Re: grounding question

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi John,

This will work.  Terry and I have done this with a 1KW coil spitten 
out 5 foot arcs.  If inside, you need to be careful on what the 
streamers hit. Best not to hit anything other than a strike target 
that is directly gounded to the system RF ground close to the base of 
the coil.  Some may also recommend a counterpoise under your coil 
that is connected to RF ground.  I presume you are on the first floor 
and this copper pipe is readily available.  You may also want to get 
the electrical stuff in the science room shut down for the demo.  A 
lot depends on what the surroundings are (above and below the coil, 
and in the walls surrounding the coil.  Keep as much clearance from 
the walls and ceiling as possible.  Dont let arcs hit the walls or 
ceiling as this may hit internal wiring or cause a fire.  If this is 
a perminent installation, much care is needed for safety.  If only a 
one time demo, the area needs to be supervised to keep unauthorized 
people at a safe distance and out of the equipment.  You be the judge.

Gerry R.

> Original poster: John <guipenguin@xxxxxxxxx>
>
> Thank you.
>
> If I am going to have my coil running in a science room.... could I 
> use the metal sink pipe as RF ground?
>
> On 10/7/06, Tesla list <<mailto:tesla@xxxxxxxxxx> tesla@xxxxxxxxxx> wrote:
> Original poster: "Gerry  Reynolds" 
> <<mailto:gerryreynolds@xxxxxxxxxxxxx> gerryreynolds@xxxxxxxxxxxxx>
>
> Hi John,
>
> If you are operating outside and the NST is under the primary (or
> very close to it), I would ground the NST to RF ground (a copper rod
> staked in the ground).  The strike ring will be tied to the base of
> the secondary. The base of the secondary will be connected to RF
> ground.  Safety of the NST chassis during operation is not as much an
> issue if located there as no one should be close to the NST while
> operating.  Any secondary strike to the strike ring will return
> directly to the base of the coil.  Any stike to the primary will arc
> to the safety gap and go to the NST chassis and then return to the
> base of the coil via RF ground.  Any overvoltage of the primary
> circuit will also be shunted via the safety gap to the NST chassis
> where it wants to go.  This grounding will help keep voltage
> transients off of the mains ground and out of the house where it can
> do damage to equipment.  The mains ground can be used to ground the
> variac and line filter, but should stop there and not go the the NST.
>
> BTW, grounding the center terminal of the safety gap directly to the
> NST chassis is correct as it is intended to protect the NST.
>
> Gerry R.
>
> >Original poster: John <<mailto:guipenguin@xxxxxxxxx> >guipenguin@xxxxxxxxx>
> >
> >I think I am going to build this simple NST protection filter for my
> >new coil.
> ><<http://hot-streamer.com/greg/filter.htm>http://hot-streamer.com/g 
> reg/filter.htm >http://hot-streamer.com/greg/filter.htm
> >
> >I see the center safety spark gap is grounded to the NST's chasse,
> >which is grounded to mains ground.
> >
> >Now, am I correct in thinking that I should NOT ground the primary
> >circuit to the same ground as the end of the secondary (as I see in
> >many schematics) as this could pose a threat from putting you in
> >contact with the primary circuit through a secondary spark?
> >for a spark gap Tesla coil, is this circuit that I linked the only
> >thing that should be ground to mains ground?     and then ONLY have
> >the end of the secondary coil to a separate RF ground?
> >
> >I want to make sure I have everything as safe as possible before I
> >even start building my design.
> >
> >
> >
> >Thanks again,
> >
> >       John.
> >
> >