Mạch nhánh & Đi dâyCâu 175 / 521
Under 240.4(D), what is the maximum overcurrent protection permitted for a 14 AWG copper branch-circuit conductor, absent a specific exception?
a.30 A
b.25 A
c.20 A
d.15 A
Giải thích
Section 240.4(D)(3) limits 14 AWG copper conductors to a maximum overcurrent device of 15 A. This is why 14 AWG is used on 15-A branch circuits. 20, 25, and 30 A all exceed the small-conductor protection limit for 14 AWG copper.
Trích dẫn luật: 2023 NEC §240.4(D)Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- Cables or raceways installed under metal-corrugated sheet roof decking must be kept at least what distance from the lowest surface of the roof decking to the top of the raceway or cable?
- What is the minimum working-space depth for electrical equipment operating at 151 to 600 volts to ground under Condition 2 (exposed live parts on one side and grounded parts on the other)?
- In a commercial (other than dwelling) building, a 125-volt, 20-ampere receptacle installed in a bathroom must have what protection?
- Under 240.4(D), what is the maximum overcurrent protection permitted for a 12 AWG copper branch-circuit conductor, absent a specific exception?
- The rating of a branch circuit supplying two or more outlets is determined by what?
- The working space required in front of electrical equipment must be kept clear and, in general, may be used for what purpose?
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