Thiết bị & Hệ thốngCâu 294 / 521
When the Table 430.52 percentage produces a value that does not correspond to a standard fuse or breaker size, NEC 430.52(C)(1) Exception No. 1 permits you to:
a.Round down to the next lower standard size
b.Use the next higher standard size of protective device
c.Double the value
d.Ignore the table and use conductor ampacity
Giải thích
430.52(C)(1) Exception No. 1 allows using the next higher standard size when the calculated maximum does not match a standard rating, so the motor can start. Rounding down could cause nuisance tripping; doubling or ignoring the table is not permitted.
Trích dẫn luật: 2023 NEC §430.52Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- Per NEC Table 430.250, what is the full-load current of a 7.5 HP, 230 V, three-phase motor?
- For the 7.5 HP, 230 V motor (FLC 22 A), what minimum branch-circuit conductor ampacity is required by NEC 430.22?
- For the 7.5 HP, 230 V motor (FLC 22 A), what is the maximum nontime-delay fuse per Table 430.52 (300%)?
- Per NEC Table 430.248, what is the full-load current of a 1 HP, single-phase, 115 V motor?
- A small single-phase motor has a nameplate FLA of 14 A, service factor 1.0, no marked temperature rise. What is the maximum overload device rating under NEC 430.32(A)(1)?
- NEC 430.75 requires that motor control circuits be arranged so that:
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