Slightly over 30 amp, but a slow trip 30 should do it. 20 amps will work though for TIG fairly well IF you are running in a delayed trip breaker on an circuit that is isolated from other current draw. I used it up to 150 amps with the pedal, and probably was in the 110 to 120 amp range most of the time and did not trip. Did trip at 110 amps with stick though.