Wiring Methods & MaterialsCâu 62 / 120
When more than two conductors are installed in a raceway, what is the maximum permitted percentage of the raceway cross-sectional area they may occupy?
a.53 percent
b.31 percent
c.40 percent
d.60 percent
Giải thích
Chapter 9, Table 1 allows 53 percent fill for one conductor, 31 percent for exactly two conductors and 40 percent for three or more. The 60 percent value applies only to a nipple not exceeding 24 inches in length between boxes or enclosures.
Trích dẫn luật: 2023 NEC Chapter 9, Table 1Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A box contains six 12 AWG conductors, one internal cable clamp and one duplex receptacle, all 12 AWG. What minimum box volume is required?
- A device box has three 14-2 NM cables with equipment grounding conductors entering through internal clamps, and one single-pole switch is installed. What minimum box volume is required?
- What is the minimum trade size of EMT required for nine 12 AWG THHN conductors?
- A short raceway nipple no longer than 24 inches connects two enclosures. What fill percentage is permitted?
- Four 3/0 AWG THWN conductors, each 0.2679 square inch in area, are pulled into rigid metal conduit. What is the minimum trade size?
- What is the minimum cover for a direct-buried UF cable installed in a residential yard on a 120-volt, 20-ampere circuit that is NOT GFCI protected?
Cập nhật gần nhất: · quy trình kiểm tra
Đội Ngũ Biên Tập PrepPass · Đối chiếu với Journeyman Electrician Licensing Exam (NEC-based) · Quy trình kiểm tra