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Sci.Electronics.Basics -> Re: Surge / Ground / Lightning
There are 13 messages in this thread.
You are currently looking at messages 1 to 13.
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Author: Franc ZabkarDate: 04:38 03-05-08
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On Thu, 1 May 2008 13:30:31 -0700 (PDT), w_tom <w_tom1@usa.net> put
finger to keyboard and composed:
>On May 1, 2:18 pm, ransley <Mark_Rans...@yahoo.com> wrote:
>> Whaaat, you say my Triplights that offer a life time warranty to
>> damages from from surges and lightning offer non such claim or
>> warranty, thats pure barf. Triplight surge protectors are only one
>> step a homeowner needs to hopefully protect you. Ive been hit several
>> times, anything you do helps a bit.
>
> Actually some things installed will decrease protection - ie the TV
>destroyed because the plug-in protector earthed an 8000 volt surge
>through it.
Can you elaborate on this by showing us the path taken by the strike
through the TV?
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
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Author: Phil HowardDate: 05:46 03-05-08
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In alt.tv.tech.hdtv Franc Zabkar <fzabkar@iinternode.on.net> wrote:
| On Thu, 1 May 2008 13:30:31 -0700 (PDT), w_tom <w_tom1@usa.net> put
| finger to keyboard and composed:
|
|>On May 1, 2:18?pm, ransley <Mark_Rans...@yahoo.com> wrote:
|>> Whaaat, you say my Triplights that offer a life time warranty to
|>> damages from from surges and lightning offer non such ?claim or
|>> warranty, thats pure barf. Triplight surge protectors are only one
|>> step a homeowner needs to hopefully protect you. Ive been hit several
|>> times, anything you do helps a bit.
|>
|> Actually some things installed will decrease protection - ie the TV
|>destroyed because the plug-in protector earthed an 8000 volt surge
|>through it.
|
| Can you elaborate on this by showing us the path taken by the strike
| through the TV?
A surge will take _every_ path. Where that ends up with a voltage difference
somewhere, anywhere, that exceeds the device breakdown voltage, then you will
have current flow across there. And if that breakdown means damage, as it
would for things like a CMOS circuit component, the device would be damaged.
--
|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) |
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Author: w_tomDate: 23:14 03-05-08
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On May 3, 4:38=A0am, Franc Zabkar <fzab...@iinternode.on.net> wrote:
> Can you elaborate on this by showing us the path taken by the strike
> through the TV?
See many posts that describe this same failure to a network of
powered off computers. Surge incoming on wires that typically carry
most surges into buildings: black (hot) AC wire. Surge arrived two
plug-in protectors - each adjacent to powered off computers. Often
that surge is trivial; does not overwhelm protection inside a
computer's power supply. Maybe - but irrelevant due to the adjacent
protector.
Protector did its job - MOVs shunted (connected, diverted) surge
current into all other AC wires including the green safety ground
wire. Green wire connects directly to motherboard and network cards -
still seeking earth ground.
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.
Plug-in protector is not for and does not claim to protect from this
typically destructive type of surge. Often surges are too trivial to
overwhelm power supply circuits. But because that protector was too
close to powered off computers and too far from earth ground, then
surge was given an alternative and destructive path to earth ground
via networked computers.
Plug-in protectors are for surges that typically don't cause
damage. When the essential 'whole house' protector is not earthed,
then plug-in protectors may earth surges destructively through
adjacent appliances. Every time? Of course not. But the same
ineffective protection is demonstrated in Bud's citation - 8000 volts
destructively on Page 42 Figure 8. That surge was permitted inside
the building. Plug-in protector did nothing to avert 8000 volts
destructively via the adjacent TV. Bud says otherwise by denying Page
42 Figure 8.
Page 42 Figure 8 eliminated by properly earthing a 'whole house'
protector. Surges that seek earth ground destructively through
household appliances must be earthed at the service entrance.
What would have avoided above network damage? Homeowner later
installed and earthed a 'whole house' protector. Solution necessary
so that plug-in protectors do not earth surges, destructively, though
adjacent appliances, even on Page 42 Figure 8. Solution necessary so
that protection from a typically destructive surge exists.
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Author: bud--Date: 21:38 04-05-08
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w_tom wrote:
> On May 3, 4:38 am, Franc Zabkar <fzab...@iinternode.on.net> wrote:
>> Can you elaborate on this by showing us the path taken by the strike
>> through the TV?
>
> See many posts that describe this same failure to a network of
> powered off computers. Surge incoming on wires that typically carry
> most surges into buildings: black (hot) AC wire. Surge arrived two
> plug-in protectors - each adjacent to powered off computers. Often
> that surge is trivial; does not overwhelm protection inside a
> computer's power supply. Maybe - but irrelevant due to the adjacent
> protector.
>
> Protector did its job - MOVs shunted (connected, diverted) surge
> current into all other AC wires including the green safety ground
> wire. Green wire connects directly to motherboard and network cards -
> still seeking earth ground.
>
> 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.
Any competent source (including the IEEE guide) along with any competent
manufacturer will tell you all interconnected equipment needs to be
connected to the same plug-in suppressor, or interconnecting wires need
to go through the suppressor. External connections, like phone, also
need to go through the suppressor. Connecting all wiring through the
suppressor prevents damaging voltages between wires going to the
protected equipment.
This is apparently way to complicated for w_ to understand.
For a more detailed explanation, read (starting pdf page 39) the IEEE
guide titled "Ground potential rise"
http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf
The same section explains how plug-in suppressors work.
>
> Plug-in protector is not for and does not claim to protect from this
> typically destructive type of surge.
Complete nonsense. Just another of w_'s bizarre ideas.
> But the same
> ineffective protection is demonstrated in Bud's citation - 8000 volts
> destructively on Page 42 Figure 8. That surge was permitted inside
> the building. Plug-in protector did nothing to avert 8000 volts
> destructively via the adjacent TV.
The illustration in the IEEE guide has a surge coming in on a cable
service. There are 2 TVs, one is on a plug-in suppressor. The plug-in
suppressor protects TV1, connected to it.
The point of the illustration for the IEEE is "to protect TV2, a second
multiport protector located at TV2 is required." Apparently a radical
idea for w_.
w_ says suppressors must only be at the service panel. In this example a
service panel protector would provide absolutely *NO* protection. The
problem is the wire connecting the cable entry block to the power
service 'ground' is too long. The IEEE guide says in that case "the only
effective way of protecting the equipment is to use a multiport protector."
>
> What would have avoided above network damage? Homeowner later
> installed and earthed a 'whole house' protector.
A power service suppressor is a real good idea. It does not protect
equipment connected to both power and signal wires if there is a high
voltage between those wires as in the example above. There are other
hazards that it also misses.
For independent advice read the IEEE or NIST guides. (Both say plug-in
suppressors are effective).
--
bud--
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Author: JittDate: 10:19 05-05-08
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In article <74683977-6a03-4695-a5a2-
156ba3653409@m45g2000hsb.googlegroups.com>, w_tom1@usa.net=20
says...
> On May 3, 4:38=A0am, Franc Zabkar <fzab...@iinternode.on.net> wrote:
> > Can you elaborate on this by showing us the path taken by the strike
> > through the TV?
>=20
> 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.
>=20
> 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.
>=20
=09I wonder why, since electrical codes in North America=20
and Britain require a ground connection at each outlet;=20
computer power cords are 3 wire?
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Author: DaveDate: 10:54 05-05-08
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>
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
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On May 5, 10:54=A0am, "Dave" <no...@nohow.not> 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.
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Author: charlesDate: 12:41 05-05-08
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In article <fvn72o$rta$1@registered.motzarella.org>,
Dave <noway@nohow.not> 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
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Author: Mike TomlinsonDate: 14:09 05-05-08
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Author: Phil HowardDate: 14:36 05-05-08
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In alt.engineering.electrical Jitt <tser827@yahoo.com> wrote:
| In article <74683977-6a03-4695-a5a2-
| 156ba3653409@m45g2000hsb.googlegroups.com>, w_tom1@usa.net
| says...
|> On May 3, 4:38?am, Franc Zabkar <fzab...@iinternode.on.net> 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?
What good is having the ground connection at each outlet if it is not used?
Are British power cords for computers only 2 wire?
2 of the wires are power conductors. Usually one of the is grounded somewhere
back along the path to the power system source. But it is possible for one to
have a connection with two hot wires (208V from three phase or 240V from single
phase in North America ... 400V from three phase in Europe ... I doubt any of
those 230/460 single phase systems are around anymore in Britain).
The 3rd wire is the groundING conductor. It is not supposed to carry any
current except in the case of a fault between a hot wire and the case or
frame of the computer (or whatever appliance is involved). While this is
a rare event, it is a more important protection in the case of appliances
that routinely get handled by people more than just being turned on and off.
An electric table lamp might not need the grounding conductor because of the
infrequent handling just to turn it on and off. A computer or cooker would
be handled more than a lamp. A computer would be subject to more handling
than the cooker, but the cooker would be subject to being wet. Both of them
are in far more need of the grounding protection than the lamp.
--
|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) |
|
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Author: JittDate: 10:54 06-05-08
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In article <fvn72o$rta$1@registered.motzarella.org>,
noway@nohow.not says...
> >
> I wonder why, since electrical codes in North America
> and Britain require a ground connection at each outlet;
> computer power cords are 3 wire?
>
>
> (snip)
>
> hot neutral ground
>
I suppose I phrased the question badly. I wonder why a surge
would wander around looking for ground, when its available
in the box!
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Author: Michael A. TerrellDate: 12:10 06-05-08
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Jitt wrote:
>
> In article <fvn72o$rta$1@registered.motzarella.org>,
> noway@nohow.not says...
> > >
> > 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
> >
> I suppose I phrased the question badly. I wonder why a surge
> would wander around looking for ground, when its available
> in the box!
They don't discriminate. They look for every possible path to
ground.
--
http://improve-usenet.org/index.html
Use any search engine other than Google till they stop polluting USENET
with porn and junk commercial SPAM
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Author: w_tomDate: 21:34 06-05-08
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On May 6, 10:54 am, Jitt <tser...@yahoo.com> wrote:
> I suppose I phrased the question badly. I wonder why a surge
> would wander around looking for ground, when its available
> in the box!
If all grounds are same, then connect lightning rods into a
motherboard ground. That would be perfect building protection because
a lightning rod is grounded?
Ground inside a stereo is different from ground inside a TV is
different from ground on the computer case is different from ground on
a wall receptacle is different from ground inside a cell phone is
different from a ground inside a breaker box is different from ground
in earth. Most all those grounds are interconnected and are still not
the same ground.
Electricity is different at both ends of a wire. That 100 amp surge
seeking earth from a wall receptacle may leave the wall receptacles at
12,000 volts - again, due to wire impedance. That plug-in protector
on Page 42 Figure 8 was so far from earth ground (via AC electric
wire) as to be >8000 volts - a destructive path via an adjacent TV to
earth.
The EE Times article entitled "Protecting Electrical Devices from
Lightning Transients" defines why a ground in a box is not a ground to
surges. Why electricity at both ends of a wire is always different.
Why that difference during a surge is so important that an effective
protection makes a 'less than 10 foot' connection to earth. Only
relevant 'ground' is the one that is ground to a surge. That is not
an 'inside the box' ground.
Typically destructive surges are an electrical connection from a
cloud to earthborne charges maybe miles away - the relevant ground.
If any part of that connection is via an appliance, then the appliance
may be damaged. Surge protection has always been about diverting a
connection from cloud to earthborne charges so that current need not
pass inside the building.
A protector is only as effective as its earth ground so that surges
need not enter a building. No earth ground means no effective
protection; means a surge creates connections to earth destructively
inside a building. Any facility that installs effective protection
does earthing connected, very short, via a 'whole house' type
protector.
Polyphaser makes a protector that has NO earth ground connection.
Earthing is so critical that their protector mounts directly ON the
earthing electrode - zero feet from earth ground. Distance to earth
ground is critical for effective protection. Which ground? Earth
ground is not found and not provide in three wire AC wall
receptacles. That is a safety ground.
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