Generator grounding

[mrkc949]

How should a commercial non portable generator be grounded that has
case a - ats that switches neutral
case b - ats that doesnt switch neutral

do you have to put ground rod at generator in either case ?

 

[mwm1752]

There are many ways to skin this cat -- install instructions generally have detail schematics showing options to your examples

 

[mwm1752]

250.30 might help

 

[texie]

How should a commercial non portable generator be grounded that has
case a - ats that switches neutral
case b - ats that doesnt switch neutral

do you have to put ground rod at generator in either case ?

Case A: Must be installed as a SDS. Bonded neutral at genset main breaker. Must have a GES connected at that point. Must have EGC on load side of genset main breaker.
Case B: Install as a non-SDS. Must NOT bond the neutral at genset. Must have EGC to genset. No GES required. You could optionally connect a GES to the the frame of the genset.

 

[cuba_pete]

Case A: Must be installed as a SDS. Bonded neutral at genset main breaker. Must have a GES connected at that point. Must have EGC on load side of genset main breaker.
Case B: Install as a non-SDS. Must NOT bond the neutral at genset. Must have EGC to genset. No GES required. You could optionally connect a GES to the the frame of the genset.

That is pretty succinct.

This should be a sticky...

 

[kwired]

How should a commercial non portable generator be grounded that has
case a - ats that switches neutral
case b - ats that doesnt switch neutral

do you have to put ground rod at generator in either case ?

Usually you are matching the ATS to the system (SDS or non SDS) more so then matching the system to the ATS.

 

[petersonra]

How should a commercial non portable generator be grounded that has
case a - ats that switches neutral
case b - ats that doesnt switch neutral

do you have to put ground rod at generator in either case ?

I seem to recall you are required to use the structure's GES if a connection to a GES is required.

 

[kwired]

I seem to recall you are required to use the structure's GES if a connection to a GES is required.

You do need to tie into the structure's GES. Nothing prohibits installing an additional "supplemental electrode" though.

 

[petersonra]

You do need to tie into the structure's GES. Nothing prohibits installing an additional "supplemental electrode" though.

the OP asked if he HAD to put in ground rods. The answer to that is they would appear to be optional.

but he does have to tie into the structure GES regardless of whether he adds ground rods or not. this is not optional IMO.