CalculationsCâu 16 / 110
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.70 A
b.80 A
c.100 A
d.90 A
Giải thích
Inverse-time breaker: 250% of FLC = 34 x 2.50 = 85 A. Where this does not correspond to a standard size, the next higher standard rating (90 A) is permitted.
Trích dẫn luật: 2023 NEC 430.52Luyện miễn phí toàn bộ 110 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- From the motor full-load current table, what is the full-load current of a 25-HP, 480-V, three-phase induction motor?
- 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 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%?
- 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?
- What is the full-load primary current of a 75-kVA, 480-V, three-phase transformer?
- What is the full-load secondary current of a 75-kVA, three-phase transformer with a 208-V secondary?
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