Ground rod at separate building?

[Mike Pettitt]

One more time please. When and under what circumstances is an additional ground rod required on a separate building such as a detached garage with sub-panel.

[Jeffrey R. Pope]

Simple version = Each building requires its own GEC if it has an electrical panel. 250.32(A)

[Mike Pettitt]

Jeff, thanks for the quick reply. Are you saying that anytime you have a separate building with an electrical panel that a ground rod is required irregardless whether its a three or four wire feed.

[Jeffrey R. Pope]

Basically, yes.

Here is the code reference. . .

Where two or more buildings or structures are supplied from a common ac service by a feeder(s) or branch circuit(s), the grounding electrode(s) required in Part III of this article at each building or structure shall be connected in the manner specified in 250.32(B) or (C). Where there are no existing grounding electrodes, the grounding electrode(s) required in Part III of this article shall be installed.

Exception: A grounding electrode at a separate building or structure shall not be required where only one branch circuit supplies the building or structure and the branch circuit includes an equipment grounding conductor for grounding the conductive non-current-carrying parts of all equipment.

[Mike Pettitt]

Thanks Jeff, thats what I needed.