252 wire feed issue, tech manual?

[TheEquineFencer]

I have a Miller 252 S/N ME380030N running on 120/240 1Ph. I have a wire feed issue. Set at 18V 250 wire feed, when I try welding I get severe burn back. It started doing it once in a while, I thought it was a kinked cable/liner issue. I've installed a new liner. After installing the liner, machine cold, I was able to burn a 1-2 inch bead on 0.120 1x2 tubing with no issue. Then one of the guys working for me tried to use the machine later and we had severe burn back.

It appears the wire feed motor does not run fast enough. It is visibly slow when running it with the door open. I can adjust the wire feed up and down and it speeds up and down, but at the 18V/250 setting it runs way too slow. It does have 30A spool gun that stays connected to it and is seldom used.

How can I troubleshoot it to determine the failed/defective part? I have a Fluke 87V DMM and know how to use it. I've not opened it up yet and looked inside yet. I'm guessing the drive motor gets a Pulse Width Modulated signal for speed control. I can probably check that using the "duty cycle" function on the Fluke 87V.

I'd like to know what values/voltages/readings I should be getting from each device that goes into and out of the PCBs that are inside the machine to start with. Once I figure out which part has failed, then I might be able to troubleshoot down to the component level if it's a board or what.

Suggestions besides taking to AirGas and having them **** me? I'd like to fix it myself.

Thanks for any help you can give.

 

[VR6ix]

Is the wire spool getting hung-up? I had similar issues with a little 110v welder, there was so much friction with a big spool of wire that the little feed motor couldn't run at normal speed.

 

[strutaeng]

Not an expert by any means, but has it just started doing this? Has it worked well before, perhaps using difference settings? Have you tried another roll of wire? Maybe try some FCAW?

That's an expensive, premium machine, but may have some glitch. Is it not under warrantee? I think they come with 3 years?

The times I had feeder issues it was usually related to the drive roll slipping. Just recently, I was using a little Lincoln DIY welder and I had apparently mis-threaded the wire roll. I fought the machine until the wire would go no more. By then I was near the end, and weld quality suffered. My fault. Little 1 lb spool was un-usable by then, had to put a new one.

 

[matt_i]

Does the motor run fast enough if you open it up (feeding no wire) and reduce the mechanical load?

Possible there's a bad bearing in the idler-wheel or the motor-wheel?

I didn't know you could run that machine on 120vac....

 

[BukitCase]

"I didn't know you could run that machine on 120vac"

Sure you can; you just need to make sure to use BOTH legs of 120 volts, one from each rail of the 240 volt supply, thru a 50 amp breaker. Mine runs just fine that way ... Steve

Not to be ONLY a smart-***, have you checked the condition of the gun connections? Kinda sounds like a slightly loose connection could duplicate the intermittents you're seeing...

 

[bdbecker]

What torch does the welder think you are running when you pull up that feed speed? Is it defaulting to the spool gun for some reason?

When you are watching the drive rolls turn, is someone else welding (arc being struck) or are you just pulling the trigger and feeding wire? If there is a reduced run-in speed setup for that specific feed speed setting, just watching the drive rolls without striking an arc is not going to tell you much.

If it were me, I'd start by disconnecting the spool gun, verifying that the MIG gun is the default, and checking the run-in setting. If that doesn't solve your problem, double-check all the basics. After that, a nice cup of coffee and a morning spent reading through the manual might give you some other clues as to what might be going on. If you don't have a manual, you can download one from Miller for free. Use the serial number search to ensure you get the right version for your machine.

https://www.millerwelds.com/support/manuals-and-parts

If all else fails you can try doing a full reset. Sending it in to Airgas would be the next step, as much as you don't want to hear that. Miller does not sell/distribute service manuals to the general public, so finding one will be very difficult.

 

[TheEquineFencer]

Is the wire spool getting hung-up? I had similar issues with a little 110v welder, there was so much friction with a big spool of wire that the little feed motor couldn't run at normal speed.

That was the first thing I checked.

 

[TheEquineFencer]

Does the motor run fast enough if you open it up (feeding no wire) and reduce the mechanical load?

Possible there's a bad bearing in the idler-wheel or the motor-wheel?

I didn't know you could run that machine on 120vac....

it's main power feed into the building is 12o/240 1Ph, yes it's a 240 1Ph machine. it's not a bad bearing I'm pretty sure.

 

[TheEquineFencer]

What torch does the welder think you are running when you pull up that feed speed? Is it defaulting to the spool gun for some reason?

When you are watching the drive rolls turn, is someone else welding (arc being struck) or are you just pulling the trigger and feeding wire? If there is a reduced run-in speed setup for that specific feed speed setting, just watching the drive rolls without striking an arc is not going to tell you much.

If it were me, I'd start by disconnecting the spool gun, verifying that the MIG gun is the default, and checking the run-in setting. If that doesn't solve your problem, double-check all the basics. After that, a nice cup of coffee and a morning spent reading through the manual might give you some other clues as to what might be going on. If you don't have a manual, you can download one from Miller for free. Use the serial number search to ensure you get the right version for your machine.

https://www.millerwelds.com/support/manuals-and-parts

If all else fails you can try doing a full reset. Sending it in to Airgas would be the next step, as much as you don't want to hear that. Miller does not sell/distribute service manuals to the general public, so finding one will be very difficult.

I did as you suggested and went to the Miller forums. Good idea. as with most forums, there are the "neigh sayers", one guy said basically I was screwed trying to get a tech manual.

BTW, the tech manual number for my machine is TM-230694V 2019−07. I'll be doing some reading tonight and testing in the morning sometime.

BTW, the manual did not come from the Miller forum, but came in a round about way through "networking" with a guy OccupantRJ hooked me up with a few years back for CO2 when I ran out on a Saturday. That guy hooked me up with one hellava nice guy, I guess I owe him a beer now.

 

[Rusty32]

I second what he says many times i flipped on the welder and the trigger was touching something when i didnt know and put it in the alternate setings menu and messed everything up.

What torch does the welder think you are running when you pull up that feed speed? Is it defaulting to the spool gun for some reason?

When you are watching the drive rolls turn, is someone else welding (arc being struck) or are you just pulling the trigger and feeding wire? If there is a reduced run-in speed setup for that specific feed speed setting, just watching the drive rolls without striking an arc is not going to tell you much.

If it were me, I'd start by disconnecting the spool gun, verifying that the MIG gun is the default, and checking the run-in setting. If that doesn't solve your problem, double-check all the basics. After that, a nice cup of coffee and a morning spent reading through the manual might give you some other clues as to what might be going on. If you don't have a manual, you can download one from Miller for free. Use the serial number search to ensure you get the right version for your machine.

https://www.millerwelds.com/support/manuals-and-parts

If all else fails you can try doing a full reset. Sending it in to Airgas would be the next step, as much as you don't want to hear that. Miller does not sell/distribute service manuals to the general public, so finding one will be very difficult.

 

[TheEquineFencer]

The more I think about it, I'm betting it might be part of the problem. It's just funny that I was able to weld a decent bead with the machine cold after installing the new liner, then it went to **** with the other guy.

 

[Milton Shaw]

I have a Miller 251 and when I was having the same problem with this, the welding initial run-in settings had gotten off. Look in your manual and see, on mine you hold down the trigger when you turn the system on and that will display the run in. Set it back to 100%. On my welder it was in the Section 3 welding setup so check your manual and setting and see if this is not your problem. The spool gun settings should be at 50% according to my manual, but look at yours to see. The manuals are available for download with model and serial number.
































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[matt_i]

This doesn't help exactly but is related to settings in Milton Shaw's post above. On a Sync 250, a guy (I think) was trying to switch from DCEN tig to DCEP stick. He cranked the polarity handle correctly, but was repeatedly powering it on with various radio buttons depressed.

This caused the tig arc to not strike for approx 10 seconds after the pedal was depressed. Huge problem to try to run a manufacturing operation without a tig welder. I was hours away from sending the thing to a Miller repair center when I decided to research the manual and found the "hidden settings section" which instantly corrected it....

 

[TheEquineFencer]

Thanks guys. I've been swamped with work at my "regular" job. I've got to get back to this "project" pretty soon because of some upcoming work I need to do at home. It's fast moving back to the top of the list.

The bright side to this little FU, my stick welding skills are getting better again!

 

[cnc-me]

Bad brushes in the feed motor? I don't know if they even have brushes in those motors anymore.

 

[BigMike782]

Millers stance on tech manuals changed in the last year or so. It used to be that Miller did not want TM given out for current equipment but knew that anyone that wanted one could get it. Some time in the last year when signing in I had to verify I understood Miller rules about TM and would abide by them. Since it's my job that gains me access I have to abide by the policy. Sorry that does not solve your issue just adding knowledge.

I would check run in speed to verify it is off, check wire spool tension to make sure it has not gotten overly tight, verify that the drive rolls are in line with the inlet guide of the mig gun.
I was having issues with burn back and the last item solved my problem.

 

[TheEquineFencer]

Millers stance on tech manuals changed in the last year or so. It used to be that Miller did not want TM given out for current equipment but knew that anyone that wanted one could get it. Some time in the last year when signing in I had to verify I understood Miller rules about TM and would abide by them. Since it's my job that gains me access I have to abide by the policy. Sorry that does not solve your issue just adding knowledge.

I would check run in speed to verify it is off, check wire spool tension to make sure it has not gotten overly tight, verify that the drive rolls are in line with the inlet guide of the mig gun.
I was having issues with burn back and the last item solved my problem.

I understand , its strange to me. It's been the best MIG I've ever used. I may get off early today and check it out after I get somethings off my plate.

 

[koditten]

Have you tried to "stall" the drive wheel? You should not be able to stop the drive from turning by using friction from your gloved hand. Obviously loosen all the tension from the wire drives. Pull the trigger and see if you can stop the drive wheels from turning.

I had a bad drive motor on my rig years ago.

 

[purplezr2]

Dumb question, have you made sure the drive it tight, I feel mine came loose at one point.