[Lowfer] Hi-pot testing of pipe cap and THHN house wire today...

[Ralph Hartwell]

> I then took a foot of #12 THHN house wire and laid it on a sheet of
aluminum
> which had the hi-pot tester connected to the stripped end of the wire
and
> the other connection to the metal sheet. I slowly ran the DC volts to
5000
> and nothing arced at all. I then applied AC volts to it and found at
2500vac
> that the wire started to make a frying sound and emitted ozone. I
continued
> to 4500vac and the sound got louder and smelled more ozone, but no
arcs were
> seen in a dark room and the insulation didn't show any damage.

<snip>

The THHN will probably fail at that power level at LF, because the loss
factor of the insulation is higher than at 60 Hz. As soon as then
insulation becomes hot enough to soften, it becomes pretty well
conductive.  Distance is your friend.

73,

Ralph   W5JGV / WC2XSR / 13

The current On-The-Air status of WC2XSR/13 is available at:
http://home.att.net/~shmrg/wc2xsr-13_log.htm

My 600 Meter Research Group files are at:
http://home.att.net/~shmrg

My Home Page is at:
http://home.att.net/~ralph.hartwell
Home of the Rife Biomedical Research Web Ring