### SEAMECH INTERNATIONAL

Houston, TX

VAPOR CYCLE AIR CONDITIONING WITH AUTOMATIC CLIMATE CONTROL

INSTRUCTIONS FOR CONTINUED AIRWORTHINESS

R

- 134a VCS

Diamond Aircraft

Model DA

- 40



## ASI

- 772216ASEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 3 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 

### Seamech International, Inc.

Service Training

Printed in U.S.A.

Document # ASI

- 772216A

All rights reserved. All information contained in

this manual is based on the latest product

information available at the time of printing.

The right is reserved to make changes at

anytime without prior notice. No part of this

publication may be reproduced, stored in a

retrieval system, or transmitted in any form or

by any means, electronic, mechanical,

photocopying, recording or otherwise, without

the prior written permission of Seamech

International, Inc. This includes text, figures

and tables.

Always check Technical Service Bulletins and

the current service information for details that

may supersede any information included in this

document.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 4 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 5 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 

# SEAMECH INTERNATIONAL

HOUSTON, TEXAS



### REVISION LOG

REVISION REVISION DESCRIPTION DATE

NUMBER PAGES OF REVISIONS

A N/A

- Initial Release of Service Instructions 03/07/2007

B Multiple

- Removed heater and defog controls

from automatic climate control

system 0 4 / 09 /2008

C 23, 2 4

34, 35, 36 - Section 6.1 was revised to include

aircraft structural inspection

requirements with regards to the

installation of the vapor cycle system.

- Updated the touch screen images. 12/23/2008

D 18, 33, 34,

35

16,35,38, 40 - Updated the touch screen images on

each of the applicable pages to

remove the OAT indication.

- The word “OAT” and “Outside Air

Temperature” Sensor has been

changed to “ATS” for Air

Temperature Sensor, on the affected

pages, to satisfy FAA request. 0 6 / 1 5 / 20 09

E 25

- 26

1 , 3 - Updated compressor drive belt

tensioning instructions.

- Changed corporate address to

Corona, CA 12/22/2009

F 12

22

26

26

28

2 8

- 31

30 - Add service precaution for belt

tensioning

- Updated tool requirements

- Updated condenser cleaning

instructions.

- Added dye penetrant inspection

- Updated 6.2 per IAW FAR Part

23.1579 Amdt. 26

- Updated compressor belt tensioning

instructions

.

- Corrected Belt P/N 06/29/2010SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 6 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G G 13

20

23

27

29

30

- 40 - Add precaution note about replacing

compressor mounting locknuts

- Corrected picture of the Air

Temperature Sensor

- Removed b reaker b ar tool from this

list and moved it to the tool list in 6.4

- Revised the illustration under the

Annual Inspection section

- Added breaker bar and R134a Refrig.

Recovery / Service Cart to list

- Completely revised section 6.5 to

address new compressor removal,

installation and belt tensioning

procedures 08/09/2011SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 7 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 8 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 

### TABLE OF CONTENTS

**Section Page** 

1.0 INTRODUCTION

................................ ................................ ................................ ........................ 10

2.0 SAFETY

................................ ................................ ................................ ................................ ..... 11

3.0 SYSTEM SERVICE PRECAUTIONS

................................ ................................ ...................... 12

4.0 SYSTEM DESCRIPTION

................................ ................................ ................................ ......... 14

4.1 AIR DISTRIBUTION

................................ ................................ ................................ ................... 22

5.0 SYSTEM EVACUATION AND CHARGING PROCEDURE

................................ .................... 23

5.1 SPECIAL TOOLS AND EQUIPMENT

................................ ................................ ...................... 23

5.2 INITIAL REFRIGERANT EVACUATION PROCEDURE

................................ ........................ 23

5.3 REFRIGERANT CHARGING PROCEDURE

................................ ................................ ............ 24

6.0 MAINTENANCE AND REPAIR

................................ ................................ ............................... 27

6.1 100 HOUR/ANNUAL INSPECTION

................................ ................................ ..................... 27

6.2 AIRWORTHINESS LIMITATIONS

................................ ................................ ....................... 29

6.3 COMPONENT ACCESS

................................ ................................ ................................ ....... 29

6.4 SPECIAL TOOLS & EQUIPMENT

................................ ................................ ....................... 29

6.5 BELT TENSIONING

................................ ................................ ................................ .............. 30

6.6 LEAK TESTING REFRIGERANT

................................ ................................ ........................... 40

6.7 EVACUATING REFRIGERANT SYSTEM NOTES

................................ ............................ 41

6.8 CHARGING REFRIGERANT SYSTEM NOTES

................................ ................................ .... 42

6.9 REFRIGERANT OIL

................................ ................................ ................................ ................ 43

6.10 PRESSURE AND PERFORMANCE DIAGNOSIS

................................ ................................ 44

7.0 AUTOMATIC CLIMATE CONTROL SYSTEM

................................ ................................ .... 47

7.1 OVERVIEW

................................ ................................ ................................ ............................. 47

7.2 DIAGNOSTICS

................................ ................................ ................................ ............................. 49

APPENDIX A

................................ ................................ ................................ ................................ ..... 55SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 9 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 10 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 

### 1.0 INTRODUCTION

The Diamond Aircraft MODEL DA

- 40 Vapor Cycle System (VCS) air

- conditioning system is not

a primary flight system and is not required for the safe flight and operation of the aircraft.

However, the system does perform the very important function of providing pilot and

passengers comfort while the aircraft is on the ground, taxiing or in flight. Aircraft air

conditioning system s must not only provide effective passenger cooling, but must also

maintain a high reliability level to minimize aircraft downtime.

This information outlines the procedure for “charging” the refrigeration system with R

- 134a

refrigerant.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 11 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 

### 2.0 SAFETY

WARNINGS AND CAUTIONS FOR R134a REFRIGERANT

**•** Avoid breathing R

- 134a air

- conditioner refrigerant and lubricant vapor or mist.

Exposure may irritate eyes, nose, and throat. Wear eye protection when serviced

the air conditioning refriger ant system. Serious eye injury can result from eye

contact with refrigerant. If eye contact is made, seek medical attention immediately.

**•** If accidental system discharge occurs, ventilate the work area before resuming

service. Large amounts of R

- 134a ref rigerant will displace oxygen and cause

suffocation. Work only in well

- ventilated areas.

**•** Do not heat refrigerant containers above 125°F or expose refrigerant to open flame.

Do not use open flame to heat refrigerant containers.

**•** Do not intentionally drop, puncture or incinerate refrigerant containers.

**•** The evaporation rate of R

- 134a refrigerant at average temperature and altitude is

extremely high. As a result, anything that comes in contact with the refrigerant will

freeze. Always protect skin or delica te objects from direct contact with refrigerant.

For personal protection, goggles and protective gloves should be worn and clean

cloth wrapped around fittings, valves and connections when doing work that includes

opening the refrigerant system. If R

- 134a refrigerant comes in contact with any part

of the body, severe frostbite and personal injury can result. Flush exposed zone

immediately with cold water and obtain prompt medical assistance.

**•** If R

- 134a refrigerant comes in contact with any part of the bod y, severe frostbite and

personal injury can result. Flush exposed zone immediately with cold water and

obtain prompt medical help.

**•** R

- 134a service equipment or aircraft air conditioning system should not be pressure

tested or leak tested with compressed shop air. Though R

- 134a is considered non

flammable, some mixtures of air and R

- 134a have been shown to be combustible at

elevated pressures. These mixtures are potentially dangerous and may result in fire

or explosion causing injury or property damage.

**•** Never add R

- 134a refrigerant to a system that has not been evacuated to 29

inches of mercury vacuum pressure.

**•** Caution: Liquid refrigerant is corrosive to metal surfaces. Follow the operating

instructions supplied with equipment bein g used.

**•** Caution: Never add R

- 12 refrigerant to an air conditioning system designed to use

R

- 134a. Damage to the system may result.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 12 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G **•** Caution: R

- 12 compressor oil cannot be mixed with the R

- 134a compressor oil.

They are NOT compatible.

**•** Caution: Do NOT use R

- 12 servicing equipment or parts on an R

- 134a air

conditioning system.

3.0 

### SYSTEM SERVICE PRECAUTIONS

 Never open or loosen a connection before discharging the system refrigerant.

 Do NOT open a refrigerant s ystem or uncap a replacement component unless it is as

close as possible to room temperature. This will prevent condensation from forming

inside of a component which is cooler than the surrounding air.

 Before disconnecting a component from the system, cle an the outside of the fittings

thoroughly.

 Immediately after disconnecting a component from the system, seal the open fittings

with a cap or plug.

 Before connecting an open fitting always install a new seal or gasket designed for the

specific component. C oat the fitting and seal with clean refrigerant oil before

connecting.

 Do NOT remove the sealing caps from a replacement component until ready to install.

 When installing a refrigerant line avoid bends which produce radiuses smaller than

specified below fo r the hose being installed.

Hose Size Minimum Bend Radius

1/2” 13mm (#10) 3.0 inch

13/32 10mm (#8) 2.5 inch

5/16” 8mm (#6) 2.0 inch

 Position refrigerant lines so to avoid exhaust components, flight controls, or items which

may chafe the line. Refer to A.C. 43

- 13, Acceptable Methods, Techniques, and

Practices for compliant methods of installation.

 Apply a light coat of Ester RL

- 500S refrigerant oil to the o

- rings of all fittings. Tighten all

fittings to torques specified in the table below. Us e an anti

- torque back

- up wrench on

ALL component fittings.

 DO NOT use Teflon® tape or thread sealants on connections or fitting threads.

 Tighten fittings only to the specified torque listed below. The refrigerant fittings will not

tolerate over

- tightening

.

Tube O.D. Thread Size Torque

Ft

- lbs.

3/8” (.375”) [#6] 5/8

- 18 11

- 13

1/2” (.500”) [#8] 3/4

- 16 15

- 20

5/8” (.625”) [#10] 7/8

- 14 21

- 27SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 13 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Trinary Switch Torque: 7 Ft

- lbs.

 When disconnecting a fitting use a wrench on BOTH halves of the fitting. This will

prevent twisting of the refrigerant lines or tubes.

 Refrigerant oil will absorb moisture from the atmosphere if left uncapped. Do NOT open

an oil container until ready to use and install the cap immediately after using. Store the

oil only in a clean moisture

- free container.

 Keep service tools and the work area clean. Contamination of the VCS air conditioning

system through careless work habits must be avoided.

 Plumbing systems in aircraft are subject to vibration and extreme temperature and

atmospheric pressure changes. Therefore, strict adherence to procedures and correct

use of material is mandatory.

 The release of static electricity can damage sensitive electronic components. Never

touch the pins of an electrical connector or the body of an electrical device without first

grounding the aircraft. Personnel servicing sensitive electronic devices should be

grounded, as required, to dissipate any static electricity build up.

 Always follow instructions for setting compressor drive belt torque . Never use pry

- bars

or similar tools for loading the compressor while setting belt tension.

 Whenever removing any of the locknuts used to secure the compressor to the

compressor mount or the compressor mount to the engine, new replacement locknuts

shall be used. GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 14 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 

### 4.0 SYSTEM DESCRIPTION

The Seamech Diamond Aircraft Model DA

- 40 VCS (Vapor Cycle System) air conditioning

system consists of an engine driven compressor, a condenser with fan, a receiver

- dryer with

Trinary pressure switch and an evaporator with an expansion valve and evaporator coil

temperature sensor. Barrier hoses connect the components. A combination of Steel and

Aluminum fittings are used.

Refrigeration CycleSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 15 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G VCS Refrigerant SchematicSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 16 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G VCS Compressor

The Diamond Model DA

- 40 utilizes a swash or wobble

- plate

- type axial compressor. The

displacement of the compressor is 131cm 3 . The compressor cycles to regulate cabin

temperature and to avoid evaporator coil freeze

- up.

The VCS compressor is engaged by a 28VDC magnetic clutch driven by a V

- Belt off the front

of the engine via the starter ring gear adapter. The magnetic clutch is switched off during air

conditioning operation anytime the refrigerant system pressure drops below 29 (+/

- 3) psig (2

(+/

- 0.2) bar) or exceeds 397 (+/

- 29) psig (27 (+/

- 2) bar) at the Trinary switch, which is mounted

on the Receiver/Dryer assembly.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 17 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Condenser Assembly

The condenser receives high

- temperature, high

- pressure vapor from the compre ssor. The

assembly is located beneath the belly of the aircraft in a composite housing. The housing has

ram cooling air ducting in the front with exhaust vents in the rear.

The vapor enters at the upper fitting of the condenser. As the vapor flows thro ugh the

condenser, it releases heat to the cooler ambient air flowing over the condenser. Giving up its

heat causes the vapor to change to a liquid. Under average load, two

- thirds of the condenser

contains refrigerant vapor and the other one

- third contain s liquid refrigerant. The liquid

refrigerant in the condenser has lost much of its heat, but sill remains at a relatively high

temperature and pressure.

The condenser fan located on the condenser and is activated, **as required** , by the Trinary

switch, loca ted on the Receiver/Dryer Assembly. During system operation, the Trinary switch

turns the condenser fans on once the refrigerant pressure rises to 2 41 (+/

- 22) psig ( 16 .6 (+/

- 1.5) bar) and turns the fans off when the refrigerant pressure decreases below 19 9 (+/

- 22)

psig ( 13

. 7 (+/

- 1.5) bar).SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 18 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Evaporator/Blower Assembly

The evaporator/blower assembly removes heat and moisture from air entering the aircraft

cabin. The unit is located in the empennage, aft of the main baggage compartment.

The Diamond Model DA

- 40 utilizes a plate and fin type evaporator coil. The plates are

hydraulically expanded into the fins to ensure good thermal conductivity. The coil assembly is

then coated to help prevent microbe growth and associated unpleasant odors. Replacement

evaporator/blower assemblies from the Parts Department will be ship ped as an assembly with

all applicable components such as the coil, housing, blower, coil temperature sensor and

expansion valve as one unit.

Low

- pressure liquid refrigerant from the expansion valve enters the evaporator. Because of

the reduced pressur e, the refrigerant boils into a vapor. The boiling refrigerant absorbs the

heat from the incoming air as it changes from a liquid to a vapor.

Expansion Valve

The expansion valve is located at the inlet to the evaporator/blower assembly. It is the

con nection point between the high

- pressure and low

- pressure side of the refrigeration system.

The expansion valve determines the flow rate of the refrigerant and provides a pressure drop,

reducing pressure on the liquid refrigerant before it enters the evapor ator.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 19 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Receiver/Dryer with

Trinary Switch

The Receiver/Dryer acts as a storage and filter unit for refrigerant and oil.

The Trinary switch serves two functions. One portion of the switch cycles the condenser fans

once the refrigerant pressure reache s 2 41 (+/

- 22) psig (16 .6 (+/

- 1.5) bar) and turns off the

fans at 19 9 (+/

- 22) psig (13 .7 (+/

- 1.5) bar). The other portion of the switch protects the

system from damage due to low refrigerant or excessive pressures by turning off the

compressor. Power to the compressor is interrupted once the refrigerant pressure drops

below 29 (+/

- 3) psig (2 (+/

- 0.2) bar) or exceeds 397 (+/

- 29) psig (27 (+/

- 2) bar) at the Trinary

switch. The Trinary switch automatically resets once pressures are restored to a safe level

.

The Trinary Switch is considered an LRU (Line Replaceable Unit) which allows it to be

replaced independently of the receiver/dryer assembly. The switch is sealed with an o

- ring on

the receiver/dryer and releases a Schrader valve upon removal thus allow ing replacement

without evacuating the refrigeration system.

The tightening torque for the trinary switch is 7 Ft

- lbs.

The receiver/dryer assembly is located under the rear seat of the aircraft.

Cabin Temperature Sensor

Cabin temperature is determined by comparing the inside temperature of the aircraft with the

desired cabin temperature setting. The temperature is regulated by cycling the compressor

and regulating the evaporator blower speed during cooling requirements.

The temperature sensor assembly contains a calibrated thermistor and fan used to draw cabin

air over the thermistor. The sensor assembly is located in the pilot’s side panel and provides

information directly to the ACCS ECU. If the sensor fails, a faul t will be noted in the ACCS and

manual air conditioning temperature control will be required by pilot input into the Control

Head.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 20 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Air Temperature Sensor

The air temperature sensor is located adjacent to the condenser, outside of the aircraft. Th is

temperature sensor continuously measures the temperature of the air entering the condenser

compartment. The sensor is used as a basic variable for temperature regulation.

ECU

Use caution when handling this component to avoid the discharge of st atic electricity.

The Electronic Control Unit (ECU) is located adjacent to the evaporator/blower assembly, aft of

the main baggage compartment. It receives signals from the ACCS Control Head and

supplies outputs accordingly. The ECU is the actual contro l unit of the system. All of the

system’s electronic circuitry is incorporated in this unit and digital processing logic is used. GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 21 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Blower Control Unit

The Blower Control Unit is located adjacent to the evaporator/blower assembly, aft of the main

baggage compartment. It regulates the evaporator blower speed based on the signal received

from the ECU. The blower speed is continually variable during autom atic operation and there

are 11 blower speeds available during manual operation. Speed control is provided by this

unit through the use of pulse width modulation circuitry. Blower output is reported back to the

Control Head as a percentage of drive from 0 to 100 percent, inclusive.

CONTROL HEAD

The Control Head receives inputs from the pilot and the ACCS components. It is considered

the pilot’s interface for the air conditioning system. Fault codes can be displayed on the LCD

screen for troubl eshooting.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 22 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 4.1 AIR DISTRIBUTION

4.1.1 Air Conditioning

When air conditioned air is required, the evaporator blower is actuated and air is

distributed through t wo ceiling vents above the front seats and three gasper vents

above and aft of the rear seats.

4.1.2 Heat

Not applicable to the DA

- 40

4.1.3 Defog

Not applicable to the DA

- 40SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 23 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 

### 5.0 SYSTEM EVACUATION AND CHARGING PROCEDURE

ONLY R

- 134a refrigerant is to be used. Other refrigerants will damage the system.

Overcharging of the system will result in reduced performance, reduced service life and/or

damage to the system components.

5.1 SPECIAL TOOLS AND EQUIPMENT

The following tools and equipment is required to charge the refrigerant system.

**•** Synthetic POE (ester) Refrigerant Oil, 2 fluid oz.

**•** Charging Station/Reclaim/Recycle Cart (R

- 134a) ~OR~ Air

- Conditioner Vacuum

Pump, R

- 134a Manifo ld Gauges and Weight Scale (0

- 50 pounds), accurate to 1 oz.

**•** Small Hand Tools and Socket Set

**•** R

- 134a Refrigerant, at least 24 oz. by weight

**•** Thermometer, 0

- 150°F

**•** Inspecti on Mirror, Adjustable

**•** Service Light or Flashlight

**•** Hand Shop Towels

**•** Electronic Refrigerant Leak Detector

**•** Gloves and eye protection

5.2 INITIAL REFRIGERANT EVACUATION PROCEDURE

5.2.1 Air Conditioner Oil

The compressor as received from the supplier is pre

- charged with air co nditioner oil. Two fluid

ounces of synthetic POE (ester) refrigerant oil shall be added to the receiver/dryer at the time

of initial installation BEFORE charging the system.

5.2.2 System Evacuation Procedure

WARNING

Review warnings and cautions listed in above sections 2.0 and 3.0 before

evacuating refrigeration system.

Prior to charging the system with R

- 134a refrigerant, the two fluid ounces of synthetic POE

ester) refrigerant oil must have been added. The system must then be evacuated for a

MINIMUM of 45 mi nutes to remove air and moisture which if not removed can damage the

system or cause the system to perform incorrectly.

5.2.3 Remove service port caps from aircraft system. They are located on the evaporator

assembly. The service ports are accessed fro m inside the aircraft’s baggage

compartment once the evaporator trim cover has been removed. GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 24 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 5.2.4 Confirm that both valves of the charging manifold are close and c onnect charging

manifold to service ports.

5.2.5 Connect manifold charging (yellow) hose to vacuum pump. Turn ON pump.

5.2.6 Open both valves of charging manifold gauge set.

5.2.7 Open both valves of charging hose quick connect fittings.

5.2.8 Observe charging manifold gauges to verify vacuum.

5.2.9 Evacuate system for 45 minutes . Fina l system vacuum should be 25 to 29 inches of

mercury. If system servicing is being done at a field elevation greater than 4000 feet

Above Sea Level, then final system vacuum should be 21 to 25 inches of mercury.

5.2.10 Close charging manifold valves. Turn OFF vacuum pump. Observe the vacuum level

for 5 minutes as a leak check of the refrigeration system. If vacuum is not maintained,

locate and repair the refrigeration system leak before continuing.

5.2.11 Disconnect manifold service hose from vacuum pump. System is ready for refrigerant

charging.

NOTE

Any change in vacuum pressure, or failure to achieve a system pressure of

25 to 29 in. hg. vacuum indicates the presence of a plumbing leak. Locate

and fix all leaks

5.3 REFRIGERANT CHARGING PROCEDU RE

There are various methods of charging refrigerant into the air

- conditioning system. These

include using refrigerant recovery/recycle unit. (Refer to the manufacturer’s instruction

manual.) Use of manif old pressure gauges, R

- 134a cylinder and weight scale is outlined in

this section.

NOTE

It is necessary to run the engine of the aircraft to finalize the complete

refrigerant charge when a Charging/Reclaim/Recycle Station is NOT used.

NOTE

If refrigerant Charging/Reclaim/Recycle Station is used, refer to applicable

equipment manufacturer instructions for VCS servicing.

5.3.1 Verify leak

- check and evacuation of the system is completed.

5.3.2 Connect yellow manifold charging hose to R

- 134a cylin der. Open valve.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 25 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 5.3.3 Very slightly open charge hose fitting at manifold gauge set and vent air from hose until

refrigerant is evidently escaping.

5.3.4 Place refrigerant bottle on 0

- 50 pound (0

- 25 kg) scale. Record weight.

5.3.5 Open both manifold gauge set valves. Add refrigerant to system until pressures

stabilize.

5.3.6 Close manifold valves and verify system pressure is 50 psig (3.4 bar) or greater.

NOTE

System’s pressure must be above 50 psig (3.4 bar) to close low pressure

cutoff switch. Otherwise compressor will not turn ON.

5.3.7 If necessary, warm the refrigerant bottle by immersion in warm water.

CAUTION

Do not use open flame to warm refrigerant bottle. Do not

heat bottle above 125 °F (51 ° C).

5.3.8 Move aircraft to run

- up area.

5.3.9 Start aircraft engine. Select “AUTO” on Automatic Climate Control head and set the

temperature to “55 ° F (13 ° C)”. Idle aircraft engine at 1200

- 1800 RPM.

CAUTION

Do NOT open high pressure (RED) valve on manifold gauge set.

5.3.10 With system operating, observe the system discharge and suction pressures.

5.3.11 With the R

- 134a cylinder connected to the charging hose, charging container shutoff

valve open and hose purged of air, slowly open the suction (BLUE) manifold valve

. The suction pressure will increase to 60

- 70 psig (4.1

- 4.8 bar).

NOTE

As refrigerant enters the compressor a slight increase

in compressor discharge pressure will be noticed.

5.3.12 Continue to add refrigerant until 24oz. (680 grams), by weight of refrigerant have been

added.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 26 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 5.3.13 Close suction manifold valve (BLUE) and let system operate for 5 to 10 minutes to

evaluate performance.

NOTE

Letting the system stabilize is required since the expansion

valve is trying to stabilize the system pr essure.

NOTE

System charge weight is 24 ounces (680 grams) of R

- 134a.

5.3.14 With the system fully charged and operating, observe the suction and discharge

pressures. Typical values at various ambient temperatures, with hot cabins, are

shown bellow. Th ese values vary according to environmental factors and are to be

used as a reference for further troubleshooting, not as a sole source.

NOTE

The pressure values listed in this document vary according

to environmental factors and are to be used only as a

gu ideline for further troubleshooting, not as a sole source.

Ambient Temperature 21 ° C

(70 ° F) 27 ° C

(80 ° F) 32 ° C

(90 ° F) 38 ° C

(100 ° F) 43 ° C

(110 ° F)

Air Temperature At

Evaporator Outlet 7

- 9 ° C

(45

- 48 ° F) 8

- 13 ° C

(46

- 55 ° F) 11

- 16 ° C

(52

- 61 ° F) 14

- 20 ° C

(57

- 68 ° F) 17

- 25 ° C

(63

- 77 ° F)

Low Side Service Port

Pressure 18

psi

30 20

psi

35 22

psi

39 25

psi

43 26

psi

47

High Side Service Port

Pressure 150

psi

220 160

psi

235 220

psi

310 250

psi

320 280

psi

340

5.3.15 Allow system to operate for 10 minutes then shutdown.

NOTE

After shutdown, both suction and discharge pressures

will begin to equalize.

5.3.16 Close refrigerant container shutoff valve. Record the refrigerant container final weight

and calculate system refrigerant charge.

CHARGE (lb.) = W initial (lb.)

- W final (lb.)

5.3.17 Turn knob on suction and discharge charging hose quick coupler to closed position and

disconnect hoses from service ports.

5.3.18 Remove yellow charging hose from refrigerant container and store manifold gauge set.

5.3.19 Install service caps on fittings of air conditioning system.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 27 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 

### 6.0 MAINTENANCE AND REPAIR

6.1 100 HOUR/ANNUAL INSPECTION

Inspections shall consist of the compressor drive belt and pulleys, hoses and air ducting/vents.

100 HOUR/ANNUAL INSPECTION:

**•** The compressor drive belt shall be inspected for chafing, cracking, tension

and/or wear. Replacement is considered to be “on

- c ondition”.

**•** The compressor drive belt pulleys shall be inspected for security, alignment,

uniform wear appearance, tightness and rotational smoothness and freedom.

Replacement is considered to be “on

- condition”.

**•** The refrigerant hoses shall be inspected for chafing, kinking, leaks and security.

Leaks will manifest themselves as an “oily” spot most common around

connections. Replacement is considered to be “on

- condition”.

**•** The air ducting and vents shall be inspected for intake and outlet obstructions or

damage. Vent hoses shall be inspected for security and chafing.

**•** Inspect and clean the condenser of any foreign objects. Condenser can be

cleaned with a soft fiber brush and clean water. Blow dry with clean shop air. Do

not bend the condenser fins. Do NOT use caustic cleaners such as Simple

Green ®

**•** Ins pect the components of the VCS f or security

- no loose fasteners.

**•** Reference Table 1 below. With the aid of the approved aircraft maintenance

manual, conduct the following additional aircraft structural in spection

requirements for an airplane equipped with a vapor cycle system.

ANNUAL INSPECTION:

**•** Remove the pivot bolt and brackets and using the dye penetrant inspection

method inspect the forward and aft pivot bolt ears on the com pressor for cracks.

( it is not necessary to remove the refrigerant hoses for this inspection). F

F

Inspect ears for

cracks using dye

penetrant Pivot bolt and

brackets GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 28 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Supplementary Aircraft Structural Inspection Requirements with Vapor Cycle SystemSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 30 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 6.5 COM PRESSOR REMOVAL, INSTALLATON AND DRIVE BELT TENSIONING

NOTE: Read through all instructions below before proceeding with any maintenance

action associated with the removal and replacement of the compressor and tensioning

of the compressor drive belt.

NOTE: Whenever removing the lock nuts from the AN7 fasteners noted below, new

lock nuts shall be used as replacements.

6.5.1 COMPRESSOR REMOVAL

1. Gain access to the compressor as required. Reference the aircra ft maintenance

manual.

2. Recover / remov e the refrigerant from the vapor cycle system using a standard

industry R134a refrigerant recovery and service cart attached to the VCS service

fittings. Follow the recovery and service cart manufacturer’s instruc tions. Make note

of the amount of refrigera nt oil recovered.

3. Disconnect the Clutch Power Wire from the aircraft mating connector.

4. Disconnect the suction and discharge refrigerant hoses from the compressor. Cap

the hoses to avoid introducing contamination into the hoses. Cap the compressor

fittings to avoid losing any compressor oil.

5. Loosen the adjustment nut on the belt tensioning bracket to loosen the compressor

drive belt. Sl ip drive belt off of compressor pulley.

6. Verify if there is a shim located between the compressor forward ear and the main

compressor mount. Save shim in the event the same compressor is being

reinstalled. Loosen and remove all the AN7 hardware securing t he compressor to

the mounting brackets and carefully remove compressor. Discard all lock nuts.

Verify all washers are accounted for. GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 31 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Photograph of a Compressor Installation G

Refrigerant Hoses

Clutch Power Wire Belt Tension Adjustment NutSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 32 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Compressor Shim Location

6.5.2 COMPRESSOR INSTALLATION AND DRIVE BELT TENSIONING

NOTE: Read through all instructions below before proceeding with any maintenance

action associated with the installation of the compressor and tensioning of the

compressor drive belt.

NOTE: New locknuts shall be used on all AN7 Bolts , shown in the illustration below, to

secure the compressor to the compressor mounting brackets. Locknut part number is

NAS1291

- 7.

NOTE: Required f astener torque data is called out in the illustration below. The torque

published includes the friction drag torque of t he locknut as defined in AC43.13

- 1 B . Do

not add additional torque to the published requirement.

N OTE : If new compressor is being installed, follow oil servicing instructions per section

6.9. In addition, add any oil removed back into the system when th e refrigerant was

recovered in section 6.5.1 G Belt

Tensioning

Bracket

Thin Washer,

if Installed Shim

Location, if

Installed

Forward

Compressor

EarSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 33 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G AN7 Bolt Locations

Compressor Attachment Hardware Torque Data

1. If a different compressor is being installed, perform this step. If the same

compressor is being installed this step is not required unless the shim

, if it was

installed from before

, is lost

. G AN7 Bolts

MS21045

- 6 Nut,

Torque to 20 ft

- lbs

NAS1291

- 7 Nut (4 places)

, Torque to 47 ft

- lbsSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 34 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Determine the required shim to be used between the compressor forward ear

and the main compressor mount. The maximum gap between the main

mount and the compressor ears shall be 0.004” or less. Measure the outside

distance of the compressor mount. Measur e the inside distance between the

compressor ears. Subtract the compressor mount measurement from the

compressor measurement. If the gap is 0.004” or less, no shimming is required.

If the gap is greater than 0.004”, then a shim from shim kit part number 1100245

shall be used to bring the gap to 0.004” or less.

Alternatively, the gap can be measured with feeler gages between the

compressor ear and main mount if the compressor is “pre

- installed” with the long

AN7 pivot bolt to facilitate gap measurement.

G ap Measurement for Shim GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 35 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Shim Location, if Needed

2. Ensure the belt tension adjustment nut is loose on the stud. It is permissible to

lubricate the shank of the long AN7 bolt with a thin film of clear lubricating oil to

facilitate sliding the bolt through the main mount. Do not get oil on the bolt

threads. Assemble the compressor to the mount with the steel bracket s and

bolts and new NAS1291

- 7 nuts. Insure shim, if required per section 6.5.2 step 1,

is installed. Install bonding strap to the aft outboard compressor ear as shown in

the exploded view below. Hardware can be assembled loose to insure all

hardware fits acceptably. Verify washers are correctly located. G If shim is required, it

shall be installed at this

location onlySEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 36 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Compressor Installation Exploded View GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 37 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 3. Tighten and torque the three short AN7 bolts with new NAS1291

- 7 nuts to 47 ft

lbs. It is permissible to use a backup wrench on the nut and torque the bolt.

4. Relocate compressor drive belt over pulley and locate on the forward most

compressor pulley sheave. Verify drive belt is properly aligned.

5. Adjust belt tension by swinging the compressor out ward, away from the e ngine to

tension the compressor drive belt by using a 3/8” b reaker b ar or equivalent in the

square adjustment hole of the belt tensioning bracket as shown in illustration

below. G

Three Short AN7 BoltsSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 38 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Drive Belt Tensioning

Install belt tension gauge ( BT

- 33

- 73F or equivalent ) on the compressor drive belt

between the engine drive pulley (starter ring gear adapter belt drive sheave) and

the air conditioning compressor driven pulley.

Tighten the belt by moving the tensioning bracket away from the engine, using

the 3/8” b reaker b ar or equivalent, to produce a compressor drive belt tension of

50

- 70 Lbs, determined by one of the following methods:

A. Use a direct reading belt tension gauge such as the Burroughs Tool No. BT

33

- 73F

B. M easure belt deflection under a five pound load at th e center of the longest

belt span. Correct deflection is 0.3

- 0.4 inches.

With the correct tension on the drive belt, t ighten the adjustment nut on belt

tensioning bracket to a torque value of 20 ft

- lbs and **remove** 3/8” b reaker b ar or

equivalent tool from front adjustment bracket square drive hole after tightening

the adjustment nut

.

Confirm that the belt tension is 50

- 70 l bs. by using one of the methods listed

above. If belt tension is not within the above tolerance, loosen th e adjustment nut

on the belt tensioning bracket and readjust the tension. **Remove** 3/8” b reaker

b ar or equivalent from the adjustment bracket.

N OTE : Belt Part Number is Gates Green Stripe XL drive belt No. 9425

. G Adjustment

Nut on Belt

Tensioning

Bracket

3/8 Square Drive

Belt Tensioning

Adjuster HoleSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 39 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G NOTE: A longer than specified or stretched drive belt will swing the compressor

out too far into the cowling area resulting in the potential for interference between

the compressor and the cowling.

CAUTION

Do NOT pry between the compressor housing and the compressor mount.

Use of 3/8” b reaker b ar or equivalent is REQUIRED for compressor belt

tensioning to prevent compressor damage.

CAUTION

3/8” b reaker b ar or equivalent must be removed after compressor belt

tensioning procedure is complete. Verify the tool is removed prior to

engine st art.

CAUTION

Do NOT over tighten belt. After approximately 5 hours of initial operation,

it is recommended that the belt tension be rechecked and adjust ed if

required to maintain correct belt tension.

6. Check the gap between the drive belt tension bracket and the forward

compressor mounting ear. If gap exists, retract the long AN7 bolt just enough to

insert only one (1) part number AN960

- 716L thin flat washer into the gap. See

illustration below. G

If gap exist, locate

only one (1) AN960

-

716L flat washer in

this position.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 40 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G Location for Thin AN 960

- 716L Flat Washer

7. Verify shim is installed, if required, between the compressor forward ear and the

main mount as established in section 6.5.2 step 1. Torque the final long AN7

bolt with a new NAS1291

- 7 nut to 47 ft

- lbs. It is permissible to use a backup

wrench on the nut and torque the bolt through the bolt head. Verify compressor

security.

8. Connect the clutch power lead to the applicable aircraft wire harness terminal

provided.

9. Remove the caps from the compressor fittings. Remove the caps from the

mating suction and discharge hoses. Install new o

- rings on the hose fittings.

Large suction hose uses a No. 10 o

- ring, P/N 0440850 . The smaller discharge

hose uses a No. 8 o

- ring P/N 0440849

.

Mate hoses to the fittings. Always use a backup wrench on the compressor

when torquing these hose fittings. Torque the No. 8 fitting to 15 to 20 ft

- lbs.

Torque No. 10 fitting to 21 to 27 ft

- lbs.

10. Reinstall aircraft parts and components wh ich were removed to conduct this

maintenance. Refer e nce the applicable aircraft maintenance manual instructions.

11. R efer to sections 6.7 and 6.8 for sy s tem evacuation and re

- charging following the

compressor replacement.

6.6 LEAK TESTING REFRIGERANT

WARNING

Review warnings and cautions listed in above sections 2.0 and 3.0

before leak testing refrigeration system.

If air conditioning system is not cooling properly, determine if system is fully charged. Refer to

Pressure and Performance Diagnosis chart, section 7.8. If the system is empty evacuate and

charge the system with 0.6lbs. (10oz. or 296 grams) of R

- 134a re frigerant. Refer to section

5.3, “Refrigerant Charging Procedure” for instructions. To detect a leak in the system, perform

the following procedures. GSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 41 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G  Operate the air conditioning system until operating temperature and pressures are

achieved based on the existing refrigerant charge. This is done by operating the engine

with the air conditioning on for 5 to 10 minutes.

 Position the aircraft in a wind free work area. The absence of wind will aid in the

detection of small leaks.

 Remove engine cowling, conde nser access panel , if required , the receiver/dryer access

panel and the evaporator housing cover prior to leak test to dissipate any accumulated

refrigerant. Aircraft cabin doors and baggage compartment door must be left open

during test operation.

 With t he engine **NOT RUNNING** , use an R

- 134a Electronic Leak Detector and search

for leaks. Move probe slowly along the bottom side of lines and fittings, because R

134a is heavier than air. Fittings, lines, or components that appear to be oily usually

indicate a refrigerant leak.

 Inspect the evaporator core for leaks

o With the engine **NOT RUNNING** , set the Automatic Climate Control temperature

to “55 ° F (13 ° C)”, select “LO” for the blower speed and check for le aks in the air

conditioning outlet vents.

o Inspect the evaporator drain tube outlet for the presence of refrigerant oil.

6.7 EVACUATING REFRIGERANT SYSTEM NOTES

Refer to section 5.2 for complete sys tem evacuation procedures.

WARNING

Review warnings and cautions listed in above sections 2.0 and 3.0

before evacuating refrigeration system.

If the air conditioning system has been open to the atmosphere, it must be evacuated before

the system can be charged. Moisture and air mixed with refrigerant will raise the compressor

head pressure above acceptable operating levels, reduce system performance and potentially

cause internal system corrosion resulting in component damage. Moisture will also boil a t near

room temperature when exposed to sufficient vacuum. To evacuate the refrigerant system

use the following procedure.

 Connect a suitable charging station and manifold gauge set to the aircraft.

 Open the low and high side valves and start the vacuum pump. When suction gauge

reads 26in. Hg (660 mm Hg) vacuum or greater, close all valves and turn off vacuum

pump. If system fails to reach specified vacuum, the system has a leak that must be

corrected. If system maintains the specified vacuum for 30 mi nutes, start the vacuum

pump then open the suction and discharge valves to evacuate the system for an

additional 40 minutes, minimum.

 Close all valves. Turn off and disconnect the vacuum pump.

The system is now ready to be charged with R

- 134a refrigerant . Refer to section 5.3.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 42 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G CAUTION

Do NOT overcharge the air conditioning system.

This will cause excessive compressor head pressure, loss of cooling, noise

and system failure.

6.8 CHARGING REFRIGERANT SYSTEM NOTES

Refer to section 5.3 for complete charging procedure.

WARNING

Review warnings and cautions listed in above sections 2.0 and 3.0 before

charging refrigeration system.

R

- 134a refrigerant is a hydro fluorocarbon (HFC) that does not contain chl orine. An R

- 134a

refrigerant Recovery/Recycling Station that meets SAE standard J2210 must be used to

discharge the refrigerant system. Refer to the operating instructions provided with the

equipment for proper operation.

The **REQUIRED** method of charging is to completely discharge and evacuate the system and

recharge using a Recovery/Recycling Station approved for R

- 134a refrigerant. Refer to the

operating instructions provided with the equipment for proper operation.

After the air conditioning system h as been tested for leaks and evacuated, a refrigerant charge

can be injected into the system. The system capacity is 24oz. (680 grams), by weight

.

CAUTION

Do NOT Overcharge System

NOTE

System charge weight is 24 ounces (680 grams) of R

- 134a.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 43 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 6.9 REFRIGERANT OIL

It is important to have the correct amount of oil in the air conditioning system. This will ensure

proper lubrication of the compressor. Too little oil will result in damage to the compressor.

Too much oil will reduce the cooling capacity of the system.

The oil used in the compressor is a synthetic ester oil: Ester RL

- 500S. This is a wax

- free

refrigerant oil. Only refrigerant oil of the same type should be used to service the system. Do

NOT use any other oil! The oil container should be kept tightly capped until it is ready for use

and then capped after use to prevent contamination. Refrigerant oil will quickly absorb any

moisture it comes in contact with.

It will not be necessary to check the oil level in the compressor or to add oil unless there has

been an oil loss. This may be due to a rupture or leak from a line, shaft seal, evaporator, or

condenser. Oil loss at a leak point will be evident by the presence of a wet shiny surface

around the l eak.

Add an additional 1 fluid oz. (29 cc) of compressor oil to the system when a receiver

dryer, condenser or evaporator core is replaced. This oil can be added into the

component being replaced.

6.9.1 Oil Level: When an air conditioning system is ass embled at the factory all components

except the compressor are refrigerant oil free. After the system has been charged and

operated, the oil in the compressor is dispersed through the system. The evaporator,

condenser, receiver

- dryer, and compressor will retain a significant amount of oil.

When a component is replaced, the specified amount of refrigerant oil must be added.

When the compressor is replaced, the new compressor is factory filled with the correct

amount of oil. Drain all the oil from the n ew compressor. Add back into the new

compressor the same amount of **new** oil that was drained out of the old compressor.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 44 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 6.10 PRESSURE AND PERFORMANCE DIAGNOSIS

Condition Possible Cause Correction

Low side and high side pressure 1. System refrigerant is low 1. Discharge, evacuate, leak test and

low charge system

Low side pressure high and high 1. Internal leak in compressor 1. Replace compressor

side pressure low 2. Drive belt slipping 2. Tension or replace belt

Low side and high side pressure 1. Condenser fins obstructed 1. Clean condenser fins

High 2. Air in refrigeration system 2. Evacuate, leak test and charge

system

3. Condenser fans inoperative 3. Troubleshoot condenser fans

4. Refrigerant system overcharged 4. Recover refrigerant and recharge

Low side pressure low and high 1. Restriction in refrigerant hose 1. Check hoses for kinks and

side pressure high 2. Restriction in receiver

- dryer replace if necessary

3. Restric tion in condenser 2. Replace receiver

- dryer

4. Expansion valve is defective 3. Replace condenser

4. Replace expansion valve

Low side and high side pressures 1. Check for correct cooling at 1. If temperature is correct check

normal (inadequate cooling ) evaporator assembly outlet for obstruction or leak in cabin

ducting

Compressor noise 1. Internal compressor damage 1. Replace compressor

2. Refrigerant system overcharged 2. Recover refrigerant and recharge

3. Loose compressor mounting 3. Tigh ten compressor mounting bolts

4. Loose or worn compressor drive to correct torque values

belt 4. Tension or replace belt

Excessive vibration 1. Incorrect belt tension 1. Tension or replace belt

2. Compressor loose 2. Tighten compressor mounting b olts

to correct torque values

3. Refrigerant system overcharged 3. Recover refrigerant and recharge

4. Drive or idler pulley worn 4. Replace defective pulley

Condensation leaking inside 1. Evaporator drain plugged or 1. Clean drain hose and check for

Aircraft kinked proper installation

Frozen evaporator coil 1. Faulty evap temp sensor 1. Replace evap temp sensor

2. Obstructed evaporator coil 2. Removed obstruction

NOTE

The pressure values listed in this docu ment vary according

to environmental factors and are to be used as a guideline

for further troubleshooting, not as a sole source.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 45 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G NORMAL 60

100 20

B 40 D F 80

E A-Normal System

B-Low Refrigerant Charge

C-Refrigerant overcharge or

Receiver/Dryer restricted

D-Expansion Valve closed

E-Expansion Valve stuck open

F-Inadequate Compressor

performance

NOTE: Chart should be

considered as an aid to

diagnostics not a single source.

300

High-Pressure 200 A C Ambient Temperature

70°F (21°C)

A-Normal System

B-Low Refrigerant Charge

C-Refrigerant overcharge or

Receiver/Dryer restricted

D-Expansion Valve closed

E-Expansion Valve stuck open

F-Inadequate Compressor

performance

NOTE: Chart should be

considered as an aid to

diagnostics not a single source. 60

100 200

High-Pressure 20 NORMAL B A D 40 F

300 C 80

E Low-Pressure Ambient Temperature

90°F (32°C)SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 46 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G High-Pressure 100 200 A

20 D

B NORMAL F

40 60

300 A-Normal System

B-Low Refrigerant Charge

C-Refrigerant overcharge or

Receiver/Dryer restricted

D-Expansion Valve closed

E-Expansion Valve stuck open

F-Inadequate Compressor

performance

NOTE: Chart should be

considered as an aid to

diagnostics not a single source. C Ambient Temperature

100°F (38°C) Low-Pressure

80

ESEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 47 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 

### 7.0 AUTOMATIC CLIMATE CONTROL SYSTEM

7.1 OVERVIEW

The Automatic Climate Control System (ACCS) for the Diamond Aircraft Model DA

- 40 is a fully

automatic air conditioning system with manual air conditioning operation capabilities. The

ACCS does NOT include operation of the defog and heat system. The defog and heat system

are controlled by the existing aircraft environmental controls.

The pilot may choose between air conditioning manual operation and fully automatic operation

where only the desired cooling temperature need be selected.

In manual or automa tic operation, the system offers 11 choices for air conditioning blower

speed by utilizing pulse width modulation control circuitry.

The button activates the compressor mode. When the compressor mode is “On” the

button is illuminated (white background). In the “On” mode, the compressor is available if the

ACCS determines that its operation is required. Pressing the button “toggles” the compressor

mode On and Off.

NOTE

When the compressor “on” mode is activated, as indicated by the illuminated (white)

button, it does **not** indicate that the compressor is operating, only that it is available for

use by the ACCS if required.

The ACCS has self

- diagnostic capabilities which can be displayed on the screen of the Control

Head.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 48 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 7.1.1 Control head functionsSEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 49 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 7.1.2 Configure Display Temperature Scale

The pilot may select a Temperature Display Scale of either Fahrenheit or Centigrade. T o

configure the display temperature scale, turn on the Automatic Climate Control System and

press the Messages button to access the Messages Screen. While viewing the Messages

Screen, press the “Configure” button at the top of the display to access the Co nfiguration

Screen. Press the button adjacent to the desired temperature display scale selection. Press

“Exit” to return to the normal display mode.

7.2 DIAGNOSTICS

7.2.1 To display the Diagnostics Fault Codes, turn on the Automatic Climate Control System

and press the Messages button to access the Messages Screen. The Control Head

display will list any active fault codes or the words “No Messages” if there are no active

faults to report. Refer to “Maintenance and Repair”, section 6.0 for additional

information. Press here

to access the

Messages Screen. Press here

to access the

Configuration Screen

Press here to select

desired Temperature

Display Scale.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 50 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 7.2.2 Fault Display Codes:

Fault

Code Information Correction

E00 No Messages

-

E01 Cabin Temp Sensor Out of Range Check cabin temp sensor wiring and sensor for correct

operation. Refer to temperature/resistance graph, section

7.2.3

E02 Air Temp Sensor Out of Range Check air temp sensor wiring and sensor for correct

operation. Refer to temperature/resistance graph, section

7.2. 4

E03 Evap Temp Sensor Out of Range Check evaporator coil temp sensor wiring and sensor for

correct operation. Refer to temperature/resistance graph,

section 7.2.5 Press here to access

the Messages

Screen. Press here to access

the Diagnostics

Information Screen

(Refer to next Section

for details).SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 51 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 7.2.3 Advanced Diagnostics

The Advanced Diagnostics display mode is activated by pressing a hidden button

located at the bottom left corner of the Messages Screen (Refer to section 7.2.1).

When active, the Advanced Diagnostics screen will display additional system status

information including:

“Cabin Temp” Cabin Temperature Sensor temperature r eading

“Evap Temp” Evaporator Coil Temperature Sensor temperature reading

“AC Mode” Indicates whether system is in Heating or Cooling mode

“Compressor” VCS compressor state (ON or OFF)

“Fan Level” Blower Speed

- Evaporator or Heater/Defog (percentage of m ax)

“Firmware” ECU Module Firmware Version

Press the “EXIT” button to return to the Messages Screen.SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 52 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 7.2.4 Cabin Temperature Sensor Resistance vs. Temperature Curve

Resistance

KΩ

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70

10 20 30 40 50 60 70 80 90 100 110 120

Temperature °F

CABIN TEMPERATURE SENSOR

°F °C

10

- 12.2

20

- 6.7

30

- 1.1

40 4.4

50 10.0

60 15.6

70 21.1

80 26.7

90 32.2

100 37.8

110 43.3SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 53 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 7.2.5 Air Temperature Sensor Resistance vs. Temperature Curve

Resistance

KΩ

900 910 920 930 940 950 960 970 980 990 1000 1010 1020 1030 1040 1050 1060 1070 1080 1090 1100 1110 1120 1130 1140 1150 1160 1170 1180 1190 1200

0 10 20 30 40 50 60 70 80 90 100 110

Temperature °F

AIR TEMPERATURE SENSOR

°F °C

10

- 12.2

20

- 6.7

30

- 1.1

40 4.4

50 10.0

60 15.6

70 21.1

80 26.7

90 32.2

100 37.8

110 43.3SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 54 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G 7.2.6 Evaporator Coil Temperature Sensor Resistance vs. Temperature Curve

Resistance

KΩ

900 910 920 930 940 950 960 970 980 990 1000 1010 1020 1030 1040 1050 1060 1070 1080 1090 1100 1110 1120 1130 1140 1150 1160 1170 1180 1190 1200

0 10 20 30 40 50 60 70 80 90 100 110

Temperature °F

EVAPORATOR COIL TEMPERATURE SENSOR

°F °C

10

- 12.2

20

- 6.7

30

- 1.1

40 4.4

50 10.0

60 15.6

70 21.1

80 26.7

90 32.2

100 37.8

110 43.3SEAMECH INTERNATIONAL, INC. R

- 134a Air Conditioning System

Diamond Aircraft DA

- 40 Instructions for Continued Airworthiness

SEAMECH INT’L, INC. PAGE 55 OF 55 VCS AIR COND. SERVICE

Seamech Doc: ASI

- 772216A Rev G APPENDIX A

DICTIONARY OF TERMS

ACCS Automatic Climate Control System

AUTO Automatic mode “on” when indicator light is illuminated

Compressor Mode is “on” (compressor is available) when button is illuminated

ECS Environmental Control System

- Air/Ventilation System

ECU Electronic Control Unit

ATS Air Temperature Sensor

R

- 134a Refrigerant, CFC

- Free

- used in the VCS

VCS Vapor Cycle System

- A sealed mechanical refrigeration (air

- conditioning) system

used to lower the temperature of the air in an aircraft cabin.