3 phase welder in 3 phase convertor

Charles, most don't actually use all three phase, just use two phases to give 415v to reduce the current - this can easily be determined opening up the back of the welder by seeing if it has a three bobbin or a one bobbin transformer. If indeed it is one using two phases you will get away using a suitably sized 240 to 415 transformer.

AWEM

(pst - want to buy a big 240 to 415v transformer as I have one surplus)

Does anyone has experience of running a 3 phase MIG welder from either

I've seen mention of using power-factor correction cap's to generate a "wild leg" for welders - it was on one of the american metalworking sites, perhaps Practical machinist? The real problem is likely to be getting 380 - 415 volts in though. I think a rotary convertor is going to need a *big* motor though, if the welder's expecting to pull (e.g.) 5 KVA form 3-phase, the motor will need to be 10HP or more to do the job, and will stiull need some way of stepping up the voltage - most often this would be an old 240/415 volt welder....

Dave H. (the other one)