Electrical – How many ground rods are required for panel and subpanel


I have a main service panel with two breakers: the main service breaker and a single large breaker to another subpanel in the same structure.

All other circuits are serviced from the subpanel.

My understanding of NEC is that each panel requires two grounding rods at least 6 feet apart.

My home uses PEX but there is a copper main coming in on the opposite side of the crawlspace.

Do I need two full ground rods per panel? So four, total, rods?

Best Answer

Do not connect the sub panel to grounding electrodes. A grounding conductor must be run back to the main service panel. The main service panel is the only connection to a grounding electrode system in a single building without a separate means such as a genset. The underground metal pipe could be used as an electrode, but it sounds distant. So you should install two ground rods near the service entrance and connect those to the service panel.