An toànCâu 443 / 521
A single ground rod electrode that does not achieve a resistance to earth of 25 ohms or less must be:
a.Removed and left ungrounded
b.Left as-is with no further action
c.Replaced with a length of copper water pipe
d.Supplemented by one additional electrode (such as a second rod) spaced at least 6 feet away
Giải thích
If a single made electrode does not meet 25 ohms or less, the Code requires adding one supplemental electrode located at least 6 feet from the first. Leaving it inadequate or removing it defeats the grounding, and a random copper pipe is not the prescribed supplemental electrode method.
Trích dẫn luật: 2023 NEC §250.53Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
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