Placement of Voltmeter in power control cabinet

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Original poster: "MIKE HARDY" <MHARDY@xxxxxxxxxx>

I have my power control cabinet essentially finished.
Variac is good for up to 90A, at 0 - 300V. The last
component before the output connector to the pig,
is my slide choke. It's a 15" long coil  of #8 PVC
insulated stranded house wire (it is 0.25 " dia.
with insulation). It's wound on a 2" square
plastic tube out to 8" O.D. A 1-3/4 square stack
(18" long) of laminations can be fully inserted,
or pulled entirely out via a motor. I have my voltmeter
from the common leg of the variac to the output
of this choke. Esentially across the input of my pig.
With the variac set for 240V, and 40A, on a jacobs ladder.
When the arc strikes, and as long as it is maintained,
 the voltmeter drops to zero. The brief open circuit V then
show full output. This would make me think all the voltage
is dropped across the choke. Since I get an intense
white-hot arc, I doubt this is the case. What am I missing here?
Should I have the meter before the choke? Hope I'm clear here.