transformer for welder

[sybrandy]

I have a 220V single phase welder. I have 480V 3phase to feed it with. I know that I can tap off of one phase and use a transformer to step down to 220V. The welder is 20Amps which would, in my calculations, equal a 5KVA transformer. Since this is intermittent duty, is there any way to downsize this transformer? 5KVA is pretty big physically.

 

[sybrandy]

Maybe this is a question for the NEC page

 

[mdshunk]

Maybe you've already checked into it, but many of the good welders have taps inside that you can change around to feed them with one of several voltages.