I have a Chicago Electric ( China) welding machine. It's a Dual Mig 131, Rated AC input 120 volts, 1 phase, 60 hertz, 21 amp. The electrical cord has a regular plug with 14AWGx3c wire. Can I install a 30 amp breaker in the main panel, and come off to a 30 amp receptecal. Then use a 50' extension cord to work outside. Would 12/3 wire be OK for the cord or would I need 10/3. Would this work OK? Any advice would be greatly appreciated. Thanks, Will