Welders Chime In Please!, Lincoln weld pak 100 shorts where wire enters gun! Options

[Jeffs9146]

Lennies914 is in the field welding on a large CoGeneration system and is having problems with the welder. The system is built into a building and wired into the electrical system. The welder is pluged into the wall and the CoGen unit is shut off.

When the welder ground is attached to the CoGen unit and he attempt to weld the wire heats up inside the feeder and the wire melts and balls up! If he disconnects the ground the wire feeds fine. I used this welder a week ago and it worked great at my house!

The question is:

What would cause this? Would the fact that the CoGen system is grounded to the same plug that the welder is pluged into cause a problem? If a battery is hooked to the CoGen system would that cause this problem? OR Is there anything else that may cause this problem?

[Lennies914]

Thanks Guys,

I just got home and tried my welder. It works fine. So I will try again Monday to make my repair on the cogen unit. At the time I was thinking the problem was in my welder but now I need to look at other options. I guess I should open the main breaker on the generator to start with, and maybe disconnect the battery (good idea regardless). I was attempting to weld on the exhaust with the ground clamped to the exhaust manifold. When I pulled the trigger (not welding, just feeding wire) the wire started glowing at the feed wheels.
Any other thoughts or an explanation?