Millermatic 211 mig runs fine but is suddenly underpowered

[michos]

Ive got an issue coming up with my 211. It always ran fine until recently. Everything works as you would expect except that it seems as though it is underpowered. I was welding some 1/4" sheet on 230v and had to crank it up as high as it would go to make any real penetration into the metal. Had a good sounding sizzle. I thought maybe it was just a fluke with the metal but then I just tried to weld some aluminum with the spool gun and it just wouldn't work. No penetration at all. I recently cleaned the connectors for the ground so I don't think thats what it is. Any ideas what might be wrong with my welder and how I might fix it?

Not sure if this is a coincidence but I did recently do a big project where I had to run it off of 110v from a 100ft cord but the cord was quite thick.

[cruizer]

Tough call. Though in all likelihood, your missing a phase on 230

[michos]

Thanks cruizer, though the 211 is a single phase welder no?

[derrickd]

Single phase 230 actually consists of two "legs" of 115v. The 3rd prong on the plug carries no current, unless you loose a "leg", then the 3rd prong would act as a neutral, the same as a reg 115v circuit.
You can test your outlet with a voltmeter. The flat prongs are the legs, the round one is ground on a standard welder receptacle. You should show about 115v between either leg and ground and 230v between the 2 legs.

[cruizer]

An add to the above, we dont check each leg to ground for the simple reason that you could have 2 legs on the same circuit each showing 115 Vac. Have to check the 2 legs to them selves.

[michos]

Thank you for the responses. I checked each leg on the outlet individually and they both read 115 and together read 230. Not sure what to test at this point to see what else may be the issue. Any thoughts?

[cruizer]

Well, try it on 110 again. If it works well there, then best to take it in for service as its not relinking for 230 properly. Nothing inside you can do.