Need some guidance please. When installing an electrical distribution system, what is the requirement for grounding the sub-panels? Are we required to drive a ground rod for each sub-panel? I think not. I've always been taught/told to bond the sub-panels to the service entrance using a grounding conductor sized for the sub-panel's feeder circuit, and the service entrance is connected to the ground rod, but I can't find the reference in the 2002 NEC. Is there one?
Is the sub panel in the same building? Is it fed with a metalic conduit?
If yes, yes, your done. If yes, no, Pull a equipment ground sized to 250.122, and do not bond the neutral to the ground in the sub panel. Terminate the EGC to a lug or ground bar bonded to the panel
