Chapter 5 Commercial 5

tray cable (TC)

A ___ is a cable that consists of two or more insulated conductors enclosed in a flame-retardant, nonmetallic jacket and is used for installation in cable trays or raceways.

twist-on wire connector

A ___ is a solderless plastic connector that uses a tapered metal coil spring to twist conductors together.

Western Union

A ___ splice is an electrical connection used where the connection must be strong enough to support long lengths of heavy conductors.

fixture

A ______ splice connects two conductors in which one of the conductors is smaller than the other, or one conductor is stranded and the other is solid.

False

A bad fuse can have continuity.

True

A conductor shield is a nonmagnetic metallic material applied over insulated conductor(s) to confine the electric field to the insulations.

True

A medium-voltage cable can be single-conductor or multiconductor and is rated from 2001V to 35,000V.

True

A messenger wire is a separate wire used to support insulated conductors or cables.

6

A(n) AWG conductor is bigger than a 12 AWG conductor.

covered

A(n) ___ conductor is covered with a material that is not recognized by the NEC.

raceway

A(n) ___ is an enclosed channel for routing and placing electrical conductors and cables.

terminal

A(n) ___ screw completes the connection between the current-carrying conductor and the component or device that it mut be connected to.

insulation resistance tester

A(n) ___ tester is a test instrument that measures current that leaks through the insulation into ground.

continuity tester

A(n) _______ is a test instrument that tests for a complete path for current to flow.

service entrance

A(n) __________ cable is a multiconductor electrical assembly with or without an overall covering.

low voltage

A(n) cable can be single-conductor or multiconductor and is rated from 0V to 600V.

armored

A(n) cable is fabricated assembly of insulated conductors in a flexible metal enclosure.

wire pulling lubricant

A(n) can be applied to conductors to help route them through lengths of conduit with several bends.

solderless

A(n) connection joins conductors without using heat to make a strong electrical and mechanical connection.

antishort bushing

A(n) is a plastic or heavy cardboard device used to protect the conductors in armored cable.

wire marker

A(n) is a self-adhesive label affixed to a conductor prior to the point where insulation is stripped and provides a unique numeric or alphanumeric identifier for that specific conductor.

conduit

A(n) is a tube or pipe used to support and protect electrical conductors.

service lateral

A(n) is any service to a structure that is achieved by burying the conductors underground.

equipment grounding conductor

A(n) is used to connect non-current-carrying metal parts of equipment or enclosures to the system grounded conductor or grounding electrode.

service entrance

A(n)___ is a location for the entry of utilities into a structure.

False

Aluminum has better conductive properties than copper.

False

An increase in resistance or current flow results in less voltage drop.

500

An insulation resistance test is performed by applying ___ V or more between the conductor and ground.

False

An insulation shield is a nonmagnetic material used to even out dielectric stresses around the conductor.

False

An insulator is a material with low resistance.

1/2" to 3/4"

Approximately ___ of insulation is stripped off the conductors to be terminated when making crimped connectoions.

14

Armored cable with 2, 3, or 4 aluminum conductors is available is AWG sizes 1 through ___.

three-year

Cables and conductors should be tested and maintained on a ___ testing cycle at minimum.

ampacity

Conductor ___ is a measure of current-carrying capacity.

False

Continuity testers only operate with circuits that have very low resistance (typically 100 Ohms or lower).

on a reel

Fish tap is supplied ___ in lengths of 50', 100', 200'.

True

Fish tapes can be coated with nylon to increase durability and make pulling conductors through conduit easier.

True

High-resistance connections result from improper connections between conductors.

mineral insulated

In addition to nonflexible metallic raceways, Type __ cable is required by the NEC for installation of emergency power circuits.

insulation multimeters (IMMs)

Insulation resistance tests can be performed with ___ or megohmmeters.

False

It is not recommended to twist conductors together prior to inserting them into a wire nut.

True

Low-voltage cables can be installed as part of a messenger system in outdoor locations.

True

Metal-clad (MC) cable does not have a bonding conductor running throughout its length.

True

Mineral-insulated cables are rated at 600V.

hacksaw

Most installers use a(n) ___ to cut armored cable.

True

Per the NEC, antishort bushings are recommended but not required for MC cable installations.

True

Per the NEC, conductors must be aluminum, copper-clad aluminum, or copper unless otherwise specified.

ohms

Resistance is measured in ___.

False

Service-entrance cables require the use of special tools for installation.

three

The NEC provides ampacity adjustment factors for single raceways containing more than ___ current-carrying conductors.

False

The NEC recommends that there be no more than a 5% voltage drop on a branch circuit or feeder.

True

The main advantage of using the continuity test mode of a test instrument is that an audible response is sometimes more desirable than reading a resistance measurement.

copper (CU)

The material with the best conductive properties is ___.

copper (cu)

The most widely used type of conductor material is ___.

voltage drop

The selection and sizing of a conductor is affected by ___.

8 through 22

Twist-on wire connectors are commonly used to connect wire with AWG sizes ____.

True

Type UF cable can also be used for the same applications as NM cable.

THWN

Type ___ insulation can be installed in both wet and and dry locations.

False

Underground service-entrance cable is restricted to maximum lengths of 8' after it enters a building.

True

When energized parts of an electrical circuit are exposed, such as where conductors are terminated at fuse or circuit breaker panels, the distance, or air gap, is used as the insulator.

True

When performing a continuity test, the conductor that has a 0.0 Ohm reading on the display of the continuity tester is the grounded conductor.

downward

When possible, conductors should be fed___.

False

When properly installed, an antishort bushing should not be visible.

Submersible pump

___ cable has two or four conductors and is used in well casings.

armored

___ cable must be used in concealed locations such as embedded in plaster finish or in air voids in masonry block.

mineral insulated

___ cables have conductors insulated with highly compressed magnesium oxide enclosed in a smooth copper sheath.

staggering

___ conductors is performed by attaching one conductor to the fish tape and then attaching the second conductor a short distance behind the first connections.

crimped

___ connections are the most common terminations in commercial and industrial applications

pressure

___ connections are used for making straight, tap, or terminal connections.

terminal

a ___ is an electicity-conducting connection of a circuit or equipment used for the connection of an external conductor.