Dịch vụ & Phân phốiCâu 77 / 521
For a 200 A single-phase dwelling service, the minimum aluminum service-entrance conductor permitted by the dwelling service conductor provisions is:
a.1/0 AWG copper
b.3/0 AWG aluminum
c.4/0 AWG aluminum
d.250 kcmil copper
Giải thích
Section 310.12 (dwelling services and feeders) permits 4/0 AWG aluminum for a 200 A single-phase dwelling service. 3/0 aluminum is undersized for 200 A, while the copper options are permitted but are not the minimum aluminum answer asked for.
Trích dẫn luật: 2023 NEC §310.12Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- In general, conductors may be connected in parallel (electrically joined at both ends) only where the individual conductors are:
- 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:
- Each panelboard must be protected by an overcurrent device having a rating:
- 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:
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