Motors & Equipment第 84 / 120 题
A 25-horsepower, 460-volt, three-phase squirrel-cage motor has a table full-load current of 34 amperes. Using 75 degrees C terminations and copper, what is the minimum branch-circuit conductor size?
a.6 AWG
b.10 AWG
c.8 AWG
d.4 AWG
解析
Single-motor branch-circuit conductors must carry at least 125 percent of the table full-load current: 34 x 1.25 = 42.5 A. In the 75 degrees C column, 10 AWG copper is 35 A and fails, while 8 AWG at 50 A is adequate. Sizes 6 and 4 AWG exceed the calculated minimum.
法律依据: 2023 NEC §430.22免费刷完整 120 道题库 — 无需注册。
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