Motors & Equipment第 103 / 120 题
A motor with a service factor of 1.16 will not start because the overload device trips, even though it is sized at 125 percent of nameplate current. To what maximum percentage may the overload device be increased?
a.140 percent
b.130 percent
c.150 percent
d.175 percent
解析
Where the overload device selected at the basic percentage is not sufficient to start the motor or carry the load, motors with a service factor of 1.15 or greater or a marked temperature rise of 40 degrees C or less may be increased to 140 percent of nameplate current. The 130 percent ceiling applies to all other motors, and 175 percent is a fuse percentage for short-circuit protection.
法律依据: 2023 NEC §430.32(C)免费刷完整 120 道题库 — 无需注册。
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