Motors & Equipment第 85 / 120 题
That same motor has a nameplate full-load current of 32 amperes and a marked service factor of 1.15. What is the maximum separate overload device rating?
a.36.8 amperes
b.40 amperes
c.42.5 amperes
d.32 amperes
解析
Overload protection is based on the nameplate current, not the table value, and a service factor of 1.15 or greater permits 125 percent: 32 x 1.25 = 40 A. The 36.8-ampere answer applies the 115 percent factor used for motors with no marked service factor or temperature rise, and 42.5 amperes wrongly applies 125 percent to the table value of 34 A.
法律依据: 2023 NEC §430.32(A)(1)免费刷完整 120 道题库 — 无需注册。
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