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Lincoln Redi-Mig255s+ can't run highest 3 voltage settings

Posted: Wed Feb 08, 2023 10:47 pm
by 5vzfehilux
Hi,

Story is I have just sold this welder so you'll probably say why bother asking, but it does have me intrigued. The buyer wanted to test drive it on the day of purchase which was fine and I had not owned the welder for long and was only ever mucking round on thin scrap. So I had never run it at than mid - range voltage settings. I also have very little mig experience. It has a 15 amp plug and I'm in Australia so 240v is the only output from a socket. We ran it from a socket that has a 15 amp line installed by an electrician.

Anyway, on the day I had it set up on gasless wire which I now hate but the buyer said he was happy enough with its performance. So we switched it over to gas wire and turned the gas on to test that whole side out and again it performed like it should, but only for all voltage settings on the click - thru dial from 1 to 9. It's an old transformer machine with a remote wire feeder setup. It has a digital amp readout and on setting 9 I saw it hit 200 amps. The buyer then wanted to push thru so up we went to setting 10 and that's when it spat it. It's like it just wanted to stall all the time and the wire feeder started acting up. Didn't snap or bird nest but just slipped and stalled like the machine overall, where it struggled to start an arc. It performed at 10 like 1 on the dial if you were trying to weld thick stock, just not enough of everything like volts and wire feed to do anything at all. But click it back to 9 and away we go again with no issues. We then tried 11 and 12 (12 is the maximum setting) but they gave the same results as 10.

We both ended up thinking it was the machine as the circuit breaker on the house never tripped, so that ruled out too much current trying to be dragged through the house. The only other thing I can think of is that I'm not sure we switched polarity on the machine when we went from gasless to gas. But that wouldn't explain why 1 to 9 seemed to work fine. May still be worth a shot though.

Anyway, if someone has experienced the same symptoms and / or knows the cause, please let me know.

Thanks,

Re: Lincoln Redi-Mig255s+ can't run highest 3 voltage settings

Posted: Wed Feb 08, 2023 11:47 pm
by Jack Ryan
I don't know the answer to your question but that machine will draw more than an I1eff of 15A. It should be on a 25A circuit.

The 15A plug is supplied "for commissioning" - you are meant to get an electrician to fit the proper plug (and the necessary circuit) before use.

Pushing the voltage up high with the required wire speed will overload the circuit. I don't know why the CB didn't trip but the voltage might have dropped causing a form of self limiting. If it did, the machine would probably do what you saw.

I haven't seen a circuit but the voltage settings would just be taps on the transformer primary - not something I would expect to fail. As the machine works OK on lower settings, the problem is likely related to the overload.

Jack

Re: Lincoln Redi-Mig255s+ can't run highest 3 voltage settings

Posted: Fri Feb 10, 2023 11:06 pm
by tweake
5vzfehilux wrote: Wed Feb 08, 2023 10:47 pm Hi,

We ran it from a socket that has a 15 amp line installed by an electrician.

. It's an old transformer machine
that would need a 32 amp plug minimum. even a 250 amp inverter is on a 32 amp plug and a transformer is less efficient so needs more power than that.

Re: Lincoln Redi-Mig255s+ can't run highest 3 voltage settings

Posted: Sat Feb 11, 2023 1:11 am
by Jack Ryan
tweake wrote: Fri Feb 10, 2023 11:06 pm that would need a 32 amp plug minimum. even a 250 amp inverter is on a 32 amp plug and a transformer is less efficient so needs more power than that.
You would think so but its rated input as per AS60974.1 is 25 amps so a 25 amp circuit would be sufficient. I did, however, forget to add the wire feeder which requires an additional 5 amps. So you are right, a 32 amp circuit would be needed for the combination.

Jack