Mạch nhánh & Đi dâyCâu 142 / 521
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)?
a.6 ft
b.8 ft
c.10 ft
d.14 ft
Giải thích
Table 344.30(B) permits a maximum support spacing of 10 ft for 1/2-in and 3/4-in RMC. Larger conduit sizes allow greater spacing. 6 and 8 ft are stricter than needed; 14 ft applies only to larger trade sizes such as 2.5 in and above.
Trích dẫn luật: 2023 NEC §344.30(B)Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- Liquidtight flexible metal conduit (LFMC) must be securely fastened within what distance of each box, cabinet, or fitting where the conduit is not fished?
- Along its length, liquidtight flexible metal conduit (LFMC) must be supported at intervals not exceeding what distance?
- Rigid metal conduit (RMC) must be securely fastened within what distance of each outlet box, junction box, or termination?
- 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?
- 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?
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