Re: [TCML] Control Cabinet, X-ray cable, RF-Mains grounding

["David Rieben" <drieben@xxxxxxxxxxx>]

Bart, Jim,

I run with my pole pig inside the one control panel
and it is about a 50 ft. run to the RF ground, near
the base of the coil. Due to the scale of my coil and
the very limited 8 ft. vertical overhead clearance, in
addition to the havoc that the Green Monster plays
on my home's sensitive electronics if I fire it too close
to the house, I have installed my RF ground system
on the opposite side of the driveway from the house,
which is about a 35 to 40 ft linear distance from the
garage door entrance. Of course, everything in one
control panel makes for a colossal control panel that
surely tips the scales at well over 1000 lbs! Nope, it
ain't too portable ;^0 and would likely require at least
partial dismantling to transport, unless I could gain ac-
cess to a fork lift truck! I surely can't get by with cheap
dollar store casters underneath this beast ;^)

It wasn't actually that hard to isolate my pig's RF
grounded exterior tank from the mains grouded control
panel. There is a plywood base that lays on the "floor"
of the control panel, on which the pig sits. The mounting
brackets of the pig are attached to two 2x4 studs that
are inside the control panel, so there is absolutely no
metal-to-metal contact between the exterior tank of
the pig and the inside of the control panel. I find that
the potential voltage difference between RF and mians
ground is typically not that high (maybe a couple thou-
sand volts, tops) so the dry wood is a good enough
insulator to isolate them, even in the humid southeast
US. The exterior teminations of the pigs output go
through a lexan plate for total electrical isolation. I
suppose I need to open myself a flickr page account
so I can direct to pics of my setup to better explain it.
You know the saying, "A picture is worth a thousand
words".

David Rieben

----- Original Message ----- 
From: "bartb" <bartb@xxxxxxxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Wednesday, December 17, 2008 10:41 PM
Subject: Re: [TCML] Control Cabinet, X-ray cable, RF-Mains grounding


> Hi Jim,
>
> Jim Mora wrote:
> > Actually, the disconnection could be made pretty easy in the control 
> > cabinet
> > with stripped back shield. This would be way better than becoming lion's
> > food. I still have the issue of RF ground verses Mains ground. Do you run 
> > a
> > significant distance to your pig with your RF ground feeder and how 
> > hearty
> > is it or is the pig nearer the coil and at distance to mains ground?
> I'm near 20 Ft. of grounding cable from/to the pig. My RF ground is "at" 
> the coil itself.
>
> > This disallows the PT being in the control cabinet unless I can run a 
> > long
> > RF connection to the PT. Furthermore, the PT core will be at mains ground 
> > if
> > the PT is kept in the desired cabinet and the RF ground would need to be
> > highly insulted where it enters the cabinet. Therein lies my problem to 
> > stay
> > self contained. Any ideas?
> No great ideas. My control and pig are separated. The pig is closer to the 
> coil than my control cabinet. If you insert your PT in the control 
> cabinet, then ground the PT case to mains ground. You may as well run to 
> hv lines out to the coil as well at that point and run the primary in 
> floated configuration. Don't try to isolate the PT and cabinet when one is 
> inside the other. Just go balls to the wall with the PT and suck up the 
> damages should they occur. Filters are nice when they can stop problems, 
> but if they cause more problems than their worth, lose them.
>
> Best regards,
> Bart
> _______________________________________________
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> Tesla@xxxxxxxxxxxxxx
> http://www.pupman.com/mailman/listinfo/tesla 

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