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Tuesday, November 8, 2022
Question:
Hi Charlie, when wiring a detached garage of a single-family house using a 20A, 3-wire circuit (2 hots and 1 neutral) does the code require ground rods to be installed at the garage? The garage has a disconnecting means that is a single 20 ampere double pole switch, one phase supplies the lights, and the other phase supplies the receptacles. Am I required to install a grounding electrode system at the garage? Thanks in advance, Tom Smith
A
Answer:
Hi Tom, looking at the Exception to Section 250.32(A) – “
A grounding electrode shall not be required where only a single branch circuit, including a multiwire branch circuit, supplies the building or structure and the branch circuit includes an equipment grounding conductor for grounding the normally non–current-carrying metal parts of equipment”. Based on the information provided in your question, the garage is being supplied by a multi-wire branch circuit. If that branch circuit includes an acceptable equipment grounding conductor as listed in Section 250.118 and sized in accordance with Table 250.122, a grounding electrode system (Ground Rods) would not be required.