ARC-GEN 330sd problems.

[FAB]

Hello all, hopefully somebody will be able to shed some light on the problems I am having with my genset.

I have an old diesel Arc-Gen Weldmaker 330sd. It has no guts on the low power anymore, just fizzles and wont arc up. It has power on the high setting but turning the current regulator (rheostat?) doesnt make any difference. 180A - 330A seems the same. Power to the 110v and 240v outlets still, both working fine.

The problems first started when I caught the earth cable melting and arcing off the job I was welding after rolling the hot job over onto the cable.

I tried to give it a service incase it was the fuel filter etc, but when turning it over and bleeding the diesel through it finally fired up and was revving way too high and wouldnt idle.

My friend who is a plant mechanic came and traced the wires back to a relay and fitted a new one which made the machine idle again, but still no welding guts on the low and no regulation of the amps on high.

I tried using it a little bit today on high power just tacking a few heavy plates with 3.25's and there was a rubbery burning smell from the set and when I switched it off the back of the positive terminal inside the machine seemed to be smoking? Almost like a dodgy earth connection in a cable would.



Does it sound like a faulty rheostat? Or even a dodgy earth/positive terminal? Hopefully something simple I can fix myself

Totally lost what to do, no body local wants to touch it or knows anything about it. Being a mobile welder I'm pretty stuck with out it too and I cant afford another machine right now.

Any help would be greatly appreciated.

FAB Mobile Welding

 

[rory1]

I have an even older weld maker 270sd that I had problems with back last year, I spoke to mark Chetter at Morris site machinery who now own arcgen and he sent me through all of the user manuals, parts lists and wiring diagrams. He also put up with multiple calls from me and spent some time on the phone assisting with my fault finding.

Considering my set is probably 30 years old the customer service was excellent and they still stock a lot of parts. Some company's just try and sell you a new machine when you have a fault but this chap was very helpful.

I'd give Them a call and get some info off them.

Rory

 

[the snooper]

if your positive connection was smoking you've probably found your problem, strip it clean it up if its crimped remove the crimp and re-join it and you'll probably cure it

 

[WALM]

As above talk to Morris site machinery, so so helpful. i have a 300sd. it will happily change throughout the ranges on both low and high, but not very keen to strike an arc below 100-80amps. fortunately not much of what i do requires anything this low, but nice if it is a rectifiable problem.

 

[Jim Davey]

Sounds like you have lost one half of the SCR stack. As said, get on the blower to Arc Gen, if you need any bits, PM me as I had 30 of these on the hire fleet at some point (all gone now, but I have a few spares kicking around still)

 

[WALM]

Very helpful thanks Jim

 

[HughF]

If you get it fixed, be worth updating your thread on weldingweb, I'm sure Duaneb would be interested.