch anything and stay away from it when
the regulator is energized. Next, connect the regulator output terminal
from which "2" was removed, to earth ground. Energize the regulator to
the highest step. Stay away from the test connection to ground. Conduct
a visual inspection of the field circuit. This time the fixtures that
were on in the last test should be out and the fixtures that were out in
the last test should be on. The visual appearance of the circuit now
should be the exact opposite of Paragraph 6.5.3 with the "good to bad"
transition area in the same location. If this is true, the open is
between the two light fixtures adjacent to the fault marker. De-energize
and lock out the regulator. Start at one light fixture and work toward
the other checking isolation transformer windings, connections, splices,
and the primary cable for opens. Repair or replace any defects as
necessary. To verify the open fault has been corrected, measure the
resistance across output "1" and "2" with an ohmmeter. If the resistance
is less than 700 ohms, the circuit is free of all opens. Anything over
700 ohms indicates the presence of an open or high resistance fault
somewhere on the circuit. Remember, every circuit will have a different
resistance value depending on the number and wattage of the light
fixtures, but 700 ohms is the maximum for any airfield circuit. Remove
the ground connection from the regulator and reconnect output "2" to the
regulator. Energize the regulator to the high step for approximately
thirty minutes. This will double check that the repair work was done
correctly. Perform a visual inspection of the circuit and remove the
fault marker(s) from the field.

## 6.6 USING HEAT SENSING EQUIPMENT TO LOCATE GROUND FAULTS.

Any time there are two shorts to ground in a series circuit, the current
flowing to ground through the breach in the cable or transformer
insulation produces heat. This is caused by the arcing that occurs when
a good solid connection is not present in an electrical circuit. In the
case of series circuits operated by constant current regulators, the
regulator can produce very high voltages and damage and heat from arcing
can be great. Some airports have learned to use this unfortunate
circumstance to their advantage. By utilizing economical infrared
thermometers, the electrician is able to measure the difference between
the temperatures of a "normal" light can or fixture and one that is
running an abnormally high temperature. Infrared thermometers are
available that use laser sighting and are effective at distances long
enough to allow their use from a moving vehicle. Using this equipment,
an electrician can drive down the runway or taxiway checking the
temperature of each light/can until one is found that exhibits a higher
temperature than the rest and then investigate that light. This method
has proven to be a great time saver at several airports. See Chapter 4,
Test Equipment, for more information on this equipment.

## 6.7 USING CABLE FAULT LOCATING EQUIPMENT TO LOCATE GROUND FAULTS.

Cable locating and fault finding technology has improved vastly over the
years with many manufacturers offering equipment capable of locating
underground cable and ground or shield faults. These units consist of a
transmitter and receiver and if equipped for fault finding, usually have
an optional A-frame pickup unit for use with the receiver. They are able
to detect the location of ground faults in direct buried cables and can
be highly accurate. See Chapter 4, Test Equipment, for more information
on this equipment.

![](media/image10.wmf)

**Figure 6-1. Typical Series Lighting Circuit**

![](media/image11.wmf)

**Figure 6-2. Typical Ground Faults**

![](media/image12.wmf)

**Figure 6-3a. Locating Ground Faults with the VOM**

![](media/image13.wmf)

**Figure 6-3b. Locating Ground Faults with the VOM**

![](media/image14.wmf)

**Figure 6-4. Alternative Method of Finding Ground Fault Using VOM or
Insulation Resistance Tester**

![](media/image15.wmf)

**Figure 6-5. Locating Open Circuit Faults**

![](media/image16.wmf)

**Figure 6-6.** **Single Load-to-Load Fault**

![](media/image17.wmf)

**Figure 6-7. Two Load-to-Load Shorts**

This figure illustrates what may happen when there are two load to load
shorts on the circuits. Notice that the lights in this condition are
affected, causing the area between the two shorts to dim on both
circuits. If the illuminated lights on the B load were to go unnoticed,
the presence of this condition could easily be confused with symptoms of
two grounds on a single circuit. The give-away is the portion of the B
load lights that are on. Driving the circuit would locate the bright/dim
transitions and the location of the shorts. Had the load between the
shorts of load A been much larger (more lights) than the load in between
the shorts of load B, the smaller load would have been brighter. In the
illustration, the loads between the shorts are equal and the current is
divided equally between the two loads.

![](media/image18.wmf)

**Figure 6-8a, b. Intentional Ground Test**

![](media/image19.wmf)

**Figure 6-9. Intentional Ground Preventive Maintenance Tool**

![](media/image20.wmf)

**Figure 6-10a, b. Grounded Output Test**

![](media/image21.wmf)

**Figure 6-11. Dangerous Isolation Transformer/Circuit Ground Faults**

**Intentionally Left Blank**

# APPENDIX A. STANDARDS AND TOLERANCES.

**A.0 PURPOSE.**

This appendix contains standards and tolerances for visual aid equipment
and systems as contained in the following tables:

[Table]{.underline} [Equipment or System]{.underline}

1.  Beacons

2.  Medium intensity approach lighting systems (MALS, MALSF, MALSR)

3.  Omnidirectional approach lighting system (ODALS)

4.  Lead-in lights

5.  Runway end identifier lights (REIL)

6.  Visual approach slope indicators (VASI)

7.  Precision approach path indicators (PAPI)

8.  Runway and taxiway lighting systems

9.  Photoelectric devices

10. Standby engine generators

+-----------------+-------------------+------------------+-------------+
| **Parameter**   | ### Standard      | **Tolerance /    | **Tolerance |
|                 |                   | Limit:**         | / Limit:**  |
|                 |                   |                  |             |
|                 |                   | **Initial**      | **          |
|                 |                   |                  | Operating** |
+-----------------+-------------------+------------------+-------------+
| 1\. Rotation    |                   |                  |             |
| speed           |                   |                  |             |
+-----------------+-------------------+------------------+-------------+
| a\. 10-inch     | 6 rpm             | Same as standard | ±1 rpm      |
+-----------------+-------------------+------------------+-------------+
|                 | 12 rpm            | Same as standard | ±1 rpm      |
+-----------------+-------------------+------------------+-------------+
| b\. 36-inch     | 6 rpm             | Same as standard | ±1 rpm      |
+-----------------+-------------------+------------------+-------------+
| 2\. Input       | Same as lamp      | ±3 percent       | ±5 percent  |
| voltage         | voltage rating    |                  |             |
+-----------------+-------------------+------------------+-------------+
| 3\. Vertical    | Locally           | ± ½ degree from  | Same as     |
| aiming          | established       | established      | initial     |
|                 | between 2-10      | angle            |             |
|                 | degrees           |                  |             |
+-----------------+-------------------+------------------+-------------+

> **Table A-1. Beacons**

+--------------------+---------------+------------------+-------------+
| **Parameter**      | **Standard**  | **Tolerance /    | **Tolerance |
|                    |               | Limit:**         | / Limit:**  |
|                    |               |                  |             |
|                    |               | **Initial**      | **          |
|                    |               |                  | Operating** |
+--------------------+---------------+------------------+-------------+
| 1\. Light units    |               |                  |             |
| operational        |               |                  |             |
+--------------------+---------------+------------------+-------------+
| a\. Steady burning | All           | All              | 15% lamps   |
|                    |               |                  | out         |
|                    |               |                  | (random) -- |
|                    |               |                  | 2 lamps     |
|                    |               |                  | out; in     |
|                    |               |                  | 5-light bar |
|                    |               |                  | -- 1 light  |
|                    |               |                  | bar out     |
+--------------------+---------------+------------------+-------------+
| > b\. Flashing     | All           | All              | 1 unit out  |
+--------------------+---------------+------------------+-------------+
| 2\. Flashing rate  | 120 fpm       | ±2 fpm           | ±2 fpm      |
+--------------------+---------------+------------------+-------------+
| 3.  Input voltage  | 120V or 240V  | ±3%              | ±5%         |
+--------------------+---------------+------------------+-------------+
| 4\. Light unit     |               |                  |             |
| alignment          |               |                  |             |
+--------------------+---------------+------------------+-------------+
| a\. Vertical       | Locally       | ±1 degree        | ±2 degrees  |
|                    | established   |                  |             |
+--------------------+---------------+------------------+-------------+
| b\. Horizontal     | Parallel to   | ±1 degree        | ±2 degrees  |
|                    | runway        |                  |             |
|                    | centerline    |                  |             |
+--------------------+---------------+------------------+-------------+
| 5\. Obstructions   | No            | Same as standard | Same as     |
| due to vegetation, | obstruction   |                  | standard    |
| etc.               |               |                  |             |
+--------------------+---------------+------------------+-------------+

> **Table A-2. Medium Intensity Approach Light Systems (MALS, MALSF,
> MALSR)**

+--------------------+---------------+------------------+-------------+
| **Parameter**      | **Standard**  | **Tolerance /    | **Tolerance |
|                    |               | Limit:**         | / Limit:**  |
|                    |               |                  |             |
|                    |               | **Initial**      | **          |
|                    |               |                  | Operating** |
+--------------------+---------------+------------------+-------------+
| 1\. Light units    | All           | All              | 1 unit out  |
| operational        |               |                  |             |
+--------------------+---------------+------------------+-------------+
| 2\. Input voltage  | 120V or 240V  | ±3%              | ±5%         |
+--------------------+---------------+------------------+-------------+
| 3\. Flashing rate  | 60 fpm        | ±2 fpm           | ±2 fpm      |
+--------------------+---------------+------------------+-------------+
| 4.  Light unit     | Level         | ±1 degree        | ±2 degrees  |
|     alignment      |               |                  |             |
+--------------------+---------------+------------------+-------------+
| 5\. Obstructions   | No            | Same as standard | Same as     |
| due to vegetation, | obstruction   |                  | standard    |
| etc.               |               |                  |             |
+--------------------+---------------+------------------+-------------+

> **Table A-3. Omnidirectional Approach Light System (ODALS)**

+--------------------+---------------+------------------+-------------+
| **Parameter**      | **Standard**  | **Tolerance /    | **Tolerance |
|                    |               | Limit:**         | / Limit:**  |
|                    |               |                  |             |
|                    |               | **Initial**      | **          |
|                    |               |                  | Operating** |
+--------------------+---------------+------------------+-------------+
| 1\. Light units    | All           | All              | 1 unit out  |
| operational        |               |                  | in 3‑light  |
|                    |               |                  | cluster     |
+--------------------+---------------+------------------+-------------+
| 2\. Flashing rate  | Locally       | ±2 fpm           | ±2 fpm      |
|                    | established   |                  |             |
+--------------------+---------------+------------------+-------------+
| 3\. Input voltage  | 120V or 240V  | ±3%              | ±5%         |
+--------------------+---------------+------------------+-------------+
| 4\. Light unit     |               |                  |             |
| alignment          |               |                  |             |
+--------------------+---------------+------------------+-------------+
| a\. Vertical       | Locally       | ±1 degree        | ±2 degrees  |
|                    | established   |                  |             |
+--------------------+---------------+------------------+-------------+
| b\. Horizontal     | Locally       | ±1 degree        | ±2 degrees  |
|                    | established   |                  |             |
+--------------------+---------------+------------------+-------------+
| 5\. Obstructions   | No            | Same as standard | Same as     |
| due to vegetation, | obstruction   |                  | standard    |
| etc.               |               |                  |             |
+--------------------+---------------+------------------+-------------+

> **Table A-4. Lead-in Lights**

+--------------------+---------------+------------------+-------------+
| **Parameter**      | **Standard**  | **Tolerance /    | **Tolerance |
|                    |               | Limit:**         | / Limit:**  |
|                    |               |                  |             |
|                    |               | **Initial**      | **          |
|                    |               |                  | Operating** |
+--------------------+---------------+------------------+-------------+
| 1\. Light units    | All           | All              | All         |
| operational        |               |                  |             |
+--------------------+---------------+------------------+-------------+
| 2\. Flashing rate  |               |                  |             |
+--------------------+---------------+------------------+-------------+
| a\. Unidirectional | 120 fpm       | ±2 fpm           | ±2 fpm      |
| type               |               |                  |             |
+--------------------+---------------+------------------+-------------+
| b\.                | 60 fpm        | ±2 fpm           | ±2 fpm      |
| Omnidirectional    |               |                  |             |
| type               |               |                  |             |
+--------------------+---------------+------------------+-------------+
| 3\. Input voltage  | 120V or 240V  | ±3%              | ±5%         |
+--------------------+---------------+------------------+-------------+
| 4\. Alignment      |               |                  |             |
| (unidirectional)   |               |                  |             |
+--------------------+---------------+------------------+-------------+
| a\. Vertical       |               |                  |             |
+--------------------+---------------+------------------+-------------+
| \(1\) With baffles | 3 degrees     | ±1 degree        | -1 degree   |
|                    |               |                  |             |
|                    |               |                  | +2 degrees  |
+--------------------+---------------+------------------+-------------+
| \(2\) Without      | 10 degrees    | ±1 degree        | ±2 degrees  |
| baffles            |               |                  |             |
+--------------------+---------------+------------------+-------------+
| b\. Horizontal     |               | ±1 degree        | ±2 degrees  |
+--------------------+---------------+------------------+-------------+
| \(1\) With baffles | 10 degrees    | ±1 degree        | ±2 degrees  |
+--------------------+---------------+------------------+-------------+
| \(2\) Without      | 15 degrees    | ±1 degree        | ±2 degrees  |
| baffles            |               |                  |             |
|                    | (away from    |                  |             |
|                    | runway        |                  |             |
|                    | centerline)   |                  |             |
+--------------------+---------------+------------------+-------------+
| 5\. Obstructions   | No            | Same as standard | Same as     |
| due to vegetation, | obstruction   |                  | standard    |
| etc.               |               |                  |             |
+--------------------+---------------+------------------+-------------+

> **Table A-5. Runway End Identifier Lights (REILs)**

+--------------------+---------------+------------------+-------------+
| **Parameter**      | **Standard**  | **Tolerance /    | **Tolerance |
|                    |               | Limit:**         | / Limit:**  |
|                    |               |                  |             |
|                    |               | **Initial**      | **          |
|                    |               |                  | Operating** |
+--------------------+---------------+------------------+-------------+
| 1\. Lamps burning  |               |                  |             |
+--------------------+---------------+------------------+-------------+
| a\. VASI           | All           | All              | Not more    |
|                    |               |                  | than one    |
|                    |               |                  | lamp out    |
|                    |               |                  | per box     |
+--------------------+---------------+------------------+-------------+
| b\. SAVASI         | All           | All              |             |
+--------------------+---------------+------------------+-------------+
| 2\. Vertical       |               |                  |             |
| aiming (VASI and   |               |                  |             |
| SAVASI)            |               |                  |             |
+--------------------+---------------+------------------+-------------+
| a\. Downwind bar   | ½ degree      | ±2 minutes       | ±6 minutes  |
| (bar no. 1)        | below         |                  |             |
|                    | established   |                  |             |
|                    | glide path    |                  |             |
|                    | angle         |                  |             |
+--------------------+---------------+------------------+-------------+
| b\. Upwind bar     | Established   | ±2 minutes       | ±6 minutes  |
| (bar no. 2)        | glide path    |                  |             |
|                    | angle         |                  |             |
+--------------------+---------------+------------------+-------------+
| 3\. Vertical       |               |                  |             |
| aiming (3-bar      |               |                  |             |
| VASI)              |               |                  |             |
+--------------------+---------------+------------------+-------------+
| a\. Downwind bar   | 2.75 degrees  | ±2 minutes       | ±6 minutes  |
| (bar no. 1)        |               |                  |             |
+--------------------+---------------+------------------+-------------+
| b\. Middle bar     | 3.0 degrees   | ±2 minutes       | ±6 minutes  |
| (bar no. 2)        |               |                  |             |
+--------------------+---------------+------------------+-------------+
| c\. Upwind bar     | 3.25 degrees  | ±2 minutes       | ±6 minutes  |
+--------------------+---------------+------------------+-------------+
| 4\. Horizontal     | Parallel to   | ± ½ degree       | ± ½ degree  |
| alignment          | runway        |                  |             |
|                    | centerline    |                  |             |
+--------------------+---------------+------------------+-------------+
| 5\. Tilt switch    | ¼ to ½ degree | Same as standard | Same as     |
|                    | below and ½   |                  | standard    |
|                    | to 1 degree   |                  |             |
|                    | above         |                  |             |
|                    | established   |                  |             |
|                    | light bar     |                  |             |
|                    | angle         |                  |             |
+--------------------+---------------+------------------+-------------+
| 6\. Lamp current   | Rated current | Same as          |             |
| (                  | of lamps      | regulator        |             |
| current-regulated) |               | currents for     |             |
|                    |               | type of          |             |
|                    |               | regulator used   |             |
+--------------------+---------------+------------------+-------------+
| 7\. Lamp voltage   | Rated voltage | ±3%              | ±5%         |
| (                  | of lamps      |                  |             |
| voltage-regulated) |               |                  |             |
+--------------------+---------------+------------------+-------------+
| 8\. Obstructions   |               | Same as standard | Same as     |
| due to vegetation, |               |                  | standard    |
| etc.               |               |                  |             |
+--------------------+---------------+------------------+-------------+

> **Table A-6. Visual Approach Slope Indicator (VASI)**

+----------------------+--------------------+------------+-------------+
| **Parameter**        | **Standard**       | *          | **Tolerance |
|                      |                    | *Tolerance | / Limit:**  |
|                      |                    | / Limit:** |             |
|                      |                    |            | **          |
|                      |                    | *          | Operating** |
|                      |                    | *Initial** |             |
+----------------------+--------------------+------------+-------------+
| 1\. Lamps burning    |                    |            |             |
+----------------------+--------------------+------------+-------------+
| a\. PAPI             | All                | All        | Not more    |
|                      |                    |            | than one    |
|                      |                    |            | lamp out    |
|                      |                    |            | per box     |
+----------------------+--------------------+------------+-------------+
| 2\. Vertical aiming  |                    |            |             |
| ^[1]{.underline}^    |                    |            |             |
+----------------------+--------------------+------------+-------------+
| a\. Unit D (close to | 3° 30'             | ±2 minutes | ±6 minutes  |
| runway)              |                    |            |             |
+----------------------+--------------------+------------+-------------+
| b\. Unit C (2^nd^    | 3° 10'             | ±2 minutes | ±6 minutes  |
| from runway)         |                    |            |             |
+----------------------+--------------------+------------+-------------+
| c\. Unit B           | 2° 50'             | ±2 minutes | ±6 minutes  |
+----------------------+--------------------+------------+-------------+
| d.  Unit A (farthest | 2° 30'             | ±2 minutes | ±6 minutes  |
|     from runway)     |                    |            |             |
+----------------------+--------------------+------------+-------------+
| 3\. Horizontal       | Parallel to runway | ± ½ degree | ± ½ degree  |
| alignment            | centerline         |            |             |
+----------------------+--------------------+------------+-------------+
| 4\. Tilt switch      | ¼ below to ½       | Same as    | Same as     |
|                      | degree above       | standard   | standard    |
|                      | established light  |            |             |
|                      | bar angle          |            |             |
+----------------------+--------------------+------------+-------------+
| 5\. Lamp current     | Rated current of   | Same as    |             |
|                      | lamps              | regulator  |             |
| (current-regulated)  |                    | currents   |             |
|                      |                    | for type   |             |
|                      |                    | of         |             |
|                      |                    | regulator  |             |
|                      |                    | used       |             |
+----------------------+--------------------+------------+-------------+
| 6\. Lamp voltage     | Rated voltage of   | ±3%        | ±5%         |
|                      | lamps              |            |             |
| (voltage-regulated)  |                    |            |             |
+----------------------+--------------------+------------+-------------+
| 7\. Obstructions due | No obstruction     | Same as    | Same as     |
| to vegetation, etc.  |                    | standard   | standard    |
+----------------------+--------------------+------------+-------------+

> ^[1]{.underline}^ Unless a different standard is established locally,
> angles shown are for a 3 degree glide path.
>
> **Table A-7. Precision Approach Path Indicator (PAPI)**

+--------------------+-------------+-------------+--------------------+
| **Parameter**      | *           | **Tolerance | **Tolerance /      |
|                    | *Standard** | / Limit:**  | Limit:**           |
|                    |             |             |                    |
|                    |             | **Initial** | **Operating**      |
+--------------------+-------------+-------------+--------------------+
| 1\. Runway lights  |             |             |                    |
+--------------------+-------------+-------------+--------------------+
| a\. Threshold      | All on      | All on      | 75% on for VFR and |
| lights             |             |             | non-precision IFR  |
|                    |             |             | runways            |
+--------------------+-------------+-------------+--------------------+
| b\. End lights     | All on      | All on      | 75% on             |
+--------------------+-------------+-------------+--------------------+
| c\. Edge lights    | All on      | All on      | 85% on except for  |
|                    |             |             | CAT II and CAT III |
|                    |             |             | runways which      |
|                    |             |             | require 95%        |
|                    |             |             | serviceable        |
+--------------------+-------------+-------------+--------------------+
| d\. Centerline     | All on      | All on      | 95% serviceable    |
| lights             |             |             |                    |
+--------------------+-------------+-------------+--------------------+
| e\. Touchdown Zone | All on      | All on      | 90% serviceable    |
| lights             |             |             |                    |
+--------------------+-------------+-------------+--------------------+
| 2\. Taxiway lights |             |             |                    |
+--------------------+-------------+-------------+--------------------+
| a\. Edge lights    | All on      | All on      | 85% on - see note  |
|                    |             |             | 3 for CAT III taxi |
|                    |             |             | routes             |
+--------------------+-------------+-------------+--------------------+
| b\. Centerline     | All on      | All on      | 90% on - see note  |
| lights             |             |             | 3 for CAT III taxi |
|                    |             |             | routes             |
+--------------------+-------------+-------------+--------------------+
| > c\. Elevated     | All on      | All on      | No more than one   |
| > Runway Guard     |             |             | light in a fixture |
| > Lights           |             |             | unserviceable      |
+--------------------+-------------+-------------+--------------------+
| > d\. In-pavement  | All on      | All on      | No more than three |
| > runway guard     |             |             | lights per         |
| > lights           |             |             | location           |
|                    |             |             | unserviceable nor  |
|                    |             |             | two adjacent       |
|                    |             |             | lights             |
|                    |             |             | unserviceable      |
+--------------------+-------------+-------------+--------------------+
| > e\. Runway stop  | All on      | All on      | No more than three |
| > bar lights       |             |             | lights per         |
|                    |             |             | location           |
|                    |             |             | unserviceable nor  |
|                    |             |             | two adjacent       |
|                    |             |             | lights             |
|                    |             |             | unserviceable      |
+--------------------+-------------+-------------+--------------------+
| 3\. Lamp current   | [Amperes]{  | [Amperes]{  | [Am                |
|                    | .underline} | .underline} | peres]{.underline} |
+--------------------+-------------+-------------+--------------------+
| > a\. 3 step, 6.6A | 6.6         | 6.40-6.70   | Same as initial    |
|                    |             |             |                    |
|                    | 5.5         | 5.33-5.67   | Same as initial    |
|                    |             |             |                    |
|                    | 4.8         | 4.66-4.94   | Same as initial    |
+--------------------+-------------+-------------+--------------------+
| > b\. 5 step, 6.6A | 6.6         | 6.40-6.70   | Same as initial    |
|                    |             |             |                    |
|                    | 5.2         | 5.04-5.36   | Same as initial    |
|                    |             |             |                    |
|                    | 4.1         | 3.98-4.22   | Same as initial    |
|                    |             |             |                    |
|                    | 3.4         | 3.30-3.50   | Same as initial    |
|                    |             |             |                    |
|                    | 2.8         | 2.72-2.88   | Same as initial    |
+--------------------+-------------+-------------+--------------------+
| > c\. 5 step, 20A  | 20.0        | 19.40-20.30 | Same as initial    |
|                    |             |             |                    |
|                    | 15.8        | 15.33-16.27 | Same as initial    |
|                    |             |             |                    |
|                    | 12.4        | 12.03-12.77 | Same as initial    |
|                    |             |             |                    |
|                    | 10.3        | 9.99-10.61  | Same as initial    |
|                    |             |             |                    |
|                    | 8.5         | 8.24-8.76   | Same as initial    |
+--------------------+-------------+-------------+--------------------+
| 4\. Lamp voltage   | Lamp        | ±3%         | ±5%                |
|                    | voltage     |             |                    |
| > (parallel        | rating      |             |                    |
| > circuits)        |             |             |                    |
+--------------------+-------------+-------------+--------------------+

> **Table A-8. Runway and Taxiway Lighting Systems**
>
> **Runway and taxiway lighting systems continued:**

1.  To provide continuity of guidance, the allowable percentage of
    unserviceable lights should not be in a pattern that would alter the
    basic pattern of the lighting system. Additionally, an unserviceable
    light should not be adjacent to another unserviceable light except
    in a barrette or a crossbar where two adjacent unserviceable lights
    may be permitted. With respect to barrettes, crossbars and runway
    edge lights, lights are considered to be adjacent if located
    consecutively and:

    Laterally - in the same barrette or crossbar; or

    Longitudinally - in the same row of the edge lights or barrettes.

2.  Threshold lights for precision runways are part of the approach
    lighting system and are not included in this table.

3.  Taxiway lighting on low-visibility (CAT III) taxi routes.

> a\. Taxiway edge lights, taxiway edge reflectors and taxiway
> centerline lights along the low-visibility route -- no two adjacent
> lights or reflectors unserviceable.
>
> b\. Taxiway clearance bar lights -- no more than one light at a
> location unserviceable.

+--------------------+---------------+------------------+-------------+
| **Parameter**      | **Standard**  | **Tolerance /    | **Tolerance |
|                    |               | Limit:**         | / Limit:**  |
|                    |               |                  |             |
|                    |               | **Initial**      | **          |
|                    |               |                  | Operating** |
+--------------------+---------------+------------------+-------------+
| 1\. Photocell      |               |                  |             |
| operation (PAPI)   |               |                  |             |
+--------------------+---------------+------------------+-------------+
| > a\. Turn-on to   | 55 ft-cd      | ±5 ft-cd         | Same as     |
| > high setting     |               |                  | initial     |
+--------------------+---------------+------------------+-------------+
| > b\. Turn-on to   | 30 ft-cd      | ±5 ft-cd         | Same as     |
| > low setting      |               |                  | initial     |
+--------------------+---------------+------------------+-------------+
| 2\. Photocell      |               |                  |             |
| operation          |               |                  |             |
| (windsock, beacon, |               |                  |             |
| runway lights)     |               |                  |             |
+--------------------+---------------+------------------+-------------+
| > a\. Turn-on      | Below 55      | ±5 ft-cd         | Same as     |
|                    | ft-cd         |                  | initial     |
+--------------------+---------------+------------------+-------------+
| > b\. Turn-off     | Above 30      | ±5 ft-cd         | Same as     |
|                    | ft-cd         |                  | initial     |
+--------------------+---------------+------------------+-------------+
| 3\. Vertical       | 25 degrees    | ±5 degrees       | Same as     |
| orientation        | from vertical |                  | initial     |
+--------------------+---------------+------------------+-------------+
| 4\. Horizontal     | True north    | ±5 degrees       | Same as     |
| orientation        |               |                  | initial     |
+--------------------+---------------+------------------+-------------+

> **Table A-9. Photoelectric Devices**

+--------------------+---------------+------------------+-------------+
| **Parameter**      | **Standard**  | **Tolerance /    | **Tolerance |
|                    |               | Limit:**         | / Limit:**  |
|                    |               |                  |             |
|                    |               | **Initial**      | **          |
|                    |               |                  | Operating** |
+--------------------+---------------+------------------+-------------+
| 1\. Starting time  | 15 seconds or | Same as standard | Same as     |
| (1)                | less          |                  | standard    |
+--------------------+---------------+------------------+-------------+
| 2\. Potential      |               |                  |             |
| relays commercial  |               |                  |             |
| power              |               |                  |             |
+--------------------+---------------+------------------+-------------+
| > a\. 120V system  | 108V          | ±3V              | Same as     |
| >                  |               |                  | initial     |
| > Dropout          | 114V          | ±3V              |             |
| >                  |               |                  | Same as     |
| > Pickup           |               |                  | initial     |
+--------------------+---------------+------------------+-------------+
| > b\. 208V system  | 191V          | ±3V              | Same as     |
| >                  |               |                  | initial     |
| > Dropout          | 191V          | ±3V              |             |
| >                  |               |                  | Same as     |
| > Pickup           |               |                  | initial     |
+--------------------+---------------+------------------+-------------+
| > c\. 240V system  | 200V          | ±3V              | Same as     |
| >                  |               |                  | initial     |
| > Dropout          | 210V          | ±3V              |             |
| >                  |               |                  | Same as     |
| > Pickup           |               |                  | initial     |
+--------------------+---------------+------------------+-------------+
| > d\. 480V system  | 455V          | -0, +5V          | Same as     |
| >                  |               |                  | initial     |
| > Dropout          | 465V          | -0, +5V          |             |
| >                  |               |                  | Same as     |
| > Pickup           |               |                  | initial     |
+--------------------+---------------+------------------+-------------+
| 3\. Potential      |               |                  |             |
| relay engine power |               |                  |             |
+--------------------+---------------+------------------+-------------+
| > a\. Pickup       | 112V          | ±3V              | Same as     |
| > voltage          |               |                  | initial     |
| >                  | 197V          | ±3V              |             |
| > 120V             |               |                  | Same as     |
| >                  | 210V          | ±3V              | initial     |
| > 208V             |               |                  | Same as     |
| >                  | 465V          | -0, +5V          | initial     |
| > 240V             |               |                  |             |
| >                  |               |                  | Same as     |
| > 480V             |               |                  | initial     |
+--------------------+---------------+------------------+-------------+
| > b\. Dropout      | N/A           | N/A              | N/A         |
| > voltage          |               |                  |             |
+--------------------+---------------+------------------+-------------+
| 4\. Pickup         | 60 Hz         | 57-60 Hz         | Same as     |
| frequency          |               |                  | initial     |
+--------------------+---------------+------------------+-------------+

> \(1\) For CAT II operations, the engine generator is normally started
> and used for prime power. In the event of generator failure during
> this time, it is required that the CAT II lighting load be switched
> back to commercial power within 1.1 seconds.
>
> **Table A-10. Standby Engine Generators**

+--------------------+---------------+------------------+-------------+
| **Parameter**      | **Standard**  | **Tolerance /    | **Tolerance |
|                    |               | Limit:**         | / Limit:**  |
|                    |               |                  |             |
|                    |               | **Initial**      | **          |
|                    |               |                  | Operating** |
+--------------------+---------------+------------------+-------------+
| 5\. Time delay     | 15 minutes    | 15-20 minutes    | Same as     |
| setting (2)        |               |                  | initial     |
+--------------------+---------------+------------------+-------------+
| 6\. Voltage        | Set to match  | ±3V              | Same as     |
| regulator          | commercial    |                  | initial     |
|                    | power         |                  |             |
+--------------------+---------------+------------------+-------------+
| 7\. Frequency      | Contacts to   | Same as standard | Same as     |
| sensing device     | open below 57 |                  | standard    |
|                    | Hz            |                  |             |
+--------------------+---------------+------------------+-------------+
| 8\. Transfer relay | 1-3 seconds   | Same as standard | Same as     |
| (3)                |               |                  | standard    |
+--------------------+---------------+------------------+-------------+
| 9\. Frequency      | 60 Hz         | ±5 Hz            | Same as     |
|                    |               |                  | initial     |
+--------------------+---------------+------------------+-------------+
| 10\. Output        |               |                  |             |
| voltage (4)        |               |                  |             |
+--------------------+---------------+------------------+-------------+
| > a\. 120V system  | 114-126V      | Same as standard | Same as     |
|                    |               |                  | standard    |
+--------------------+---------------+------------------+-------------+
| > b\. 280V system  | 197-218V      | Same as standard | Same as     |
|                    |               |                  | standard    |
+--------------------+---------------+------------------+-------------+
| > c\. 240V system  | 228-252V      | Same as standard | Same as     |
|                    |               |                  | standard    |
+--------------------+---------------+------------------+-------------+
| > e\. 480V system  | 456-504V      | Same as standard | Same as     |
|                    |               |                  | standard    |
+--------------------+---------------+------------------+-------------+

> \(2\) Maximum before transfer to commercial power -- not valid where
> manual transfer to commercial power is made.
>
> \(3\) At facilities where the commercial power source has a record of
> momentary transience resulting in voltage drops, unnecessary engine
> starts and power transfer may be eliminated by increasing the
> tolerances of the PR relays or under-voltage devices dropout and
> pickup voltage settings shown in this table. The tolerances may be
> extended to, but not exceed, the acceptable frequency and voltage
> characteristics of the facility equipment. Any voltage regulators
> installed to stabilize the commercial voltage to the facility will be
> considered facility equipment. The TR relay or device time delay may
> be extended beyond 3 seconds to where, under normal starting
> conditions, the power from the engine generator will be available to
> the facility within 15 seconds after commercial power failure. The
> locally established tolerances shall be posted on the inside of the
> engine generator control panel door near the PR and TR relays.
>
> \(4\) Adjust output voltage to match service entrance voltage or
> facility requirements.
>
> **Table A-1. Standby Engine Generators (continued)**

**Intentionally Left Blank**