Help from a electrician!
I'm a licensed electrician by trade in NJ. As far as welders go in the code book, the gauge of the wire is determined BY THE SIZE OF THE WELDER AND DUTY CYCLE, NOT THE CIRCUIT BREAKER SIZE. Welders aren't continious duty. They have a very short duty cycle and as such, the wire is derated in size. It could be very possible to use #10 AMG for a 60 amp welder! At 240V, I would not be worried about voltage drop. Comparing a 240 volt circuit compared to a 120 volt circuit, both operating at the same wattage, the 240 volt circuit could be 4 times longer in distance before voltage drop becomes a problem. Ohms law.
Most likely you'll need 10/3 SJ or SJO cord, 50 foot will be no problem. You do not need a neutral because you do not have a 120 volt load.
Welders are covered under article 630 in the NEC
Last edited by Huskinhano; 01-08-2004 at 08:24 AM.