Surge / Ground / Lightning

In article 74683977-6a03-4695-a5a2-
,
says...
On May 3, 4:38*am, Franc Zabkar wrote:
Can you elaborate on this by showing us the path taken by the strike
through the TV?

Path to earth was through the network and into a third computer.
Through that third computer's motherboard, through modem, and to earth
via phone lines. Semiconductors in these paths were damaged.

We literally traced this path by replacing ICs. Some ICs (ie
network interface chips) even had cracks on packages where surge
current entered or exiting those ICs. Absolutely no doubt as to how
surge currents found earth ground, destructively, via adjacent
computers.

I wonder why, since electrical codes in North America
and Britain require a ground connection at each outlet;
computer power cords are 3 wire?

I wonder why, since electrical codes in North America
and Britain require a ground connection at each outlet;
computer power cords are 3 wire?


(snip)

hot neutral ground

On May 5, 1:44*am, wrote:
In alt.tv.tech.hdtv bud-- wrote:| wrote:

| In alt.engineering.electrical Leonard Caillouet wrote:| | wrote in message

| ...
| | In alt.tv.tech.hdtv Franc Zabkar wrote:
| |
| |
| | The MOVs will act like conductors when they are clamping. *The surge will
| | take both paths ... the path through the MOVs, and the path going past the
| | MOVs. *In general, about 50% will go each way. *That can vary at higher
| | frequencies.
| |
| | Why would you assume that 50% will go each way when you don't know the
| | impedance of each direction? *When conducting, or at failure, the MOV has a
| | very low impedance.
|
| There is a distinction between "go each way" and "what comes back" due to
| the impedance. *It will be about 50% that goes each way _because_ the power
| itself does not (yet) know the impedance (at a distance), until it gets
| there.
|
| Another installment of Phil's Phantasy Physics using transmission line
| theory.

Not understanding it is your loss.


I have to agree that this is Phantasy Physics. We're supposed to
believe that a surge reaching a MOV is going to split 50-50, with half
of it going to the MOV path and half moving on down the line,
reagrdless of the impedance of the two paths? That would render all
surge protection about 50% effective.




| Two sources directly contradict Phil.

What sources? *Your truncated out of context quotes?

| Phil has provided no sources to support phantasy physics.

I don't care.

--
|WARNING: Due to extreme spam, I no longer see any articles originating from *|
| * * * * Google Groups. If you want your postings to be seen by more readers |
| * * * * you will need to find a different place to post on Usenet. * * * * *|
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

Ï "Tantalust" Ýãñáøå óôï ìÞíõìá
. ..
"NB" wrote in message
...
Who is W_TOM and why has he appeared in every single thread that has
contained those keywords since 2001???

He an obsessive-compulsive disorder victim, apparently driven by some kind
of bizarre fetish involving ground rods.


What kind of ground rods? I prefer steel core, copper clad ones:-) I even
have the special heavy hammer


--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr

On May 5, 10:54*am, "Dave" wrote:
I wonder why, since electrical codes in North America
and Britain require a ground connection at each outlet;
computer power cords are 3 wire?

(snip)

hot neutral ground


Meanwhile, I'm still waiting for an explanation from w_ about how
surege protection inside that computer can work? Where is that
direct connection to earth ground, without which w_ says surge
protection is impossible? Does the computer have a mythical earth
ground inside? The answer is it doesn't. It is acting under exactly
the same limitations and uses the same components, typically MOVs to
do what a plug-in surge supressor does. w-'s answer to this is to
claim that electronics, appliances, etc do not use MOVs, a claim
previously smashed, because of course they do. Plus it really has
nothing much to do with the question anyway, because the computer,
appliance, etc still HAS NO DIRECT EARTH GROUND, without which w- says
protection is impossible.

In article ,
Dave wrote:

I wonder why, since electrical codes in North America
and Britain require a ground connection at each outlet;
computer power cords are 3 wire?


(snip)

hot neutral ground


or, as we call it, Live, Neutral & Earth

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

On Mon, 5 May 2008 09:28:05 -0700 (PDT), wrote:

On May 5, 10:54*am, "Dave" wrote:
I wonder why, since electrical codes in North America
and Britain require a ground connection at each outlet;
computer power cords are 3 wire?

(snip)

hot neutral ground


Meanwhile, I'm still waiting for an explanation from w_ about how
surege protection inside that computer can work? Where is that
direct connection to earth ground, without which w_ says surge
protection is impossible? Does the computer have a mythical earth
ground inside? The answer is it doesn't. It is acting under exactly
the same limitations and uses the same components, typically MOVs to
do what a plug-in surge supressor does. w-'s answer to this is to
claim that electronics, appliances, etc do not use MOVs, a claim
previously smashed, because of course they do. Plus it really has
nothing much to do with the question anyway, because the computer,
appliance, etc still HAS NO DIRECT EARTH GROUND, without which w- says
protection is impossible.

I'm curous to know how surge suppression can work without a ground
(earth) of any sort. Does the "black box" detect overvoltage and
disconnect the power like an earth leakage safety switch?

This might be fine for a TV, but surely not for a computer.

I don't recall any computer I've owned that did not have a three wire
connection to the mains. That and a MOV is OK for smallish surges, but
I believe that for a large surge, the sort that will blow a telephone
off the wall, one needs a large, short-path earth for the surge
detector to dump the extra power down.

I've got a few plug in protectors here and there to sop up a small
spike, but when a storm is within a few km, I pull the phone wire out
of the ADSL router, and the plug out of the mains. If I'm working at
the time, I might just keep a watch on the weather radar and count
lightning fashes to thunder times. It's rare that I get interrupted. I
have underground power and phone lines so that gives a little extra
protection, I believe. I've been told that Australian phone lines are
the most vulnerable, and the most urgent to protect or disconnect.
I hope to be going wireless soon which obviates this problem.

jack

On Mon, 5 May 2008 19:21:16 +0300, "Tzortzakakis Dimitrios"
wrote:


Ï "Tantalust" Ýãñáøå óôï ìÞíõìá
...
"NB" wrote in message
...
Who is W_TOM and why has he appeared in every single thread that has
contained those keywords since 2001???

He an obsessive-compulsive disorder victim, apparently driven by some kind
of bizarre fetish involving ground rods.


What kind of ground rods? I prefer steel core, copper clad ones:-) I even
have the special heavy hammer

I'm on 2000' of sand, and at the moment, my house earth is the copper
water pipes, but the water corp keep adding plastic bits here and
there, so I don't really trust it. I was going to hammer in a 20'
length of 3/4" copper pipe under a large tree which gets the drain
from my grey water. Probably the best I can do.

I'm not a full bottle on earth loops yet so i don't know about leaving
the water mains connection still connected.
What's the best way to test an earth?
I heard once that a large electric radiator (fire) connected between
active (hot) and the earth will glow as per normal if the earth has
good capacity. Perhaps a current comparison between the earth return
and neutral return would be more informative?


jack

On Mon, 5 May 2008 09:24:41 -0400, "Tantalust"
wrote:

"w_tom" wrote

Yes, plug-in protectors do have limited protective functions.

Look at poor w_tom starting his back-pedalling.
Back-pedalling, back-pedalling, back-pedalling.


As I understand it, there is not "protection", or "no protection"
That is, it is not black and white, but degrees of protection, as
there are degrees of surge, or spike.

There is absolute protection of whole of house costing many thousands
of dollars, with tinfoil hats thrown in at no extra cost
And there is $7 protection against weeny little spikes/surges, and
then there is everything in between at varying prices.

The old saw "you get what you pay for" is generally bull**** IMHO
You get what the ******* will let you get away with IME

jack

In article , Jitt
writes

I wonder why, since electrical codes in North America
and Britain require a ground connection at each outlet;
computer power cords are 3 wire?

Many older domestic installations in N America are two-wire only (no
ground.)

In the UK and much of Europe, all outlets are grounded, so surge
protectors do work effectively. w_tom has been informed of this fact
many times but continues telling blatant lies, spreading FUD, and
misrepresenting what others write.

--
(\__/) Bunny says NO to Windows Vista!
(='.'=) http://www.cs.auckland.ac.nz/~pgut00...ista_cost.html
(")_(") http://www.cypherpunks.to/~peter/vista.pdf