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Re: Welder question not coil related

Original poster: <tesla@xxxxxxxxxxxxxxxxxxx>

On Mon, 24 Jan 2005, Tesla list wrote:

> Original poster: JBarrett@xxxxxxxxxxxxxxxx
> Hello,
> I purchased an old Hollup welder manufactured by National Cylinder and Gas
> company of Chicago, Ill. This welder was bought at a swap meet in New York.
> The welder works very well BUT the other day I had my hand on the housing
> and touched the ground clamp. OUCH! It shocked me so hard it made me sick!
> I've had a couple of electricians look at my wiring in the garage and the
> welder. They say it is hooked up correctly. The case is not energised but
> the ground clamp has 120 volts to ground. The thing that confuses me the
> most is I can take the ground clamp and ground it out and nothing
> happens.  No sparks, no blown breakers nothing but if I touch the ground
> clamp on the welder and a earth ground it bites hard.
> Is the ground clamp and the equipment ground the same? There isn't
> continuity between the case and the ground clamp on this welder.

This sounds like a leakage problem. There may be just enough resistance in
whatever is putting 120 volts on the ground to not make sparks and blow
breakers. It doesn't take much current to feel a shock. This is why you
use CGFI breakers near water, people being electrocuted may not draw over
15 amps and trip the normal breaker. See if you can light up a small lght
bulb, like a 7 watt nightlight across the ground terminal and real ground.
Is the wiring inside cracked and touching stuff it should not? I had a
broken surge arresting outlet strip that gave nasty shocks and made sparks
between it's grounded sockets and the the ground pin on it's cord.