Re: Tubing for high voltage wire

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

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

Silicone (the usual stuff from Rowe)... we were using water as a uniform
"other electrode".  The actual application was in a vacuum (i.e. outer
space) in a very small diameter feedthrough hole.  For what it's worth, I
believe some form of Kynar was what we eventually wound up using, but at the
price, I wouldn't advocate it for casual TC use. It's pretty stiff, too.



----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Wednesday, January 01, 2003 7:22 PM
Subject: Re: Tubing for high voltage wire


 > Original poster: "Crow Leader by way of Terry Fritz <teslalist-at-qwest-dot-net>"
<tesla-at-lists.symmetric-dot-net>
 >
 > May I ask what the insulation was made of in the underwater test?
 >
 > KEN
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Wednesday, January 01, 2003 6:17 PM
 > Subject: Re: Tubing for high voltage wire
 >
 >
 >  > Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>"
 > <jimlux-at-earthlink-dot-net>
 >  >
 >  >
 >  > ----- > <SNIP>
 >  >  >  >
 >  >  >  >Also, are there any readily available kinds of tubing that have a
 > high
 >  >  >  >dielectric rating to make HV wire with?  I haven't found a listing
 > for
 >  >  >  >clear vinyl tubing's puncture voltage yet. If anyone knows this
 > please
 >  >  >  >tell me.
 >  >  >  >
 >  >  >
 >  >  > I don't have any specs, but I can tell you from personal experience
 > that
 >  >  > the clear tubing used with oxygen masks in hospitals withstands my
14.4
 >  >  > KV pig power with no punctures!  Make friends with a nurse or doctor
 > and
 >  >  > you'll have a ready supply, as they are only used once then tossed
out.
 >  >  > I use teflon insulated # 16 wire pulled through the tubing for all
of
 >  >  > my high voltage leads, save for the high current ones in the
primary.
 >  >  >
 >  > Interesting.. so, you actually have two layers of insulation. The first
 >  > being teflon (generically, PTFE) in close contact with the conductor
which
 >  > is roughly 0.05 inches in diameter.
 >  >
 >  > How do you know there are no punctures?  I've been involved in testing
a
 >  > variety of insulated wire for 18-20 kV over the past year, and it's
pretty
 >  > subtle when it starts to fail. For example, a piece of 30 kV rated wire
 > was
 >  > immersed in a conductive liquid (impure water) and run at 20 kV DC for
a
 >  > number of hours.  We watched for two things: 1) partial discharge and
2)
 >  > increase in leakage current, both of which inevitably occurred after
36-48
 >  > hours or so.  We also did tests with the wire laying on a metal plate.
In
 >  > all these, you couldn't see the pinholes developing, although in an
 >  > egregious case, you could see the corona in the dark.
 >  >
 >  >
 >  >
 >
 >