Generator Grounding as a separately derived system

[cjreng2014]

For a generator that is grounded as a separately derived system, is it common to bring the ground electrode conductor back to the building ground electrode system or create a new ground electrode system (ground rods in generator area)? If a new ground electrode system is provided is it required to bond to the building ground electrode system?

 

[Dennis Alwon]

From what I understand unless the manufacturer requires ground rods or some other electrode at the generator itself then it is not required.

 

[cjreng2014]

So since its a separately derived system that requires a ground electrode connection, you would suggest bringing a ground electrode conductor directly to the building ground electrode system?

 

[cjreng2014]

I guess to answer my own question, 250.30 (A) (7) would require the ground electrode to be as near as practical, which in my opinion would mean driving ground rods in a outdoor generator application. I guess my only other question is do I need to bond this electrode to building ground electrode system

 

[Smart $]

Assuming the generator has an integral disconnecting means with OCPD, the bonding will be handled by the EGC run with the feeder.

 

[Smart $]

I guess to answer my own question, 250.30 (A) (7)...

BTW I think you mean 250.30(A)(4).