E2 Overcurrent Protection Devices

Question 1

Per NEC 240.4(D), what is the maximum overcurrent protection permitted for 14 AWG copper conductors in a commercial installation?

Accepted Answer

15 amperes

Answer

20 amperes

Answer

25 amperes

Answer

30 amperes

Question 2

According to NEC 240.4(D), what is the maximum overcurrent protection allowed for 12 AWG copper conductors?

Accepted Answer

20 amperes

Answer

15 amperes

Answer

25 amperes

Answer

30 amperes

Question 3

Under NEC 240.4(D), what is the maximum overcurrent protection for 10 AWG copper conductors?

Accepted Answer

30 amperes

Answer

20 amperes

Answer

25 amperes

Answer

35 amperes

Question 4

Which of the following is a standard ampere rating for overcurrent devices per NEC 240.6(A)?

Accepted Answer

45 amperes

Answer

55 amperes

Answer

65 amperes

Answer

85 amperes

Question 5

Per NEC 240.21, overcurrent protection for conductors shall generally be provided at:

Accepted Answer

The point where the conductor receives its supply

Answer

The load end of the conductor run

Answer

The midpoint of long conductor runs

Answer

The main service disconnect only

Question 6

Under NEC 240.21(B)(1), what is the maximum length of a feeder tap conductor that does not require overcurrent protection at the tap point, provided it is enclosed in a raceway and meets all other conditions?

Accepted Answer

10 feet

Answer

15 feet

Answer

25 feet

Answer

50 feet

Question 7

Per NEC 240.21(B)(2), what is the maximum length for a feeder tap conductor whose ampacity is not less than 1/3 the rating of the overcurrent device protecting the feeder?

Accepted Answer

25 feet

Answer

10 feet

Answer

15 feet

Answer

50 feet