Re: safety gaps at high power

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

Original poster: "Bert Hickman by way of Terry Fritz <twftesla-at-uswest-dot-net>" <bert.hickman-at-aquila-dot-net>

David,

Try using a pair of "horn gap" - sort of like miniature Jacobs Ladders.
The power company sometimes uses gaps like these to clear arcs on
powerlines, so it'll definately work on a pig. If you do get a power
arc, it'll self-clear with no problem. A picture of this approach in my
system can be ssen at:

http://www.aquila-dot-net/bert.hickman/photos/safety1.jpg

The center rod is grounded, and teh rods are made from 1/4" brass rod,
but copper tubing would have worked as well with less fabrication
hassle.

-- Bert --
-- 
Bert Hickman
Stoneridge Engineering
Email:    bert.hickman-at-aquila-dot-net
Web Site: http://www.teslamania-dot-com


Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<Tesla729-at-cs-dot-com>
> 
> Hi all,
> I've got a quick question for y'all. I have a safety gap that I installed
> on my 10 kVA pole pig. The problem that I have with this SG is that
> when it is set to where it does occasionally fire, it immediately power
> arcs, when it fires, due to the heavy current, and will only extenguish
> when I turn the power control variac way down. If I set it where it dosen't
> fire at all, then I am defeating the purpose of having it in the first place.
> I was wondering if any of you other "pig" coilers had noticed this pro-
> blem. I remeber reading an article by Richard Hull in one of the TCBA
> volumes, and he stated that he didn't even use safety gaps at power
> levels over 5 kVA due to this problem. BTW, my pig is externally bal-
> lasted with an arc welder. Comments anyone?
> 
> David Rieben