Originally Posted by SirPorkaLot
Not exactly. The circuit breaker is there to protect the wire.
In theory it will trip before a wire gets hot enough to melt and short circuit.
NEC requires a 12 awg wire to be protected at 20A and a 14 awg wire to be protected at 15A.
14 awg wire will run 20 amps fine, but will get warm.
It is voltage drop that will get ya.
Running a welder on 14 awg wire over a long distance will lower the voltage (due to the resistance), which increases the current draw (amps) of the welder.
I imagine if you were to put a voltmeter on the circuit in question while you welding, you would probably see a significant voltage drop (10-15 volts) from the panel to the welder. So even if you are leaving panel at 120V, you may only be seeing 105 volts at the welder.
Which of course raises the amps the welder is pulling, and tripping the breaker.
Either way...I would look at how many Amps the welder is rated to draw and make sure that the outlet it was plugged into had a dedicated breaker rated for those Amps. And I don't think I would run less than a 20 Amp breaker for a buzz box welder. But that may be just me being paranoid from seeing what the out come can be because of running a lower amp breaker and outlet.
It causes concern to hear that a breaker is tripping often when welding is occuring and nothing is changing to keep it from hapenning. It's telling you that some thing in the electrical system can't handle what you're doing and things can get real ugly real fast if some thing doesn't change. I'd had to see some one get hurt when it's avoidable is all.