Services, Grounding & Bonding第 48 / 120 题
A metal underground water pipe qualifies as a grounding electrode only if it is in direct contact with the earth for at least what length?
a.20 feet
b.10 feet
c.8 feet
d.5 feet
解析
The metal underground water pipe electrode must have 10 feet or more in direct contact with the earth, including any metal well casing bonded to it. The 20-foot value belongs to the concrete-encased electrode, and 5 or 8 feet do not meet the requirement.
法律依据: 2023 NEC §250.52(A)(1)免费刷完整 120 道题库 — 无需注册。
同考点相关题目
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- A concrete-encased electrode may be formed by at least 20 feet of which of the following?
- When a metal underground water pipe is used as a grounding electrode, what else is required?
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