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38 Cards in this Set
- Front
- Back
What size conductors are required for a 1 hp, single-phase, 115V motor with terminals rated 75°C? |
14 AWG |
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What size conductors are required for a 2 HP, single-phase, 230V motor? |
14 AWG |
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What size conductors are required for a 5 HP, single-phase 208V motor? |
8 AWG |
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Motors and their associated equipment must be protected against overcurrent (overload, short circuit, or ground fault), but because of the special characteristics of induction motors, overcurrent protection may be generally accomplished by having the overload protection separate from the short-circuit and ground-fault protection. True or false? |
True |
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Which parts of Article 430 contains the requirements for motor short-circuit and overload protection? (a) Motor and branch-circuit overload protection part 3 (b) Motor branch circuit short circuit and ground fault protection part 4 (C) a and b (d) None of these |
a and b |
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What's the FLC for a 5 HP, 120V, direct-current motor? |
40A |
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What's the FLC for a 5 hp, 115V, single-phase motor? |
56A |
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What's the FLC for a 5 HP, 200V, single-phase motor? |
32.20A |
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What's the FLC for a 5 HP, 230V, three-phase motor? |
15.20A |
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What size conductors are required for a 1 hp, single-phase, 115V motor with terminals rated 75°C? |
14 AWG |
|
What size conductors are required for a 2 HP, single-phase, 230V motor? |
14 AWG |
|
What size conductors are required for a 5 HP, single-phase, 208V motor? |
8 AWG |
|
What size conductors are required for a 5 HP, single-phase, 230V motor? |
8 AWG |
|
What size branch-circuit conductors are required for a 5 HP, three-phase, 208V motor with terminals rated 75°C? |
12 AWG |
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What size branch-circuit conductors are required for a 7 1/2 HP, three-phase, 230V motor? |
10 AWG |
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What size branch-circuit conductors are required for a 25 hp, three-phase, 460V motor with terminals rated 75°C? |
8 AWG |
|
What size branch-circuit conductors are required for a 7 1/2 HP, three-phase, 230V motor? The nameplate FLA is 20A, rated for 5-minute service, used for intermittent duty, and the terminals are rated 75°C. |
14 AWG |
|
What size branch-circuit conductors are required for a 7 1/2 hp, three-phase, 230V motor? The nameplate FLA is 20A, rated for 30 minute service, and used for short time duty. |
10 AWG |
|
What size feeder conductors are required for a 5 HP and 3 HP, single-phase, 230V motor? |
6 AWG |
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What size feeder conductors are required for two 7 1/2 HP, three-phase, 230V motors with terminals rated 75°C? |
8 AWG |
|
What size feeder conductors are required for two 7 1/2 HP and one 15 HP, three-phase, 230V motors with terminals rated 75°C? |
3 AWG |
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Overload is the condition where the current is greater than the equipment rating, resulting in equipment damage due to dangerous overheating [Article 100]. Overload protective devices, sometimes called "heaters" are intended to protect the ______ from dangerous overheating. |
All of these |
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22. The NEC requires motor overload protection devices to be sized according to the motor full-load current ratings listed in Tables 430.247, 430.248, or 430.250. True or false? |
False |
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23. If the motor overload protection relay sized according to 430.32(A)(1) isn't capable of carrying the motor starting and running current, a larger overload can be used if it's sized according to the requirements of 430.32(C). True or false |
True |
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24. Motors with a nameplate service factor (SF) rating of 1.15 or more must have the overload protective device sized at no more than _____ percent of the motor nameplate current rating. |
125 |
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25. Motors with a nameplate temperature rise rating not over 40°C must have the overload protective device sized at no more than ______ percent of the motor nameplate current rating. |
125 |
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26. Motors that have a service factor rating of 1.10 must have the overload protective device sized at not more than ______ percent of the motor nameplate ampere rating. |
115 |
|
27. If a dual-element time-delay fuse is used for overload protection, what size fuse is required for a 5 HP, 208V, three-phase motor with a service factor of 1.15 and a motor nameplate current rating (FLA) of 16A? |
20A |
|
28. If a dual-element time-delay fuse is used for overload protection, what size fuse is required for a 30 HP, 460V, three-phase synchronous motor, with a nameplate current rating of 32A, and a temperature rise of 39°C? |
40A |
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30. In addition to overload protection, each motor and it's accessories require branch-circuit short-circuit and ground-fault protection according to 430.52. When sizing the branch-circuit protective device, which of the following factors must be considered? |
All of these |
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31. The NEC requires motor branch-circuit short-circuit and ground-fault protection to be sized not greater than the percentages listed in Table 430.52. When the branch-circuit short-circuit and ground-fault protective device value determined from Table 430.52 doesn't correspond with the standard rating of overcurrent devices as listed in 240.6(A), the next _____ device size is permitted to be used. |
Larger |
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32. To determine the percentage of the motor FLC from Table 430.52 that's to be used to size the motor branch-circuit short-circuit and ground-fault protective device, which of the following steps should be used? |
All of these |
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33. Where the next size up dual-element time-delay fuse isn't sufficient for the starting current of a motor, the rating of the fuse is permitted to be increased but must im no case exceed____ percent of the motor's full-load current. |
225 |
|
34. Conductors are sized at _____ percent of the motor full-load current, overloads from _____ percent, and the motor short-circuit and ground-fault protective device (inverse time circuit breaker) is sized up to ______ percent of the motor full-load current. |
125, 115, 250 |
|
36. What size conductor and inverse time circuit breaker are required for a 2 HP, 230V, single-phase motor? |
14 AWG conductor and a 30A breaker |
|
37. What size nontime delay fuses are required for a 2 HP, 230V, single-phase motor? |
40A |
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38. What size dual-element time-delay fuses are required for a 2 HP, 230V, single-phase motor? |
25A |
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40. What size conductor and inverse time circuit breaker is required for a 5 HP, 208V, single-phase motor? |
10 AWG conductor and a 60A breaker |