Using a Generator to Run a Welder?

[Dennis McGill]

I have a Campbell Hausfeld 115 Volt MIG / Flux-Core Welder

• Output range: 30-100 Amps
• Duty cycle: 70 Amps @ 20%
• Provides consistent wire speed for smooth welds
• 8' gun assembly and ground cable

Can I run it using a generator? And if so, how big a generator do I need? I don't have power where I want to build my arch and sugar shack.

Thanks for any thoughts.
McGill

[maple flats]

What are the input ratings of the welder? For running a welder you generally want a generator with a constant output of at least 2x the input of the welder for a good weld. The other way to find out is to use an amp gauge and plug the welder in at your shop with the gauge connected. Then strike an arc a few time and take the highest amp reading. Your generator wants to be at least 1.25% of that highest reading for it's constant rated output, not surge output.

[Dennis McGill]

Dave thanks for your info. It appears that the input rating is 20amps. Does that make sense?

[VT_K9]

20 AMPS sounds reasonable for a small machine. Many outlets for welders are 30 AMP circuits. I have a Miller 180 mig welder. I have 2 6500 watt generators which can handle 30 AMP, or so the claim is. My Generac does not run the welder. My Champion does run the welder. The Generac is about 17 years old and has never failed me. I would recommend a 6500+ watt generator if you want to be able to run a welder with any reliability. If price is a concern or specific generator is on your mind list which one and you may get more or better responses.

Mike

[maple flats]

Dave thanks for your info. It appears that the input rating is 20amps. Does that make sense? It could be, but don't go just by the statement it may say, to plug it into a 20A circuit. See if there is in smaller print, an actual input amp rating, there should be. Then work up from that. While it says to plug into a 20A outlet, household power is more constant, it does not have much of an initial drop in voltage upon start up. A generator must sense the load and then respond, thus there is more of a temporary voltage drop. This would happen each time you draw an arc and it will be harder to get a nice weld at each new arc strike. For that reason, you need a bigger welder than just one that says it will run a 20A circuit.

[Cedar Eater]

Does the welder have a normal 3-prong 115V plug? If it does, that's only rated for 15A continuous. 15 X 115 = 1725W. Theoretically, a 2000W generator could drive that, but I personally wouldn't go lower than 1.5 X the plug rating. 1.5 X 15 X 115 = 2587W continuous. There are two ratings on generators, the continuous and the peak. Make sure you look at the continuous rating.

[Dennis McGill]

Thanks CE, Your explanation is the info I've been looking for.

[BreezyHill]

Don't for get about the inrush of the unit on the generator. If you undersize the generator you will burn up the wielder with low voltage. When I have welded off a generator you will hear the generator slow and speed up due to the inrush of power to the wielder. I would rather see you go with Daves 2x to be safe. I have burned up wielders on low grid voltage before and it is costly to repair.

Ben