Multiple electrical services one generator.

[Rioslives]

My name is Christopher Rios and i am the project manager/ electrician in Southampton new york. I have an electrical question that perhaps you might be able to answer and if not maybe it can be passed along to someone that might have the answer.
We have a customer that would like to have one generator installed to control two electrical services that are on the same property and owned by the same owner. We were thinking of using two transfer switches. One for each 100 amp electrical service. Would it be necessary to switch the neutral conductor as well as the phase conductors for each electrical service in order to be NEC compliant? Also, can anyone foresee any issues with doing this. If so why?
Thanks,

 

[waross]

No problem. I did an installation with four services. The supply was single phase, 120:240 Volts. I was able to use two, four pole transfer switches with a solid neutral. (This installation was not under the jurisdiction of the NEC or of the CEC.)
I see no technical reason why a common neutral in a two meter enclosure may not be extended to and through the transfer switch. It is ahead of the individual service panels so it will have no effect on the "One connection from neutral to ground" rules.
I have had several issues with open neutrals due to a failure of a switched neutral transfer device.
But as for NEC compliance, the last word is the AHJ. In my estimation, avoiding issues with a possible open neutral are more important than the extra cost of a neutral switching adder to the transfer switches.
I understand that there are some situations where a switched neutral is needed, but I only switch a neutral when it is the only acceptable option.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[enverd]

You shouldn't have a problem at all.
We did a couple of installations where we had a similar setup and on one occasion we had two services in the same building.

The biggest item to look out for is to have one common grounding point because you need to eliminate potential differences in the building.