What Generator do I need to power my Welding set

The doc says:
Generator friendy, min 10 kVA rating..

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Tim, Con, don't understand your responses to Tom's q

But Tom I don't understand your q either. For the benefit of the few idiots amongst us (me), what's a Mig (Do I remember a German airplane by that moniker....)

..and most of us understand what's meant by pf and amps, the "250A" puzzles an undereducated (me again)

I'm going to answer your question, Dale, even though I know you'll forget it in the next five minutes.

A Mig 250A is a Metal Inert Gas welding device model.

When used with a generator, the latter needs to be a 10 kVA rating.

MiG planes were Russian/Soviet.


The welding arc is generated using around 15 to 25 volts, and the 250 A (ampere) rating is the maximum current at that voltage than can be supplied to the arc.

Alas Tim you've got me pegged

Thanks again Tim as I has imagined it to mean 250 Amps. So the "250A" is a serial no. of some sort


Edited to remark that Con above has confirmed it's indeed 250 amps but I'm still not sure what's rated so much higher, apparently, than needed

Just wait til you're 86

Thanks once more Con, I'm just beginning to get it

250 amps at 25 volts = (250 x 25) VA = 6.25 kVA but there will be losses in the controller unit and - importantly - arc welding is cruel to any power supply. Big spikes (inrush currents) e.g. when the arc is struck. You want a beefy generator, even with a "generator friendly" welding set. Some 250 A sets specify a 7 kVA generator minimum.

When I was a kid you could see in small ads in auto magazines, cheap welding outfits that were just an electrode holder and a return current clamp with leads to connect to a car battery. Believe me those batteries didn't have a long life.

Thanks Con; what had me puzzled was the diff 'tween the two amp ratings. Clearly the 250 is a peak ("big spikes")

I guess

No, it is the maximum continuous low voltage DC current available to the arc during a weld. The unit pulls 38.2 A from the AC power source (power utility or generator) at full power. I suspect this is 220 volts, so we are looking at around 8.4 kVA but they wisely say use a 10 kVA minimum generator.

Con thanks for your patience. I see now that an input of about 40A at about 200 v is about 8 kva. Even my old head....

So ignoring precise detail of arith and eff, output of 250A at about 8 kVA is roughly 30 v

Yes. Arc voltage will vary between around 15 to 30 volts depending on conditions selected by the operator.

Thanks again Con, it's not everyday that...