Generator grounding 2 questions

[cppoly]

A generator is only required to be grounded at the generator with a grounding electrode system if it is separately derived using a 4 pole transfer switch correct? Meaning do not provide a grounding electrode conductor at the generator if a 3 pole ATS is used?

Also, if a 3 pole ATS is used, is an equipment grounding conductor required to be run from the 3 pole ATS back to the generator so that the generator metal frame is bonded to the EGC?

 

[ActionDave]

A generator is only required to be grounded at the generator with a grounding electrode system if it is separately derived using a 4 pole transfer switch correct? Meaning do not provide a grounding electrode conductor at the generator if a 3 pole ATS is used?

Correct, but some manufacturer instructions, Generac notoriously, ask for a ground rod.

Also, if a 3 pole ATS is used, is an equipment grounding conductor required to be run from the 3 pole ATS back to the generator so that the generator metal frame is bonded to the EGC?

Correct. 250.35

 

[cppoly]

Correct, but some manufacturer instructions, Generac notoriously, ask for a ground rod.



Correct. 250.35

Thanks!

Regarding your first answer, is it allowed to do a ground a rod if the manufacturer installation requires it, but then you'd be creating stray current back on this system??

 

[raider1]

Thanks!

Regarding your first answer, is it allowed to do a ground a rod if the manufacturer installation requires it, but then you'd be creating stray current back on this system??

The ground rod would be installed as an Auxiliary Grounding Electrode in accordance with 250.54 and the ground rod would be connected to the Equipment Grounding conductor not the grounded conductor.

Chris

 

[cppoly]

Thanks