Maintenance Electrician Flash Cards
Metal conduit installed in indoor wet locations must have a MINIMUM airspace clearance of _____ between the conduit and the wall or supporting surface.
1/4 inch
When an electrical trade size ¾ 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.
10
Given: A 9 kW rated 208-volt, 3-phase electric steamer is to be installed in the kitchen of a commercial establishment; the steamer will have an approximate current draw of _____ amperes.
25
In general, electrical nonmetallic tubing (ENT) shall be securely fastened at intervals NOT exceeding _____.
3 feet
How much clear working space is required to be maintained between a 3-phase 480Y/277-volt main switchboard and a concrete block wall?
3 foot 6 inches
What is the MAXIMUM overcurrent protection permitted for a size 10 AWG copper conductor with THHN insulation?
30 Amperes
The MINIMUM required width of the working space in front of panelboards, switchboards, disconnects, and motor controllers operating at 480 volts shall be the width of the equipment or NOT less than _____, whichever is greater.
30 inches
A 240-volt, single-phase, 10 KW rated commercial dishwasher has an approximate current draw of _____ amperes.
42 amperes
A branch circuit supplying a 7½ HP, 240-volt, single-phase, induction type, continuous-duty, Design B, AC motor shall have an ampacity of at LEAST _____ amperes.
50
Generally, the ampacity of a size 8 AWG THWN copper conductor is _____.
50 amperes
Where branch-circuit conductors supplying a fluorescent or HID luminaire are contained within the ballast compartment and are within 3 in. of the ballast, the conductors are required to have an insulation temperature rating NOT lower than _____.
90 Degrees C
Which of the following fuses, if any, shall be used for replacement only in existing installations and not permitted for use in new installations? I. Edison-base fuse II. Class H renewable cartridge fuse
Both I and II
A motor with nine leads coming out of it is a _____.
Dual voltage motor
When checking for continuity between a circuit breaker and the neutral bar of a panelboard using a continuity tester, positive continuity is indicated. The reason may be _____. I. a conductor grounded II. a luminaire or an appliance may be turned on
Either I or II
For continuous-duty motors, the motor nameplate current rating is used to determine the size of the _____ required for the motor.
Motor overload protection
Electrical equipment rooms or enclosures housing electrical apparatus of not over 1000 volts that are controlled by a lock(s) shall be considered accessible to _____.
Qualified persons only
As a general rule, where the ampacity of a specific conductor does not match the rating of a listed standard overcurrent device, _____ of the NEC® permits the use of the next standard overcurrent device where loads are 800 amperes or less
Section 240.4(B)
Where more than three (3) current-carrying conductors are installed in a raceway, the ampacity adjustment factors shown in _____ of the NEC® shall be applied.
Table 310.15(C)(1)
If the voltage-drop of a branch circuit is too great, which of the following, if any, may be the result? I. unsatisfactory illumination of lighting fixtures II. overheating of a motor or unsatisfactory motor speed
both I and II
The portion of a wiring system that is between the final overcurrent device protecting the circuit and the outlets is defined as a _____.
branch circuit
When a 20-ampere, 125-volt receptacle outlet is installed, in which of the following listed locations is the receptacle required to have GFCI protection? A in the lobby of a movie theater B in a classroom of an educational facility C under an outdoor canopy, near the entrance of a public library D in the walkway of an indoor retail shopping mall
c
The National Electrical Code® (NEC®) is NOT:
designed for future expansion of electrical use.
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.
orange
Electrical wiring installed _____ is considered to be installed in a damp location.
under canopies or roofed open porches
6 AWG neutral grounded insulated conductor is in what color
white/Gray
As a general rule, 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.
125
The full-load running current of a 3-hp, 208-volt, single-phase, continuous-duty AC motor is _____.
18.7 amperes
Where a 120-volt branch circuit is to supply only fifteen (15), 150 watt incandescent luminaires, what is the approximate current draw of the branch-circuit?
18.75 amperes
As a general rule, when a 20-ampere rated branch circuit supplies a single receptacle outlet, the rating of the receptacle must NOT be less than _____ amperes.
20
Disregarding exceptions, the overcurrent protection for size 12 AWG copper conductors, regardless of the insulation type, shall NOT exceed _____ amperes.
20
The current load on a size 8 AWG THHN 90°C copper conductor is limited to _____ where connected to a disconnect switch with terminals rated 60°C.
40 amperes
Which one of the following listed circuit breakers is NOT a standard ampere rating listed in the NEC®?
75 amperes
Unless listed and identified otherwise, terminations and conductors of circuits rated 100 amperes or larger shall be rated at _________.
75 degrees C
Where the copper conductors supplying the previous referenced motor will have a temperature rating of 75°C, determine the MINIMUM size as required by the NEC®.
8 AWG
Given: An electrical metallic tubing (EMT) 50 feet in length to be installed will contain a total of nine (9) conductors. Six (6) of these wires are considered to be current-carrying. What is the adjustment factor, in percent, that must be applied to the ampacity of the current-carrying conductors?
80%
When inverse time 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 _____. I. SWDII. HID
II only
The ampacity of a conductor is defined by the NEC® to be the maximum current, in amperes, a conductor can carry continuously under the conditions of use WITHOUT exceeding ______.
Its temperature rating
The NEC® mandates specific branch circuits, receptacle outlets, and utilization equipment to be provided with a ground-fault circuit interrupter (GFCI); this device is intended _____.
for the protection of personnel
When installing electrical metallic tubing (EMT), there shall be NO more than _____ 90° bends in the tubing between boxes and/or pull points.
four
Under normal conditions, an equipment grounding conductor will _____.
not carry current
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.
125
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 FMC does NOT exceed _____.
6 feet
When exceptions are not a consideration, all switches and circuit breakers used as switches shall be located so that they may be operated from a readily accessible place. They shall be installed so that the center of the grip of the operating handle of the switch or circuit breaker when at its highest position is NOT more than _____ above the floor or platform.
6 feet 7 inches
What is the MINIMUM height of the working space required from the floor to the ceiling in front of a 480-volt, 3-phase, 400 ampere rated motor control center, disconnect switch, or main switchboard?
6 feet, 6 inches, or the height of the equipment
When an insulated black conductor is identified by three (3) continuous white stripes along its entire length, it is considered a/an _____.
grounded conductor
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 _____.
inductive heat
Insulated conductors and cables installed in underground installations shall be _____.
listed for use in wet locations
Where the premises wiring systems has branch circuits supplied from more than one nominal voltage system, each ungrounded conductor of a branch circuit shall be identified by _____ at the panelboard.
phase and system
In compliance with the NEC®, a 4 inch x 1½ inch metal octagon box with a flat blank cover may contain a MAXIMUM of _____ size 14 AWG conductors.
seven
When exceptions are not a consideration, electrical metallic tubing (EMT) shall be securely fastened within ____ feet of each junction box, panelboard, or other conduit termination.
three