First off you'll have to tell me what kind of conductors you are using. Even with the allowances for welder #4 copper (at any rating) isn't big enough. Depending on what you are using you will need something along the lines of 1/0 or 2/0 for that size welder.

The other issue is voltage drop, but 2/0 wouldn't be a bad idea.

The supply conductors for a dedicated welder circuit are sized using the rated AC input amps and the duty cycle for the maximum rated welding amps. So first we need to know the input amps off the name plate, next we need to know what the duty cycle is at the maximum rated output (welding amps). (The actual welding amps that you gave us are not used for sizing the circuit).

This post was edited by joefixit2 on Sat, Feb 22, 14 at 11:12

Gack JoeFixit is right. My mind was elsewhere. You need to know what the AC input rating is. Many of the smaller ones can run on either 120 or 240, so you get by with lower required amps and less voltage drop on 240.

The output rating of the welder is irrelevant. What is the input rating?

This is a welder i was looking at buying (miller syncrowave 250dx tig runner)what i found out is that input v@220 -77amp- Min. Conductor #6- Max.lenght 119' - min. ground #6 so i dont think i can use this welder in this location were i have 60amp 2/#4 and 2/#6 @ 210' I guess ill have to go with a smaller machine

#6 would be acceptable except for the very long run. #4 would have a reasonable voltage drop at 77 Amps.

Just a thought. I run a Miller Dialarc AC/DC 250A. It can be wired for 220v or 440v. I run it off a 220v 50A circuit.

Technically it is capable of drawing something like 90A input, but I've never needed near that much current. Hell I'm not welding 2" plate steel with it. Most of what I weld is 1/4" or 3/8". For that, a 50A input is plenty. I can crank it up so hot to melt welding electrodes and never blown the breaker.

I weld with a heavy duty industrial welder not because I need all the amps, but because it's continuous duty with 1/8" rod and welds much more smoothly than a typical buzz box.

I'm sure there are people who will point out my circuit is sized too small but there is just no need for such a heavy duty circuit unless you are welding some serious heavy duty plate.

If anyone can point out a significant safety concern with my setup, I'll stand corrected.