Dịch vụ & Phân phốiCâu 79 / 521
Under the 2023 NEC, the maximum number of overcurrent devices permitted in a lighting and appliance branch-circuit panelboard is:
a.30
b.42
c.60
d.Not limited to a fixed number; governed by the panelboard's listing
Giải thích
The former 42-circuit limit was removed; per 408.54 a panelboard must not have more overcurrent devices than the number for which it is designed, rated, and listed. There is no universal fixed cap such as 30 or 42; the manufacturer's listing controls.
Trích dẫn luật: 2023 NEC §408.54Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A feeder has a maximum unbalanced (neutral) load of 250 A. Applying the neutral demand provisions, the minimum neutral conductor ampacity is:
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- Each panelboard must be protected by an overcurrent device having a rating:
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