CalculationsQuestion 11 of 110
For a 200-A dwelling service using the 83% conductor allowance, what is the smallest copper ungrounded conductor (75 C) permitted for the main power feeder?
a.#3/0 AWG
b.#1/0 AWG
c.#2/0 AWG
d.#4/0 AWG
Explanation
200 A x 0.83 = 166 A required ampacity. At 75 C, #2/0 Cu is rated 175 A, which satisfies 166 A, so #2/0 is the smallest permitted.
Law Reference: 2023 NEC 310.12Practice all 110 questions free — no signup required.
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