idealarc tig 250/250 tripping breakers

yesterday my machine started tripping the panel's
breaker, immediatly on power up. resetting at the
fusebox fixed it ...but now it trips the breaker
about 1 in 5 times i turn it on . the welder is
working properly , tig and stick ...and had no
complaints welding 5/8 " plate w/ 1/4" electrode
at 240A dc. in the last few days.

i tried disconnecting ground , looked to see if
the cabling had a hole that could be grounding
to something...nothing . maybe the contactor?

i've never had this machine apart + don't really know where to start .
i have the idealarc tig 250/250 from the mid
1980's - the red one (orange now) with the square
enclosure + louvers .....
i know there's tons of these machines out
there , so someone must've had a similar problem?

Tnmg, is it tripping the fuse box in your wall or is it the machine itself that is kicking off? If it is the machine itself that is kicking off, it may be the safety circuit that shuts off the power when the OCV exceeds 80 volts. I have seen these older Lincolns do this on a number of different machines. There are numerous wire bundles in some of these machines that are taped together and held in place with paper tape. As the tape dries out with age these wire bundles can drop down and hover close to the 80 OCV safety circuit. If a fallen wire bundle is close and has enough current running thru it, it can induce enough current into the safety circuit to trip out the machine. Take off your side panels and if you have any fallen wire bundles just tie them back up with some plastic zip ties. If it is tripping your wall panel then you may be in for a more expensive repair.

I would take an amp meter and measure current on start up. If that is normal then breaker is undersized or worn out. If you use the breaker as a switch worn out is more likely.

tnmgcarbide:
Be aware that a number of machines of your type were shipped from the factory with the control circut wired backwards to the reactor. They work fine for awhile, then problems. Got this information from an engineer at Lincon when i bought one of these machines used. Check it out. Also some of these have impediance matching capacitors on the imput line (option) without this option the operating current for your welder goes to over 70 amps. If your machine has the capicators they may have failed and the start current has gone to the moon without them.
Maybe not the trouble , but worth checking out...
Cheers Ross

"I would take an amp meter and measure current on start up. If that is normal then breaker is undersized or worn out. If you use the breaker as a switch worn out is more likely. "

thanks, sarge.... you hit it on the head with
that one. i'm running it off a 70 A breaker ,which
gets used as a master disconnect at the end of
the day....

since this machine pulls a max of 92A w/ 220ac
@ 275 AMPS welding ,
i'm sure i've been tempting it with my recent heavy
loads... i'll switch it out and try that first.

I've got an Ideal Arc 250 thatI bought used.
Previous owner warned me it would kick any breaker under 100 amp when worked hard.
So I used 100 amp wire and breaker. No problems except a failed contactor and failed relay in gas cutoff switch in my 10 years of use.
IIRC, the manual calls for 100 amp service.