A commercial building has a single 120/240V, 3-phase, 4-wire service. What is the minimum grounding electrode conductor size required?

Texas Master exam practice question · Wiring Methods & Materials

A commercial building has a single 120/240V, 3-phase, 4-wire service. What is the minimum grounding electrode conductor size required?

A6 AWG
8 AWG
C10 AWG
D12 AWG

Exam tip

Always refer to the specific requirements for grounding electrode conductor sizes in the NEC.

Why B is correct

According to 2026 NEC Article 250.66(A), the minimum grounding electrode conductor size for a 120/240V, 3-phase, 4-wire service is 8 AWG. The correct answer is 8 AWG.

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A commercial building has a single 120/240V, 3-phase, 4-wire service. What is the minimum grounding electrode conductor size required?

A commercial building has a single 120/240V, 3-phase, 4-wire service. What is the minimum grounding electrode conductor size required?

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