Dịch vụ & Phân phốiCâu 7 / 521
A single ground rod is installed. Under what condition is a supplemental electrode NOT required?
a.The rod is 10 ft long
b.The rod is copper-clad
c.The rod's resistance to earth is 25 ohms or less
d.A GEC of 6 AWG is used
Giải thích
Per 250.53(A)(2) Exception, a single rod, pipe, or plate electrode with a resistance to earth of 25 ohms or less needs no supplemental electrode. Rod length, cladding, and GEC size do not exempt the second-electrode requirement.
Trích dẫn luật: 2023 NEC §250.53(A)(2)Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A feeder is protected by a 100 A overcurrent device. Per Table 250.122, what is the minimum copper equipment grounding conductor (EGC)?
- 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 ground ring is used as a grounding electrode. What is the minimum size and length required?
- Service-entrance conductors are 3/0 AWG copper. Per Table 250.102(C)(1), what is the minimum copper main bonding jumper?
- When the grounded (neutral) service conductor is run to the service disconnect, its minimum size is based on which table?
Cập nhật gần nhất: · quy trình kiểm tra
Đội Ngũ Biên Tập PrepPass · Đối chiếu với California CSLB C-10 Electrical Trade Examination · Quy trình kiểm tra