Stick welder always too cold

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Hello everyone, this is my first post so bear with me. Im a longtime hobbyist who loves building things and a year ago i thought I would upgrade my small home shop's capabilities by buying a used airco stick welder off craigslist. Its an older unit but stick welders seem to be pretty bulletproof so i bought it anyway. Its a 250amp AC/DC unit.All that being said, ive been having a lot of trouble with it. It doesnt seem to have anywhere near the amperage its rated for, as all of my welds seem to be too cold. At a reasonable 100-120 amp setting i can barely even maintain an arc. For kicks and giggles i turned it all the way up to 250amps and the arc was much better but it still barely penetrated the metal.. and also i only have it hooked up to a 30 amp 230v circuit (its rated for a 50 amp circuit) so 250 amp output should have kicked the breaker but it did not, which leads me to believe it is not putting out as many amps as it should be. I took it a part to have a look at the innards but I could not see anything wrong.Any ideas? Here are some pics.
Reply:Are you sure you actually have 230V to the machine?  Two hots and a ground ..."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Man that machine is a pos! I used one just like it on a job and had to set it at 200 to run 3/32 6011s!Not to mention the rectifier wasn't working and I got hit with AC while welding some boiler pipe. Scrap the pos and get a lincoln or hobart.....I'd give ya $50 just to let me drop it off a bridge
Reply:If it works fine on AC, but is weak on DC, it's bad rectifiers. If one rectifier goes out, it will only be passing half the DC current, which will result in a weak and erratic DC arc.Everlast PA160-STH... and that's about it!
Reply:Originally Posted by jamesyarbroughI'd give ya $50 just to let me drop it off a bridge
Reply:Yup, weld with it on AC and see if it's ok.If that works, I would check the diodes.Dave J.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Check the selector knob is on in the right position.
Reply:Actually, those are pretty nice machines- not as smooth as an Idealarc but quite decent. To expand on what Walker said, the amp selector is coupled to an iron shunt. When the selector is at the lowest setting, the shunt is all the way inside the core. At the highest setting, the iron part of the shunt should be all the way outside of the core.As stated above:Make sure you really have 230V on the primary side. Easy to mess up if using a dryer or range outlet.Test the diodes. If you're not sure how, ask someone with knowledge of electronics. You will need a good quality meter and will have to disconnect one end of each diode.Turn it all the way up. Run a few beads. UNPLUG THE WELDER and check internal and external connections to see if any are getting hot. If any connections are more than luke warm, disassemble them, wire brush everything, and reassemble with Noalox or anti-seize compound.That should about cover it, not much else to go wrong in those old transformer machines.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Make sure you really have 230V on the primary side. Easy to mess up if using a dryer or range outlet.