New pig & wire

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Original poster: "Sean Taylor by way of Terry Fritz <twftesla-at-qwest-dot-net>" <taylorss-at-rose-hulman.edu>

Hi all,
I just got my 10 kVA 14.4 kV pig, and also some nice 2/0 (I think) wire
that's insulated for 25 kVDC.  There are 2 pieces of the wire in a flex
conduit with a braided shield.  I hooked up the wires (one to ground, the
other to the HV of the pig, it's a one bushing unit), and the braid to
ground, and turned on the pig with current limiting of course.  Immediately
I heard tons of corona in the conduit and at the ends of the conduit. I
turned of the transformer, and smelled around, and there was plenty of ozone
. . .

So here's my question: Is the wire just old and the insulation losing is
insulating properties (it was used . . .), or is it the AC that's the
problem?  The peak of the AC is only 20 kV, but the rating is 25 kVDC, which
doesn't take into account that whole capacitive coupling thing.  But, it is
only 60 Hz.

Anyhow, I tried disconnecting the shield from the ground, and still heard
plenty of corona (and could smell it too) when the transformer was powered.
In this situation, there are 2 thicknesses of insulation between ground and
the HV.

And here's the second question:  Is the corona a problem, ie will the ozone
generated and the coronal discharge eventually break down the insulation?
If so, about how long - years or minutes?  Basically, am I safe to run it
like this?  I probably should measure the current that I'm drawing from
corona, and see if it's reasonable, though I don't have an analog
milliammeter, and I'm not about to put my digital at that high of a
potential :-)

Thanks!
Sean Taylor