Greg's Ballast problem.

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Original poster: "Gregory Peters by way of Terry Fritz <twftesla-at-qwest-dot-net>" <s371034-at-student.uq.edu.au>

Hello all,

I believe that with the welder leads open circuit, practically NO 
urrent should flow. I did some tests, described in the email below. I 
have read agreeable results in the archives. I feel that Greg 
Hunter's welder may have a minor internal fault. The previous owner 
said he could never weld well with it. I think maybe his welder has a 
minor short somewhere or something, which is decreasing the primary 
impedance, allowing unusually large current flow with the leads open 
circuit. Here is the email:

Greg (Hunter),

I tested my welder ballast with and without shorted leads. You may
be interested in the results. Here is what I did. The welder is a
240v, 140A (thats 140A output) unit.

First I drew an arc off the pig with the welder leads shorted and the
shunt set to minimum current. This made a nice orange flamy arc,
probably 6 inches long and drew about 7-10 amps.

I then moved the current shunt to the maximum current setting,
leaving the leads shorted. This drew about 25-30 amps, and made a
huge white/orange flamy arc about a foot long.

I then moved the current shunt to the minimum setting, and
disconnected the secondary welder leads. The arc I drew was LITERALLY
like that from an automotive ignition coil. It was blue, very thin,
and snappy. About 3/4" long at most. The current draw was
immeasurable on my clamp meter. The arc can not even begin to compete
with my 7kV/30mA NSTs!!

Leaving the leads disconnected, I moved the shunt to the maximum
current setting. The same result.

To make sure nothing had happened to the welder or pig, I shorted the
leads together again. Once again, I got the thick, long flamy orange
arcs, with current draw ranging from about 8-30A, depending on the
shunt position.

I repeated this entire procedure with both my welders, and achieved
the same results. I CAN NOT draw any real current (over, say, an amp)
with the leads not shorted, no matter what position the current
control is in. 

Cheers,

Greg (Peters)