314

What minimum size conductors are required to connect a 75 hp, three-phase, 460-volt motor to a 400-amp feeder that has been pulled into a 24" × 24" box? The feeder consists of 600 kcmil copper wire. The tap length is to be 15 feet.

1/0 AWG

A 300-amp, 240-volt, three-phase feeder consisting of 350 kcmil conductors is tapped to feed a 30 hp, three-phase motor. If the tap conductor length is 18 feet, what is the minimum size tap conductor permitted?

2 AWG

A 3-pole breaker is installed in Panel K. A set of motor feeder conductors are then run from the breaker to a large junction box where taps are made to three 3Ø motors. Motor #1 = 5 hp Motor #2 = 25 hp Motor #3 = 40 hp Short-circuit and ground-fault protective devices are the maximum permitted size as per NEC® 430.52(C)(1)(a).Refer to the information shown in Scenario 234.401. Panel K is a 120/208-volt, 3Ø, 4-wire panel. The maximum size circuit breaker permitted to be installed in the panel to protect the three motors is a ___ Amp.

350

A three-phase, 240-volt feeder is going to supply power to one 5 hp 3Ø motor, three 2 hp 3Ø motors, and two 1 hp 3Ø motors. The minimum size aluminum THWN/THHN conductors permitted for this feeder are ___ AWG.

6

A three-phase, 240-volt feeder is going to supply power to one 5 hp 3Ø motor, three 2 hp 3Ø motors, and two 1 hp 3Ø motors. The minimum size conductors permitted for this feeder are ___ AWG.

8

To allow for additional capacity, a set of 750 kcmil motor feeder conductors were installed between a 3-pole 450 A breaker in Panel LA and a gutter. Panel LA is 120/240-volt, 3Ø, 4-wire.The tap conductor length from the gutter to the line side of the Motor #1 fused safety switch is 8 feet. Motor #1 is a 5 hp 230-volt, 3Ø motor.The tap conductor length from the gutter to the line side of the Motor #2 fused safety switch is 16 feet. Motor #2 is a 30 hp 230-volt, 3Ø motor.The tap conductor length from the gutter to the line side of the Motor #3 fused safety switch is 31 feet. Motor #3 is a 50 hp 230-volt, 3Ø motor.Short-circuit and ground-fault protective devices are the maximum permitted size as per NEC® 430.52(C)(1)(a).Refer to the information shown in Scenario 234.400. For Motor #1 the minimum permitted size of the tap conductors (from the gutter to the switch) is ___ AWG.

8

2

Although only 3 motors are shown, the feeder and the feeder OCPD were installed to supply power to (future) additional motors. The motor circuits are tapped in the gutter and the tap lengths are:Motor # 3 - 12 ft Motor # 2 - 23 ft Motor # 1 - 51 ft.The minimum tap conductor size for Motor 3 would be ___ AWG or kcmil, as determined from the information provided above in Figure 234.155.

350

Feeder to serve these three motors. Short-circuit and ground-fault protective devices are the maximum permitted size as per NEC® 430.52(C)(1)(a).Refer to the information shown in Figure 234.140. The largest 3-pole circuit breaker permitted to be installed in a 120/240-volt, 3Ø, 4-wire panelboard for this motor feeder is a ___ A.

175

Feeder to serve these three motors. Short-circuit and ground-fault protective devices are the maximum permitted size as per NEC® 430.52(C)(1)(a).Refer to the information shown in Figure 234.140. The largest 3-pole circuit breaker permitted to be installed in a 277/480-volt, 3Ø, 4-wire panelboard for this motor feeder is a ___ A.

4/0

Feeder to serve these three motors. Short-circuit and ground-fault protective devices are the maximum permitted size as per NEC® 430.52(C)(1)(a).Refer to the information shown in Figure 234.140. The smallest conductors permitted to be installed from a 120/240-volt, 3Ø, 4-wire panelboard for this motor feeder are ___ AWG or kcmil.

300

Feeder to serve these three motors. Short-circuit and ground-fault protective devices are the maximum permitted size as per NEC® 430.52(C)(1)(a).Refer to the information shown in Figure 234.141. Without regard to the future motors, the smallest conductors permitted between Panel LC and the gutter are ___ AWG or kcmil.

10

Left to right, continuously operated motors 1, 2, and 3 are supplied by conductors that are tapped from a feeder. The feeder, inside the gutter, originates in a 277/480-volt, 3Ø, 4-W switchboard or panelboard. The tap conductors exit the gutter and terminate in either a fused safety switch or a breaker enclosure (with an inverse-time circuit breaker), located near each motor. The tap lengths, between the gutter and the switch (or ITCB) for each motor, are as follows:Motor #1 is 8 feet. Motor #2 is 37 feet. Motor #3 is 15 feet.Refer to the information shown in Figure 234.153. The smallest feeder conductors permitted to be installed are ___ AWG or kcmil.

175

Left to right, motors 1, 2, and 3 are supplied by a feeder that enters a gutter. The feeder originates in a 277/480-volt, 3Ø, 4-W switchboard or panelboard. The motor circuits are tapped in the gutter and terminate in either a fused safety switch or a breaker enclosure (with an inverse-time circuit breaker), located near each motor. The tap length from the gutter to the switch (or ITCB) for Motor #1 is 8 feet. The tap length from the gutter to the switch (or ITCB) for Motor #2 is 17 feet. The tap length from the gutter to the switch (or ITCB) for Motor #3 is 30 feet.All motors will be operated continuously. Short-circuit and ground-fault protective devices are the maximum permitted size as per NEC® 430.52(C)(1)(a).Refer to the information shown in Figure 234.151. The maximum permitted rating for an ITCB for the feeder would be ___ A.

250

Left to right, motors 1, 2, and 3 are supplied by a feeder. The feeder originates in a 120/240-volt, 3Ø, 4-W switchboard or panelboard and feeds the gutter. The motor circuits are tapped in the gutter and terminate in either a fused safety switch or a breaker enclosure (with an inverse-time circuit breaker), located near each motor. The tap length from the gutter to the switch (or ITCB) for Motor #1 is 8 feet. The tap length from the gutter to the switch (or ITCB) for Motor #2 is 17 feet. The tap length from the gutter to the switch (or ITCB) for Motor #3 is 30 feet.All motors will be operated continuously.Refer to the information shown in Figure 234.150. The maximum permitted size for DETD fuses for the feeder would be ___ A.

8

Refer to the information shown in Figure 234.142. Motor 1 is rated at 30 hp and Motor 2 is rated at 71/2 hp. The smallest conductors permitted between the gutter and the switch for Motor 1 are ___ AWG.

8

Refer to the information shown in Figure 234.142. Motor 1 is rated at 30 hp and Motor 2 is rated at 71/2 hp. The smallest conductors permitted between the gutter and the switch for Motor 2 are ___ AWG.

8

Refer to the information shown in Figure 234.143. The smallest conductors permitted between the fused switch and Motor 1 are ___ AWG.

4

Refer to the information shown in Figure 234.143. The smallest conductors permitted between the gutter and the switch for Motor 2 are ___ AWG.

450

Refer to the information shown in Figure 234.144. The breaker is in a 120/240-volt, 3Ø, 4-wire panel. The breaker is permitted to have a rating not greater than ___ amps where the feeder conductors are as small as permitted.

1/0

Refer to the information shown in Figure 234.144. Where the 3-pole breaker is in a 277/480-volt, 3Ø, 4-wire panel, the smallest feeder conductors permitted between the breaker and the wireway are ___ AWG.

1

Refer to the information shown in Figure 234.146. When the conductor length from the gutter to the line side of the motor #1 fused safety switch is 9 feet, the minimum permitted size of the tap conductors (from the gutter to the switch) is ___ AWG.

300

Refer to the information shown in Figure 234.146. When the conductor length from the gutter to the line side of the motor #2 fused safety switch is 19 feet, the minimum permitted size of the tap conductors (from the gutter to the switch) is ___ AWG.

250

Refer to the nameplates & information shown in Figure 234.145. The smallest feeder conductors permitted to be installed between the 120/240-volt, 3Ø, 4-wire panel and the gutter are ___ AWG or kcmil.

175

Refer to the nameplates and information shown in Figure 234.147. The safety switch is supplied with 120/240-volt, 3Ø, 4-wire power. The DETD fuses installed in the switch can have a rating not greater than ___ amps. The feeder conductors are as small as permitted for the motors shown.