Dịch vụ & Phân phốiCâu 52 / 521
As a general rule, how must a panelboard be protected against overcurrent?
a.By the branch-circuit breakers only
b.By an OCPD not exceeding the panelboard rating, on the supply side
c.It requires no separate overcurrent protection
d.By a GFCI device
Giải thích
Per 408.36, each panelboard must be protected by an overcurrent device not exceeding its rating, located on the supply side (or within the panelboard as main). Branch breakers alone do not protect the busbar, and GFCI protects people, not the bus rating.
Trích dẫn luật: 2023 NEC §408.36Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- Conductors are connected to a transformer secondary without an OCPD at the secondary terminals. What set of rules governs their length and sizing?
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