Services, Grounding & Bonding第 38 / 120 题
A 100-ampere feeder originally sized with 3 AWG copper (52,620 circular mils) is upsized to 1/0 AWG copper (105,600 circular mils) for voltage drop. What is the minimum equipment grounding conductor?
a.4 AWG copper
b.8 AWG copper
c.6 AWG copper
d.2 AWG copper
解析
When ungrounded conductors are increased in size, the equipment grounding conductor must be increased in the same proportion by circular-mil area. The ratio is 105,600 / 52,620 = 2.0, and the base 100-ampere equipment grounding conductor of 8 AWG (16,510 circular mils) doubles to about 33,100 circular mils; 6 AWG has only 26,240 circular mils, so 4 AWG at 41,740 circular mils is the smallest that qualifies. Leaving it at 8 AWG ignores the proportional rule.
法律依据: 2023 NEC §250.122(B)免费刷完整 120 道题库 — 无需注册。
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