Want to add new circuit from existing 150amp/ 120/240v,1P panel. Will be adding a welding machine rated input is 50amp @240v. My question is what breaker size and wire gauge should I use? The distance from the existing panel to the new outlet will be about 100 feet in length.

Thanks

TShimaitis

TS, I would use #6 thwn on a 2p 50a c.b.