Mạch nhánh & Đi dâyCâu 145 / 521
Under Table 300.5, what is the minimum burial depth for a direct-buried rigid metal conduit (RMC) installed under a residential driveway of a one-family dwelling?
a.12 in
b.18 in
c.24 in
d.6 in
Giải thích
Table 300.5 requires 18 in minimum cover for RMC and IMC located under one- and two-family dwelling driveways. General non-driveway locations allow 6 in for RMC, but the driveway column increases this. 12 in and 6 in are too shallow here; 24 in is required for direct-buried cable, not RMC under a driveway.
Trích dẫn luật: 2023 NEC §300.5Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- For 1/2-inch through 3/4-inch trade size rigid metal conduit (RMC), what is the maximum spacing between supports on a straight horizontal run per Table 344.30(B)?
- For 1/2-inch through 1-inch trade size rigid PVC conduit, what is the maximum support spacing per Table 352.30?
- Expansion fittings for rigid PVC conduit must be provided to compensate for thermal expansion and contraction where the length change is expected to be at least how much?
- Per Table 300.5, what is the minimum cover for direct-buried UF cable (without other protection) not under a driveway, in a residential branch circuit application?
- Where cables or raceways are run parallel to framing members, the wiring must be kept at least what distance from the nearest edge of a wood stud where nails or screws are likely, unless protected by a steel plate?
- Branch-circuit conductors must have an ampacity not less than the maximum load to be served and, before the application of adjustment or correction factors, not less than what portion of the continuous load?
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