Dịch vụ & Phân phốiCâu 1 / 521
A 200 A service uses 250 kcmil copper ungrounded service-entrance conductors. Per Table 250.66, what is the minimum copper grounding electrode conductor (GEC)?
a.4 AWG copper
b.2 AWG copper
c.1/0 AWG copper
d.6 AWG copper
Giải thích
In Table 250.66 the row 'over 3/0 through 350 kcmil' requires a 2 AWG copper GEC, so 250 kcmil falls here. 4 AWG serves only 2/0-3/0, 6 AWG serves 1 or 1/0, and 1/0 is not required until conductors exceed 350 kcmil.
Trích dẫn luật: 2023 NEC §250.66Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- The GEC from a service runs only to a driven ground rod (rod/pipe electrode). What is the largest copper GEC required for this connection?
- The only grounding electrode is a concrete-encased electrode (Ufer). What is the largest copper GEC that must be run to it?
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- What is the minimum copper EGC for a circuit protected by a 200 A breaker, per Table 250.122?
- What is the minimum length that a ground rod electrode must be in contact with the soil?
- A single ground rod is installed. Under what condition is a supplemental electrode NOT required?
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