RE: GFI NST Inside Photos!!

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>

Interesting that the primary terminals are marked with a (+) and (-)
notation.  I wonder why that should matter in sign applications?  That
should make paralleling them easier.

Gary Lau
MA, USA

 -----Original Message-----
From: 	Tesla list [mailto:tesla-at-pupman-dot-com] 
Sent:	Saturday, May 04, 2002 8:15 PM
To:	tesla-at-pupman-dot-com
Subject:	GFI NST Inside Photos!!

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi All,

Scott Hanson has provided some fascinating pictures of some insides of the new
GFI NSTs that were damaged in a fall from a truck...

http://hot-streamer-dot-com/temp/NSTGFI-gnd-reset%26ACpolarity.JPG
http://hot-streamer-dot-com/temp/NSTGFI-lidoff.JPG
http://hot-streamer-dot-com/temp/NSTGFImidpointreturnterminal.JPG
http://hot-streamer-dot-com/temp/NSTGFImodule.JPG

I think it is removable :-)))

-----------
Terry, Ralph -
 
Attached are a few photos of a new UL 2161 GFI-equipped NST. I believe this one
was a 15/30.
 
First, note that there are NINE wires from the GFI module disappearing down
into the tar! Additionally, there is the yellow "midpoint return" wire leading
to the external "return" terminal. Upon depotting, I found that there were two
individual primary coils, and that the LV ends of each secondary were not
grounded to the core but brought out separately to the GFI.
 
If I recall, the wiring to the GFI module was as follows:
 
    (1) Case ground;
    (2) Core ground;
    (3) two leads from primary "A";
    (4) two leads from primary "B";
    (5) LV end of secondary "A";
    (6) LV end of secondary "B";
 
I don't remember where the leads from the reset button went.
 
I have not actually tested one of these GFI-equipped NST's in a Tesla coil
application. I think the 15 ma secondary leakage current trip point of the GFI,
plus the lack of a conventional secondary center-point ground make these
suitable for depotting only.
--------------

Cheers,

        Terry