Planning & EstimatingQuestion 402 of 521

Using Table 250.66, for copper service-entrance conductors of 3/0 AWG, what is the minimum size copper grounding electrode conductor?

a.6 AWG
b.8 AWG
c.4 AWG
d.2 AWG

Explanation

Per Table 250.66, service conductors over 2/0 through 3/0 AWG copper require a 4 AWG copper grounding electrode conductor. 8 AWG serves 2 AWG or smaller, and 2 AWG GEC is for larger service conductors.

Law Reference: 2023 NEC §250.66

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