Services & DistributionQuestion 1 of 521
A 200 A service uses 250 kcmil copper ungrounded service-entrance conductors. Per Table 250.66, what is the minimum copper grounding electrode conductor (GEC)?
a.4 AWG copper
b.2 AWG copper
c.1/0 AWG copper
d.6 AWG copper
Explanation
In Table 250.66 the row 'over 3/0 through 350 kcmil' requires a 2 AWG copper GEC, so 250 kcmil falls here. 4 AWG serves only 2/0-3/0, 6 AWG serves 1 or 1/0, and 1/0 is not required until conductors exceed 350 kcmil.
Law Reference: 2023 NEC §250.66Practice all 521 questions free — no signup required.
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