Big supply advice

[Zahid Nawab]

Hello all. I have be asked to do a job on a large installation with multiple AC unit exceeding 300amps per phase. This is not including the general items so it's safe to say around 400amps. The supply there at the moment is a 100amp three phase so I would like to know how to go about it. I obviously need a bigger supply from the dno, but how much would it cost roughly and would it require a standalone transformer? My second question is as it enters the building, is it best to run it into a buss bar first and then split off to my isolators or into a 3 phase panel and then to my other three phase boards. What would be the easiest option or have I missed something out. The size is a first for ne, never really worked above 100amps three phase. Thank you in advance

 

[James]

I would be looking at a main distribution board to split supply off to local boards for the loads.

However, it is nor possible to specify without knowing the expected loading.

Do your investigations and calculations exactly the same as you would for a smaller supply.