IEC YEAR 2 FINAL COMPREHENSIVE TEST
PAPER QUESTIONS AND SOLUTIONS GRADED
A+
◉ The service disconnecting means for a 3-phase service is
permitted to consist of ___.
Answer: any of the above
◉ Nontime-delay fuses are to be installed in a safety switch adjacent
to a motor. See Figure 230.225. Fuses with a rating not exceeding ___
A are permitted.
Answer: 100
◉ The classification of a location, where ignitable concentrations of
flammable liquid-produced vapors or combustible liquid-produced
vapors exist under normal operating conditions, is ___.
Answer: Class I, Division 1
◉ If a 4-wire, wye-connected supply system has a line-to-line
voltage of 13.5 kV, what is the line-to-neutral voltage?
Answer: 7,800
,◉ Refer to the motor nameplate shown in Figure 230.108. A NEMA
starter will be used for this motor. The fewest number of heaters
that can be installed in the starter per the NEC ® is ___. The motor
circuit is supplied from a 2-pole breaker in a 120/240-volt, 3Ø, 4-W
panel.
Answer: 1
◉ A transformer has a primary rated voltage of 120 and a secondary
rated voltage of 16. If the current in the circuit conductors connected
to the primary is 1.1 amps, the load that is connected to the
secondary must be drawing ___ amps.
Answer: 8.25
◉ A set of wires (black, red, blue and green) are installed between a
3-pole safety switch and a 3Ø motor. The direction of rotation of the
motor can be changed by swapping the ___ wire connections on the
load side of the switch.
Answer: black and blue
◉ ___ is permitted to be installed in a concrete floor slab.
I. Schedule 40 PVC
II. FMC
III. aluminum MC cable
Answer: I only
, ◉ A(n) ___ refrigerant motor-compressor is a combination
compressor and motor in the same housing, having no external shaft
or shaft seals, with the motor operating in the refrigerant.
Answer: hermetic
◉ In a 60 Hz circuit, containing a 1.3 mh inductor, the inductive
reactance is ___ ohms.
Answer: .49
◉ ___ is the measure of a circuit's ability to store an electrical charge.
Answer: Capacitance
◉ A sine wave will hit its peak value ___ time(s) during each cycle.
Answer: 2
◉ Where a 2/0 AWG THHN/THWN copper is connected to a breaker
with 75° terminations, its ampacity is limited to ______ amps.
Answer: 175
◉ Refer to Figure 205.8, shown above. Where not subject to physical
abuse, the smallest permitted GEC to the ground rod from Panel LC
is ___ AWG. Panel LC has a 400 amp main breaker and is supplied
power by the transformer with a set of 600 kcmil conductors.
PAPER QUESTIONS AND SOLUTIONS GRADED
A+
◉ The service disconnecting means for a 3-phase service is
permitted to consist of ___.
Answer: any of the above
◉ Nontime-delay fuses are to be installed in a safety switch adjacent
to a motor. See Figure 230.225. Fuses with a rating not exceeding ___
A are permitted.
Answer: 100
◉ The classification of a location, where ignitable concentrations of
flammable liquid-produced vapors or combustible liquid-produced
vapors exist under normal operating conditions, is ___.
Answer: Class I, Division 1
◉ If a 4-wire, wye-connected supply system has a line-to-line
voltage of 13.5 kV, what is the line-to-neutral voltage?
Answer: 7,800
,◉ Refer to the motor nameplate shown in Figure 230.108. A NEMA
starter will be used for this motor. The fewest number of heaters
that can be installed in the starter per the NEC ® is ___. The motor
circuit is supplied from a 2-pole breaker in a 120/240-volt, 3Ø, 4-W
panel.
Answer: 1
◉ A transformer has a primary rated voltage of 120 and a secondary
rated voltage of 16. If the current in the circuit conductors connected
to the primary is 1.1 amps, the load that is connected to the
secondary must be drawing ___ amps.
Answer: 8.25
◉ A set of wires (black, red, blue and green) are installed between a
3-pole safety switch and a 3Ø motor. The direction of rotation of the
motor can be changed by swapping the ___ wire connections on the
load side of the switch.
Answer: black and blue
◉ ___ is permitted to be installed in a concrete floor slab.
I. Schedule 40 PVC
II. FMC
III. aluminum MC cable
Answer: I only
, ◉ A(n) ___ refrigerant motor-compressor is a combination
compressor and motor in the same housing, having no external shaft
or shaft seals, with the motor operating in the refrigerant.
Answer: hermetic
◉ In a 60 Hz circuit, containing a 1.3 mh inductor, the inductive
reactance is ___ ohms.
Answer: .49
◉ ___ is the measure of a circuit's ability to store an electrical charge.
Answer: Capacitance
◉ A sine wave will hit its peak value ___ time(s) during each cycle.
Answer: 2
◉ Where a 2/0 AWG THHN/THWN copper is connected to a breaker
with 75° terminations, its ampacity is limited to ______ amps.
Answer: 175
◉ Refer to Figure 205.8, shown above. Where not subject to physical
abuse, the smallest permitted GEC to the ground rod from Panel LC
is ___ AWG. Panel LC has a 400 amp main breaker and is supplied
power by the transformer with a set of 600 kcmil conductors.
