NEC Branch Circuit Requirements 2

Question 1

What is the maximum overcurrent protection allowed on a 14 AWG copper branch circuit conductor?

Accepted Answer

15 amperes

Answer

Per NEC 240.4(D), 14 AWG copper is limited to 15-ampere overcurrent protection.

Question 2

A 20-ampere branch circuit supplying receptacles requires conductors of at least which size copper?

Accepted Answer

12 AWG

Answer

A 20-amp circuit requires 12 AWG copper conductors per NEC 240.4(D).

Question 3

On a multi-outlet branch circuit, the rating of any single cord-and-plug-connected utilization equipment must not exceed what percentage of the branch-circuit rating?

Accepted Answer

80%

Answer

NEC 210.23(A)(1) limits a single plug-connected load to 80% of the branch-circuit rating.

Question 4

What is the maximum rating of a branch circuit permitted to supply standard 15-ampere receptacles when more than one receptacle is on the circuit?

Accepted Answer

20 amperes

Answer

Per NEC Table 210.21(B)(3), 15-amp receptacles may be used on a 20-amp circuit with multiple outlets.

Question 5

Branch circuits rated 30 amperes are permitted to supply which type of load in a dwelling unit?

Accepted Answer

Fixed appliances and equipment only

Answer

NEC 210.23(B) limits 30-amp circuits to fixed equipment, not general-use receptacles in dwellings.

NEC Practice Test

NEC Practice Test

NEC Branch Circuit Requirements 2