Lincoln Invertec 205T HF Fault

[Big_Al76]

I have the weirdest fault with a tig machine, im wondering if anyone can offer any advice?
its a lincoln invertec 205t which has hf escaping onto the case.
The baffling part is that it is only when i connect the torch to the dinse plug on the front.
if i trigger the machine without a torch attached it is fine.
if i plug the dinse adaptor in, it is fine...
as soon as i screw the torch onto the dinse adaptor, hf on the case?
i have replaced the dinse sockets and bought a new torch but its still the same!
Anyone got any ideas?
Cheers
Al

 

[xmetal]

I may be wrong but I would have thought the case would be grounded. I wonder if it's a grounding or filtering problem on the case.

 

[Jim Davey]

Take the casing off, switch of the lights and trigger it, you might see the HF tracking out and have an idea what to do next then.

 

[Richard.]

I had a dc only Rehm tiger a little while back that was doing the same thing. It would struggle to strike because the HF was leaking and it turned out from doing exactly what jim suggests it was also going to the case from this big round thing that sat about 1 mm from the case. All I did was put a sheet of insulation between them which immediately cured it. I looked through the parts list and also discovered that originally there was thin tufnal type thing supposed to be there which someone perhaps forgot to put back on. (Was a used machine when I had it so god knows).
Jim will know better than me but Id suggest getting it sorted sharpish as I don't think the electronics will like that hf in there unshielded.

 

[Big_Al76]

great, thanks ill give all that a go and let you know how i get on!