Dịch vụ & Phân phốiCâu 85 / 521
The general minimum vertical clearance of overhead service conductors above a roof surface (voltage not over 300 V to ground) is:
a.3 ft
b.6 ft
c.8 ft
d.10 ft
Giải thích
Per 230.24(A), the general clearance above a roof is 8 ft (2.5 m), measured over the area where the conductors pass. Reduced clearances (such as 3 ft) apply only under specific listed exceptions like limited slope or attachment conditions.
Trích dẫn luật: 2023 NEC §230.24Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
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