step up transformer

[hardworkingstiff]

I need a 75-KVA NEMA 3R step up transformer (240 to 480, single-phase). Any input as to the best place to find it? After reading previous posts about the issues in using a transformer hooked up backwards to perform this function, I figure it's better to just buy one that is built for my purpose. (Actually a 240 to 600 would be better).

 

[e57]

Any input as to the best place to find it?

Quotes from local supply houses that know they are competing for your money.....

Never gotten anything that heavy on the internet - no wait got a 2000lbs UPS once... Shipping was a PITA.... Had to rent a fork-lift to get it off the truck and on-site....

 

[lbwireman]

Go here

Go here

www.acmepowerdist.com
Ask to talk to a tech (Ronald's very sharp). They're very helpful. Also get their catalogue. Best xformer resource you'll find.

 

[john reese]

square D can help. according to our rep their transformers work just as good in either direction or you can pay them some extra bucks and get the nameplate to read the way you want it to. we use the standard transformer backwards frequently for tower cranes and havent had any problems.

 

[winnie]

Note that there are significantly fewer problems associated with _single_ phase transformers when reverse connected.

The biggest problems with reverse connected transformers are associated with proper grounding of the secondary. Delta secondaries are a pain to ground properly. But there are no wye/delta issues with single phase transformers.

You may still have difficulties with the inrush current associated with the different 'leakage inductance' associated with the primary and secondary windings. You are very likely to find single phase transformers that are suitable for either step-up or step-down service.

-Jon