Wiring Methods & MaterialsCâu 80 / 120
Direct-buried conductors emerging from grade must be protected by an approved enclosure or raceway from below grade to what height?
a.8 feet above finished grade
b.6 feet above finished grade
c.10 feet above finished grade
d.4 feet above finished grade
Giải thích
Protection must extend from below grade to at least 8 feet above finished grade, and the underground portion must reach at least 18 inches below grade. Six feet leaves the conductors within easy reach of damage, and neither 4 nor 10 feet is the code value.
Trích dẫn luật: 2023 NEC §300.5(D)(1)Luyện miễn phí toàn bộ 120 câu hỏi — không cần đăng ký.
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