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 Chapter 8 Electrical Aspects of a Housing 

 Inspection

I. Definitions

II. Flow of Electric Current

III. Electric Service Entrance

IV. Grounding

V. Two- or Three-Wire Electric Services

VI. Residential Wiring Adequacy

VII. Wire Size and Types

VIII. Electric Service Panel

IX. Overcurrent Devices

X. Electric Circuits

XI. Common Electrical Violations

XII. Steps Involved in Actual Inspection

XIII. Wattage Consumption of Electrical Appliances

XIV. Motor Currents

There are two basic codes concerned with residential wiring that are of importance to the housing inspector. The first is the local 

electrical code. The purpose of this code is to safeguard persons and buildings and their contents from hazards arising from the

use of electricity for light, heat, and power. The electrical code contains basic minimum provisions considered necessary for safety. 

Compliance with this code and proper maintenance will result in an installation essentially free from hazard but not necessarily

efficient, convenient, or adequate for good service or future expansion.

The majority of local electrical codes are modeled after the National Electrical Code, published by the National Fire Prevention

Association. Further reference to the Code in the remainder of this chapter will indicate the National Electrical Code, 1975 Edition. 

(1)

Just because an electrical installation was safe and adequate under the provisions of the electrical code at the time of installation 

does not indicate that the system is safe and adequate for use today. Hazards often occur because of overloading of wiring 

systems by methods or usage not in conformity with the code. This occurs because initial wiring did not provide for increases in

the use of electricity. For this reason it is recommended that the initial installation be adequate and that reasonable provisions for 

system changes be made as may be required for future increase in the use of electricity.

The other code that contains electrical provisions is the local housing code. It establishes minimum standards for artificial and 

natural lighting and ventilation, specifies the minimum number of electric outlets and lighting fixtures per room, and prohibits

temporary wiring except under certain circumstances. In addition, the housing code usually requires that all components of the 

electrical system be installed and maintained in a safe condition so as to prevent fire or electric shock.

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This chapter contains electrical terms and major features of a residential wiring system that should be familiar to the housing 

inspector. It also contains a review of the steps involved in the electrical inspection, as well as commonly found conditions.

I. Definitions

A Electricity - is energy that can be used to run household appliances; it can produce light and heat, shocks and numerous other 

effects.

B Current - the flow of electricity through a circuit.

1 Alternating current is an electrical current that reverses its direction of flow at regular intervals: For example, it would 

alternate 60 times every second in a 60-cycle system. This type of power is commonly found in homes.

2 Direct current is an electric current flowing in one direction. This type of current is not commonly found in today's homes.

C Ampere - the unit used in measuring intensity of flow of electricity. Symbol for it is "I."

D Volt - the unit for measuring electrical pressure or force, which is known as electromotive force. Symbol for it is "E."

E Watt - is the unit of electric power. Volts X Amperes = Watts.

F Circuit - the flow of electricity through two or more wires from the supply source to one or more outlets and back to the source.

G Circuit Breaker - a safety device used to break the flow of electricity by opening the circuit automatically in the event of 

overloading or used to open or close it manually.

H Short Circuit-is a break in the flow of electricity through a circuit due to the load caused by improper connection between hot 

and neutral wires (have the electrical inspector check for its location).

I Conductor - any substance capable of conveying an electric current. In the home, copper wire is usually used.

1 Bare conductor is one with no insulation or covering.

2 Covered conductor is one covered with one Or more layers of insulation.

J Fuse - a safety device that cuts off the flow of electricity when the current flowing through the fuse exceeds its rated capacity.

K Ground - to connect with the earth-as to ground an electric wire directly to the earth or indirectly through a water pipe or some 

other conductor. Usually a green-colored wire is used for grounding the whole electrical system to the earth. A white wire is then 

usually used to ground individual electrical components of the whole system.

L Conductor Gauge - a numerical system used to label electric conductor sizes, given in American Wire Gauge (AWG). The larger 

the AWG number the smaller the wire size.

M Hot Wires - those that carry the electric current or Power to the load; they are usually black or red.

N Service - the conductor and equipment for delivering energy from the electricity supply system to the wiring system of the 

premises.

O Service Drop - the overhead service connectors from the last pole or other aerial support to and including the splices, if any, 

connecting to the service entrance conductors at the building or other structure.
P Insulator - a material that will not permit the passage of electricity.

Q Neutral Wire - the third wire in a three-wire distribution circuit; it is usually white or light gray and is connected to the ground.

R Service Panel - main panel or cabinet through which electricity is brought to building and distributed. It contains the main 

disconnect switch and fuses or circuit breakers.

S Voltage Drop - a voltage loss when wires carry current. The longer the cord the greater the voltage drop.

II. Flow of Electric Current

Electricity is usually generated by a generator that converts mechanical energy into electrical energy. The electricity is then run 

through a transformer where voltage is increased to several hundred thousand volts and in some instances to a million or more 

volts. This high voltage is necessary in order to increase the efficiency of power transmission over long distances.

This high-transmission voltage is then stepped down (reduced) to normal 115/230-volt household current by a transformer located 

near the point of use (residence). The electricity is then transmitted to the house by a series of wires called a "service drop." In 

areas where the electric wiring is underground, the wires leading to the building are buried in the ground.

In order for electric current to flow, it must travel from a higher to a lower potential voltage. In an electrical system the hot wires 

(black or red) are at a higher potential than the neutral or ground wire (white or green). Therefore, current will flow between the 

hot wires and the neutral or ground wires.

The voltage is a measure of the force at which electricity is delivered. It is similar to pressure in a water supply system.

Current is measured in amperes and is the quantity of flow of electricity. It is similar to measuring water in gallons per second.

A watt is equal to volts times amperes. It is a measure of how much power is flowing. Electricity is sold in quantities of watt-hours.

The earth, by virtue of moisture contained within the soil, serves as a very effective conductor. Therefore, in power transmission, 

instead of having both the hot and neutral wires carried by the transmission poles, one lead of the generator is connected to the 

ground, which serves as a conductor (see Figure 8-1). Only hot wires are carried by the transmission towers. At the house, or 

point where the electricity is to be used, the circuit is completed by another connection to ground.

The electric power utility provides a ground somewhere in its local distribution system; therefore, there is a ground wire in addition 

to the hot wires within the service drop. In Figure 8-1 this ground can be seen at the power pole that contains the stepdown 

transformer.

In addition to the ground connection provided by the electric utility, every building is required to have an independent ground,

called a "system ground."

The system ground provides for limiting the voltage upon the circuit, which might otherwise occur through exposure to lighting, or 

for limiting the maximum potential to ground due to normal voltage. Therefore, the system ground's main purpose is to protect the 

electric system itself and offer limited protection to the user.

Figure 8-1. Electrical Power Flow

The system ground serves the same purpose as the power company's ground, however, being closer to the building it has a lower 

resistance.

The "equipment ground," which we will discuss later in this chapter, protects man from potential harm during the use of certain 

electrical equipment.
The system ground should be a continuous wire of low resistance and of sufficient size to conduct current safely from lightning and 

overloads.

III. Electric Service Entrance

A Service Drop

The "Entrance Head" (see Figure 8-2) should be attached to the building at least 10 feet above ground, to prevent accidental 

contact by people. The conductor should clear all roofs by at least 8 feet and residential driveways by 12 feet. For public streets, 

alleys, roads, and driveways on other than residential property the clearance must be 18 feet.

The wires or conductor should be of sufficient size to carry the load and not smaller than No. 8 copper or equivalent.

Figure 8-2. Entrance Head

For connecting wire from the entrance head to the service drop wires, the National Electrical Code requires that the service 

entrance conductors be installed either (I) below the level of the service head, or (2) below the termination of the service entrance 

cable sheath. Drip loops must be formed on individual conductors. This will prevent water from entering the electric service 

system.

The wires that form "entrance cable" should extend 36 inches from the entrance head, to provide a sufficient length to connect 

service drop wires to the building with insulators (see Figure 8-2).

The entrance cable may be a special type of armored outdoor type of wire or it may be enclosed in a conduit. The electric power 

meter may be located either within or outside the building. In either instance, the meter must be located before the main power 

disconnect.

Figure 8-3 shows an armored cable service entrance. The armored cable is anchored to the building with metal straps spaced 

every 4 feet. The cable is run down the wall and through a hole drilled through the building. The cable is then connected to the

service panel, which should be located within 1 foot of where the cable enters the building.

The ground wire need not be insulated. This ground wire may be either solid or stranded copper, or a material with an equivalent

resistance.

Figure 8-3. Service Entrance, Armored Cable

Figure 8-4 shows the use of thin-wall conduit in a service entrance.

Figure 8-4. Service Entrance, Conduit Type

B Underground Service

When wires are run underground they must be protected from moisture and physical damage. The opening in the building 

foundation where the underground service enters the building must be moisture proof. Local codes should be referred to, 

concerning allowable materials for this type of service entrance.

C Electric Meter

The electric meter may be located inside or outside the building, as shown in Figure 8-3 or 8-4. The meter itself is weatherproof 

and is plugged into a weatherproof socket (see Figure 8-5). The electric power company furnishes the meter, the socket may or 

may not be furnished by the power company.
Figure 8-5. Electric Meter

IV. Grounding

The system ground consists of grounding the neutral incoming wire as well as the neutral wire of the branch circuits. The 

equipment ground consists of grounding the metal parts of the service entrance, such as the service switch, as well as the service 

entrance conduit, armor, or cable.

The usual ground connection is to a water pipe of the city water system. The connection should be made to the street side of the

cold water meter as shown in Figure 8-6.

Figure 8-6.View of a Typical Service Entrance

If the water meter is located near the street curb, then the ground connection should be made to the cold water pipe as close as

possible to where it enters the building.

It is not unusual for a water meter to be removed from a building for service. If the ground connection is made at a point in the 

water piping system on the building side of the water meter, the ground circuit will be broken upon removal of the meter. This 

broken ground circuit represents a shock hazard if both sides of the water meter connections should be touched simultaneously.

In some instances the connections between the water meter to pipes are electrically very poor. In this case, if the ground 

connection is made on the building side of the water meter, there may not be an effective ground.

In order to prevent the two aforementioned situations the code requires that an effective bonding shall be provided around any 

equipment that is likely to be disconnected for repairs or replacement. This is illustrated in Figure 8-7. The same jumper 

arrangement would be required for a water meter that is installed near the curb. In many installations the water meter mounting 

bracket is designed to serve as an electric jumper.

Figure 8-7. Water Meter Jumper

Often an amateur mechanic, in the process of doing a household repair, will disconnect the house ground. Therefore, the housing 

inspector should always check the house ground to see if it is properly connected.

Figure 8-8 shows a typical grounding scheme at the service box of a residence. In this figure, only the grounded neutral wires are 

shown. The neutral strap is an uninsulated metal strip that is riveted directly to the service box. The ground wires from the service 

entrance, branch circuits, and house ground are joined by this strip.

Figure 8-8. Typical Grounding Scheme at Entrance

When a city water supply is not available for grounding, a substitute must be made. The most common ground is a pipe or rod that

is driven into the ground a distance of at least 8 feet. If the pipe is made of steel or iron, it must be 3% inch in diameter and 

galvanized. A copper ground pipe of 34 inch diameter is sufficient.

The code requires that a ground rod be entirely independent of and kept at least 6 feet from any other ground of the type used for 

radio, telephone, or lightning rods.

V. Two- or Three-Wire Electric Services

One of the wires in every installation is grounded. This neutral wire is always white. The hot wires are usually black or red or some 

other color. but never white.

The potential difference or voltage between the hot wires and the ground or neutral of a normal residential electrical system is 115 

volts. Thus, where we have a two-wire installation (one hot and one neutral) only 11 5-volt Power is available (see Figure 8-9).
When three wires are installed (two hot and one neutral) either 115- or 230-volt power is available. In a three-wire system the 

voltage between the neutral and either of the hot wires is 115; between the two hot wires it is 230 volts.

Figure 8-9. Ground Connection

The major advantage of a three-wire system is that it permits the operation of heavy electrical equipment such as laundry dryers, 

cooking ranges, and air conditioners, the majority of which require 230-volt circuits. In addition, the three-wire system is split at 

the service panel into two 115-volt systems to supply power for small appliances and electric lights. The result is a doubling of the 

number of circuits, and possibly a corresponding increase in the number of branch circuits, with a reduction of the probability of 

fire caused by overloading electrical circuits.

VI. Residential Wiring Adequacy

The use of electricity in the home has risen sharply since the 1930's. Many home owners have failed to repair or improve their 

wiring to keep it safe and up to date. The National Electrical Code recommends that individual residences be provided with a 

minimum of 100-ampere three-wire service. This type service is sufficient in a one-family house or dwelling unit to provide safe

and adequate electric supply for the lighting, refrigerator, iron, and an 8,000-watt cooking range, plus other appliances requiring a 

total of up to 10,000 watts altogether.

Some homes have a 60-ampere, three-wire service. It is recommended that these homes be rewired for at least the minimum of 

100 amperes recommended in the National Code since they are safely capable of supplying current only for lighting and portable 

appliances such as a cooking range and regular dryer (4,500 watts), or an electric hot-water heater (2,500 watts) and cannot 

handle additional major appliances.

Other homes today have only a 30-ampere, 115-volt, two-wire service. This system can safely handle only a limited amount of 

lighting, a few minor appliances, and no major appliances. Therefore, this size service is substandard in terms of modern 

household needs for electricity. Furthermore, it constitutes a fire hazard and a threat to the safety of the home and the occupants.

VII. Wire Size and Types

A Wire Size

Electric power flows over wire. It flows with relative ease (little resistance) in some materials such as copper and with a substantial 

amount of resistance in iron. If iron wire were used it would have to be 10 times as large as copper wire.

Copper wire sizes are indicated by a number. No. 14 is most commonly used in residential branch circuits. No. 14 is the smallest

permitted by the Code for use in a branch circuit with a 15-ampere capacity. No. 16, 18, and 20 are progressively smaller than No. 

14 and are usually used for extension wires. As the number of the wire becomes smaller the size and current capacity of the wire

increases. No. 1 is the heaviest wire usually used in ordinary household wiring.

Wire of correct size must be used for two reasons: current capacity and voltage drop.

1. When current flows through a wire it creates heat. The greater the amount of flow, the greater the amount of heat 

generated. (Doubling the amperes without changing the wire size increases the amount of heat by four times.) The heat is 

electric energy that has been converted into heat energy by the resistance of the wire; the heat created by the coils in a 

toaster is an example. This heat developed in an electrical conductor is wasted, and thus the electric energy used to 

generate it is wasted. If the amount of heat generated by the flow of current through the wire becomes excessive, a fire may 

result. Therefore, the code sets the maximum permissible current that may flow through a certain type and size wire.

The following are examples of current capacities for copper wire of various sizes:

Size wire(AWG) #14 #12 #10 #8 

 

Max. capacity, 15 20 30 40 amperes
1. In addition to heat generation there will be a reduction in voltage as a result of attempting to force more current through a 

wire than it is capable of carrying. Certain appliances, such as induction-type electric motors, may be damaged if operated at 

too low a voltage.

B Wire Types

1. Wire markings - All wires must be marked to indicate the maximum working voltage, the proper type letter or letters for the 

type wire specified in the code, the manufacturer's name or trademark. and the AWG size or circular-mil area. 

2. Insulations used-There are a variety of wire types which can be used for a wide range of temperature and moisture 

conditions. The 1975 National Electrical Code should be consulted to determine the proper wire for specific conditions. 

C Types of Cable

1. Nonmetallic Sheathed Cable - This type of cable consists of wires wrapped in a paper layer, followed by another spiral layer 

of paper, and enclosed in a fabric braid, which is treated with moisture-resistant and fire-resistant compounds. Figure 8-10 

shows this type of cable, which often is marketed under the "Romex" name. This type of cable can be used only indoors and 

in permanently dry locations. 

2. Armored Cable - This type of cable is commonly known by the BX or Flexsteel trade names. Wires are wrapped in a tough 

paper and covered with a strong spiral flexible steel armor. This type of cable is shown in Figure 8-11 and may be used only 

in permanently dry indoor locations. Armored cable must be supported by a strap or staple every 6 feet and within 24 inches 

of every switch or junction box, except for concealed runs in old work where it is impossible to mount straps. 

3. Other Cable -Cables are also available with other outer coatings of metals such as copper, bronze, and aluminum for use in a 

variety of conditions.

D Flexible Cords

Flexible cords are used to connect lamps, appliances, and other devices to outlets. Each wire consists of many strands of fine wire 

for flexibility. Extension cords in AWG sizes 16 to 18 are usually fine for lamps and smaller appliances, if the cord is not too long. A 

commonly accepted standard limits their length to 8 feet of unspliced cord. This keeps the cords short enough to prevent the 

excessive voltage drops, minimizes the possibility of fire caused by overheating of the wire due to overload, and also minimizes the 

danger of someone's tripping over them.

E Open Wiring

Open wiring is a wiring method using knobs, nonmetallic tubes, cleats, and flexible tubing for the protection and support of 

insulated conductors in or on buildings and not concealed by the structure. The term "open wiring" does not mean exposed, bare 

wiring. In dry locations when not exposed to severe physical damage, conductors may be separately encased in flexible tubing. 

Tubing should be in continuous lengths not exceeding 15 feet and secured to the surface by straps not more than 4? feet apart. 

They should be separated from other conductors by at least 2? inches and should have a permanently maintained airspace 

between them and any and all pipes they cross.

Figure 8-10. Nonmetallic Sheath Cable

Figure 8-11. Armored Cable

F Concealed Knob and Tube Wiring

Concealed knob and tube wiring is a wiring method using knobs, tubes, and flexible nonmetallic tubing for the protection and 

support of insulated wires concealed in hollow spaces of walls and ceilings of buildings. This wiring method is similar to open 

wiring, and like open wiring, is usually found only in older buildings.
VIII. Electric Service Panel

Service Switch

This is a main switch that will disconnect the entire electrical system at one time. The main fuses or circuit breakers are usually 

located within the "Service Switch" box. The branch circuit fuse or circuit breaker may also be located within this box.

According to the code, the switch must be "externally operable." This condition is fulfilled if the switch can be operated without the 

operator's being exposed to electrically active parts. Older switches use external handles as shown in Figure 8-12.

Figure 8-12. Two Wire Single Phase Grounded Service Panel (Fuse Type)

Most of today's service switches do not have hinged switch blades. Instead, the main fuse is mounted on a small insulated block 

that can be pulled out of the switch. When this block is removed, the circuit is broken just as if the blades had been operated with 

a handle.

The neutral terminal or wire of a grounded circuit must never be interrupted by a fuse or circuit breaker. In some installations the 

service switch is a "solid neutral" switch. This means that the neutral wire in the switch is not broken by the switch or a fuse.

When circuit breakers instead of fuses are used in homes, the use of main circuit breakers may or may not be required. If it takes 

not more than six movements of the hand to open all the branch circuit breakers, no main breaker or switch or fuse will be 

required ahead of the branch-circuit breakers. Thus, a house with seven or more branch circuits requires a separate disconnect 

means or a main circuit breaker ahead of the branch circuit breakers (see Figure 8-13).

Figure 8-13. Three Wire Grounded Single Phase Circuit Breaker Service Panel

IX. Overcurrent Devices

The amperage (current flow) in any wire is limited to the maximum permitted by using an overcurrent device of a specific size as

specified by the code. Two types of overcurrent devices are in common use: circuit breakers and fuses; both are rated in amperes. 

The overcurrent device must be rated at equal or lower capacity than the wire of the circuit it Protects.

A Circuit Breakers (Fuseless) Service Panels

A circuit breaker (see Figure 8-14) looks something like an ordinary electric light switch. There is a handle that may be used to 

turn power on or off. Inside is a simple mechanism that, in case of a circuit overload, trips the switch and breaks the circuit. The 

circuit breaker may be reset by simply flipping the switch. A circuit breaker is capable of taking harmless short-period overloads 

(such as the heavy initial current required in the starting of a shut off valve washing machine or air conditioner) without tripping 

but protects against prolonged overloads. After the cause of trouble has been located and corrected, the power is easily restored 

by flipping the circuit breaker switch (circuit breakers are modem substitutes for fuses). Fuseless service panels are usually broken 

up into the following circuits.

Figure 8-14. Circuit Breaker

1 A 100-ampere or larger main circuit breaker that shuts off all power.

2 A 40-ampere circuit for an appliance such as an electric cooking range.

3 A 30-ampere circuit for clothes dryer, hot water heater, or central air conditioning.

4 A 20-ampere circuit for kitchen, small appliances, and power tools.
5 A 15-ampere circuit for general purpose lighting, TV, and vacuum cleaner.

6 Space for circuits to be added if needed for future IICP.

B Fused Ampere Service Panel or Fuse Box

Fuse-type panel boxes are generally found in older homes. They are equally as safe and adequate as a circuit breaker of 

equivalent capacity, provided fuses of the proper size are used.

A fuse (see Figure 8-15), like a circuit breaker, is designed to protect a circuit against the dangers of overloading and short circuits 

and does this in two manners:

a When a fuse is blown by a short circuit the metal strip is instantly heated to an extremely high temperature, and this heat 

causes it to vaporize. A fuse blown by a short circuit may be easily recognized because the window of the fuse usually 

becomes discolored.

b In a fuse blown by overload the metal strip is melted at its weakest point, and this breaks the flow of current to the load. 

In this case the window of the fuse remains clear; therefore, a blown fuse caused by an overload may also be easily 

recognized.

Sometimes, although a fuse has not been blown, the bottom of the fuse may be severely discolored and pitted. This indicates a 

loose connection due to the fuse's not being screwed in properly.

Generally, all fused panel boxes are wired similarly for two- and three-wire systems. In a two-wirecircuit panel box the black or red 

hot wire is connected to a terminal of the main disconnect, and the white or light gray neutral wire is connected to the neutral

strip, which is then grounded to the pipe on the street side of the water meter.

In a three-wire system the black and red hot wires are connected to separate terminals of the main disconnect, and the neutral 

wire is grounded the same as for a two-wire system (see Figure 8-12). Below each fuse is a terminal to which a black or red wire is 

connected. The white or light gray neutral wires are then connected to the neutral strip. Each fuse indicates a separate circuit.

1. Non-tamperable Fuses - All ordinary plug fuses, shown in Figure 8-15, have the same diameter and physical appearance 

regardless of their current capacity. Thus, if a circuit designed for a 15-ampere fuse is overloaded so that the 15-ampere 

fuse blows out, nothing will prevent a person from replacing the 15-ampere fuse with a 20- or 30-ampere fuse, which may 

not blow out. If a circuit wired with No. 14 wire (current capacity 15 amperes) is fused with a 20- or 30-ampere fuse and an 

overload develops, more current than the No. 14 wire is safely capable of carrying could pass through the circuit. The result 

would be a heating of the wire and a potential fire.

Type S fuses, shown in Figure 8-15, have different lengths and diameter threads for each different amperage capacity. An 

adapter is first inserted into the ordinary fuse holder, which adapts the fuse holder for only one capacity fuse. Once the 

adapter is inserted, it cannot be removed. 

2. Cartridge Fuses

Figure 8-15 shows two different types of cartridge fuses. A cartridge fuse protects an electric circuit in the same manner as 

an ordinary plug fuse already described protects it. Cartridge fuses are often used as main fuses.

Figure 8-15. Types of Fuses

X. Electric Circuits

An electric circuit in good repair carries electricity through two or three wires from the source of supply to an outlet and hack to 
the source.

A Branch Circuit

A branch circuit is an electric circuit that supplies electric current to a limited number of electric outlets and fixtures. A residence 

generally has many branch circuits. Each is protected against short circuits and overloads by a 15- or 20 ampere fuse or circuit

breaker.

The number of outlets per branch circuit varies from building to building. The code requires enough light circuits so that 3 watts of 

power will be available for each square foot of floor area in a house. A circuit wired with No. 14 wire and protected by a 15-ampere 

overcurrent protection device provides 15 X 115 or 1,725 watts; each circuit is obviously enough for 1,725/3 or 575 square feet.

Note that 575 is a minimum figure; if future use is considered, 500 or even 400 square feet per branch circuit should be used

B Special Appliance Circuits

The branch circuit will provide electric power for lighting, radio, television, and small portable appliances. However, the larger 

electric appliances usually found in the kitchen consume more power and must have their own special circuit.

Section 220-3b of the code requires two special circuits to serve only appliance outlets in kitchen, laundry, pantry, family-room, 

dining room, and breakfast room. Both circuits must be extended to the kitchen; the other rooms may be served by either one or 

both of these circuits. No lighting outlets may be connected to these circuits, and they must be wired with No. 12 wire and 

protected by a 20-ampere overcurrent device. Each circuit will have a capacity of 20 X 115 or 2,300 watts, which is not too much

when one considers that toasters often require over 1,600 watts.

C Individual Appliance Circuits

It is customary to provide a circuit for each of the following appliances:

1. Range 

2. Water heater 

3. Automatic laundry 

4. Clothes dryer 

5. Garbage disposer 

6. Dishwasher 

7. Furnace 

8. Water pump

Note that these circuits may be either 115 volts or 230 volts, depending on the particular appliance or motor installed.

D Outlet Switch and Junction Boxes The code requires that every switch, outlet, and joint in wire or cable be housed in a box. 

Every fixture must be mounted on a box. Most boxes are made of metal with a galvanized finish. Figure 8-16 shows a typical 

outlet box.

When a cable of any style is used for wiring, the code requires that it be securely anchored with a connector to each box it enters.

Figure 8-16. Outlet Box

E Grounding Outlets

An electrical appliance may appear to be in good repair, and yet it might be a danger to the user. Consider a portable electric drill. 

It consists of an electric motor inside a metal casing. When the switch is depressed, the current flows to the motor, and the drill 

rotates. As a result of wear, however, the insulation on the wire inside the drill may deteriorate and allow the hot side of the power 
cord to come in contact with the metal casing. This will not affect the operation of the drill.

A person fully clothed using the drill in the living room, which has a dry floor, will not receive a shock, even though he is in contact 

with the electrified drill case. His body is not grounded, because of the dry floor. If, however, the operator should be standing on a 

wet basement floor, his body might be grounded, and when he touches the electrified drill case, current will pass through his body.

In order to protect man, the drill case is usually connected to the system ground by means of a wire called an "appliance ground." 

In this instance, as the drill is plugged in, current will flow between the shorted hot wire and the drill case and cause the 

overcurrent device to break the circuit. Thus the appliance ground has protected man.

The appliance ground is the third wire found on many appliances.

The appliance ground on the appliance will be of no use unless the outlet into which the appliance is plugged is grounded. The 

outlet is grounded by being in physical contact with a ground outlet box. The outlet box is grounded by having a third ground wire, 

or a grounded conduit, as part of the circuit wiring.

All new buildings are required to have grounded outlets (as shown in Figure 8-17). The outlet may be tested by using a circuit 

tester. The circuit tester should light when both of its leads are plugged into the two elongated parallel openings of the outlet. In 

addition, the tester should light when one lead is plugged into the round third opening and the other is plugged into the hot side of 

the outlet.

If the conventional two-opening outlet is used, it still may be grounded. In this instance the screw that holds the outlet cover plate 

is the third-wire ground. The tester should light when one lead is in contact with a clean paint-free metal outlet cover plate screw 

and the hot side of the outlet. If the tester fails to light then the outlet is not grounded. If the outlet is not grounded then the 

tester will not function.

If a two-opening outlet is grounded, it may be adapted for use by a three-wire appliance by using an adapter. The loose-wire 

portion of the adapter should be secured behind the metal screw of the outlet plate cover.

Many appliances such as electric shavers and some new hand tools are double insulated and are safe without having a third 

ground wire.

Figure 8-17. Grounded Type Receptacle

XI. Common Electrical Violations

A The most apparent requirements that a housing inspector must check are the existence of the power supply; the types, 

locations, and conditions of the wiring in use; and the existence of the number of wall outlets or ceiling fixtures required by his 

local code and their condition. In making his investigations, these considerations will serve as useful guides:

1. Power Supply - Where is it located, is it grounded properly, and is it at least of minimum capacity required to supply 

current safely for lighting and the major and minor appliances in the dwelling? 

2. Panel Box Covers or Doors - These should be accessible only from the front and should be sealed in such a way that they 

can be operated safely without the danger of contact with live or exposed parts of the wiring system. 

3. Switch, Outlets, and Junction Boxes-These also must be covered to protect against danger of electric shock. 

4. Frayed or Bare Wires- These are usually the result of long use and a drying out and cracking of the insulation, which leave 

the wires exposed, or else a result of constant friction and rough handling of the wire, which cause it to fray or become bare. 

Wiring in this condition constitutes a safety hazard, and correction of such defects should be ordered immediately. 

5. Electric Cords Under Rugs or Other Floor Coverings - Putting electric cords in locations such as these is prohibited 

because of the potential fire hazard caused by continuing contact over a period of time between these heat-bearing cords 
and the flammable floor coverings. Direct the occupant to shift the cords to a safe location, explain why, and make sure it is 

done before you leave. 

6. Bathroom Lighting - It should include at least one permanently installed ceiling or wall light fixture with a wall switch and 

plate so located and maintained that there is no danger of short circuiting from use of other bathroom facilities or splashing 

of water. Fixture or cover plates should be insulated or grounded. 

7. Lighting of Public Hallways, Stairways, Landings, and Foyers - A common standard here is sufficient lighting to 

provide illumination of 10 foot-candles on every part of these areas at all times. Sufficient lighting means that a person can 

clearly see his feet on all parts of the stairways and halls. Every public hall and stairway in a structure containing less than

three dwelling units may be supplied with conveniently located light switches controlling an adequate lighting system that 

may be turned on when needed. instead of full-time lighting. 

8. Habitable Room Lighting - The standard here may be two floor convenience outlets - although floor outlets are dangerous 

unless protected by proper dust and water covers-or one convenience outlet and one wall or ceiling electric light fixture. This 

number constitutes an absolute and often inadequate minimum given the contemporary widespread use of electricity in the 

home. The minimum should be that number required to provide adequate lighting and power to accommodate lighting and 

appliances normally used in each room. 

9. Octopus Outlets or Wiring - This term is applied to outlets into which plugs have been inserted and are being used to 

permit more than two lights or portable appliances, such as a TV, lamp, or radio, to be connected to the electrical system. 

The condition occurs where the number of outlets is insufficient to accommodate the normal use of the room. This practice 

overloads the circuit and is a potential source of fire, which may be caused by overloading the circuit. 

10. Outlet Covers- Every outlet and receptacle must be covered by a protective plate to prevent contact of its wiring or 

terminals with the body, combustible object or splashing water.

The following items are conditions that cause needless dangers and must also be corrected:

Excessive or faulty fusing -The wire's capacity must not be exceeded by the fuse or circuit breaker capacity or be left 

unprotected by faulty fusing or circuit breakers. Fuses and circuit breakers are safety devices designed to "blow" as a means of

protection against over loadings of the electrical system or one or more of its circuits. Pennies under fuses are put there to bypass 

the fuse. These are illegal and must be removed. Overfusing is done for the same reason. The latter can be prevented by the 

installation of modern fusestats, which prevent use of any fuse of a higher amperage than can be handled by the circuit it serves.

Cords run through walls or doorways and hanging cords or wires-This is a makeshift-type installation and most often is 

installed by an unqualified handyman or do-it-yourself occupant. The inspector should check with his local electrical section to

determine the policy regarding this type of insulation and govern his action in accordance with the electrical section's policies.

Temporary wiring - This type of installation should not be allowed, with the exception of extension cords that go directly from 

portable lights and electric fixtures to convenience outlets.

Excessively long extension cords - This requirement does not apply to specially designed extension cords for operating portable 

tools and trouble lights. Cities operating under modern code standards limit the length of loose cords or extension lines to a 

maximum of 8 feet. This is necessary because those that are too long will overheat if overloaded or if a short circuit develops and 

thus create a fire hazard. Even shorter lengths are feasible in housing with new or updated wring systems that include one 

convenience outlet every 12 feet around the perimeter of the room.

Dead or dummy outlets - These are sometimes installed to deceive the inspection agency. This is why all outlets must be tested 

or the occupants questioned to see if these are alive and functioning properly. A dead outlet cannot be counted to determine 

compliance with the code.

XII. Steps Involved in Actual Inspection

A Testing Tools
The basic tools required by an inspector of housing for making an electrical inspection are a fuse and circuit tester and a flashlight.

B Danger of Techniques

The first thing is to remember you are in a strange house and the layout is unfamiliar to you. The second thing to remember is 

that you are dealing with electricity-take no chances. Go to the water meter and check the ground. It should connect to the water 

line on the street side of the water meter or else be equipped with a jumper wire. Do not touch any box or wire until you are sure 

of the ground. Go to the main fuse box and check all fuses in all boxes. Note the condition of the wiring and of the box itself and 

check whether it is overfused or not. Examine all wiring in the cellar. Make sure you are standing in a dry spot before touching any 

electrical device. Do not disassemble the fuse box or other devices. Decisions must be made on what you see. If in doubt, consult 

your supervisor.

Make note whether any fuse boxes or junction boxes are uncovered. Examine all wiring for frayed or bare spots, improper splicing, 

or rotted, worn, or inadequate insulation. Avoid all careless touching. When in doubt - DON'T! If you see bare wire, have 

the owner call an electrician. Look for wires or cords in use in the cellar. Many work benches are lighted by an old lamp that 

was once in the parlor and now has a spliced or badly frayed cord or both. Be certain all switch boxes and outlets are in a tight, 

sound condition.

Make sure that the emergency switch for the oil burner is at the top of the cellar stairs, not on top of the unit.

If you find an electric clothes washer-clothes dryer combination in a dwelling, it should have a 240-volt circuit 30-ampere service 

connected to a separate fuse or circuit breaker. Washer-dryer combinations and other portable appliances in the entire house 

should be served by sufficiently heavy service. If either of these special lines is not available under the above-stated conditions, 

consult your supervisor.

An electric range needs a 50-ampere circuit, 240 volts. A dishwasher needs a 20-ampere, 120-volt circuit. A separate three wire 

circuit must be installed for an electric water heater. Continue your inspection this way through the house. In the bathroom look 

for the usual items, but also check for dangerous items such as radios or plug in portable electric heaters. Have them removed 

immediately. Such items have killed thousands of people either because they touched them after getting out of the bathtub or 

shower while still wet or because the appliance fell into the water. Look for brass pull chains in bathroom lighting fixtures. If one 

exists, have owner attach a string to the end of it as a temporary precaution, then order it replaced with a wall switch as required 

by the electrical code.

To sum up, in broad terms, the housing inspector's investigation of specified electrical elements in a house is made to detect any 

obvious evidence of an insufficient power supply, to ensure the availability of adequate and safe lighting and electrical facilities, 

and to discover and correct any obvious hazard. Because electricity is a technical, complicated field, the housing inspector, when in 

doubt, should consult his supervisor. He cannot, however, close the case until appropriate corrective action has been taken on all 

such referrals

XIII. Wattage Consumption of Electrical Appliances

XIV. Motor Currents

Table of Contents | Acknowledgements | Foreword | Chapter1 | Chapter 2

Chapter 3 | Chapter 4 | Chapter 5 | Chapter 6 | Chapter 7

Chapter 8 | Chapter 9 | Chapter 10 | Chapter 11

 
 

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