Re: [CAD_CAM_EDM_DRO] OT Capacitors & Welding

"John H. - UK" wrote:

> Hello all,
>
> I have a cheap 100 amp something MIG set. It's not a Miller Pulse Master
> Turbo 900001+ but it is very useful for speedy, neat welds. I have possibly
> the most annoying problem on Earth with it however. We have some circuit
> brakers here and whenever I go to weld with the set one trips. I have done
> lots of experimenting and found that it will only trip when the wire is not
> in direct contact with the work piece when the current is turned on. It will
> trip even when I pull the trigger with the gun a metre or so from the work
> piece. It's indescribably, hand bittingly, wicky. Especially since all the
> lights in the garage are on that braker as well so I then have to mavourver
> out the garage in the dark (You haven't seen our garage!). Occasionally the
> braker for the a hole block of brakers will trip but it's almost always just
> the one for the garage circuit.
>
> My thinking:
> Perhaps there is ground leakage?

Do these breakers include what we in the States call a ground fault
interrupter?
I think they call them earth circuit protectors over there. IF so, it is
very possible that the HF starting circuit (if it has that) or some other
feature of the arc starting causes a large electrical transient that is
fooling the GFI into falsely tripping. It may be necessary to attach
an extra ground to the unit, or even to ground the workpiece to a
ground rod. You may also be able to get a special non-GFI breaker
to be used specifically with welding machines.

Jon