Calculations第 14 / 110 题
A single continuous-duty motor has a table full-load current of 34 A. What minimum conductor ampacity is required for its branch circuit?
a.34 A
b.42.5 A
c.40 A
d.50 A
解析
Motor branch-circuit conductors must be at least 125% of the FLC: 34 A x 1.25 = 42.5 A minimum ampacity.
法律依据: 2023 NEC 430.22免费刷完整 110 道题库 — 无需注册。
同考点相关题目
- 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?
- An electric range has a Column C demand of 8,000 VA. Using the 70% neutral demand for ranges, what is the range contribution to the feeder neutral load?
- From the motor full-load current table, what is the full-load current of a 25-HP, 480-V, three-phase induction motor?
- A motor with a service factor of 1.15 has a nameplate full-load current of 34 A. What is the maximum overload protection setting at 125%?
- For a motor with a 34-A full-load current, what is the maximum inverse-time circuit breaker for branch-circuit short-circuit and ground-fault protection (250%, then next higher standard size)?
- A feeder supplies three motors with full-load currents of 34 A, 28 A, and 22 A. What minimum conductor ampacity is required for the feeder?