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Miller Multimatic 220, question about 120v operation

4.7K views 2 replies 3 participants last post by  Broccoli1  
#1 · (Edited)
Maybe I'm missing something but can you actually even run this thing effectively on 120v?

Obviously it has a 1-15P for it but it draws up to 24 amps even running on 120v. So you would want to run it on a 30 amp breaker but as far as I know, those 1-15r receptacles are only good up to 20 amps. Is the idea that you would put it on a 20 amp circuit and just try not to trip it?
Seems like if I'm going to run it dependably I'm gonna need to install a 30 amp breaker anyway so it seems like I might as well just make it 240 while I'm at it.

This brings me to my next question: If I'm not going to be doing much stick welding I'd probably be fine on a 30 amp breaker, but that nema 6-50 is meant for 50 amps. Can I put that 50 amp receptacle on a 30 amp circuit or do I really need to go for the heavier gauge wire and bigger breaker and everything?
 
#2 ·
Is the idea that you would put it on a 20 amp circuit and just try not to trip it?


In a nutshell, yes. You're limited to roughly 90-100A on a 120V/20A breaker when using a decent quality inverter welder, regardless of brand. 105A if you can keep the arc voltage low.
 
#3 ·
"Can I put that 50 amp receptacle on a 30 amp circuit or do I really need to go for the heavier gauge wire and bigger breaker and everything?"

Yes.

If you have to run a new line, might as well put in a 40amp breaker #8 wire.

But if you already have a 30amp circuit and just need to change the plug to 6-50, that will work for what you mentioned.