We've been asked to put an outdoor generator at a commercial property. The existing service conductors, 800A, 2 sets of (4) 500's, runs from the utility transformer to the building below ground. The utility metering is at the transformer. The service bonding is in the building at the main disconnect. A service rated transfer switch can be used however there's no neutral running to the building just the two sets of (4) 500's. So essentially we're bonding the generator, running through the generator circuit breaker to the service entrance rated transfer switch and then reusing the old service through the other side of the transfer switch and then to the building.
I've never done this before and I want to be certain it's acceptable. I spoke to the electrical inspector and he said it's fine, happens all the time. His feeling is that downstream of the ATS, we're simply providing a service. I checked in the code and we meet the requirements for 250.32 " buildings or structures supplied by feeders or branch circuits", B, exception. Battery charger, heater power, etc are supplies off the transfer switch so there's no ground between the ATS and the building. It's not clear to me that we have to meet 250.32 - the inspector feels it does not apply.
Thanks for the help.
I've never done this before and I want to be certain it's acceptable. I spoke to the electrical inspector and he said it's fine, happens all the time. His feeling is that downstream of the ATS, we're simply providing a service. I checked in the code and we meet the requirements for 250.32 " buildings or structures supplied by feeders or branch circuits", B, exception. Battery charger, heater power, etc are supplies off the transfer switch so there's no ground between the ATS and the building. It's not clear to me that we have to meet 250.32 - the inspector feels it does not apply.
Thanks for the help.
