Wiring Methods & MaterialsCâu 78 / 120
How must liquidtight flexible metal conduit be secured on a normal run?
a.Within 12 inches of each box and at intervals not exceeding 6 feet
b.Within 3 feet of each box and at intervals not exceeding 10 feet
c.Within 12 inches of each box or fitting and at intervals not exceeding 4 and 1/2 feet
d.Support is not required for lengths of 6 feet or less in any application
Giải thích
LFMC is secured within 12 inches of each box, cabinet or fitting and supported at intervals not exceeding 4 and 1/2 feet. Certain short lengths used for flexibility or for connections to luminaires are exempt, but that exemption is narrow and does not apply to ordinary runs, and the 10-foot spacing belongs to rigid raceways.
Trích dẫn luật: 2023 NEC §350.30(A)Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- A cable passes through a bored hole in a wood stud. If the edge of the hole is less than 1 and 1/4 inches from the nearest edge of the stud, what is required?
- A pull box is used for a straight pull, and the largest raceway entering it is 3 inch trade size. What is the minimum required length of the box in the direction of the pull?
- An angle pull box has one 2-inch raceway and one 1-inch raceway entering the same wall, with conductors turning 90 degrees. What is the minimum distance from that wall to the opposite wall?
- How many 12 AWG conductors may be installed in a 4-11/16 inch by 2-1/8 inch square box with a volume of 42.0 cubic inches, assuming no clamps, devices or fittings?
- Direct-buried conductors emerging from grade must be protected by an approved enclosure or raceway from below grade to what height?
- What is the maximum fill percentage when exactly two conductors are installed in a raceway?
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