Maintenance Electrician Exam #2

25 terms by JoeDaddy

Create a new folder

Like this study set?

Create a free Quizlet account to save it and study later.

Sign up for an account

Already have a Quizlet account? .

Create an account

Advertisement Upgrade to remove ads

In computing the load of luminaires that employ ballast, transformers, or autotransformers, such as fluorescent lighting units, the load must be based on the _____.
a) total wattage of the lamps
b) VA of the lamps
c) length of the lighting fixture
d) ampere ratings of the complete units

D: ampere ratings of the complete units
Ref: 220.18(B)

A branch-circuit inverse-time circuit breaker rated in amperes shall be permitted as a controller for _____.
a) continuous-duty motors
b) intermittent-duty motors
c) torque motors
d) all motors

D: all motors
Ref: 430.83(A)(2)

Compliance with the provisions of the NEC® will result in an electrical installation that is essentially _____.
a) free from hazard
b) a good electrical system
c) an efficient system
d) all of these

A: free from hazard
Ref: 90.1(B)

Under normal conditions, an equipment grounding conductor will _____.
a) improve current flow
b) not carry current
c) carry current
d) reduce circuit resistance

B: not carry current
Ref: Art. 100; Trade Knowledge

Cord-and-plug-connected vending machines located in break rooms of commercial establishments are required to be provided with _____.
I) a power supply cord not smaller than size 12 AWG with a length not exceeding 4 feet.
II) GFCI protection
a) I only
b) II only
c) both I and II
d) neither I nor II

B: II only
Ref: 422.51

A motor with nine leads coming out of it is a _____.
a) two-phase motor
b) two-speed motor
c) dual-voltage motor
d) multi-speed motor

C: dual-voltage motor
Ref: Trade Knowledge

On a four-wire, delta-connected system, the conductor having the higher voltage to ground (high-leg) shall be identified as _____ in color, if the grounded conductor is also present to supply lighting or similar loads.
a) white
b) red
c) green
d) orange

D: orange
Ref: 110.15

When an electrical trade size 3⁄4 inch electrical metallic tubing (EMT) is in excess of 24 inches in length, the conduit is permitted to contain no more than _____ size 10 AWG conductors with THWN insulation.
a) six
b) ten
c) eight
d) fourteen

B: ten
Ref: Annex C, Tbl. C.1

Given: an electrical metallic tubing (EMT) 50 feet in length to be installed will contain a total of nine conductors. Six of these wires are considered to be current-carrying. What is the derating factor, in percent, that must be applied to the ampacity of the current-carrying conductors?
a) 80 percent
b) 70 percent
c) 60 percent
d) 50 percent

A: 80 percent
Ref: Tbl. 310.15(B)(2)(a)

The reason the NEC® requires all grounded and ungrounded conductors of a common circuit to be installed together in the same ferrous metal raceway is to reduce _____.
a) expense
b) inductive heat
c) voltage drop
d) resistance

B: inductive heat
Ref: 300.20(A)

In general, electrical metallic tubing (EMT) shall be securely fastened within ____ of each junction box, panelboard, or other conduit termination.
a) 3 feet
b) 6 feet
c) 8 feet
d) 10 feet

A: 3 feet
Ref: 358.30(A)

One horsepower is equal to _____ watts.
a) 746
b) 1,000
c) 1,250
d) 1,500

A: 746
Ref: General Knowledge

For continuous-duty motors, the motor nameplate current rating is used to determine the size of the _____ required for the motor.
a) disconnecting means
b) branch-circuit conductors
c) motor overload protection
d) short-circuit protection

C: motor overload protection
Ref: 430.6(A)(2)

In general, branch-circuit conductors that supply a single AC motor used in a continuous-duty application shall have an ampacity of NOT less than _____ percent of the motor's full-load running current rating.
a) 125
b) 100
c) 150
d) 115

A: 125
Ref: 430.22(A)

Unless listed and identified otherwise, terminations and conductors of circuits rated 100 amperes or larger shall be rated at _____.
a) 60 degrees C
b) 75 degrees C
c) 90 degrees C
d) 120 degrees C

B: 75 degrees C
Ref: 110.14(C)(1)(b)(1)

When circuit breakers are used to switch 120-volt and 277-volt, high-intensity discharge lighting branch-circuits, the circuit breakers shall be listed and marked _____.
a) I only
b) II only
c) either I or II
d) neither I nor II

B: II only
Ref: 240.83(D)

An insulated branch circuit conductor with a continuous yellowcolored insulation is considered to be a/an _____.
a) equipment grounding conductor
b) grounded conductor
c) switch-leg
d) ungrounded conductor

D: ungrounded conductor
Ref: 310.12(C); 200.6; 250.119

When an insulated black conductor is identified by three continuous white stripes along its entire length, it is considered a/an _____.
a) grounded conductor
b) ungrounded conductor
c) equipment grounding conductor
d) phase of a delta-connected system

A: grounded conductor
Ref: 200.7(A)(2)

Given: a 9 kW rated 208-volt, three-phase electric steamer is to be installed in the kitchen of a commercial establishment, the steamer will draw _____ amperes.
a) 43
b) 4.3
c) 25
d) 75

C: 25
Ref: 3-Phase Cureent Formula
Sol: I = P/E x 1.732

I = (9 kw x 1,000) / (208 x 1.732) = 9,000 watts / 360.25 = 24.9 amperes

What is the approximate MAXIMUM distance a single-phase, 240-volt, 42-ampere load may be located from a panelboard, given the following related information: (1)copper conductors, K = 12.9; (2)size 8 AWG THWN/THHN conductors are used; (3)limit voltage drop to 3 percent
a) 50 feet
b) 110 feet
c) 160 feet
d) 195 feet

B: 110 feet
Ref: Chapter 9, Table 8; Distance Formula
Sol: VD = 240 volts x 3 percent = 7.2 volts

D = (CM x VD) / (2 x K x I) = (16,510 x 7.2) / (2 x 12.9 x 42) = 118,872 / 1,083.6 = 109.7 ft.

The NEC permits electrical trade size 3⁄8 inch flexible metal conduit (FMC) to be used for tap conductors (fixture whips) to luminaires, provided the length of the flex does not exceed _____.
a) 4 feet
b) 6 feet
c) 8 feet
d) 10 feet

B: 6 feet
Ref: 348.20(A)(2)c

The MINIMUM required width of the working space in front of panelboards, switchboards, disconnects, and motor controllers shall be the width of the equipment or _____ , whichever is greater.
a) 2 feet
b) 3 feet
c) 4 feet
d) 30 inches

D: 30 inches
Ref: 110.26(A)(2)

In general, branch-circuit conductors serving continuous loads, such as luminaires in an office building or commercial plant, shall have an ampacity of NOT less than _____ percent of the load.
a) 125
b) 115
c) 150
d) 80

A: 125
Ref: 210.19(A)(1)

A SPD (surge arrester or TVSS) device may be installed on circuits of up to _____ volts.
a) 150
b) 300
c) 600
d) 1,000

C: 600
Ref: 285.3(1)

In general, the overcurrent protection for size 12 AWG copper conductors, regardless of the insulation type, shall not exceed _____ amperes.
a) 15
b) 20
c) 25
d) 30

B: 20
Ref: 240.4(D)(5)

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set