Home generator grounding

[romeo]

Home generator grounding

Unless the specs calls for it.We've been installing 4/0 cu. around the foundation with 4 rods , 2 to the rebar matts 1 to the frame 1 to the gen terminals ground bar 1 for the house panel.All that for non SDS.

No parallel neutral then?? Some engineers idea I think.

 

[iwire]

Unless the specs calls for it.We've been installing 4/0 cu. around the foundation with 4 rods , 2 to the rebar matts 1 to the frame 1 to the gen terminals ground bar 1 for the house panel.All that for non SDS.

Why are you doing all that?

I thought this thread was about Home Generator Grounding

IMO that is major overkill for a home generator and really could be overkill for a commercial installation for non-SDS.

We should keep in mind that a non-SDS gen set is always connected to a grounding electrode system via the EGC.

 

[tryinghard]

I seem to get different answers for the need to put a seperate copper ground stake in on a 120/240 home generator system. Some have said you must install an 8 foot 5/8 copper stake. Others say if the generator is grounded through wiring to the home, ( which they are ) you would be creating a ground loop.
What is the correct way for this application...

And

I am still not clear, I seem to be getting different answers. This is an Automatic start and automatic transfer unit. The generator sits outside permanently, sometimes it sits on a preformed concrete slab, sometimes on a Polly slab over some pea gravel. It has a ground wire from the generator to the transfer switch and to the panel which is grounded to utility ground.

Your generator is a supply source and its circuit is a feeder, it is not a service. If the transfer switch breaks the neutral it causes this generator supply source to be a separately derived system (SDS) and you?ll need to re-establish the ground and neutral bond to enable lightning and ground fault protection.
If the transfer switch does NOT break the neutral (most common) it is not a SDS and you do not have to re-establish the ground and neutral bond because the feeder circuit will already include these through the neutral and equipment grounding with the feeder. In other words these will have connection at the feeder destination from the existing service because your transfer switch isn?t breaking them. 250-24(A) will be met because you still have one service-supplied system.

I agree with Pierre C Belarge post #8 ?Separate structures SUPPLIED by the house would require a grounding electrode system. Generators are not supplied by the house, hence that requirement is not applicable.?

But as dezwitinc states post #12 ?If you are still connected to the utility neutral (non SDS) then you do not need a ground rod.
Guardian/Generac requires a ground rod for lightning "protection". So because of manufacture requirement you may have to provide an electrode (for lightning protection, 250-4(A)(1)). You will still need a 4-wire feeder (A, B, N, & G) and you simply install an electrode with an electrode conductor that terminates on the transfer switch metal case, do not bond the neutral. The EGC with the generator feeder will need to be sized from 250-122.
I think in your application you only need an electrode at the generator if the manufacture requires it, NEC doesn?t.