3 Phase Welders running of a 3 phase converter

I would say yes to a rotary converter. There will be a large current spike when the arc is struck although the leakage reactance of the Transformer would limit this. I would also say that the rotary converter should also have a large (can't quantify though) flywheel such that it will be able to smooth out the incoming current spike...the kinetic energy in the flywheel supplying most of this initial energy.

Rob.

Charles, Is it a genuine 3 phase welder? I ask because a lot are two phase, ie they only have one coil and both ends are a phase so in effect it's a

440v input. These will run off single phase but only output 1/2 the power. Often this type is also dual voltage with the 240 input at double the amps.

John S.

what it says on the asthmatic website

Booster=99 three phase conversion with welders Boosters=99 are designed to run induction motors most efficiently. Welders can also be operated but the converter size should be chosen to be larger than the welder input power by 50%. If no power rating is shown then multiply the welding current by 50 for A series converters or by 30 for D series converters. The result will be the converter power rating in Watts for 100 % duty factor, often misnamed duty cycle.

all the best.markj