Re: R.I.P. one 14kV pole pig!
---------- Forwarded message ----------
Date: Mon, 6 Oct 1997 17:45:53 -0400 (EDT)
From: Charles Brush <cfbrush-at-interport-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: R.I.P. one 14kV pole pig! (fwd)
[snips from Bert Hickman's reply]
>Congratulations, Charles - you may have the dubious distinction of being
>the first to actually to take out a pig! :^(
Hi Bert! Looks like Greg beat me to it, and did it in style.
>However, even if you only had a safety gap going across the bushings, it
>might not have prevented this disaster. A direct strike to the primary
>circuit is seeking ground, and it takes a safety gap that includes a
>path to the RF ground to protect you (sort of like that used on neons).
Mmmm...yes a gap with a center ground electrode is definitely called for.
>BTW, safety gaps across the
>cap(s) are also a good idea for an additional measure of protection. If
>you can anticipate where stikes could hit, and then provide a safe path
>to ground via safety gaps (or even power distribution arresters!) so
>that neither bushing sees a voltage above its Basic Impulse Level (BIL),
>you'll have a bulletproof system. This "insulation coordination" is
>exactly the process utilities use to protect their equipment.
Well I am going to redesign my tank circuit strike shield, add a "cap gap"
(excellent idea), and make some beefier safety gaps that can be permanent
on my remaining two pigs. I don't want to lose any more!
> Thnaks for
>an informative and sobering post!
>And, safe coilin' to you, Charles!
Thanks for the suggestions Bert, and safe "non-pig blowing" coiling to you
and every one else here!