50 ft of 14 will drop 8 volts on the way in with that machine juiced right up, about 4 on 50ft 12. The cord is 14 in the strip, that don't hurt it much but it spikes current way past that cheap breaker in it. It will tolerate some drop in the wire but it needs a 20A breaker unless you had it turned down to weld foil and that is iffy. I bought a nice 12 for welders and lost it along the way, bought a couple more on super sale at Menards, they are not quite as good but were 15$ for 25 maybe. I really had to look to find them. I carry 50 ft on my truck, I lose a little but 1 cord does it all.