Welder Woes

[MoRo]

I have a portable welder made my the National Gas Company of Chicago Illinois. Has an Onan engine with a 60V gen. I can't get more than 2V at the welder lead terminals. I've cleaned all contacts in the welder area, and have repaired a couple of broken wires. Any suggestions where else to go? If I have to open the gen up, how'll I go about removing it from the engine?
Thanks
MonteR.

[B.Sparks]

It's hard to give specific suggestions based only on the names of the welder and engine maker. It would be helpful to know the approximate age of the unit as well as the circumstances surrounding the failure.

With that said, here's an educated guess. The 2 volts (open circuit) that are present on the electrodes is an indicator that the generator end and heavy current wiring (switches, inductor etc.) system is probably intact and in working condition. The 2 volts you see are probably a result of residual magnetism, which indicates that the shunt field winding is not working. That's where the vintage of the set would be helpful. If your welder is of more recent manufacture (1960's or newer) the problem might be as simple as a diode or rectifier. (I once repaired a large Miller welder, bought for pennies on the dollar at auction. A $2.00 diode was all it needed.)

You mentioned repairing "broken wiring." How did the wiring get broken? Did somebody attempt to 'repair' this unit before you got it? The wiring associated with the shunt field is lighter gauge as it only handles a few amps. Polarity is important. If the shunt field wiring is connected backwards the generator will demagnetize itself. No harm done, but it has to be reflashed.

[MoRo]

I'm not sure which wire was broken, but the welder worked wonderfully after I repaired the one broken wire I found and cleaned all the contacts I could find. I was adding a few touches to the cart that the unit sits on, so I used the welder to weld said touches to the cart. It was then that it quit working again.
As to vintage.........I can't be sure. If I could find serial numbers is there someone(place) I could find out more information?
MonteR.

[MoRo]

Oh yeah, as for HOW the wiring got broken: It's the cloth-covered type, and just seems to have fatigued from vibration and age.
~M~

[Doogdoog]

Aloha,
" I was adding a few touches to the cart that the unit sits on, so I used the welder to weld said touches to the cart. It was then that it quit working again". By doing this, the current from the electrode my have backfed into the welder and probably did some damage. I would check for some damaged component or components. Hope this helps.

Mahalo,
doogdoog

[MoRo]

I was afraid something like that might have happened. So if I were to want to remove the gen from the engine.........do I have to go through the crankcase to take bolts out? The end of the gen comes off easily enough, but that's it. I'm assuming that the armature is part of the actual crankshaft, so that won't just slip out. Am I right?
~M~

[MoRo]

Also.........what sort of damage would I look for? In case you haven't noticed...I'm rather dumb about this stuff. I know what things are supposed to do, just need to be pointed in the right direction.
~M~

[MoRo]

Sa-a-a-a-a-a-ay-y-y-y-y!! Could I have depolorized something? If so, how would I go about repolorizing?
~M~

[MoRo]

Haven't worked on the unit since before posting this thread. Question: Up, under the hood, where all the "welder stuff" is located, there's some sort of coil. The wires leading to it are pretty small, prob'ly #10 or so. There's a ring of brass or copper surrounding the coil, which is covered with a paper coating. This ring is on the outside of the covering. What does this coil do? What can I replace it with if that's what's burned out? I'm still lookin' for some suggestions.
~M~

[Fullboattuggie]

This coil is most likely called a reactor coil and its purpose is to keep the load at the rod from causing brush burning at the armature or what is knowen at the winding shop as burnback, you can buy a welder reactor coil good for 300 amps at www.surpluscenter.com ask for the wiring diagram when ordering.