RuralTowner
Member
Now for how long it's been doing this I've no clue since it didn't seem to impede the welder's function in the slightest. Before I try to describe what's going on I'll elaborate (briefly) on what I have.
Aforementioned 350D Miller w/ the 2 dials. Left-hand is range. Right is fine tuning. The rig used to see duty at oil rigs in New Mexico and dates from about 1981. I got it about 3 years ago.
It is in the vicinity of the FINE tune rheostat that it will get abnormally warm to hot enough that holding a bare hand on the panel in the upper corner...or on top directly above...will get uncomfortable. It was being used in the 65-130 range (though this is probably unrelated) with FINE setting about midway...about 100A. Wasn't being used on anything particularly major or thick (only 5/16") and for only about 30min total.
It also did so this morning when it was fired up to use it as a generator to keep the all important fridge//freezers from getting too warm after storms knocked out power last night. Ran it in 1hr intervals to permit cool down even though the draw of the 3 appliances was nowhere NEAR what welding pulls.
After the 1st time (after shutdown of course) I lifted the sides to look and tentatively feel. The rheostat was HOT...warm I'd expect but not singing hot.
This second time I took a closer look during interim downtime and did note that the sliding contact looks quite worn down just from PO (ab)use. If it's making poor contact then yes that would do it...BUT I'd like to seek other opinions.
Also, behind the rheostat are 2 cylindrical bars...almost resemble corncobs in appearance except they have zigzag raised lips with leads clamped to different distances along them. One of them is connected to the minimum side of the FINE range.
Images forthcoming.
Aforementioned 350D Miller w/ the 2 dials. Left-hand is range. Right is fine tuning. The rig used to see duty at oil rigs in New Mexico and dates from about 1981. I got it about 3 years ago.
It is in the vicinity of the FINE tune rheostat that it will get abnormally warm to hot enough that holding a bare hand on the panel in the upper corner...or on top directly above...will get uncomfortable. It was being used in the 65-130 range (though this is probably unrelated) with FINE setting about midway...about 100A. Wasn't being used on anything particularly major or thick (only 5/16") and for only about 30min total.
It also did so this morning when it was fired up to use it as a generator to keep the all important fridge//freezers from getting too warm after storms knocked out power last night. Ran it in 1hr intervals to permit cool down even though the draw of the 3 appliances was nowhere NEAR what welding pulls.
After the 1st time (after shutdown of course) I lifted the sides to look and tentatively feel. The rheostat was HOT...warm I'd expect but not singing hot.
This second time I took a closer look during interim downtime and did note that the sliding contact looks quite worn down just from PO (ab)use. If it's making poor contact then yes that would do it...BUT I'd like to seek other opinions.
Also, behind the rheostat are 2 cylindrical bars...almost resemble corncobs in appearance except they have zigzag raised lips with leads clamped to different distances along them. One of them is connected to the minimum side of the FINE range.
Images forthcoming.