interNACHI How to Perform Residential Electrical Inspections

A _____ _____ is a device designed to open and close a circuit by non-automatic means and to open the circuit automatically when there's an overcurrent.

Circuit Breaker

Bonded

Connected to establish electrical continuity and conductivity.

Screw-in fuses are more properly called _________.

Edison base fuses

T/F: The inspector is required to test for voltage drop on electrical receptacles.

False

T/F: Unlinked double-pole breakers should not be reported as a problem with an electrical panel.

False

GFCI

Ground-Fault Circuit-Interrupter GFCI is a device that protects a person by deenergizing a circuit when a current to ground exceeds the value for the device.

kcmil

In North America, conductors larger than 4/0 AWG are generally identified by the area in thousands of circular mils (kcmil), where 1 kcmil = 0.5067 mm². The next wire size larger than 4/0 has a cross section of 250 kcmil.

Line

Line refers to the INCOMING power. The line side of the equipment will be where the source of the power is terminated.

Load

Load refers to the OUTGOING power.

________ are the units used to measure resistance.

Ohms

Current

Rate of flow of electricity through a conductor. Current is measured in amps.

Ampacity

The maximum current in amps that a conductor can carry without exceeding its maximum temperature rating.

T/F: 120/240-volt would describe most residential services.

True

T/F: 240-volt breakers are connected to two separate bus bars in the panel.

True

T/F: All panel enclosures need to be bonded to ground.

True

T/F: Electric water heaters should be fed with 10-awg minimum copper conductors.

True

T/F: Fused neutral circuits were common in the 1920's.

True

T/F: Most homes constructed between 1930 and 1950 originally had a 60-amp service.

True

T/F: The grounded and grounding conductors can share a common bus in the service panel.

True

T/F: The home inspector is required to test a representative number of receptacles.

True

T/F: The inspector will find overheating with any type of defective breakers.

True

Resistance

limits the conductor's ability to allow the flow of electrons, just as friction causes losses in any pipe or duct work. This is expressed in Ohms.

The available service amperage is based on the _________-rated component.

lowest

Properly bonding all ____________ within an electrical system helps ensure a low-impedance fault current path.

metal parts

100 amps is the __________________________ service required for a new single-family home.

minimum

The ungrounded and grounding conductors can share a common bus __________.

never

Most circuits in North America are wired with _______________ cable type.

non-metallic (NM)

The following item is safe to insert into an electrical panel: _________.

none of these

The maximum breaker rating must _____ the allowable ampacity of the conductor.

not exceed

The clearance for open overhead service conductors from the front, bottom, and sides of windows that ______ is 3 feet.

open

Zinsco electrical panels are problematic due to __________.

poor connections to the bus

REMOVE Electrical panels do not have to be fully enclosed as long as no hole is bigger than _________.

safety glasses, non-synthetic clothing, electrician's gloves

Which of the following should the inspector be wearing while evaluating electrical panels?

safety glasses, non-synthetic clothing, electrician's gloves

Most areas require two means of____________ grounding .

separate

An electrical service mast that extends 5 feet or more above the roof surface needs to be supported ____________.

separately

An underground service entrance is called a __________.

service lateral

A bonding connection ______________________ connect the grounding bus to the electrical enclosure. (should OR should not)

should

The electrical supply _________________ able to be shut down with 6 or fewer moves of the hand.

should be

Because there are also small gaps between the strands, a ________ ______ will always have a slightly larger overall diameter than a solid wire with the same AWG.

stranded wire

Wiring within 1-1/4 inches to the front of a __________ requires protection.

stud

If a service disconnect is not present at a panelboard, the panelboard is sometimes called a _____________.

sub-panel

Water dripping from an electrical panel should be __________________.

tagged as an immediate hazard and deferred to an electrician

In a false grounded receptacle, the ground wire is connected to _________.

the grounded conductor

Every 5 to 6 feet, rigid service masts should be secured to ________________.

the structure points

GFCI breakers have _____ conductors.

two

"Romex" cable that is not actually of the brand Romex is more properly called _______.

type-NM cable

A live wire is sometimes called a(n) __________.

ungrounded conductor

On a standard 120-volt outlet, what is the smaller slot?

ungrounded conductor

Current (or amps) is equal to the ________ divided by the _________.

voltage (or volts), resistance (or Ohms)

A service drop should be at least ________ away from any nearby trees.

5 to 6 feet

The minimum size for a copper grounding electrode rod _______.

5/8-inch diameter and 8 feet long

Branch Circuit

A branch circuit are the conductors between the final overcurrent device protecting the circuit and the outlet(s).

Disconnecting Means

A device by which the conductors of a circuit can be disconnected from their source of supply.

Panelboard

A panelboard is a single panel, including buses and automatic overcurrent devices, and equipped with or without switches for the controlling of light, heat or power circuits, and is mounted in a cabinet, and is accessible only from the front.

How can you bond a remote distribution panel?

By connecting the enclosure to the grounding bus

Service

The conductors and EQUIPMENT for DELIVERING ENERGY from the service utility to the wiring system of the home.

Feeder

The feeder is a circuit of conductors between the service equipment and the final overcurrent device. Circuits feeding subpanels are called feeders. The conductors between two overcurrent devices are called feeder conductors.

COPALUM is the only approved repair to _____________ wire terminations.

aluminum

Receptacle

A receptacle is a contact device installed at the outlet for the connection of an attachment plug.

A(n) __________________ cause of arc flashes when removing panel fronts is incorrect fasteners.

common

The maximum breaker rating must not exceed the allowable ampacity of the _______.

conductor

The method for installing a UF cable is __________.

direct burial

Conductors between the main service disconnect to the distribution panels are called __________.

feeders

A service entrance with ________ connected conductor(s) is a 3-phase supply.

four

Gas supply piping cannot be used as a ____________.

grounding means

REMOVE The inspector should not report all _______________ electrical splices as improper.

in-panel

Power

is the amount of work that the electrical flow can do. This is expressed as watts or kilowatts (1,000 watts).

Electromotive Force

is what drives electrons along the conductor, and is expressed as voltage or volts.

A split-bus electrical panel uses a double-pole breaker to ______________ the 120-volt circuits.

isolate

Grounding gets rid of damage due to transient over-voltages caused by what?

lightning

Device

A unit of an electrical system, other than a conductor, that is intended to carry or control but not utilize electricity. Examples of devices are switches and thermostats.

_____________ is a nonmetallic sheathed bundle of four solid 10 AWG wires having a bare ground and three insulated conductors twisted into a round-shaped NM-B orange-colored sheath. The insulated conductors are black, white, and red. Some cable of this type may be flat to save copper.

#10/3 with ground (also written "10-3 w/gnd").

________ is a nonmetallic sheathed bundle of three solid 12 AWG wires having a bare ground in the middle of two insulated conductors in a flat-shaped NM-B yellow-colored sheath. The color is a North American industry standard for cables made since 2003, and aids identification.

#12/2 with ground (also written "12-2 w/gnd")

_______ is a nonmetallic sheathed bundle of two solid 14 AWG wires. The insulation surrounding the two conductors is white and black. This sheath for 14 AWG cable is usually white when used for NM-B wiring intended for electrical distribution in a dry location. Newly manufactured cables without a separate ground wire are obsolete.

#14/2 (also written "14-2")

4 AWG (proper) could also be written as:

#4; No. 4; No. 4 AWG; 4 ga.

The typical supply for a Square brand electric meter is a ______ amps.

100

Fused main disconnects are usually a maximum of _____.

100 amps

A _________ conductor should be connected to a 15-amp fuse or breaker.

14 awg

Common wires are:

14/2; 12/2; 10/3

For a 14-gauge copper wire, the maximum overcurrent protection rating is _____ amps.

15

A _____-amp breaker should supply a minimum #12 conductor.

20

What circuits should bathroom outlets be on?

20-amp, GFCI-protected

Most modern 200-amp electrical meters are marked _______.

200 CL

Electric panel buses colored red, blue and black are indicative of a _____________.

3-phase supply

000 AWG (proper for large sizes) could also be written as:

3/0 (common for large sizes), which is pronounced 3 aught; 3/0 AWG; #000; #3/0

Electrical service panels should be in a clear space measuring _____________.

30" wide by 78" high by 36" deep

AWG means _____ and is a standardized wire gauge system

American Wire Gauge

AWG

American wire gauge (AWG) is a standardized wire gauge system used since 1857 predominantly in North America for the diameters of round, solid, nonferrous, electrically conducting wire. The cross-sectional area of each gauge is an important factor for determining its current-carrying capacity. Increasing gauge numbers denote decreasing wire diameters.

Outlet

An outlet is a point on the wiring system where current is taken to supply equipment. Examples of an outlet are receptacles, light fixtures, smoke detectors and appliances. A switch would not be an outlet, because no current is taken at a switch. Current simply passes through a switch.

Receptacle Outlet

An outlet where one or more receptacles are installed.

AFCI

Arc-Fault Circuit Interrupter AFCI is a device that provides protection from the effects of arc-faults by recognizing arcing and deenergizing the circuit when an arc-fault is detected.

Romex

Romex is a trade name for a type of NM cable. Romex is the most commonly used wiring in homes. The proper name for this cable is nonmetallic sheathed cable. A 14/2 with ground would contain three 14-gauge conductors: one black insulated conductor (the hot); one white insulated conductor (the neutral); and one bare conductor (the ground wire).

Upgrading to ___ fuses stops over-fusing.

S

SE and SEU Cable

SE Cable stands for "SERVICE ENTRANCE cable", which is not commonly used for service cable any longer but is used for branch circuit and feeder wiring in homes. SEU is an SE cable and the U stands for UNDERGROUND. SEU cable will usually contain three conductors, two of which will be insulated and one will be a bare equipment grounding conductor. SE cables are jacketed with gray, sunlight-resistant polyvinyl chloride.

AFCI breakers made by ________ were subject to a recall notice.

Square D

Zinsco electrical panels are sometimes branded as ________.

Sylvania

___________ electrical wiring in an attic should not be within 6 feet of the entrance opening.

Unprotected

_____________ cable assemblies should not be in crawlspaces.

Unsupported

Overcurrent Protection Device

Usually CIRCUIT BREAKERS and FUSES. An overcurrent protection device set to open a circuit when the current exceeds a set value.

Common Ohms Laws

Watts = Volts x Amps, or W = E x I. Amps = Watts / Volts, or I = W / E.