transformer calculation

[ghenderson]

i have a client w/ a 277/480v, 3p distribution. i need to install a 400a single phase panel to primarily feed four 60amp, welders and 4 fractional h.p. exhaust blowers as well as misc local area lighting. What size transformer should i use?

 

[augie47]

A question best answered by one of the engineers here, but I would ask (a) what voltage secondary, (b) can all (4) welders operate at the same time, and (c) what is the duty cycle on the welders.

 

[charlie b]

To that list of questions I will add the more specific question, what voltage do the welders use (i.e., 120, 208, 240, something else)?