Welder Weirdness

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Gregory Hunter by way of Terry Fritz <twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>

Dear List,

I messed around with my new welder last night, and I
got some peculiar results.  The unit is a "Buz Box"
brand 230 amp AC stick welder.  I plugged it into
240vac and shorted the rod holder to the work clamp. 
With the shunts fully inserted into the core, the
thing drew 28 Amps from the wall outlet (according to
my borrowed clamp-on ammeter).  I raised the shunts
out about half way, and it drew 48A, which is supposed
to be maximum. Hmmm...  Wonder what's going on with
that?  I tried it with the welding leads open circuit,
and it drew 7 Amps with the shunts all the way in, and
8 Amps with them all the way out.  Not much I can do
with that.

I wired the thing in series with my 5kva pole
transformer, and cautiously tried it with the welder
leads open circuit and the shunts fully inserted.  The
6" x 30" Tesla coil exploded with streamers and put on
a heckuva show, with multiple hits to the floor,
ceiling, the bottle cap, a nearby junk bench, etc. 
The sparks were also brighter and more blue than
usual. I think it's the best my 6" coil has ever done.
 The amp clamp, still attached to an isolated 240vac
lead, said the welder was drawing 30 Amps!  I don't
believe the digital amp clamp.  I suspect the
intermittent nature of the load is screwing it up. 
For one thing, the cable from the welder to the pole
xfmr is only 12AWG extension cord, and it didn't even
get warm.  It used to get warm when I was using two
MOTs as a ballast at only 20A.  Also, the single
static sucker gap didn't get hot.  I grabbed the 1"
Copper reducers, which are the actual electrodes, and
they were tepid. They used to get quite toasty when I
was using the twin MOT ballast.

Next, I shorted the welding leads together, left the
shunts fully inserted, and hit the switch again.  The
insane performance was repeated, but with even longer
streamers.  Also, for the first time I felt that my
location was not far enough from the coil--that maybe
a streamer could reach me from the other side of the
garage!  It must have been pulling a little more
current than before. The amp clamp said 50A, which I
dismissed as silly.  Again, the 12GA cord to the pole
xfmer was room temperature, and the gap electrodes
barely warm. They should have been hot as branding
irons.  What's going on?

I think the digital ammeter is confused by the pulsed
nature of the load, and can't read it properly.

I also suspect that the coil system is far, far more
efficient when using the welder as ballast as opposed
to the twin MOTs.  I think I'm actually getting
longer, brighter sparks with much less current, as
evidenced by the cool power cord and spark gap. I wish
a had a big analog ammeter.

Any of you welder/pig users have insight to share?

Greg
http://hot-streamer-dot-com/greg



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