Fire pump controller ATS and separately derived generator


Senior Member
I have fire pump controller and ATS all in one. The breakers are not part of ATS controller. The ATS is three poles and the generator is separately derived existing with three other generator breakers feeding some other loads.

Yes I know huh how can generator be separately derived while controller ATS is 3 pole. From the generator side their is no neutral coming but their is equipment grounding conductor coming from the generator breaker to ATS.

In 4 pole ATS neutral is switched not the equipment grounding conductor. EGC remains unswitched. However in case of 3 pole fire pump ATS their is no neutral to switch no neutral is brought and just like 4 pole ATS EGC is not switched. So I dont see what the problem is wiring 3 pole fire pump ATS controller with separately derived generator. No neutral is being brought so not a matter of switching the neutral while EGC remains unswitched just like 4 pole ATS.

The inspector came and said the generator has to be separately derived or the ATS 4 poles per NEC 2014 Article 250.30. Well they dont make 4 poles ATS fire pump controller all in one. I explained what first two paragraphs says but he says where is it in NEC 2014.

He looked at me funny and left. Not sure is my setup 3 poles Fire Pump ATS controller combo with separately dervied generator ok or something is not per code? Am I missing something?


Senior Member
If there is no neutral brought to the Fire Pump ATS, then there is no need for a 4 pole fire pump ATS, even if there is a N-G bond at the generator (SDS)