Welding Tips and Tricks

New to the forum and hope this post is in the right spot. I just bought an old Airco 300 amp AC/DC heliwelder with lots of extras for great price. Brought home and fired it up. Several seconds for it to start running,like a car with low battery trying to turn over. Once fan kicked in, machine was humming but just didn't sound full go. Shut it down, removed panels, blew out generous amount of dust. Cleaned jumpers, ground, leads. Tried switch again, loud click, machine humming low pitch, fan jerked ever so slightly but now not rotating. Humming sounds like it is coming from fan motor? I shut it down and am reaching out for advice. I know nothing about these large old machines, only experience with Lincoln tombstone and oxyacetylene. I would be grateful for any advice. Thanks, Dave....Airco model 3a/ddr - 224hpa/b-d

Not familiar with that model but sounds like bridge links were set for a different input voltage maybe ? couple of guys here have that or similar model should be able to advise.

noddybrian wrote:Not familiar with that model but sounds like bridge links were set for a different input voltage maybe ? couple of guys here have that or similar model should be able to advise.

Thanks for the info. Turned out that the welder itself was fan, but the bearings in the fan motor were completely seized. Replacements in and running great! Now I just need to learn how to TIG. Very nice stick welder as well.


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