312

The motor branch circuit short-circuit ground-fault protection device must be selected so that it ___.

-opens when subjected to ground faults or short circuits -remain closed while the motor is starting

A 115/230-V, 1Ø, 3 hp motor is fed from a circuit supplied by a 1-pole breaker in a 120/240-V, 1-ph, 3-W panel. The safety switch adjacent to the motor has the smallest permitted DETD fuses installed. The minimum size EGC permitted is ___ AWG where minimum permitted size circuit conductors are used for this circuit.

10

The smallest permitted circuit conductors are to be installed to feed a 2 hp, 115/230-V, single-phase motor. The circuit is supplied from a 1-pole breaker in a 120/208-V, 3-ph, 4-W panel. The maximum permitted size DETD fuses were installed for the motor circuit. Under these conditions, the minimum size EGC permitted is ___ AWG.

10

What maximum size inverse time circuit breaker is permitted for a single-phase, 7.5 hp motor operating at 208 volts?

110

When a motor branch circuit consists of 12 AWG wire and 60 amp fuses, the largest equipment grounding conductor required by the NEC® is ___ AWG.

12

A 1 hp 115/230-V, 1Ø motor circuit is fed from a single-pole breaker in a 120/240-V, 1-ph, 3-W panel. The minimum size circuit conductors are used. The maximum permitted rating of an ITCB was installed in the panel. For this installation the minimum size EGC permitted is ___ AWG.

14

A 2-pole breaker in a 120/208-V, 3-ph, 4-W panel supplies power to a circuit. This circuit uses the smallest permitted conductors and is connected to a 2 hp, 208-V, 1Ø motor. A safety switch is to be installed adjacent to the motor. DETD fuses with a maximum permitted rating were installed in the switch. The minimum size EGC permitted is ___ AWG for this installation.

14

A single-pole breaker in a 120/240-V, 1-ph, 3-W panel supplies power to a motor circuit consisting of the smallest permitted conductors. The largest permitted DETD fuses are installed in a safety switch for the 115/230-V, 1Ø, 1 hp motor. The minimum size EGC permitted for this installation is ___ AWG.

14

The maximum permitted rating of nontime-delay fuses were installed in a fused disconnect located near a 1 hp 115/230-V, 1Ø motor. A circuit is fed from a single-pole breaker in a 120/240-V, 1-ph, 3-W panel. The smallest permitted circuit conductors are used. For this installation the minimum size EGC permitted is ___ AWG.

14

A 3-phase, 10 hp, 230/460-volt, Design B motor has a nameplate FLA = 26/13. If operated at 230 volts, about ___ amps of starting current (LRC) would flow in each branch circuit conductor.

162

A motor nameplate shows 54 full-load amps. Use the rule-of-thumb method to determine the locked rotor current.

324

Motor Nameplate Information: 3 hp 208-V 1Ø Branch Circuit Supply: 2-pole breaker in a 120/208-V, 3-ph, 4-W panel Refer to Scenario 230.27. A safety switch is used as the disconnecting means for the motor. The maximum size DETD fuses permitted to be installed are ___ A.

35

Motor Nameplate Information: 208-V 1Ø 2 hp Branch Circuit Supply: 2-pole breaker in a 120/208-V, 3-ph, 4-W panel Refer to Scenario 230.26. A safety switch will be installed as the disconnecting means for the motor. Nontime-delay fuses with a maximum permitted rating of ___ A would be installed in this switch.

40

The locked-rotor current of a 10 hp, single-phase motor is ___ amps. It operates at 120 volts and the nameplate shows a code letter of F.

466

Motor Nameplate Information: 5 hp 208-230/460-V 3Ø Branch Circuit Supply: 3-pole breaker in a 120/208-V, 3-ph, 4-W panel Nontime-delay fuses with a rating of ___ A are the largest permitted to be installed in a disconnect switch for the motor shown in Scenario 230.28.

50

Using the rule of thumb for a typical motor, about how much locked-rotor current will a 75 hp, 460-volt, three-phase motor draw?

576

Motor Nameplate Information: 115/230-V 1Ø 3 hp Supply: 1-pole breaker in a 120/240-V, 1-ph, 3-W panelThe maximum size DETD fuses permitted are ___ A.

60

A 115/230-V, 1Ø, 3 hp motor is fed from a circuit supplied by a 1-pole breaker in a 120/240-V, 1-ph, 3-W panel. The smallest permitted ITCB was installed for this circuit. The minimum size EGC permitted is ___ AWG where minimum permitted size circuit conductors are used for this circuit.

8

A 115/230-V, 1Ø, 3 hp motor is supplied power from a 1-pole breaker in a 120/240-V, 1-ph, 3-W panel. The maximum size nontime-delay fuses permitted were selected. The circuit conductors are the smallest permitted. For this installation, the minimum size EGC permitted is ___ AWG.

8

A single-phase 3 hp motor is rated to operate at 460 volts. The NEC® table FLC for this motor is ___ amps.

8.5

25

DETD fuses are to be installed in a safety switch adjacent to the motor shown in Figure 230.224. Fuses with a rating of not greater than ___ A are permitted.

___ torque is the torque a motor produces when the rotor is stationary and full power is applied to the motor.

Locked-rotor

___ torque is the torque required to bring a load up to its rated speed.

Pull-up

125

Refer to the information shown in Figure 230.230. The largest 3-pole breaker permitted to be installed in Panel LA is a ___ amp.

100

Refer to the motor nameplate shown in Figure 230.108. The largest 2-pole circuit breaker that can be installed in a 120/240-volt, 3Ø, 4-wire panelboard for this motor is a ___ A.

25

Refer to the motor nameplate shown in Figure 231.114. The largest DETD fuses that can be installed in a safety switch for this motor are ___ A, when the circuit line voltage is 480.

58.1

Refer to the nameplate and information shown in Figure 230.131. When this motor is running normally at rated voltage, it is drawing ___ A.

9.6

Refer to the nameplate and information shown in Figure 230.242. When this motor is running normally at rated voltage, it is pulling ___ A of current through each pole of the circuit breaker.

39.2

Refer to the nameplate and information shown in Figure 233.241. When this motor is running normally at rated voltage, it is drawing ___ A.

300.8

Refer to the nameplate and information shown in Figure 233.241. When this motor tries to start with 3Ø power available, it will pull ___ A. For this motor's Code Letter, use nameplate voltage and the range value that results in the highest current.

40

Refer to the nameplate shown in Figure 230.122. The branch circuit for the motor is supplied from a 120/240-volt, 3Ø, 4-wire panelboard. The maximum size motor branch circuit time-delay fuses can be installed in a safety switch are ___ A.

397

Refer to the nameplate shown in Figure 230.126. When the circuit originates in a 120/240-volt, 3-phase, 4-wire panelboard, the motor should draw ___ A of current when it starts. Use nameplate voltage and the range value that results in the highest current.

70

Refer to the nameplate shown in Figure 230.127. The branch circuit for the motor is supplied from a 120/208-volt, 3Ø, 4-wire panelboard. The maximum size ITCB that can be used on the motor branch circuit is ___ A.

40

Refer to the nameplate shown in Figure 230.128. The branch circuit for the motor is supplied from a 480/277-volt, 3Ø, 4-wire panelboard. The maximum size DETD fuses that can be used on the motor branch circuit is ___ A.

80

The maximum size ITCB permitted to be installed in the panel is ___ A. Refer to the information given in Figure 230.225.

175

When a safety switch is installed adjacent to the motor shown in Figure 230.222, the maximum size nontime-delay fuses permitted are ___ A.

70

Wire connected to the motor must have the correct ampacity according to the 75° column. However, inside the conduit between the panel and the wireway ampacity corrections are made, as usual, in the 90° column. The specifications require that separate equipment grounding conductors be installed in each raceway. The engineer who wrote the specs means that a metal raceway can't be used as the only EGC. But remember that only one EGC must be installed in each conduit.Refer to the drawing shown below to answer questions that refer to this figure. Refer to Figure 230.261. The largest permitted breaker that can be installed in the panel for Motor 1 is ___ A.

60

Wire connected to the motor must have the correct ampacity according to the 75° column. However, inside the conduit between the panel and the wireway ampacity corrections are made, as usual, in the 90° column. The specifications require that separate equipment grounding conductors be installed in each raceway. The engineer who wrote the specs means that a metal raceway can't be used as the only EGC. But remember that only one EGC must be installed in each conduit.Refer to the drawing shown below to answer questions that refer to this figure. Refer to Figure 230.261. The largest permitted breaker that can be installed in the panel for Motor 3 is ___ A.

A motor branch circuit short-circuit ground-fault protection device provides protects the ___ against short circuit and ground fault.

circuit conductors

Typically, the short-circuit ground-fault protection device for a motor branch circuit ___ and is/are connected where the branch circuit originates.

is a circuit breaker or are fuses

A 200-A fused safety switch with 125-amp fuses is installed in a motor circuit. When 8 AWG conductors are installed in flexible metal conduit between the safety switch and a motor, an equipment grounding conductor installed in the flex ___.

must be at least 8 AWG in size

The starting current of a typical motor is about 6 times the FLA shown ___.

on the motor nameplate

For a motor branch circuit, the EGC can be ___ than that required by NEC® Table 250.122.

smaller and larger