Welder troubleshooting

Grommit327 · Oct 9, 2006

I have an older MM150 that really hasn't seen a whole lot of use until I got it a couple of years ago. All of a sudden a while ago the definite purpose contactor that runs everything started not engaging when you pull the trigger. At first if I pulled the trigger a few of times it would finally engage but towards the end it wouldn't engage at all. I can hold the trigger down and if I press the contacts down they will stay down allowing gas to flow, wire to feed, and the arc to start. I can then restart the arc within a few seconds if I don't ground the wire to drain the juice in the capacitors. I can see the contacts in the relay kicking over so I don't think it is the relay and I have already replaced the definite purpose contactor.

Help!!!

Joe

zip1 · Oct 10, 2006

Try here...

http://www.offroadfabnet.com/

Grommit327 · Oct 11, 2006

So if nobody has any ideas on troubleshooting is there a decent welding forum out there where someone might know?

JPFREAK · Jan 8, 2007

Grommit327 said:
I have an older MM150 that really hasn't seen a whole lot of use until I got it a couple of years ago. All of a sudden a while ago the definite purpose contactor that runs everything started not engaging when you pull the trigger. At first if I pulled the trigger a few of times it would finally engage but towards the end it wouldn't engage at all. I can hold the trigger down and if I press the contacts down they will stay down allowing gas to flow, wire to feed, and the arc to start. I can then restart the arc within a few seconds if I don't ground the wire to drain the juice in the capacitors. I can see the contacts in the relay kicking over so I don't think it is the relay and I have already replaced the definite purpose contactor.

Help!!!

Joe

Check the contacts of the relay, they might be pitted/corroded.
Just pop the cover off the relay and clean up the contacts- its the only problem I have had with my Miller.

ToyZuki · Jan 8, 2007

JPFREAK said:
Check the contacts of the relay, they might be pitted/corroded.
Just pop the cover off the relay and clean up the contacts- its the only problem I have had with my Miller.

x2
10 characters

Grommit327 · Jan 8, 2007

Wow this thread is resurrected:flipoff:

Both the definite purpose contactor and the relay have been replaced so no go there. I have gotten good at welding with one hand and using the other on for triggering the contactor. Use the head motion to flip down the helmet:haha:

The bonus is if I ever get the welder fixed I'll have a free hand for.....ummmmm.....other things :innocent:

skrause · Jan 8, 2007

Grommit327 said:
The bonus is if I ever get the welder fixed I'll have a free hand for.....ummmmm.....other things :innocent:

Probably NOT something to put on your resume for that welding job. :haha:

rickibrat2 · Jan 9, 2007

the sleeve inside the hose may need to be changed or the tip could be bad

Grommit327 · Jan 9, 2007

rickibrat2 said:
the sleeve inside the hose may need to be changed or the tip could be bad

I don't see how that would cause a problem (although the sleeve was changed a while ago). The relay is being activated by the gun trigger so I know it's getting power to that point. It's whatever feeds power to the contactor to pull the contacts down that isn't working (I think

)

Jim1 · Jan 21, 2007

Grommit327 said:
I don't see how that would cause a problem (although the sleeve was changed a while ago). The relay is being activated by the gun trigger so I know it's getting power to that point. It's whatever feeds power to the contactor to pull the contacts down that isn't working (I think )

Because the machine has a short circuit protection circuit that will cause the exact problem you described.
Good luck.

Grommit327 · Jan 23, 2007

Unfortunately at this point I've pretty much given up on it. Time to pony up for a new welder but I'm moving and the new place won't have a 220 drop in the garage. So it will prob sit at my dads collecting a ton of dust