What size wire ?

10 gauge is the smallest you can consider. At full power with 10 gauge wire you would lose about 6 volts, dropping your 240 volts down to 234, probably ok. With 8 gauge wire the voltage drop would only be 3.8 volts. Since you probably rarely will run the welder flat out, 10 gauge is probably ok. This is assuming copper wire.

Good luck-

Paul T.

For wire buried in the house walls, #8 is the very minimum with #6 preferred (watch your codes carefully!). If you are talking about an extension cord, you can go one size smaller than the NEC would allow since it is in the open air and stays cooler.

I use a 25' #10 extensi> I am getting an old Lincoln 225 stick welder given to me. You know the type,

A 50 Amp branch ckt should be wired with #6 wire. ...lew...

#6 is probably the best size and may be required for a 50A breaker although there may be allowances for using a 50A breaker with #8 since a welder is an intermittent load. You would have to check your codes to see if this is allowed in your area and you may have to connect the welder is such a manner that it is the only load possible.

Personally I would go with #8 and a 40A breaker unless you think you are going to run it flat out. I have a 225A Miller that I run on the end of about 75' of #8 but granted, I am usually under 160A. I did run a rod with it cranked up to 225 without any problem. I have never tripped the breaker even with the rod stuck down an glowing (about 130A setting). If #8 is OK for you, it is cheaper than #6 and much easier to work with due to its smaller size. billh

He should check the code in his jurisdiction. Here, code recognizes welding as inherently an intermittent activity and therefore allows a 60 amp breaker wired to a welder outlet with #8 wire.

Ted

Do it with #6, and never think about it again. Only a few bucks more to do it right the first time.

Steve

Personally I would run 4 gauge. Overkill never hurt.