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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 into these outdated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?