Old Hobart G3010 300 Amp 6 Cylinder weld

By shaker Date 10-14-2003 23:56

I recently acquired an old Hobart 6 cylinder gas driven 300 amp welder but can't get any output from it. No a.c. power, no d.c. power, no welding power. I have been all over it with a volt meter and can only measure very minimal voltages from the leads coming out of the generator, and basically nothing from the 115 volt or 220 volt outlets. The 6 cyl. Crysler engine runs like a top and I would like to make the machine work again. Does anybody know of any quirks in the generator portion of this machine or any other problems that might be causing this? I have been working on the electronic throttle control (soaked in water) and it works sometimes. When I step it up to 1800 rpm, shouldn't I be able to read voltages on the recepticles or at least on the leads coming out of the gen. end? Any and all assistance is greatly appreciated.

Thank You,
scott#2

By boiler tube (*)

Date 10-15-2003 01:08

Hello, Scott#2 I ran one of those old hobarts for about 8 years and was very happy with its performance. It did the same thing yours is doing and the problem was a bad diode that is located on the back side of the front of the machine. I hope that may lead you in the right direction.
Good Luck
Ray

By shaker Date 10-15-2003 02:44

Thanks Ray,

If your referring to that 1 of 2 square componets on the back of the control panel below the 2, 220v twist locks, I've already replaced it and still no luck. The thing is is that I can't even read voltage out of the head leads on the power side or the welding side, no dcv either. The 3, I guess commutators on the armature are worn a little, but not bad enough in my opinion (whatever thats worth) to affect it that badly. Brushes are seating well too. Any other ideas? I've heard some talk about motoring the unit. Is this a possibility?

Thanks You,

scott#2

By brande

Date 10-16-2003 06:07

The generator may need polarized or flashed, if you are absolutely sure there are no "open" wires or connections in the entire circuit. Do not take anything for granted. Check them all. A megger check for a short might be in order as well.

With no schematic or diagram, I cannot give instructions reliably.If the machine was in my shop, I'd have a better idea.

Call Thermal Arc, who purchased the 250 amp and higher Hobart machines a while back.
800-462-2782

They should have a schematic for your machine. They should also be able to diagnose your problem.

Most of the guys there are good. I usually talk to Keith, though.

Hope this helps-let us know what you find!!

Good Luck

brande

By shaker Date 10-17-2003 22:51

Thanks for your reply. I've been all over the machine with a meter looking for shorts, opens, voltage,floating grounds and anything suspicious looking. Haven't found anything wrong. There are 3 brushes on the armature and I suspect that you flash it there. The problem is which one is the positive one that needs the 12volt 2 second flash?. Of these 3, 2 go to a small square electronic componet on the back of the control panel and the other one goes to local/remote control switch.

Any ideas?
Thanks,
scott#2

I will call T.A. on Monday

By flatjwl (*)

Date 10-17-2003 23:07

Usually you can simply use the electrode holder and ground clamp for polarizing. Touch the electrode holder to positive. I suggest doing this some distance from the battery by using jumper cables or a similar extension, rather than directly onto the battery terminals.

By shaker Date 10-18-2003 02:03

I still can't tell where on the generator I'm supposed to apply the 12volts flash. A hobart guy said "pick the wrong place and up in smoke it goes" (possibly) .I'm still waiting on a book.

scott#2

By brande

Date 10-18-2003 06:10

He is absolutely correct. Misapplication of flashing polarity can quicly reduce a machine that "can be fixed" to one that "will not be fixed"

Good Luck

brande