Re: ~In reply to Jimlux - Grounding question

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, February 15, 2002 5:39 PM
Subject: ~In reply to Jimlux - Grounding question


> Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<dbanse-at-comcast-dot-net>
>
> In reply to:
> Me: I want to test my NST with just the spark gap, and the capacitor.
> You: "This is hard on the NST... Why not just run the NST with the gap
> alone..."
>
>
>
> Well, I wanted to test the Geek Bucket cap that I am making, and....
>
> Won't the NST just cause a constant arc from one side of the static gap to
> the other??...without a cap that is.
>
> ...and are you saying I would be able to run this setup...(NST, Cap, Gap)
> with this wiring....

Running the NST+cap+gap can cause the voltage to rise higher than it would
in normal operation (no load on it, as there would be with the entire coil
hooked up.)  On the other hand, it might not.  It all depends on the
relative values of leakage L in the NST and C in your bucket cap and the
various losses. (i.e. the overall Q).

And yes, the gap will arc continuously, but it will do that in normal
operation, won't it? (unless it's the safety gap)


>
> Lamp cord to the two 'mains' IN......and the ground on the other side
> connected to a water pipe....or some type of ground???
>
> I guess my question is.....is the ground on the opposite side of the
> transformer the same ground that would be connected to the green wire on a
> lamp cord?? (or whatever)

It's case ground, and connected to the midpoint of the HV winding.
>
> If this is the case, why would they place it on the opposite side of the
> transformer from the 'mains' IN??

Just how it's made. The case is metal, so it really doesn't matter where the
connection is, as long as it is connected.  Two of my NSTs have the ground
on the LV end.
>
> Hope I didn't confuse you much,
> Thanks,
> Jaime
>
>
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Friday, February 15, 2002 7:06 PM
> Subject: Re: *****Grounding question
>
>
> > Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <jimlux-at-earthlink-dot-net>
> >
> >
> >
> > Tesla list wrote:
> > >
> > > Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> > <dbanse-at-comcast-dot-net>
> > >
> > > I have a 15kV60mA NST....
> > >
> > > I have an older house where none of the sockets are grounded....(they
> > were all
> > > 2 prongers....I just 'put in' three prong outlets....(but no wire to
> ground
> > > with)
> > >
> > > I want to test my NST with just the spark gap, and the capacitor.
> >
> > This is hard on the NST... Why not just run the NST with the gap
alone...
> >
> > >
> > > What will happen if I just plug it in with no variac or anything else?
> > > Will I get the shit shocked out of me?
> >
> > Well.. probably not that bad, but it very well might hurt a lot, and you
> > might start a fire inside the wall..
> >
> > The risk is that one of the HV terminals will short to the case or to
the
> > low voltage primary (the short might be a spark breakdown inside the
> > transformer, and be invisible, and not present when transformer's not
on).
> > Then you've got several bad scenarios:
> >
> > 1) Case at HV
> > 2)  case at HV shorted to power line, putting HV back into the line,
where
> > it will hopefully be shorted to ground by something along the way (loose
> > screw, corona discharge, the power companies transformer).  Depending on
> > all the impedances along the way, the voltage might be fairly high
> (several
> > hundred volts).. enough to breakdown the feeble insulation designed for
> > 300V (when it was newly installed).  If your house is wired with "knob
and
> > tube"... words fail me...
> >
> >
> >
> > >
> > > My NST has two output terminals....which are obviously the 'OUTS'
> > >
> > > It also has a 'GRD' terminal on the other side...which I am pretty
sure
> means
> > > 'Ground'...........do I use this for anything, and if so, what do I
> > connect it
> > > to? ...a water pipe or something?
> > The third prong on the plug, which should THEN be connected to a water
> pipe
> > or something.
> >
> > Seriously, if you're going to be fooling with HV, you do need to pay
> > attention to safety grounds.  When you start making RF High Voltage the
> > problem gets worse.
> > >
> >
> > For what it's worth, putting 3 prong outlets in without grounding the
> third
> > prong is an egregious safety hazard (and probably illegal as all get
out,
> > but that is really beside the point.. we've all done things that are
> > illegal but safe).  At least with the two prong outlet, you know it's
> > unsafe, but some unsuspecting person might think that the grounded
outlet
> > really is grounded.  There is a big difference in design between "double
> > insulated" appliances (designed for two prong ungrounded outlets) and
> > appliances designed for a third wire safety ground.
> >
> > In something designed for ungrounded operation, a single failure
typically
> > cannot result in line voltage being applied to the surface or operating
> > controls.  In things designed for a safety ground, a short of line to
case
> > will result in fault current through the safety ground, hopefully
blowing
> > the fuse or circuit breaker, and in any event, the case won't be at 120V
> > relative to ground.
> >
> > This is particularly important if you are, for instance, standing in
bare
> > feet on the concrete/tile floor.
> >
> > Bear in mind also that ground fault interrupters (like the ones on
> > hairdryers, etc.) won't work with ungrounded outlets (at least in the
> > preventing shocks sense...).  You don't want to return to the days of 16
> > people a year dying from using a hairdryer in the shower, do you.
> >
> > > Thanks,
> > > Newbie coiler,
> > > HyFlyOne
> >
> >
> >
>
>
>