I have a building w/ a 1 phase 400a service. CT Cab w/ 250 feeders which are tapped to 4/0 through a meter socket and into a 400a Main breaker MDP. Understanding, that the building is only reading about 180a. under load. 2nd I have a 200a 240v 3 phase service. Have a 70a 3p hvac unit I need to power on a generator along with the entire single phase load. Now my associate who has a generator business whom I have worked w/ before and is a friend, says he see's this all the time and sparky's he hass used will wire a back up system this way. Meaning, Use a three phase generator, one 3phase Auto transfer switch and power both systems. I do not see in the code where this is prohibited, but it doesn't seem right. Can someone shed some light and give advise???
Safe to assume that there are no 120V loads? I don't follow, is there two buildings or one building with two services. Will this be an Article 700, 701 or 702 type generator. What will the load side of the ATS serves, a distribution board?
[This message has been edited by Ron (edited 03-26-2004).]
This is one building Ron. I assume you know this A typical a 1phase service and a 3 phase to one building. The significnat load IS 120v. Mainly lighting and office receptacles. This would be a pad mount Onin generator (diesel with automatic transfer switch. There is aprox 180A of load on single phase service. There is a seperate Disconnect off of the 3 phase service which feeds an HVAC unit (70a) I am not seeing how I can feed both services with the generator. What if they are fed from seperate xfmrs on the street. This is in the city and I am not certain where supply is from
[This message has been edited by ayrton (edited 03-26-2004).]