Re: New pig & wire

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

Original poster: "Dr.Resonance by way of Terry Fritz <twftesla-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>


Ground one of the pigs bushings.  No need to run two HV's from a pig.

Run the other through your flex but use a standard GTO wire (neon sign xmfr)
HV insulated wire.  Run the ground separately and not through the same
conduit.  This will end your problem.

Dr. Resonance


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, November 29, 2002 5:51 PM
Subject: New pig & wire


 > 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
 >
 >