Branch Circuits & FeedersQuestion 13 of 120
A feeder supplies a 100-ampere continuous load. Using 75 degrees C terminations and copper THWN, what is the minimum feeder conductor size?
a.1 AWG
b.2 AWG
c.1/0 AWG
d.3 AWG
Explanation
The feeder conductor must have an ampacity of at least 100 x 1.25 = 125 A. In the 75 degrees C column, 2 AWG copper is 115 A and falls short, while 1 AWG copper is 130 A and satisfies the requirement. 1/0 AWG at 150 A is larger than necessary, and 3 AWG at 100 A does not cover the continuous-load multiplier.
Law Reference: 2023 NEC §215.2(A)(1)Practice all 120 questions free — no signup required.
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