Re: R.I.P. one 14kV pole pig!

To: tesla-at-pupman-dot-com
Subject: Re: R.I.P. one 14kV pole pig!
From: Tesla List <mod1-at-pupman-dot-com>
Date: Mon, 6 Oct 1997 21:57:13 -0600 (MDT)
Approved: mod1-at-poodle.pupman-dot-com



---------- 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!



Charles Brush
http://www.foundrygroup-dot-com/cbrush