[LazyPup]

The welders input power draw is 230v 15a.

The output power to the welding leads is 36v and an adjustable amperage range from 30-120amps.

At 120a it has a maximum duty cycle of 15% which means you can only run an arc for 9 seconds out of every minute at the maximum amp draw of 120amps, otherwise you run a risk of overheating the unit.

There should be a table printed on the unit that will define what the duty cycle is for each amperage available.

i can't imagine anyone dumb enough to use a 40amp breaker to feed AWG 14 wire. I don't have a wire ampacity chart handy but I would suspect that AWG 14 wire would vaporize from heat before the breaker would trip. Wire is just tooo cheap to take chances like that.

The post doesn't state how long the run is from the main electrical panel to the point where the welder outlet is but if it were me, I would consider keeping the 40a breakers at the main panel and running a new wire to a small 4 slot sub-panel where I could install a dual 15am breaker for the welder and a couple 120v 20A circuits for a Grinder and sawzall at the welding station.

Perhaps Hayzee will pop in and tell us what size wire he would need.