Dịch vụ & Phân phốiCâu 68 / 521
At a grounded AC service, the grounded (neutral) conductor run to the service disconnecting means must be sized:
a.Only large enough to carry the neutral load
b.The same as the equipment grounding conductor
c.No smaller than 6 AWG copper in all cases
d.Not smaller than required by Table 250.102(C)(1) and never less than the neutral load
Giải thích
Per 250.24(C), the grounded conductor brought to the service must be at least the size shown in Table 250.102(C)(1) (based on the ungrounded conductors), and also not smaller than needed to carry the neutral load. Sizing it only for neutral load can leave it too small to serve as the effective fault-current path.
Trích dẫn luật: 2023 NEC §250.24Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A feeder supplies a continuous load of 40 A and a noncontinuous load of 60 A. The minimum feeder conductor ampacity before applying any adjustment factors is:
- A feeder overcurrent device protecting a feeder that supplies continuous loads must have a rating not less than:
- A service is supplied with 3/0 AWG copper service-entrance conductors. Using Table 250.66, the minimum size copper grounding electrode conductor is:
- The main bonding jumper in service equipment serves to:
- A feeder is protected by a 100 A overcurrent device. Using Table 250.122, the minimum size copper equipment grounding conductor is:
- At other than dwelling units, service equipment must be legibly field-marked with:
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