Unit 6

What's the minimum size THHN conductor required for a 150A circuit breaker

1/0 AWG

What size branch circuit is required for a 2,500W, 240V water heater?

15A

What's the ampacity of 10 THHN conductors if there are thirty-one conductors in the cross-sectional area of a wireway?

16A

What size conductor is required for a 70A breaker that supplies a 65A noncontinuous load?

4 AWG

What's the minimum size THHN conductor permitted to terminate on a 50A circuit breaker or fuse if the circuit breaker and equipment terminals are listed for 75°C conductor sizing?

6AWG

Which of the following is(are a standard size for circuit breakers and fuses?

All of these

The neutral conductor of a balanced 4-wire, three-phase wye circuit that's more than 50 percent loaded with nonlinear loads (electric-discharge lighting, electronic ballasts, dimmers, controls, computers, laboratory test equipment, medical test equipment, recording studio equipment, and so forth) isn't considered a current-carrying conductor for the purpose of applying bundle adjustment factors.

T

What size conductor is required for a 400A breaker that supplies a 300A continuous load?

500 kcmil

What's the ampacity of 1/0 XHHW-2 aluminum conducts the ambient temperature is 154°F?

78A

What size branch-circuit conductor (THHN) is required for a 32A continuous nonlinear load that requires three phase conductors and a neutral (four current-carrying conductors)?

8 AWG

What size THHN/THWN conductor is required for an air-conditioning unit if the nameplate requires a conductor ampacity of 34A? The terminals of all the equipment and circuit breakers are rated 75°C and the raceway is installed outaoors in a wet location.

10 AWG

Where a circuit supplies continuous loads or any combination of continuous and noncontinuous loads, the rating of the overcurrent protective device must not be less than the noncontinuous load plus ______percent of the continuous load.

125 %

What's the minimum size THHN conductor permitted to terminate on a 50A circuit breaker or fuse if the circuit breaker and equipment terminals are listed for 75°C conductor sizing?

8 AWG

What size branch-circuit conductor is required for a 2,500W, 240V water heater?

14 AWG

The smallest size conductors) permitted for branch circuits, feeders, and services for residential, commercial, and industrial locations is

14 AWG copper and 12 AWG

What's the ampacity of 1/0 XH-2 conducts temperature is 108F

148A

What size THHN copper conductor can be used to interconnect 90°C rated power distribution blocks that are protected by a 200A overcurrent device serving a 150A continuous load?

2/0 AWG

What size overcurrent devse i be rear in supplying a 100 continuous and a 100 noncontional

225A

When four or more current-carrying conducts are us together for more than______ in., the conducto alon ampacity must be reduced according to the factors s Table 310.15(C)(1).

24

What's the ampacity of 10 THHN conductors when there are eight current-carrying conductors instailed in the same raceway in a dry location and the ambient temperature is 100°F?

25A

What size aluminum feeder conductor wil be repures feeder supplying a 100A continuous and a 100A mon uous load?

300 kcmil

What size conductor and overcurrent device are required for a 7,500W, 240V fixed electric space heater that has a 3A blower motor with 75°C terminals?

45A overcurrent device and an 8 AWG conductor

overcurrent protective devices must be designed and rated to clear fault current and must have an adequate short circuit interrupting rating for the available fault levels. If the minimum interruption rating isn't marked on the overcurrent protective device, according to the NEC the minimum for circuit breakers_______and _________for fuses.

5,000A, 10,000A

What size conductors (paralleled in two raceways) are required for an 800A breaker that supplies a 600A continuous load?

500 kcmil

What's the ampacity of 8 THI/THW conducts if the ampancy temperature is 100F

50A

What size conductor is required for a 70A breaker that supplies a 65A noncontinuous load where the terminals are rated 75°C?

6 AWG

The neutral conductor of a 3-wire wye circuit from a 4-wire, three-phase, wye system isn't considered a current-carrying conductor for the purpose of applying bundle adjustment factors.

False

The neutral conductor that carries only the unbalanced current from a 3-wire 120/240v circuit or 4-wire, 120/208v three-phase wye circuit, is considered a current-carrying conductor for the purpose of applying the adjustment factors of Table 310.15(C)(1).

False

ithe ampacity of a conductor doesn't correspond with the standard ampere rating of a fuse or circuit breaker, the next size up overcurrent protective device is permitted. This applies only i the conductors supply multioutlet receptacles for portable cord-and-plug-connected loads.

False

What's the ampaity of 1/0 THHN conductors when there are 38. four current carrying conductors installed in a racewayinadry location?

136A

What's the adjusted ampacity of 10 THHN conductors when nine current-carrying conductors are installed in a raceway or cable?

28A

What's the minimum size THHN conductor required for a 200A circuit breaker or fuse?

3/0 AWG

What size overcurrent protection will be required for a branch circuit supplying a 32A continuous nonlinear load?

40A

What's the ampacity of four current carrying 8 THHN conductors installed in an ambient temperature of 90°F?

42A

What's the minimum size THHN conductor permitted to terminate on a 50A circuit breaker or fuse?

6 AWG

What size conductors (paralleled in three raceways) are required for a 1,200A breaker that supplies a 900A continuous load?

600 kcmil

What's the ampacity of an 8 THHN conductor when in a walk in cooler if the ambient temperature is 50F

63A

What size aluminum conductor is required for a 150A breaker that supplies a 120A continuous load?

3/0 AWG

One of the purposes of conductor overcurrent protection is to protect the conductors against excessive or dangerous heat.

True

The maximum overcurrent protective device size for 14 AWG is 154, 12 AWG is 20A, and 10 AWG is 30A. This is a general rule, but it doesn't apply to motor or air conditioner loads according

True

What's the adjusted ampacity of 10 TriN conductors when four current-carrying conductors are installed in a raceway or cable?

32A

What size conductor is required for a 90A breaker that supplies an 85A noncontinuous load where the terminals are rated 75°C?

4 AWG

What size conductor is required for a 90A breaker that supplies an 85A noncontinuous load?

4 AWG

What's the minimum size THHN conductor permitted to terminate on a 70A circuit breaker or fuse?

4 AWG

Conductor sizes are expressed in American Wire Gage (AWG) from 40 AWG through 4/0 AWG. Conductors larger than are expressed in circular mils.

4/0 AWG

What size aluminum conductor is required for a 200A breaker that supplies a 180A noncontinuous load?

4/0 AWG

What size feeder conductor wil equires. a 100A continuous and a 100A noncontinuous lat.

4/0 AWG