Re: [TCML] surge arrestor for pole pig

[Yurtle Turtle <yurtle_t@xxxxxxxxx>]

When I "liberated" my Westinghouse 25 kVA 14.4 kV pig:

http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_1.jpg

http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_2.jpg

http://www.hot-streamer.com/adam/garage/pig_14.4kV_25kVA_3.jpg

it was mounted on the pole with a "Surgemaster LV Arrester USA 7-78 18 kV Gap 1":

http://www.hot-streamer.com/adam/garage/gap_18kV_1.jpg

http://www.hot-streamer.com/adam/garage/gap_18kV_2.jpg

Since 14.4 kV RMS is over 18 kV Peak, I'm assuming the arrester is also rated in RMS. I know we use 15 kV arresters at work for 12.47 kV.

I thought it was interesting that the arrester calls itself a "gap". A quick Google search indicates that "Surgemaster" was apparently never copywrited, making it difficult to find anything on it.

However, I'm using mine on my coil without any problems so far, even when pushed to 280 volts.

Adam

--- On Wed, 9/17/08, David Rieben <drieben@xxxxxxxxxxx> wrote:

> From: David Rieben <drieben@xxxxxxxxxxx>
> Subject: Re: [TCML] surge arrestor for pole pig
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Date: Wednesday, September 17, 2008, 7:40 PM
> Hi Aaron,
> 
> No, I can't be sure of the internal construction of
> either but from the ones
> that I have autopsied, they all seem to have those same
> line of cylinders, 
> of
> SiC, I presume. One of the older porcelain jacketed ones
> had what
> appeared to be a little spark gap in between each of those
> cylinders.
> The 18 kV one that failed as a dead short also had those
> cylinder
> looking thingies seriesed inside (not sure what their
> composition was
> but they appeared to be pretty much the same SiC-like
> material)? but
> no spark gaps. This one WAS one of the newer style butyl
> rubber type,
> too. I've always thought that they were all MOV based
> and the electrical
> characteristics of the cylindracal blocks allowed for MOV
> type clipping
> action. I really don't KNOW this, though. Maybe someone
> can chime in
> who actually does know ;^)
> 
> On my first big pole pig driven coil, I originally had a 12
> kV rated one
> on a 14.4 kV pig. When I would turn the variac up past
> about 80% on
> the dial, the output would start "clipping" but
> would stop once the voltage
> was decreased back below the "cutoff" voltage.
> The arrestor never was
> damaged in this fashion, though. I finally replaced with a
> higher voltage
> unit because of this was annoying.
> 
> David
> 



      
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