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Miller 452 contactor problem

M. Moore

Titanium
Joined
Jun 8, 2007
Location
Vancouver Island, B.C. Canada
My Dimension 452 has developed a little problem. The main contactor switch flutters occasionally, it doesn't shut off and stay off it just clicks once or twice and comes back on, this just started happening in the last few days.
I checked the incoming voltage from the disconnect to the machine, all is well. It is set up at 208 volts 3 phase and has been working well other than the display problem I posted about earlier.
What could cause the contactor to flutter like that? Bad contact in the main on off switch? Dirty contacts inside the mag switch?
The contactor is quite easy to get at and replace but I am not 100% sure it is the problem.
Any help is much appreciated.

Thanks,
Michael
 
No way more likely to be dust and crap jamming a relay some were, the electro magnetism tends to suck the iron dust out of the air and they jam - flutter.

That said have had the same issue on a 350 amp CEA mig, changing the small PCB mount relay that drives the main contractor has cured it twice now. Seams to get - need changing every 7 years or so. That plant in-till really recently did one hell of a lot of short welds though.
 
Thanks for the replies.

Moonlight, I think that is the place to start, should I be looking at the main on switch at the front of the machine?
I don't really understand electrical schematics very well but I have some abilities to diagnose problems, this is a magnetic contactor but not a push button start so no
relay on the contactor itself, just the main switch I would think? Is there any other relay that can turn off the main contactor?

Just to be clear the machine welds fine, the weld circuit contactor is working, the main power on contactor or mag switch is the one that is fluttering occasionally.

Adama, the iron dust problem seems like a potential culprit, just a matter of finding the guilty party.


Michael
 








 
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