Millermatic 135 Problem

aubrieheeler · Mon Feb 17, 2014 7:55 pm

My Millermatic 135 just started melting the wire just in front of the feed roller the second I strike an arc. Wire is hot and balls up at the entrance to the sleeve.

Mon Feb 17, 2014 8:02 pm

Sounds like you have a short. Inspect your entire whip (as well as the path of the ground lead around the feed rollers) for bare wire.

Welcome to the forum.

Steve S

aubrieheeler · Mon Feb 17, 2014 8:28 pm

Otto Nobedder wrote:Sounds like you have a short. Inspect your entire whip (as well as the path of the ground lead around the feed rollers) for bare wire.

Welcome to the forum.

Steve S

I called the local Nexair and their tech said it sounded like a board problem, and they would have to take it apart and analyze it.....I find that not accurate.

Mon Feb 17, 2014 8:38 pm

I don't buy "board problem" either. Only a direct short would cause the wire to melt anywhere before the tip.

Sounds like a "phone support" person trying to make a buck.

Steve S

Superiorwelding · Mon Feb 17, 2014 8:42 pm

What wire are you running? I ask because if you switched polarity for flux core, did you accidently bolt the terminals back down so they are touching?

AKweldshop · Mon Feb 17, 2014 10:57 pm

Are the drive rollers turning?
If they aren't, then....
Wait, does the gun have to wires coming of the lead that have spade hook-ups on them?
Try switching them.
I had the exact same problem with my Hobart 135, the wire would get red hot and started to eat into the plastic guide thingy.
I would pull the wire out of the gun and see.
Report back on what you find, and please don't take it to the repair shop, cause the problem(I'm sure) is something simple.

~John

noddybrian · Tue Feb 18, 2014 5:14 am

Maybe wrong here - but reading the OP it sounds like for reasons unknown the machine is working correctly - but power is not going up the torch & making electrical contact at the tip as it should - hence when an arc is struck the wire is earthed to the material & heats up back to where it is getting a power connection ( at the machine coupler / feed rolls ) - so an investigation into the torch & it's connection to the machine are in order first ? even test with a meter you have power at the tip with the trigger pulled - ( unless I'm mis reading this )

aubrieheeler · Tue Feb 18, 2014 9:08 am

noddybrian wrote:Maybe wrong here - but reading the OP it sounds like for reasons unknown the machine is working correctly - but power is not going up the torch & making electrical contact at the tip as it should - hence when an arc is struck the wire is earthed to the material & heats up back to where it is getting a power connection ( at the machine coupler / feed rolls ) - so an investigation into the torch & it's connection to the machine are in order first ? even test with a meter you have power at the tip with the trigger pulled - ( unless I'm mis reading this )

The machine was working perfectly all day - this just happened on the last two welds of the day. No changes in wiring or hookup, no changes whatsoever. I will take apart the liner and gun this morning and look for problems. The only similar problem I ever had was a stray wire at the center of the roll that was grounding back at the spool. I have repaired the feed before once where it separated from someone (me) pulling the machine by the line rather than moving it.

aubrieheeler · Tue Feb 18, 2014 9:09 am

AKweldshop wrote:Are the drive rollers turning?
If they aren't, then....
Wait, does the gun have to wires coming of the lead that have spade hook-ups on them?
Try switching them.
I had the exact same problem with my Hobart 135, the wire would get red hot and started to eat into the plastic guide thingy.
I would pull the wire out of the gun and see.
Report back on what you find, and please don't take it to the repair shop, cause the problem(I'm sure) is something simple.

~John

Rollers turn fine, everything is fine until the second I strike an arc.

aubrieheeler · Tue Feb 18, 2014 9:54 am

Otto Nobedder wrote:I don't buy "board problem" either. Only a direct short would cause the wire to melt anywhere before the tip.

Sounds like a "phone support" person trying to make a buck.

Steve S

Took everything apart and checked it. The only thing I can see which may have caused it is a poor ground clamp connection - the spring in the clamp is almost shot. I am replacing it - After reassembling it, it works fine. I must assume the problem was a poor ground.
Thanks!

AKweldshop · Tue Feb 18, 2014 5:24 pm

Most times with feeding, and arcing problems, its something simple.

Glad you found the problem.

~John

aubrieheeler · Tue Feb 18, 2014 7:59 pm

aubrieheeler wrote:
Otto Nobedder wrote:I don't buy "board problem" either. Only a direct short would cause the wire to melt anywhere before the tip.

Sounds like a "phone support" person trying to make a buck.

Steve S
Took everything apart and checked it. The only thing I can see which may have caused it is a poor ground clamp connection - the spring in the clamp is almost shot. I am replacing it - After reassembling it, it works fine. I must assume the problem was a poor ground.
Thanks!

Its back to not working again....I must assume its a contactor problem or some such. Biting the bullet and taking it to the shop.

Tue Feb 18, 2014 8:13 pm

aubrieheeler wrote: Its back to not working again....I must assume its a contactor problem or some such. Biting the bullet and taking it to the shop.

It's a short. The contactor will not cause this. The board will not cause this. Only a flow of current where it's not supposed to go will cause this.

If it's burning at the feed rollers, the current is feeding back from the feed rollers into the spool or the leader in front of the feed rollers. If it's burning "before" the feed rollers, the spool itself or the feeder tube is shorted. If it's burning just after the feed rollers, the whip or the exit tube is shorted.

There is no other logical explanation.

Have a second look, before you overpay someone to fix it.

Steve S