Looked at a Miller Legend NT for sale. The 60 and 100 Hz output
seemed ok (slightly low) and the AC welding output worked. There
was no DC welding output. We looked at the rectifier and found
nothing visibly wrong: Connections seemed tight, no signs of
overheating. I could not make sense of the rectifier in-circuit,
it seemed to have continuity in all directions with less than
1 V drop, but the test current is only a couple milliamps, so
it likely isn't relevant.
Has anybody encountered this problem? Google found essentially
nothing on the likely keywords. The rectifier seems available,
but the inductor (called DC-Z in the parts list) is not. Being
flummoxed I only offered $400, but the seller said he was in for
$1500 and didn't want to take the loss. I'd raise the offer if
I had a clue to what's wrong.
The welder is in fair shape: 3500 hours, starts easily, puffs
smoke on start but clears up. Oil and air filter appear to have
never been changed. Slip rings are good, visible but not feelable
grooves. Tin is beat up but complete. I'm unlikely to wear it out.
Thanks for reading,
8 years ago