RE: Down to earth

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Peter Birk" <birk@xxxxxxx>

You're right Bart - the worst case scenario is an ungrounded case shorted to
the hot side.

I'm an old fart and I can tell you it was very common in the 'old days' to
get shocked by touching a radio chassis or appliance while leaning on a
steam radiator.  Grounds just seem to be unreliable (?galvanic corrosion).
So I guess there's no perfect solution - if there was, the three wire system
wouldn't have been needed. So for now keep those appliances out of the
bathroom.  As we used to say around high voltage - keep one hand in your
pocket.

Regards
Pete

-----Original Message-----
From: Tesla list [mailto:tesla@xxxxxxxxxx]
Sent: Saturday, November 04, 2006 12:09 AM
To: tesla@xxxxxxxxxx
Subject: Re: Down to earth


Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>

Hi Peter,

Your right in that this type of house wiring is a bad idea. That's
why the NEC changed it, however, there are many houses with this old
wiring configuration. But, I'm not about to tear out the walls and
rewire the house.

I politely disagree. If I were to leave the new outlets ground prong
unconnected, than should a hot short to the housing or frame work
within an appliance, then the appliance housing or frame work will be
live (and the circuit breaker won't trip). This type of situation is
the worst case and has caused many deaths. Because neutral is earthed
at the house, it is best to tie the ground prong to this earthed
connection. Then, should something short to the housing or frame
work, the circuit breaker will feel the short and trip preventing a
nasty shock or even electrocution.

Yes, the safest approach is to rewire the entire house. But that is
easier said than done.

Take care,
Bart


Tesla list wrote:

>Original poster: "Peter Birk" <birk@xxxxxxx>
>
>Wiring your neutral and ground together sounds like a bad idea to me.  If
>your ground connection breaks or deteriorates then you have a floating
>voltage on the neutral wire.  By connecting the ground to neutral you are
>putting this voltage just where you don't want it - on the metal shell of
>all your appliances and tools.  Better to leave it unconnected or best go
>ahead and rewire with 3 conducter Romex.
>
>Pete
>
>
>
>-----Original Message-----
>From: Tesla list [mailto:tesla@xxxxxxxxxx]
>Sent: Thursday, November 02, 2006 11:11 PM
>To: tesla@xxxxxxxxxx
>Subject: Re: Down to earth
>
>
>Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>
>
>Hi Matt,
>
>Your right, there are different configurations. What is preferred
>depends on the coiler and the situation. For starters, some houses
>(built in the 60's such as my own) do not have a mains line ground.
>The 120V receptacles have only 2 prongs. The ground prong is
>non-existent. I traced my neutral back to the breaker box and beyond.
>Neutral is actually connected to the ground rod stake next to my fire
>place about 3 feet from my breaker box. Because I've needed to plug
>in my modern electronics (TV, fridge, etc..) into these outdated
>outlets, I replaced the 2 prong receptacles with standard 3 prong
>outlets. In the process, I tied the ground receptacle to the neutral
>in order to ensure that the grounding is tied to ground (since my
>neutral is tied to ground).
>
>Ok, so now, Tesla Coils. What to do, what to do. Well, what type of
>coil would I be running?
>
>1) Pig powered coil. 240VAC with "ground" at neutral on my house. OK,
>realize that Tesla Coil strikes cause transient voltages that over
>volt most everything that might come in contact with it. In this
>case, I felt it was "best" to run RF ground to my secondary bottom
>winding, primary inner winding, and no where else. Mains ground, the
>pig case, gets mains ground, as well as the power cabinet which
>includes the PLC, PS, Filter, Variacs, Contactors, etc. This case
>minimizes the transients felt at my TV, Microwave, PC, etc...
>
>2) NST powered coil. 120VAC with "ground" at neutral. Hmmm, well, in
>my case, to minimize transients to all my house components, it made
>sense to tie everything near the coil to RF ground. This includes my
>NST and Terry Filter. Thus, the only "mains ground" is at the variac
>where I adjust voltage. Yes, my NST case is RF grounded, not mains
>grounded. There are only 2 wires running out to the NST for Neutral
>and Line voltage. This is the best configuration to minimize
>transients back to the house for my particular situation.
>
>Thus, I am a firm believer that "you" need to analyze your particular
>house electrical situation, and then design your Tesla Coil
>electrical accordingly to minimize transients back into your house wiring.
>
>I have one of the worst cases to deal with. So, I look at it from a
>safety stand point. And thus, the components that I'm physically
>adjusting, I ensure mains ground is attached to those components I
>come in contact with. But, for the rest of my components which I
>don't have contact with, I revert the transients to the RF ground I
>have set up for coiling.
>
>For others who have a dedicated mains ground, there are more
>opportunities to ensure safety and transient elimination to the house
>components. My point here is that it is important to first determine
>your particular situation and then if unsure, ask what is best in
>that situation.
>
>Take care,
>Bart
>
>
>Tesla list wrote:
>
> >Original poster: Matt Gillott <mcg@xxxxxxxxxxxxx>
> >
> >Hi all
> >Question about earthing.
> >Ive seen a lot of different designes on the net for earthing
> >configurations mainly the three as follows though:
> >1. RF ground to the bottom of the secondary only.  Mains/line earth
> >to all the other earthing points in the circuit (transformer casings
etc).
> >2. RF ground to all the earths, both bottom of the secondary and any
> >other earthing points.  Mains/line earth connected to nothing
> >3. RF ground connected to mains/line earth and all earths on the circuit.
> >
> > From reading I hear that the 3rd configuration is rather dangerous,
> > whats the genreral oppinion about using mains/line earths and whats
> > the prefered configuration?
>
>
>
>
>