WorksheetsNCCER Electrical 3 Module 6
Total questions: 29
Worksheet time: 15mins
Busbars are typically made of _____.
uncoated copper only
uncoated copper or tin-plated aluminum
silver-plated or tin-plated copper or tin-plated aluminum
platinum-plated copper or tin-plated aluminum
The continuous current that a circuit breaker can carry without exceeding a standard
temperature rise is known as the _____.
trip current
overload rating
interrupting rating
rated current
The basic purpose of switchgear is to provide a means of switching or disconnecting power
system apparatus and _____.
provide power system protection by automatically isolating faulty components
provide protective grounding for equipment
provide a grounding system for AC systems between 50V and 1,000V
insulate conductors from hazardous atmospheres
The three sections of switchgear enclosures are the front section, the bus section, and the
_____.
interrupter section
unit substation
cable or termination section
cubicle section
A downed power line is MOST likely to result in a(n) _____.
ground fault
phase failure
arc fault
short circuit
The maximum 60Hz voltage that can be applied to a switch for one minute without causing
insulation failure is known as the _____.
withstand rating
BIL
switch kV
fault close
A test that can be used to detect loose connections is a(n) _____.
insulation resistance test
core ground test
heat scanning test
ratio test
Substation transformers used to reduce the voltages and currents in the primary circuits to the
levels used in metering equipment are known as _____.
distribution transformers
sealed self-cooled transformers
pole-mounted transformers
instrument transformers
A type of oil-filled current transformer is the _____.
bar
donut type
vacuum
bushing
The standard output voltage of potential transformers is 120V or _____.
24.5V
69.3V
132.5V
244.6V
According to the NEC®, neutral conductors size No. 6 and smaller MUST have a continuous
marking of white or _____.
gray
yellow
black
red
Field marking of service equipment shall include the _____.
time of installation
identification of phase wires
date the fault current calculation was performed
location of disconnecting means
Which of the following abbreviations is used on electrical drawings to represent an
oscilloscope?
SYN
CRO
OHM
TDD
Nonstandard abbreviations on electrical prints will typically be defined on the _____.
one-line diagram
revision notes
title block
legend
Connection diagrams are used to _____.
show the internal wiring connections between the parts that make up an apparatus
show the wiring of instrument and electrical control devices in an elementary ladder or
schematic form
show the actual wiring connections between unit assemblies or equipment
indicate the paths, interconnections, and component parts of an electric circuit
The resistance of switchgear should be checked using a _____.
480V multimeter
600V megger
600V multimeter
1,000V megger
Thermographic surveys are conducted using a(n) _____.
infrared imager
contactless voltage detector
proving unit
phasing tester
When performing thermographic surveys, a major deficiency is indicated by a gradient of
_____.
3°C
6°C
12°C
16°C
The three basic methods of sensing ground faults are zero sequence, residual, and _____.
ground-return
repeating
inductive heating
saturation
Wires from a ground fault relay to a trip coil should be no longer than _____.
10'
25'
50'
100'
Which of the following is true with regard to
switchboards?
Switchboards are always installed in cabinets.
Switchboards are only used at the service
entrance.
Switchboards are used to subdivide large blocks
of power.
Switchboards are designed to prevent access to
the panel.
When installing wiring within switchgear, use
self-adhesive cable ties every _____.
12" (300 mm)
16"(400 mm)
24" (600 mm)
36" (900 mm)
The maximum voltage that a piece of equipment
can withstand is known as its _____.
interrupting capacity
basic impulse insulation level (BIL)
current limit
frequency
Bolted pressure switches are often used in place of
_____.
circuit breakers
pushbutton switches
main fuses
MVL switches
Per NEC Section 408.3(E), AC phasing in
switchboards must be labeled _____.
C, B, A from front to back, top to bottom, or left
to right when read facing the front of the
switchboard
C, A, B from front to back, top to bottom, or left
to right when read facing the front of the
switchboard
A, B, C from front to back, top to bottom, or left
to right when read facing the front of the
switchboard
On a typical electrical diagram, the standard
abbreviation for a phase meter is _____.
PM
PH
3M
S/TM
The typical insulation resistance of equipment rated
480V is _____.
10 megohms
50 megohms
100 megohms
1,000 megohms
A typical overpotential test voltage for a used piece
of equipment with a nominal voltage class of 600V
is _____.
600VDC
1,000VDC
1,500VDC
2,000VDC
A ground fault relay should be mounted in an
enclosure in a _____.
vertical position with the terminal block at the
lower end
horizontal position with the terminal block at the
lower end
vertical position with the terminal block at the
upper end
horizontal position with the terminal block at the
upper end
