I’ve used an XMT for years, just not this particular machine. Picked this one up off of eBay, from a reputable seller. Works great in pulsed MIG (with an Optima). Set my machine up for Lift Arc TIG last night, worked great – but had a sporadic issue.
Was initiating an arc, and all of a sudden the machine starting chattering (contactor) – bead was horrible, and it was almost "split" lengthwise in appearance. Stopped welding immediately, and cycled the machine on and off. Didn’t occur again for the remainder of the evening. Also, I’ve noticed that the machine will "tick" softly while it’s sitting idle. I’ve never heard this noise with the other XMTs that I’ve used, though they were also being used in a noisier environment.
I checked that the lugs on the main board were within torque spec as soon as the machine arrived, however – I’m going to recheck things today. Also, I will inspect the power contactor, to ensure that the springs aren’t gummed up with junk.
Any other suggestions?
Thanks,
Jake