Hi
I have a Ozito 135 Amp mig 220V has a blown varistor with no ID only thing I can tell you it is green about the size of a small coin and thin, just interested in getting it going so any idea..
Much involved in upgrading?? seem to me the WFM stops for a split second so I end up with a bad weld..
thanks
The wirefeed shouldnt be affected by the varistor, its there primarily to prevent noise from getting back onto the mains caused by switching transients.
I couldnt just guess a value, depends on many factors, can you get a diagram, or is there anything at all visible on the old part.
Being across the main bridge rectifier assy it's likely only a 100- 200 volt device. A quick and rather effective fix is to install .1 uf 200 volt (or higher voltage rated) non polar capacitors across the two plates plus one across each diode.