A high-rise apartment building is to be served by a 400A, 480V, 3-phase feeder. What is the minimum size of the grounding electrode conductor required according to 250.66(A)(1)?

Texas Master exam practice question · Feeders

A high-rise apartment building is to be served by a 400A, 480V, 3-phase feeder. What is the minimum size of the grounding electrode conductor required according to 250.66(A)(1)?

A1/0 AWG
2/0 AWG
C3/0 AWG
D4/0 AWG

Exam tip

Always refer to 250.66(A)(1) for the minimum size of grounding electrode conductors.

Why B is correct

According to 250.66(A)(1), the minimum size of the grounding electrode conductor required for a 400A, 480V, 3-phase feeder is 2/0 AWG. The other options are larger and not necessary for this application.

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A high-rise apartment building is to be served by a 400A, 480V, 3-phase feeder. What is the minimum size of the grounding electrode conductor required according to 250.66(A)(1)?

A high-rise apartment building is to be served by a 400A, 480V, 3-phase feeder. What is the minimum size of the grounding electrode conductor required according to 250.66(A)(1)?

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