Dịch vụ & Phân phốiCâu 78 / 521
Each panelboard must be protected by an overcurrent device having a rating:
a.Not greater than that of the panelboard
b.Exactly twice the panelboard rating
c.Equal to the largest branch circuit
d.Determined only by the feeder length
Giải thích
Per 408.36, a panelboard must be individually protected by an overcurrent device rated not greater than the panelboard's rating, located on the supply side (with limited exceptions). Doubling the rating or sizing to a single branch circuit would leave the busbar unprotected.
Trích dẫn luật: 2023 NEC §408.36Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- When conductors are installed in parallel, the paralleled conductors of each phase, neutral, or grounded circuit conductor must:
- A feeder has a maximum unbalanced (neutral) load of 250 A. Applying the neutral demand provisions, the minimum neutral conductor ampacity is:
- For a 200 A single-phase dwelling service, the minimum aluminum service-entrance conductor permitted by the dwelling service conductor provisions is:
- Under the 2023 NEC, the maximum number of overcurrent devices permitted in a lighting and appliance branch-circuit panelboard is:
- Under the 2023 NEC, the service supplying a dwelling unit must be provided with a:
- Which type of surge-protective device is permitted to be connected on the line side of the service overcurrent device (service disconnect)?
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