RE: lightning arresters

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <tesla729-at-cs-dot-com>

"Tesla list" <tesla-at-pupman-dot-com> wrote:

>Original poster: "Godfrey Loudner by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <ggreen-at-gwtc-dot-net>
>
>I have some lightning arresters for from the local junkyard and have no idea
>as to their reliability. If one of the arresters is
>placed across an x-ray transformer with a short spark gap in series,
>bringing up the voltage with a variac causes little
>blue sparks across the gap. As the voltage is increased, the intensity of
>the blue sparks increases until a flame appears.
>In the past, I mistakenly thought the appearance of the flame was a sudden
>switching on of the arrester. But actually the current becomes high enough
>to support a flame. The appearance of the flame is gradual, not sudden. Is
>this how
>arresters are suppose to behave? I thought that the arrester would suddenly
>switch on. Quite possibly the arresters
>are bad. There are a couple of guys on the list who wanted one for their
>14,400 volt pole pigs, but the is no use shipping such heavy objects for
>only shipping charges if they are bad.
>
>Godfrey Loudner
>
>
>
>
>
Hi Godfrey,

I had talked to you about getting an arrester for my pig, but I just
recently aquired three 15 kV rated ones off of ebay. The 15 kV ones
seem to be about right as they don't start shunting out my pig's 
output to the coil at only about 70% variac setting like the 12 kV
rated one did.

Regarding your query about the reliability of the ones that you
retrieved from a junk yard: I think what you described is "normal"
operation for a lightning arrester, as I'm noticed this same 
phenomenon in my 12 kV rated arrester and it definitely "worked"
in my coil system (the 12 kV rating made it cut off too fast with
my 14.4 kV pig).

Sparkin' in Memphis,
David Rieben