EEP Unit 6
Feeder grounded conductors that are not connected to an overcurrent device shall be permitted to be sized at _____ percent of the continuous and noncontinuous load.
100
The minimum size copper conductor permitted for voltage ratings up to 2,000V shall be _____ AWG.
14
What size branch-circuit conductor is required for a 2,500W, 240V water heater?
14 AWG
If cables meeting the requirements in 310.15(C)(1)(d)(1) through (C)(1)(d)(3) with more than 20 current-carrying conductors are installed longer than 24 in. without maintaining spacing, are stacked, or are supported on bridle rings, a _____ percent adjustment factor shall be applied.
60
Conductor adjustment factors shall not apply to conductors in raceways having a length not exceeding _____ in.
24
What's the adjusted ampacity of 10 THHN conductors when nine current-carrying conductors are installed in a raceway or cable?
28A
What size aluminum feeder conductor will be required for a feeder supplying a 100A continuous and a 100A noncontinuous load?
300 kcmil
What's the adjusted ampacity of 10 THHN conductors when four current-carrying conductors are installed in a raceway or cable?
32A
For circuits rated 100A or less, when the equipment terminals are listed for use with 75°C conductors, the _____ column of Table 310.16 shall be used to determine the ampacity of THHN conductors.
75°C
Overcurrent protection shall not exceed _____.
All of these 1. 15A for 14 AWG copper 2. 20A for 12 AWG copper 3. 30A for 10 AWG copper
Which of the following is(are) a standard size for circuit breakers and fuses?
All of these 1. 25A 2. 90A 3. 350 A
One of the purposes of conductor overcurrent protection is to protect the conductors against excessive or dangerous heat.
True
What size branch circuit is required for a 2,500W, 240V water heater?
15A
What size conductors (paralleled in three raceways) are required for a 1,200A breaker that supplies a 900A continuous load?
300 kcmil
Conductors shall have their ampacity determined using the _____ column of Table 310.16 for circuits rated over 100A, or marked for conductors larger than 1 AWG, unless the equipment terminals are listed for use with higher temperature-rated conductors.
75°
A(An) _____ conductor that carries only the unbalanced current from other conductors of the same circuit shall not be required to be counted when applying the provisions of 310.15(C)(1).
Neutral
What size aluminum conductor is required for a 200A breaker that supplies a 180A noncontinuous load?
4/0 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 outdoors in a wet location.
10 AWG
What's the ampacity of 1/0 THHN conductors when there are four current-carrying conductors installed in a raceway in a dry location?
136A
The branch-circuit overcurrent device and conductors for fixed storage-type water heater having a capacity of _____ gallons or less shall be sized not smaller than 125 percent of the rating of the water heater.
120
If a branch circuit supplies a single nonmotor-operated appliance, the rating of overcurrent protection shall not exceed _____ if the overcurrent protection rating is not marked and the appliance is rated 13.30A or less.
20 A
What size conductor is required for a 90A breaker that supplies an 85A noncontinuous load?
3 AWG
What size conductor is required for a 70A breaker that supplies a 65A noncontinuous load?
4 AWG
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's the ampacity of four current-carrying 8 THHN conductors installed in an ambient temperature of 90°F?
42 A
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 is _____ and _____ for fuses.
5,000A 10,000A
What size conductor is required for a 400A breaker that supplies a 300A continuous load?
500 kcmil
What size conductors (paralleled in two raceways) are required for an 800A breaker that supplies a 600A continuous load?
500 kcmil
What size conductor is required for a 70A breaker that supplies a 65A noncontinuous load where the terminals are rated 75°C?
6 AWG
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'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
In accordance with Article 310, temperature correction and adjustment factors are permitted to be applied to the ampacity for the temperature rating of the _____, if the corrected and adjusted ampacity does not exceed the ampacity for the temperature rating of the termination in accordance with the provisions of 110.14(C).
Conductor
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.
False
The ampacities listed in Table 310.16 apply only when the ambient temperature is 40°C and there are no more than two current-carrying conductors bundled together. If the ambient temperature isn't 40°C, or there are more than two current-carrying conductors in a raceway, the allowable ampacities must be corrected and/or adjusted to reflect the ampacity under the conditions of use.
False
The _____ rating of a conductor is the maximum temperature, at any location along its length, which the conductor can withstand over a prolonged period of time without serious degradation.
Temperature
Feeder conductors shall be permitted to be sized at 100 percent of the continuous and noncontinuous load where a portion of the feeder is connected at both its supply and load ends to separately installed pressure connections.
True
Unless marked otherwise, equipment terminals rated 100A or less (receptacles, switches, circuit breakers, fuses, and so on) and pressure connector terminals for 14 AWG through 1 AWG conductors must have the conductor sized according to the 60°C temperature rating as listed in Table 310.16, regardless of conductor insulation temperature rating.
True
The branch-circuit overcurrent device and conductors for fixed storage-type water heater having a capacity of 120 gallons or less shall be sized not smaller than 125 percent of the rating of the _____.
Water Heater
In a 3-wire circuit consisting of two phase conductors and the neutral conductor of a 4-wire, three-phase, _____ connected system, the common conductor is a current-carrying conductor and subject to the adjustment provisions of 310.15(C)(1).
Wye-
THHN can be described as _____.
thermoplastic insulation with a nylon outer cover having a maximum operating temperature of 90°C