Powermig 255c hooked up to generator

[trev]

Well, decided to upgrade today. Went from a Lincoln 175 to the Powermig 255c. I have successfully used both of my generators (a generac 7500 and another 10000 watt), on my 175 and an AC-225 for a while with excellent results. This machine won't even turn on. Can't figure it out, Lincoln says it won't run on a generator? What should I do, I want to keep this size but they are willing to return it for another or a smaller version like the 215 from lincoln. Any help would be great. I use both home power and generator a lot of the time because of mobility. Thanks

[MicroZone]

Man, all you guys and your Lincoln issues... :laugh: ...just messin'.

Really, the 175 is a 175 amp machine, while the 225 is a 300 amp machine. I doubt a generator will even attempt to run a 300a machine. It's giving up before even trying. Do you even NEED a 300a machine? What are you primarily working on? Size your welder to your main tasks and things should get easier.

If you wanted mobility, you might have opted for the Ranger 250 or 305G.

Good luck, I know it's a pain re-working what you have.

[littlefuzz]

I had bought the 255 powermig to hook up to my 250 Ranger (the salesman said it would pull it) It welded fine on the low end but when I cranked it up on the high end (where I usually run) it would cut off. So I swapped for a
LN-25 and it works great, I sure wanted to keep that powermig though :(

[Patriot Performance]

The 255C is a beautiful machine, but you won't be running it off a generator I'm afraid. I haven't even attempted it with mine as I only have a 6500 watt unit.

I'm sure the 255C probably has some sort of circuit protection to not allow you to run it without ample supply.

[ss42768]

We found out the hard way on this issue as well, sold a Powermig 255 a year ago to a guy, didn't ask the right questions, and he didn't tell us he was going to run it off of a PTO generator. The main problem is the voltage fluctuations from the generator kept the unit from running properly, I would suspect that the digital readout circuitry are what prevents these from running on a generator, suspect the Miller MM251 would have the same issues, but am not sure. We gave this customer his money back and he bought a Powermig 215, and he was happy with the way it performed on his generator.

Lessons Learned!

[Doolittle]

Interesting... I was looking at the Powermig255 myself, Im kinda thinking about that thermal arc 251 too but keep shying away from it. Its not like I need all that horsepower yet. What baffles me is why the 255 would even care what the input is. If the generator has a filtered output and constant frequency, it shouldnt even notice...

Your saying it doesnt even power up, thats whats killing me. I could see it shutting down, or throwing an error code, but to not power up from a decent power source is pretty wild.

This is a way they might get away with doing this.. Lincoln might have a 'on' circuit that bypasses the (via a relay more than likely) machine and does a test load and reads the voltage. If the voltage drops too much on the load, the mains relay or whatever never kicks in. A way to test this is to put a voltmeter on the 2 hots of the cord with the machine off, turn the machine on and look for a dip in the output voltage. If it cant handle a 5 volt drop, Lincoln needs to address it. If there is a way to increase the ouput voltage of the 220 outlet on the generator that might help. wonder if theres a choke or rheostat or something that can be tweaked. Gotta be carful, cause you could change frequency as well... hmmmm

BTW, any good electrical engineer knows how to regulate dc and compensate for any tolerances that might bounce around. I dont think its because of freq fluctuations or anything, I thinks its because of the load/voltage drop. The pulse features (chopper) should be internal, and have nothing to do with the input frequency thats simply smoothed out for DC.

Does the generators motor load up when you turn the unit on? Theres another thing that might be causing it not to kick on. What Im getting at, is that if the generator is output is properly filtered, it would compensate for the motor sag (at least for a brief moment), until it stabilized. whew. Good thing to watch out for when looking at generators eh?

BTW, the miller might not care as much as the lincoln, since diamond core and all that other smoothing business isnt happening with it. It might not even have a load test on the input. Ive worked on copiers that do this input test, and I can even read voltage fluctuations at the machine (keeps a history of lows and highs). Most of the machines I work on are 220v single phase with a couple of 3 phase here and there.

Just thought of a step up transformer.. Ive used em in low voltage situations (189~200 volts) These things way a ton, and would have to be bigger than the one in the welder to be effective though.

Do you know anyone with say an 18k generator? It would be interesting to see if there is any change.

[David R]

Ihave an older lincoln 255 mig. It will not run on any generator. Not even my ranger 250. Its something to do in the feed circut. Ever notice it starts the wire slow then turns it on to your dialed in speed? It would not run off a military 4 cyl 10KW generator either.

The instructions in the ranger 250 says its not near enough power because of the surge when you first start to weld.

I too have an LN-25. Had it for almost 20 years and am buying another one. Its the only way to fly portable.

David

[Doolittle]

Wow... Learn something new everyday.