Is there some way to protect a house from lightning strikes? We got whacked
last week & have a lot of damaged electronic goodies. I don't want to go
through this again! It struck my 10 ft satellite dish & came into the house
& got into the mains panel. From there it went to every circuit in the
house. I have 2 GFI circuits in the house and they both tripped and nothing
on those circuits was damaged. That's why I asked about something that could
cover the entire house.

Thanks

Patch wrote:
Is there some way to protect a house from lightning strikes? We got whacked
last week & have a lot of damaged electronic goodies. I don't want to go
through this again! It struck my 10 ft satellite dish & came into the house
& got into the mains panel. From there it went to every circuit in the
house. I have 2 GFI circuits in the house and they both tripped and nothing
on those circuits was damaged. That's why I asked about something that could
cover the entire house.

Thanks


do you have a unified ground?
everything should be grounded at the same place. including the satellite
dish.

Patch wrote:
Is there some way to protect a house from lightning strikes? We got whacked
last week & have a lot of damaged electronic goodies. I don't want to go
through this again! It struck my 10 ft satellite dish & came into the house
& got into the mains panel. From there it went to every circuit in the
house. I have 2 GFI circuits in the house and they both tripped and nothing
on those circuits was damaged. That's why I asked about something that could
cover the entire house.

Thanks



Your house should be protected from lightning strikes and this has
nothing to do with surges. Is your satellite grounded? I don't know
the codes but I am almost positive it should be. Everything outside of
my house is grounded, and even on my last house which was build in
1920s. That way it would have never entered your house. There is NO
protection from a direct lightning strike. That the GFCIs tripped was
probably from noise due to the hit, but not likely a real hit. In fact
you probably got a sympathetic stroke anyway, a direct hit would have
blown some 8hit up. Including yourself.

How do you know where the stroke came in and how it travelled?
Lightning just wants to get to earth, surprising it would get to the
main box, then go back into the house again.


Anyway, that dish should probably have a ground line on it. Tying to
ground outside of the house.


--
Respectfully,


CL Gilbert

A whole house surge protector is an excellent idea, but it sounds like
it wouldn't have helped in this case. The surge protector will protect
against most lightening induced surges on the incoming AC, but if it
enters the house elsewhere, it won't stop it. Like others have
suggested, I'd check the grounding/installation of the dish.

Patch wrote:
Is there some way to protect a house from lightning strikes? We got
whacked last week & have a lot of damaged electronic goodies. I don't
want to go through this again! It struck my 10 ft satellite dish &
came into the house & got into the mains panel. From there it went to
every circuit in the house. I have 2 GFI circuits in the house and
they both tripped and nothing on those circuits was damaged. That's
why I asked about something that could cover the entire house.

Thanks

Protection from lightning comes in at least two flavors. One is the
physical damage including fire from a direct strike. For that see your
local lightning rod company. That is not a do it yourself job.

As for wiring, I suggest that you start by replacing the GFI, they may
have given their all in the effort. As Joe noted, make sure your home
grounds are are properly designed installed and have not been damaged.
Note: a lightning strike can damage wiring so that it could cause a fire or
other problems later. I would contact my insurance company and they may
suggest and supply or pay for a professional inspection and repair.

I would suggest adding whole house surge protection. I have it on my
home. If you feel comfortable with replacing or adding a circuit breaker,
you may be ready to DIY. However if opening up the circuit breaker box
makes you a little uneasy and you don't know what you are looking at in
there, I suggest having them installed professionally.

As for personal experience; I had a lightning strike about 18" away from
my A/C compressor unit. It blew out part of the controller circuit board,
but did no damage in the house. I was able to re-wire the board eliminating
the damaged section as that function was duplicated by my thermostat.

Good Luck

--
Joseph Meehan

Dia duit

Patch wrote:
Is there some way to protect a house from lightning strikes? We got whacked
last week & have a lot of damaged electronic goodies. I don't want to go
through this again! It struck my 10 ft satellite dish & came into the house
& got into the mains panel. From there it went to every circuit in the
house. I have 2 GFI circuits in the house and they both tripped and nothing
on those circuits was damaged. That's why I asked about something that could
cover the entire house.

Thanks


Hi,
Poor grounding for the whole house including the dish? If you get a
direct hit like that nothing much can help it.
Tony

"Patch" wrote in message
news:1120654233.30c80013e498bf82b6b21f32db6489d2@t eranews...

Is there some way to protect a house from lightning strikes?

Lightning rods. /www.howstuffworks.com/lightning9.htm

RM ~

Patch wrote:
Is there some way to protect a house from lightning strikes? We got
whacked last week & have a lot of damaged electronic goodies. I don't
want to go through this again! It struck my 10 ft satellite dish &
came into the house & got into the mains panel. From there it went to
every circuit in the house. I have 2 GFI circuits in the house and
they both tripped and nothing on those circuits was damaged. That's
why I asked about something that could cover the entire house.

Thanks

Lots of replies imply that grounding will handle a lightning strike,
especially mentioned is grounding the satellite dish.

You need to understand that grounding a dish, or almost anything else, does
nothing to mitigate a lightning strike. If you're struck, you're toast. No
piddly #12 wire is going to handle 50,000 amps at (up to) millions of volts.

What these ground rods do - also lightning rods - is act as a preventative
to lightning by discharging the positive earth charges into the surrounding
atmosphere - an invisible shield around the device - satellite dish or
lightning rod. This shield, however, can be penetrated by a sufficiently
large lighting bolt.

So, then, get a lighting rod up (or more than one) and individually protect
each critical device plugged into the mains.

Good luck.

PS
If you live in a mobile home, nothing helps. Mobile homes attract tornados,
lighting, and stray dogs.

The telco has overhead wires everywhere in town connected to
a $multi-million switching computer. So the telco must be
down for about 1 week every year replacing their computer?
Not likely. Direct strikes are easily earthed without damage.

If that 12 AWG (typically used for 20 amp service) was
carrying 50,000 amps continuous, then that wire would be
vaporized. Well that wire can carry up to 300 amps
continuous. Note the word 'continuous'. That wire can carry
hundreds of thousands of amps IF the current is very short.
Notice how current capacity changes when we change the
period. What is the typical lightning strike? Most are less
than 20,000 amps. And these transients are so short
(microseconds) as to not damage that 12 AWG wire.

How many amps can a 24 AWG wire carry? Well that MOV with
24 AWG wire leads is rated to carry something on the order of
5,000 amps. Furthermore, the wire is not vaporized by those
5,000 amps. The attached MOV (not its wire leads) fail if
current significantly exceed 5,000 amps. 5,000+ amps on a 24
AWG wire? Not a problem because we add an additional fact -
time of the 5,000+ amps. Time is so short that those leads
easily handle a quick 5000+ amps.

Also incorrect (a product of the urban myth machine) is that
lightning rods discharge the air. Somehow a lightning rod
will discharge "the positive earth charges into the
surrounding atmosphere"? One small problem. Charges that
create lightning are located miles away in the cloud and often
miles away elsewhere on the earth. Lightning is electricity -
not electrostatic charges. Lightning connects charges in that
cloud to other, distant, and earth borne charges. Tell us
that a lightning rod will somehow discharge a cloud that is
miles away? This is the myth promoted by ESE industry.

Early Streamer Emission industry claim their devices
discharge the atmosphere. But ESE manufacturers never provide
science reason nor experimental evidence for their myths.
Myths? Without both theory and experimental evidence, then a
fact does not exist. The ESE industry provides neither.

The ESE industry tried to create NFPA 781 standard. When
rejected, they attempted to get the well respected NFPA 780
standard eliminated. The ESE industry were even accused of
blackmail - sue the non-profit NFPA into bankruptcy - to get
their scam product approved.

How foolish is this idea that lightning rods discharge the
atmosphere?
http://www.nfpa.org/assets/files/PDF/700Minutes.pdf
(see PDF page 18+) 00-60 D#00-22 starting with mention of
Heary Brothers Lightning Protection Company, Inc., Bryan
Panel Report follows:
The proponents of that technology, primarily those associated
with the Heary Brothers Lightning Protection Company, Inc., ...
have extolled the technology and, in particular, have claimed
that ESE terminals offer a vastly increased zone of protection
over that of traditional lightning rods. Those claims have been
disputed and, most recently, a special panel created to
consider information and to issue a report concerning ESE
lightning protection technology to the Standards Council (Bryan
Panel Report), firmly rebutted the claims of ESE proponents that
the technology had been adequately validated, concluding, among
other things, as follows:
The ESE lightning protection technology as currently developed
in the installation of complete systems does not appear to be
scientifically and technically sound in relation to the claimed
areas of protection or the essentials of the grounding system

There is a fundamental problem with HeyBub's post. It is
based on speculation; not based on science concepts,
experimental evidence, or even a responsible citation. You
have a choice. Either believe the NFPA (authors of the
National Electrical Code) or believe HeyBub.

HeyBub wrote:
Lots of replies imply that grounding will handle a lightning strike,
especially mentioned is grounding the satellite dish.

You need to understand that grounding a dish, or almost anything
else, does nothing to mitigate a lightning strike. If you're
struck, you're toast. No piddly #12 wire is going to handle 50,000
amps at (up to) millions of volts.

What these ground rods do - also lightning rods - is act as a
preventative to lightning by discharging the positive earth
charges into the surrounding atmosphere - an invisible shield
around the device - satellite dish or lightning rod. This
shield, however, can be penetrated by a sufficiently
large lighting bolt.
...

Three electric wires enter your house. One connects to
earth ground. How are the other two wires earthed? Not
earthed if a 'whole house' protector is not properly
installed. Two of the three AC electric wires (not earthed by
a 'whole house' protector) carry destructive surges (such as
lightning) into a building; finding earth ground,
destructively, via household appliances. In most homes, only
one of three AC electric wires is earthed. In some homes,
even that ground is missing or compromised.

It has been routine for generations to earth direct
lightning strikes without damage. However homes were not
designed to protect transistors. Unfortunately we still build
new homes without superior and inexpensive earthing. So we do
the best we can as an after thought. Still that after thought
is sufficient to earth direct strikes without damage. But
that means every wire - all three electric - both telephone
wires, etc - make a short connection to the same earth ground
either by direct connection or via a surge protector.

"CL (dnoyeB) Gilbert" wrote:
Your house should be protected from lightning strikes and this has
nothing to do with surges. Is your satellite grounded? I don't know
the codes but I am almost positive it should be. Everything outside of
my house is grounded, and even on my last house which was build in
1920s. That way it would have never entered your house. There is NO
protection from a direct lightning strike. That the GFCIs tripped was
probably from noise due to the hit, but not likely a real hit. In fact
you probably got a sympathetic stroke anyway, a direct hit would have
blown some 8hit up. Including yourself.

How do you know where the stroke came in and how it travelled?
Lightning just wants to get to earth, surprising it would get to the
main box, then go back into the house again.

Anyway, that dish should probably have a ground line on it. Tying to
ground outside of the house.

Polyphaser is an industry benchmark. Their application
notes are considered legendary among industry professionals.
Polyphaser also discusses "discharging the positive earth
charges into the surrounding atmosphere":
http://www.polyphaser.com/ppc_TD1020.aspx

HeyBub wrote:
...
What these ground rods do - also lightning rods - is act as a
preventative to lightning by discharging the positive earth
charges into the surrounding atmosphere - an invisible shield
around the device - satellite dish or lightning rod. This
shield, however, can be penetrated by a sufficiently large
lighting bolt.

w_tom wrote:

The telco has overhead wires everywhere in town connected to
a $multi-million switching computer. So the telco must be
down for about 1 week every year replacing their computer?
Not likely. Direct strikes are easily earthed without damage.

I'm going to install an outdoor TV antenna, but am confused about how
to ground it. Its mast will be 12' above the ground and about 25' over
from the house's breaker box ground rod.

Should I use stranded wire instead of solid?

Should I install a ground rod into the dirt directly below the mast, or
can I simply run a #4 ground wire from the mast to the breaker box
ground rod?

Is there ever any harm in installing a second ground rod, provided it's
bonded to the main one?

On Wed, 06 Jul 2005 08:57:03 -0400, joe wrote:
do you have a unified ground?
everything should be grounded at the same place. including the satellite
dish.

Several years ago I had my main panel upgraded to 200A, covered by
circuit breakers (original system was fuzes). Installer said the
above issue was the most important. After he drove in the rod and
connected the power system ground to it, he told me to get hold of the
phone company and the cable guys and insist that they relocate their
grounds to that ground.
Once done, previous problems I had had with lightning strikes taking
out TVs, etc., went away and I have not had that kind of a problem
since.
YMMV, I guess

Lots of replies imply that grounding will handle a lightning strike,
especially mentioned is grounding the satellite dish.

You need to understand that grounding a dish, or almost anything else,
does nothing to mitigate a lightning strike. If you're struck, you're
toast. No piddly #12 wire is going to handle 50,000 amps at (up to)
millions of volts.

What these ground rods do - also lightning rods - is act as a preventative
to lightning by discharging the positive earth charges into the
surrounding atmosphere - an invisible shield around the device - satellite
dish or lightning rod. This shield, however, can be penetrated by a
sufficiently large lighting bolt.

So, then, get a lighting rod up (or more than one) and individually
protect each critical device plugged into the mains.

Good luck.

PS
If you live in a mobile home, nothing helps. Mobile homes attract
tornados, lighting, and stray dogs.
I'm leaning towards lightning rods. Yesterday I found a 3 ft long, 3 in
wide piece of wood in my yard while mowing. It was the same color as my
house. I started looking to see where it came from and saw damage at the
very top of the roof. A one foot area had missing shingles & wood along the
eave was splintered as though a pipe bomb had gone off. Next question,
where do you buy lightning rods?

Thanks

w_tom wrote:
Three electric wires enter your house. One connects to
earth ground. How are the other two wires earthed? Not
earthed if a 'whole house' protector is not properly
installed. Two of the three AC electric wires (not earthed by
a 'whole house' protector) carry destructive surges (such as
lightning) into a building; finding earth ground,
destructively, via household appliances. In most homes, only
one of three AC electric wires is earthed. In some homes,
even that ground is missing or compromised.


Well the electrical code should be such that these 3 wires are always
present together. A strike is going to prefer the 'earthed' wire over
the ones not earthed. Even if you install a surge device, the 'earthed'
wire is still going to be the easier path to ground.

Its a surge protector, not a lightning protector. It will protect you
to some degree from a borked transformer or some odd occurance likely
generated local to your neighborhood (Frankenstein). It will absolutely
not offer any protection from lightning strikes, direct or indirect.


It has been routine for generations to earth direct
lightning strikes without damage. However homes were not
designed to protect transistors. Unfortunately we still build
new homes without superior and inexpensive earthing. So we do
the best we can as an after thought. Still that after thought
is sufficient to earth direct strikes without damage. But
that means every wire - all three electric - both telephone
wires, etc - make a short connection to the same earth ground
either by direct connection or via a surge protector.

"CL (dnoyeB) Gilbert" wrote:



Lightning will utterly obliterate a surge protector.


--
Respectfully,


CL Gilbert

wrote:
On Thu, 07 Jul 2005 10:42:05 -0400, "CL (dnoyeB) Gilbert"
wrote:


It will absolutely
not offer any protection from lightning strikes, direct or indirect.



20 years of experience here in Florida with hundreds of customers and
their computers seems to dispute that. We have more lightning strikes
on a typical summer afternoon than most of the country sees in a year.
Effective grounding and transient protection works.

effective grounding works. "Surge" protectors protect from surges, not
lightning.

--
Respectfully,


CL Gilbert

CL (dnoyeB) Gilbert wrote:
wrote:
On Thu, 07 Jul 2005 10:42:05 -0400, "CL (dnoyeB) Gilbert"
wrote:


It will absolutely
not offer any protection from lightning strikes, direct or indirect.



20 years of experience here in Florida with hundreds of customers and
their computers seems to dispute that. We have more lightning strikes
on a typical summer afternoon than most of the country sees in a
year. Effective grounding and transient protection works.

effective grounding works. "Surge" protectors protect from surges,
not lightning.

Very true, but surges may accompany lightning. Both for sensitive
equipment.

--
Joseph Meehan

Dia duit

"Joseph Meehan" wrote in
message
...
CL (dnoyeB) Gilbert wrote:
wrote:
On Thu, 07 Jul 2005 10:42:05 -0400, "CL (dnoyeB)
Gilbert"
wrote:


It will absolutely
not offer any protection from lightning strikes,
direct or indirect.



20 years of experience here in Florida with
hundreds of customers and
their computers seems to dispute that. We have more
lightning strikes
on a typical summer afternoon than most of the
country sees in a
year. Effective grounding and transient protection
works.

effective grounding works. "Surge" protectors
protect from surges,
not lightning.

Very true, but surges may accompany lightning.
Both for sensitive equipment.

--
Joseph Meehan

Dia duit

Whole house protection is a standard option these days
for the Mains boxes and is readily avaliable. However,
that does not negate the need for surge protection on
sensitive equipment like computers: It's a different
level of protection and also surges are created within
the house environ also.
NOTHING will protect against all lightning strikes,
especially if they are close by.

HTH

Pop wrote:
"Joseph Meehan" wrote in
....

Whole house protection is a standard option these days
for the Mains boxes and is readily avaliable. However,
that does not negate the need for surge protection on
sensitive equipment like computers: It's a different
level of protection and also surges are created within
the house environ also.
NOTHING will protect against all lightning strikes,
especially if they are close by.

HTH

Not only do I agree with that, I practice it as well.


--
Joseph Meehan

Dia duit

"Joseph Meehan" wrote in
message
...
Pop wrote:
"Joseph Meehan" wrote
in
...

Whole house protection is a standard option these
days
for the Mains boxes and is readily avaliable.
However,
that does not negate the need for surge protection
on
sensitive equipment like computers: It's a
different
level of protection and also surges are created
within
the house environ also.
NOTHING will protect against all lightning
strikes,
especially if they are close by.

HTH

Not only do I agree with that, I practice it as
well.

=== I try to, but I think I just lost a printer due to
a lightning surge yesterday. It popped the UPS on so I
know it was a good hit, and the UPS shows it as a surge
132Vac; and the printer quit working. Turns out I
plugged the printer directly into the wall instead of
one of the surge outlets. Dumb! ;=(.



--
Joseph Meehan

Dia duit

Don't have a whole house protector but think it's a good idea. I do use
those strip surge protectors on just about everything. One time I had two in
series and we caught a powerline overload and the first protector basically
exploded, burned the carpet it was sitting on but a police scanner,
shortwave radio and tel answering machine connected to it survived. The
second surge protector which had a computer and printer hooked to it went
untouched.
These were standard "metal cased" MOV (metal oxide varistor) 5 outlet
surge protectors. I'm convinced we would have had a house fire if the surge
protectors had been encased in a plastic rather than metal. RM ~

When an MOV protector fails catastrophically, then it was
grossly undersized. It operated in a region not defined by
its manufacturer - in violation of the part's intent. But if
a power strip protector is undersized, then the homeowner will
know of the surge. That promotes more sales of undersized
protectors that really don't provide the protection and, as
Rob Mills demonstrates, can even create a house fire.

The effective protector earths a surge; and the homeowner
never knows it happened.

Protectors that provides effective protection are located
close to earth ground AND are properly sized. This is called
a 'whole house' protector. Where it is located? Not on a
pile of papers on a desk, or behind the furniture, on a rug,
or within dust balls. Just more reasons why plug-in
protectors (that cost so much money) are so ineffective.

Rob Mills wrote:
Don't have a whole house protector but think it's a good idea. I
do use those strip surge protectors on just about everything.
One time I had two in series and we caught a powerline overload
and the first protector basically exploded, burned the carpet
it was sitting on but a police scanner, shortwave radio and tel
answering machine connected to it survived. The second surge
protector which had a computer and printer hooked to it went
untouched.
These were standard "metal cased" MOV (metal oxide varistor) 5
outlet surge protectors. I'm convinced we would have had a
house fire if the surge protectors had been encased in a
plastic rather than metal. RM ~

Volts500 provided a complete description of grounding a
house. I believe this in the newsgroup alt.home.repair
entitled "Grounding Rod Info" on 12 July 2003 also included
how to earth the TV antenna per code requirements at:
http://tinyurl.com/hkjq

Meanwhile, a larger number of ground rods tied together will
usually improve the building earthing system. The code
provides a rather subjective number that may require a second
ground rod. Many electricians don't even bother to measure.
Since the second earthing rod will improve conductivity, they
just install the second rod automatically.

larry moe 'n curly wrote:
I'm going to install an outdoor TV antenna, but am confused about how
to ground it. Its mast will be 12' above the ground and about 25' over
from the house's breaker box ground rod.

Should I use stranded wire instead of solid?

Should I install a ground rod into the dirt directly below the mast, or
can I simply run a #4 ground wire from the mast to the breaker box
ground rod?

Is there ever any harm in installing a second ground rod, provided it's
bonded to the main one?

Love it when people are so knowledgeable that they only need
make a declaration, never need provide any numbers, never
provide examples, demonstrate no grasp of technical facts, and
insist they should be believed blindly. Only they can be
trusted to know.

Your telco's $multi-million switching computer connects to
overhead wires everything in town. Since nothing can protect
from lightning, then one week every year, phone service is out
while a lightning damaged computer is replaced. Those cell
phone towers stop providing service for a full week to replace
destroyed equipment - annually. Commercial FM and TV
transmitters atop the Empire State Building are out of service
for 26 weeks due to 26 direct lightning strikes every year.
No wonder those communication and equipment manufacturers are
so profitable.

When was Pop going to reconcile real world examples with his
knowledge? Or are we to believe only he knows what is right?
Pop never provides any supporting theory, numbers, or
technical citation with his claim. He just knows. In the
real world, it is routine to suffer direct lightning strikes
without damage.

Whole house protection is not standard in most homes. If
the homeowner does not specifically request it during new
construction (only in recent years) OR has not has it
installed, then 'whole house' protection does not exist.
Furthermore, if the building's earthing system is not to a
single point - is not properly installed - then even the
'whole house' protector is ineffective.

Unfortunately most homes still don't have protection
sufficient for transistor appliances. Effective protectors
for lightning cost about $1 per protected appliance.

Pop wrote:
Whole house protection is a standard option these days
for the Mains boxes and is readily avaliable. However,
that does not negate the need for surge protection on
sensitive equipment like computers: It's a different
level of protection and also surges are created within
the house environ also.
NOTHING will protect against all lightning strikes,
especially if they are close by.

Love it when people are so knowledgeable that they only need
make a declaration, never need provide any numbers, never
provide examples, demonstrate no grasp of technical facts, and
insist they should be believed blindly. Only they can be
trusted to know.

Your telco's $multi-million switching computer connects to
overhead wires everything in town. Since nothing can protect
from lightning, then one week every year, you are without
phone service when the lightning damaged computer is
replaced. Those cell phone towers stop providing service for
a week to replace destroyed equipment. Commercial FM and TV
stations atop the Empire State Building are out of service for
26 weeks every year due to the 26 direct lightning strikes
every year. No wonder those communication and equipment
manufacturers are so profitable.

When was Pop going to reconcile these examples with his
knowledge? Or are we to believe only he knows what is right?
Pop never provides any supporting theory, numbers, or
technical citation with his claim. He just knows.

It is routine to earth lightning before it gets inside the
building; no damage. If nothing can protect from lightning,
then why install any surge protector? What else overwhelms
protection already inside appliances if not lightning?

Appliances already have internally any protection that is
effective on the power cord. Protection that assumes the
seriously destructive transient such as lightning will be
earthed before it can enter the building. Computers are some
of the most robust appliances. For example, look at a
computer grade UPS output when in battery backup mode. 120
volts on this one is really two 200 volt square waves with up
to a 270 volt spike between those square waves. This output
can even damage some small electric motors. But this output
is perfectly fine for computers because computer power
supplies are (as required by Intel specs) so robust.

But even computer internal protection can be overwhelmed it
destructive lightning is permitted to find earth ground,
destructively, via that computer. Even the robust computer
needs lightning to be earthed before it can enter the
building. This is called 'whole house' protection - on every
incoming utility wire.

Whole house protection is not standard in most homes. If
the homeowner does not specifically request it during new
construction (only in the past few years) OR has not has it
installed, then 'whole house' protection does not exist.
Furthermore, if the building's earthing system is not to a
single point - is not properly installed - then the 'whole
house' protector is still ineffective.

We earth every incoming utility, either via a 'whole house'
protector or via a dedicated ground wire, to the single point
ground. That is for lightning protection - so that lightning
will not overwhelm protection already inside all appliances.
IOW we first learn what was well proven and well understood
more than 60 years ago. Back then, the only buildings with
electronics to protect were telephone switching centers,
commercial broadcasters, communication towers, etc. Today
every building has transistors - requires properly earthed
protection especially from lightning. Its called learning
from those who proved the science before declaring nothing can
protect from lightning. It is routine to suffer direct
lightning strikes to incoming utility wires and not suffer
damage. The technology was that well proven for too many
decades.

Unfortunately most homes still don't have protection
sufficient for transistor appliances. Using protectors that
cost about $1 per protected appliance.

Pop wrote:
Whole house protection is a standard option these days
for the Mains boxes and is readily avaliable. However,
that does not negate the need for surge protection on
sensitive equipment like computers: It's a different
level of protection and also surges are created within
the house environ also.
NOTHING will protect against all lightning strikes,
especially if they are close by.

"w_tom" wrote in message
...
When an MOV protector fails catastrophically, then
it was
grossly undersized.
=== Undersized how? They're rated for x joules, more
than that causes the MOVs to conduct, until they open
the ckt. If you mean undersized to protect against
monsrous surges, OF COURSE!! The sentence means
nothing.

It operated in a region not defined by
its manufacturer - in violation of the part's intent.
=== How do you know that?

But if
a power strip protector is undersized,
=== What does that mean?

then the homeowner will
know of the surge.
=== It's more likely the homeowner will NOT know of
the surge, since the vast majority of the time an MOV
fails OPEN once it conducts, he may not even know it
was surged unless it has indicators for functionality.

That promotes more sales of undersized
protectors that really don't provide the protection
and, as
Rob Mills demonstrates, can even create a house fire.
=== NO surge protector can protect beyond the number
of joules it's rated at, and it would very UNlikely to
have started a fire if nothing else in the house was
bothered. That surge, if it really happened, was large
enough to jump the gaps of the MOVs once they opened
up, and thus was capable of jumping many other gaps.
Sometimes though, a protector CAN sacrifice itself for
the equipment, which sounds like what happened, but ...
it wouldn't have started a fire unless it was sitting
inside a pile of tinder that sparks could have ignited.
The plastic would nto have melted or other equipment
would have been damaged. Black stuff only indicates
spark, not flame.

The effective protector earths a surge; and the
homeowner
never knows it happened.
=== No, protectors do much more than that; they are
wye-connected varistors usually with inductive walls to
keep the lines within safe ranges of each other whether
it's earth or hot to neutral or ... and so on.

Protectors that provides effective protection are
located
close to earth ground AND are properly sized.
=== What the hell do you mean by "properly sized"?
And what the heck does "close to ground" mean anyway?

You have no idea what you're talking about, do you?

This is called
a 'whole house' protector. Where it is located? Not
on a
pile of papers on a desk, or behind the furniture, on
a rug,
or within dust balls. Just more reasons why plug-in
protectors (that cost so much money) are so
ineffective.
=== Wrong, proton breath; they are quite effective and
useful and are recommended for very good reasons. I
hope you aren't using any and that you shortly suffer
several power and phone line lightning hits within 5
miles of your home or less, preferably the transoformer
you're fed from. You're a moron in this area.
So, uhhh, just where is it located, by the way? Do
you even know?

Pop

"w_tom" wrote in message
...
Love it when people are so knowledgeable that they
only need
make a declaration, never need provide any numbers,
never
provide examples, demonstrate no grasp of technical
facts, and
insist they should be believed blindly. Only they
can be
trusted to know.
=== Aha, kaners abound here too don't they? Don't go
away mad, just go away.

Your telco's $multi-million switching computer
connects to
overhead wires everything in town. Since nothing can
protect

It took me a sec to recognize your spew, but I see it
now.

Taken a crap lately dude? Yeah, I know; you just did!

MOVs don't open the circuit. Even grossly undersized power
strips that have vaporized MOVs still connect an appliance to
AC mains. Where is this disconnection that Pop claims? It
does not exist.

A vaporized MOV operates outside of what the manufacturer
has intended and designed. Pop, if he had used facts rather
than post insults, would have first read those MOV datasheets
rather than learn from a BestBuy salesman.

Effective 'whole house' protectors install sufficient
joules. The owner never knows a surge exists AND the protector
remains functional. Power strips that are undersized will
vaporize leaving the appliance exposed to that surge. Then
the naive will recommend them and buy more useless protectors
at tens of times more money per protected appliance.

The naive will declare, "the protector sacrificed itself to
save my computer." Protection already inside the adjacent
computer saved that computer. The surge was too small to
overwhelm internal computer protection. But the same tiny
surge vaporized an undersized, overpriced, and ineffective
protector. Why put sufficient joules inside a protector when
less joules means Pop will recommend it?

If MOVs worked as Pop claims, then removed MOVs (same as
vaporized MOVs) would cause the power strip to stop working.
Reality: even the OK light remains illuminated after all MOVs
are removed:
http://www.zerosurge.com/HTML/movs.html
Why do power strips with vaporized MOVs still provide power?
Because they do not operate as Pop has posted.

Meanwhile code demands that all surge protectors not create
flames even if operated beyond its specs. Pop instead tells
us that "That surge ... was large enough to jump the gaps of
the MOVs once they opened up" Therefore a fire is
acceptable? When MOVs vaporize, the spark can continue
jumping across the vaporized MOV. That can mean fire. MOVs
are not designed to operate open circuited and are not
designed to vaporize. MOVs that vaporize - go open circuit -
can even create house fires. Why? Because the protectors was
so grossly undersized; too few joules.

Learn from what Rob Mills has posted. The last place you
want a grossly undersized power strip protector is on a desk
full of papers, in dust balls behind furniture, or on a rug.
Some pictures demonstrate the problem with grossly undersized
plug-in protectors:

http://www.westwhitelandfire.com/Art...Protectors.pdf

http://www.nmsu.edu/~safety/programs...tectorfire.htm
http://www.ddxg.net/old/surge_protectors.htm
http://www.ehs.washington.edu/LabSaf/surge.htm
http://www.cob.org/fire/safety/surge.htm
http://www.hanford.gov/lessons/sitell/ll00/2000-02.htm

And finally: http://www.rbs2.com/fire.htm
A particularly horrifying fact is that many commercial surge
suppressors in the USA put the thermal disconnector and
varistor in series, so that — after the disconnector opens —
the vulnerable equipment downstream from the suppressor is
exposed to whatever voltage killed the varistor.

Funny. That is not how Pop said they work. Funny. Pop
would even call plug-in protector house fires acceptable when
the surge is too large. Funny. He is so knowledgeable that
he insults rather than provide numbers, science concepts, or
citations. Worry about those grossly undersized power strip
protectors as even Rob Mills demonstrates.

Pop wrote:
=== Undersized how? They're rated for x joules, more
than that causes the MOVs to conduct, until they open
the ckt. If you mean undersized to protect against
monsrous surges, OF COURSE!! The sentence means
nothing.
...

Rob Mills demonstrates, can even create a house fire.
=== NO surge protector can protect beyond the number
of joules it's rated at, and it would very UNlikely to
have started a fire if nothing else in the house was
bothered. That surge, if it really happened, was large
enough to jump the gaps of the MOVs once they opened
up, and thus was capable of jumping many other gaps.
Sometimes though, a protector CAN sacrifice itself for
the equipment, which sounds like what happened, but ...
it wouldn't have started a fire unless it was sitting
inside a pile of tinder that sparks could have ignited.
The plastic would nto have melted or other equipment
would have been damaged. Black stuff only indicates
spark, not flame.

The effective protector earths a surge; and the
homeowner
never knows it happened.
=== No, protectors do much more than that; they are
wye-connected varistors usually with inductive walls to
keep the lines within safe ranges of each other whether
it's earth or hot to neutral or ... and so on.

Protectors that provides effective protection are
located
close to earth ground AND are properly sized.
=== What the hell do you mean by "properly sized"?
And what the heck does "close to ground" mean anyway?

You have no idea what you're talking about, do you?

This is called
a 'whole house' protector. Where it is located? Not
on a
pile of papers on a desk, or behind the furniture, on
a rug,
or within dust balls. Just more reasons why plug-in
protectors (that cost so much money) are so
ineffective.
=== Wrong, proton breath; they are quite effective and
useful and are recommended for very good reasons. I
hope you aren't using any and that you shortly suffer
several power and phone line lightning hits within 5
miles of your home or less, preferably the transoformer
you're fed from. You're a moron in this area.
So, uhhh, just where is it located, by the way? Do
you even know?

Pop

"w_tom" wrote in message
...
MOVs don't open the circuit. Even grossly
undersized power
strips that have vaporized MOVs still connect an
appliance to
AC mains. Where is this disconnection that Pop
claims? It
does not exist.
MOVs conduct until the heat causes them to BECOME an
open circuit! I haven't seen anyone say the CREATE an
open circuit.

A vaporized MOV operates outside of what the
manufacturer
has intended and designed. Pop, if he had used facts
rather
than post insults, would have first read those MOV
datasheets
rather than learn from a BestBuy salesman.
That's nonsensical crap above. It means nothing. You
obviously not only don't know much about the subject
and your reading comprehension appears to be even
worse.

Effective 'whole house' protectors install
sufficient
joules.
"INSTALL JOULES"? Do you even know what a joule IS,
or what an equivalency might be? You don't "install"
joules.

The owner never knows a surge exists AND the protector
remains functional.
Sometimes. And sometimes everything works fine, but
the MOVs have done their job and BECOME OPEN CIRCUITS,
which will no longer have a knee voltage at which they
begin to turn on at.
That does NOT say they open the ckt; it says the
MOVs become an open ckt. Learn to read if you're going
to give advice. It would also help if you knew what
you were talking about.

Power strips that are undersized will
vaporize leaving the appliance exposed to that surge.
Like I said: What is "undersized"? HOW do you
under/over size a power strip? A "power strip"
literally does NOT have ANY surge protection. Your
terminology is all mixed up.

Then
the naive will recommend them and buy more useless
protectors
at tens of times more money per protected appliance.
Possible; anything's possible. Cnn you give a specific
example?

The naive will declare, "the protector sacrificed
itself to
save my computer."
So will knowledgeable and experienced electrical
engineers and technicians and those with horizontal
experience records. "Naive" appears to be a word you
like, but not one that is descriptive in the context
you're using it in.

Protection already inside the adjacent
computer saved that computer.
NOT if the surge protection clamped the surge down to
usable levels. It's also possible after such an event,
that the "protection" inside the computer (it's
actually in the power supply and telephone connection
ckts, by the way) could concievably be no longer in
existance. The MOVs could easily have also done their
job, and been blown before the "power strip" clamped.
You'd have to know the knee voltages and the clamping
times to make such a statement as you' ve tried to
argue here.

The surge was too small to
overwhelm internal computer protection. But the same
tiny
surge vaporized an undersized, overpriced, and
ineffective
protector.
HOW was it undersized? Are you aware of the joule
ratings used in most PC supplies? And those in the so
called "power strips"? I am, and I've evaluated and
repaired a LOT of them. THEN you have to go further
and consider CMOS damage, whether it's lost ITS
protection, and so on.

Why put sufficient joules inside a protector when
less joules means Pop will recommend it?
You don't PUT JOULES INSIDE a protector!


If MOVs worked as Pop claims, then removed MOVs
(same as
vaporized MOVs) would cause the power strip to stop
working.
Reality: even the OK light remains illuminated after
all MOVs
are removed:
Of COURSE, you idiot! This is getting comical, and
rather pathetic, so I'm going to write you off as a
troll and you'll not hear further from me until/unless
you find something sane and sensible to say. Your
record is pathetic and you are a dangerous person to
rely on.
http://www.zerosurge.com/HTML/movs.html
Why do power strips with vaporized MOVs still provide
power?
Because they do not operate as Pop has posted.
They operate EXACTLY as I said.

This is getting comical, and rather pathetic, so I'm
going to write you off as a troll and you'll not hear
further from me until/unless you find something sane
and sensible to say. Your record is pathetic and you
are a dangerous person to rely on.

You're a troll.\

PLONK! Thud!

"Pop" wrote:
snip some extremly rude stuff

Most of the posts I have read here are very friendly. What is your problem?
Is it because it's Usenet and no one knows who you really are? Pop, someday
you may find out that things are not so cut and dried as they may seem to
be to you. Life (facet) is to short and what we hold dear we hold near.
Good luck with your struggle Sir.

:-)

. wrote:
"Pop" wrote:
snip some extremly rude stuff

Most of the posts I have read here are very friendly. What is your problem?
Is it because it's Usenet and no one knows who you really are? Pop, someday
you may find out that things are not so cut and dried as they may seem to
be to you. Life (facet) is to short and what we hold dear we hold near.
Good luck with your struggle Sir.

:-)

I have a feeling Pop will be here long after you've come, condescended,
and disappeared...

G Henslee wrote:
. wrote:
"Pop" wrote:
snip some extremly rude stuff

Most of the posts I have read here are very friendly. What is your
problem? Is it because it's Usenet and no one knows who you really are?
Pop, someday you may find out that things are not so cut and dried as
they may seem to be to you. Life (facet) is to short and what we hold
dear we hold near. Good luck with your struggle Sir.

:-)

I have a feeling Pop will be here long after you've come, condescended,
and disappeared...
Just maybe you are right...as I have only about 6 months (more or
less)lurking at Usenet. But then maybe not. I believe in treating others as
I myself would want to be treated. I simply implied that he is rude, and
asked "nobody" simple questions. Thank you for your answer. (-:

And you don't realise that Pop is engaged in a war of words with a guy
that is well know for starting flaming threads about surge protection
in multiple groups. There is no reasoning with w_tom. Anyone that has
valid real world experience with using a plug in surge protector that
saved equipment, w_tom tries to either ignore or turn around so that
it looks like the surge protector caused damage. Nothing will change
his mind. He's hell bent on the idea that plug in surge protectors are
of no value, despite many of us having seen them save equipment. Any
reasonable person knows that a whole house surge protector is best, but
if you don;t have one for whatever reason eg living in an
apartment/rental where you have no control, then a plug in is way
better than nothing at all. Plus many of the plug ins offer protection
for cable and phone, which a whole house does not.

Both cable TV and telephone line installations are required
to provide a connection to earth ground according to NEC and
FCC regulations. However, those utilities cannot properly
earth protection connections if the homeowner did not first
provide a common earth ground.

Yes, even phone lines in N America have a 'whole house' type
protector where their wires encounter interior phone wires.
One that I am currently holding was manufactured in May 1991
and has a UL approval stamp. Plug-in protector manufacturers
just sort of forget to mention this already installed
protector.

wrote:
And you don't realise that Pop is engaged in a war of words with a guy
that is well know for starting flaming threads about surge protection
in multiple groups. There is no reasoning with w_tom. Anyone that has
valid real world experience with using a plug in surge protector that
saved equipment, w_tom tries to either ignore or turn around so that
it looks like the surge protector caused damage. Nothing will change
his mind. He's hell bent on the idea that plug in surge protectors are
of no value, despite many of us having seen them save equipment. Any
reasonable person knows that a whole house surge protector is best, but
if you don;t have one for whatever reason eg living in an
apartment/rental where you have no control, then a plug in is way
better than nothing at all. Plus many of the plug ins offer protection
for cable and phone, which a whole house does not.

MOV data sheets provide no spec for becoming an open
circuit. The charts for MOVs relate three parameters: number
of transients, transient current, and time. All factors that
determine MOV *degradation*. Degradation means no open
circuit failure. Properly sized MOVs degrade - do not
vaporize - with use.

A datasheet from one Taiwan MOV manufacturer even defines a
number for degradation. A 10% change in the Vb voltage. They
provide examples of how an MOV can degrade by 10%. For the 18
series MOVs, a 200 amp (classic 8/20 usec) transient is
applied 10,000 times. No open circuit (vaporizing) condition
in these tests. 18 series MOV degrades after about 10,000
pulses. Degradation - not vaporization - not open circuit
failure - is how MOVs fail when properly sized. An MOV
becoming an open circuit (as Pop recommends) is a violation of
what MOV manufacturers intend.

In the late 1980s, PC Magazine published two articles about
power strip protector failures. MOVs were so undersized as to
vaporize - some actually spitting flames. When MOVs became
open circuits, then MOVs created a serious human safety risk.
A previous post provides numerous pictures of the fire
danger. Power strip protectors vaporizing MOVs to create
potential house fires.

Since those 1980s articles, the UL created a standard:
UL1449 2nd Edition. Urban myth promoters cite UL1449 as proof
that a protector is effective. But UL does not care whether a
protector protects anything. In fact, the protector can
completely fail during testing - and the protector still gets
a UL approval. Why? UL's only concern is that a protector
does not harm human life. UL does not care whether the
protector is effective. They worry about the MOV going open
circuit - vaporizing - endangering human life.

How is this UL rating obtained? MOVs are placed in series
with a tiny thermal fuse. Fuse that (should) blow before an
MOV vaporizes - so that human life is protected. IOW the
undersized protector disconnects even quicker - leaving
adjacent appliances connected longer to a destructive
transient. It blows a fuse so that the MOVs do not go open
circuit, do not create fires, protect even less, and get a
UL1449 approval.

Pop insists that vaporization is how protectors are suppose
to work. Who do we believe? Pop? Or do we believe the UL,
MOV manufacturer datasheets, the West Whiteland Fire
Department, government laboratories, and the reason for
thermal fuses?

Number of joules inside a protector determines it life
expectancy. To fail catastrophically, power strip protectors
are routinely undersized - too few joules. Therefore humans
who don't have technical knowledge will insist vaporization
(or blowing thermal fuse) is a normal failure mode, recommend
those ineffective protectors to friends, and buy more grossly
overpriced, undersized plug-in protectors.

An open circuit MOV even endangers human life. Best
solution for effective protection is a properly sized and
properly earthed 'whole house' protector. A protector that is
not located in dust balls, on a carpet, or on a desk full of
papers. A protector sufficiently sized so that it remains
functional after every surge. The important number here is
joules so that MOVs do not vaporize. Essential is a 'less
than 10 foot' connection to earth ground.

Pop wrote:
"INSTALL JOULES"? Do you even know what a joule IS,
or what an equivalency might be? You don't "install"
joules.
...

Sometimes. And sometimes everything works fine, but
the MOVs have done their job and BECOME OPEN CIRCUITS,
which will no longer have a knee voltage at which they
begin to turn on at.
That does NOT say they open the ckt; it says the
MOVs become an open ckt. Learn to read if you're going
to give advice. It would also help if you knew what
you were talking about.
...

So will knowledgeable and experienced electrical
engineers and technicians and those with horizontal
experience records. "Naive" appears to be a word you
like, but not one that is descriptive in the context
you're using it in.
...

NOT if the surge protection clamped the surge down to
usable levels. It's also possible after such an event,
that the "protection" inside the computer (it's
actually in the power supply and telephone connection
ckts, by the way) could concievably be no longer in
existance. The MOVs could easily have also done their
job, and been blown before the "power strip" clamped.
You'd have to know the knee voltages and the clamping
times to make such a statement as you' ve tried to
argue here.
...

HOW was it undersized? Are you aware of the joule
ratings used in most PC supplies? And those in the so
called "power strips"? I am, and I've evaluated and
repaired a LOT of them. THEN you have to go further
and consider CMOS damage, whether it's lost ITS
protection, and so on.

...
You don't PUT JOULES INSIDE a protector!

w_tom wrote:
MOVs don't open the circuit. Even grossly undersized power
strips that have vaporized MOVs still connect an appliance to
AC mains. Where is this disconnection that Pop claims? It
does not exist.

A vaporized MOV operates outside of what the manufacturer
has intended and designed. Pop, if he had used facts rather
than post insults, would have first read those MOV datasheets
rather than learn from a BestBuy salesman.

Effective 'whole house' protectors install sufficient
joules. The owner never knows a surge exists AND the protector
remains functional. Power strips that are undersized will
vaporize leaving the appliance exposed to that surge. Then
the naive will recommend them and buy more useless protectors
at tens of times more money per protected appliance.

The naive will declare, "the protector sacrificed itself to
save my computer." Protection already inside the adjacent
computer saved that computer. The surge was too small to
overwhelm internal computer protection. But the same tiny
surge vaporized an undersized, overpriced, and ineffective
protector. Why put sufficient joules inside a protector when
less joules means Pop will recommend it?

If MOVs worked as Pop claims, then removed MOVs (same as
vaporized MOVs) would cause the power strip to stop working.
Reality: even the OK light remains illuminated after all MOVs
are removed:
http://www.zerosurge.com/HTML/movs.html
Why do power strips with vaporized MOVs still provide power?
Because they do not operate as Pop has posted.

Meanwhile code demands that all surge protectors not create
flames even if operated beyond its specs. Pop instead tells
us that "That surge ... was large enough to jump the gaps of
the MOVs once they opened up" Therefore a fire is
acceptable? When MOVs vaporize, the spark can continue
jumping across the vaporized MOV. That can mean fire. MOVs
are not designed to operate open circuited and are not
designed to vaporize. MOVs that vaporize - go open circuit -
can even create house fires. Why? Because the protectors was
so grossly undersized; too few joules.

Learn from what Rob Mills has posted. The last place you
want a grossly undersized power strip protector is on a desk
full of papers, in dust balls behind furniture, or on a rug.
Some pictures demonstrate the problem with grossly undersized
plug-in protectors:

http://www.westwhitelandfire.com/Art...Protectors.pdf

http://www.nmsu.edu/~safety/programs...tectorfire.htm
http://www.ddxg.net/old/surge_protectors.htm
http://www.ehs.washington.edu/LabSaf/surge.htm
http://www.cob.org/fire/safety/surge.htm
http://www.hanford.gov/lessons/sitell/ll00/2000-02.htm

And finally: http://www.rbs2.com/fire.htm

A particularly horrifying fact is that many commercial surge
suppressors in the USA put the thermal disconnector and
varistor in series, so that — after the disconnector opens —
the vulnerable equipment downstream from the suppressor is
exposed to whatever voltage killed the varistor.


Funny. That is not how Pop said they work. Funny. Pop
would even call plug-in protector house fires acceptable when
the surge is too large. Funny. He is so knowledgeable that
he insults rather than provide numbers, science concepts, or
citations. Worry about those grossly undersized power strip
protectors as even Rob Mills demonstrates.

Pop wrote:

=== Undersized how? They're rated for x joules, more
than that causes the MOVs to conduct, until they open
the ckt. If you mean undersized to protect against
monsrous surges, OF COURSE!! The sentence means
nothing.
...


Rob Mills demonstrates, can even create a house fire.

=== NO surge protector can protect beyond the number
of joules it's rated at, and it would very UNlikely to
have started a fire if nothing else in the house was
bothered. That surge, if it really happened, was large
enough to jump the gaps of the MOVs once they opened
up, and thus was capable of jumping many other gaps.
Sometimes though, a protector CAN sacrifice itself for
the equipment, which sounds like what happened, but ...
it wouldn't have started a fire unless it was sitting
inside a pile of tinder that sparks could have ignited.
The plastic would nto have melted or other equipment
would have been damaged. Black stuff only indicates
spark, not flame.

The effective protector earths a surge; and the
homeowner
never knows it happened.

=== No, protectors do much more than that; they are
wye-connected varistors usually with inductive walls to
keep the lines within safe ranges of each other whether
it's earth or hot to neutral or ... and so on.

Protectors that provides effective protection are
located
close to earth ground AND are properly sized.

=== What the hell do you mean by "properly sized"?
And what the heck does "close to ground" mean anyway?

You have no idea what you're talking about, do you?

This is called

a 'whole house' protector. Where it is located? Not
on a
pile of papers on a desk, or behind the furniture, on
a rug,
or within dust balls. Just more reasons why plug-in
protectors (that cost so much money) are so
ineffective.

=== Wrong, proton breath; they are quite effective and
useful and are recommended for very good reasons. I
hope you aren't using any and that you shortly suffer
several power and phone line lightning hits within 5
miles of your home or less, preferably the transoformer
you're fed from. You're a moron in this area.
So, uhhh, just where is it located, by the way? Do
you even know?

Pop


I agree with all stated here except the retributory insults to Pop.
Transformers have a way of mellowing out a surge. A surge typically has
to pass through a couple of transformers before it reaches a damageable
component.

A surge protector does not function like a circuit breaker. In fact
breaking the circuit can be worse as it can effectively create a
negative surge or an additional voltage spike.

The hardest work for a relay or a switch is breaking the current flow.

--
Respectfully,


CL Gilbert

Pop,

There's no nice way to say this. w_tom is an engineer who thoroughly
understands earthing. He understands it from not only a theoretical
standpoint, but from a practical one as well. You would do well to
listen and learn from him. I did, and I'm an electrical engineer with
30 years of experience in communications, which has involved a lot
time dealing with remote sites.

When he says "install joules" he means install devices capable of
absorbing the energy produced by a lightning strike. When he tells
you that most "whole house surge protectors" are woefully inadequate,
he is right. Don't listen to me - I'm just an ee who has dealt with
this stuff for 30 years - please read the literatu a lot of it is
available on the internet.
--

Larry
Email to rapp at lmr dot com

wrote:
And you don't realise that Pop is engaged in a war of words with a guy
that is well know for starting flaming threads about surge protection
in multiple groups. There is no reasoning with w_tom. Anyone that has
valid real world experience with using a plug in surge protector that
saved equipment, w_tom tries to either ignore or turn around so that
it looks like the surge protector caused damage. Nothing will change
his mind. He's hell bent on the idea that plug in surge protectors are
of no value, despite many of us having seen them save equipment. Any
reasonable person knows that a whole house surge protector is best, but
if you don;t have one for whatever reason eg living in an
apartment/rental where you have no control, then a plug in is way
better than nothing at all. Plus many of the plug ins offer protection
for cable and phone, which a whole house does not.

There are at least two whole house protectors that offer protection to
all wired utilities that enter the building. Square D's offering can be
seen at
http://www.squared.com/us/products/surge_protection.nsf/unid/DFD1DBCD6854AFA685256A78006DD636/$file/surgebreakerplushome.htm
--
Tom Horne

L. M. Rappaport wrote:
Pop,

There's no nice way to say this. w_tom is an engineer who thoroughly
understands earthing. He understands it from not only a theoretical
standpoint, but from a practical one as well. You would do well to
listen and learn from him. I did, and I'm an electrical engineer with
30 years of experience in communications, which has involved a lot
time dealing with remote sites.

When he says "install joules" he means install devices capable of
absorbing the energy produced by a lightning strike. When he tells
you that most "whole house surge protectors" are woefully inadequate,
he is right. Don't listen to me - I'm just an ee who has dealt with
this stuff for 30 years - please read the literatu a lot of it is
available on the internet.
--

Larry
Email to rapp at lmr dot com

FWIW I am also an EE and CE.(computer)

--
Respectfully,


CL Gilbert

Let's see how a transformer can mellow out a surge.
Pictures demonstrate how the primary protection system must be
inspected and how it can be compromised:
http://www.tvtower.com/fpl.html

Assume that protection at the base of a transformer has been
compromised by a stray automobile. Lightning strikes wires
highest on pole. Lightning seeks earth ground. Normally it
would conduct via that earth ground wire (in pictures). But
that earthing wire has been cut by a stray automobile. So
transient voltage increases until transformer breakdown
voltage is obtained. Now we have a plasma wire from
transformer primary to transformer secondary. Now we have a
short circuit through transformer that lightning uses to enter
a house and damage computer. Once the transformer breakdown
voltage is exceeded, then transformer primary and secondary
are shorted together. Transformer is not mellowing out the
surge because the essential earth ground was disconnected.

Lightning is not an ideal voltage source. Lightning is a
current source. Therefore voltage between transformer primary
and secondary will increase until that current flows. IOW
voltage will increase until the transformer's breakdown
voltage is exceeded. If current has no other path to earth,
then current will create a short circuit inside transformer.

Still that internal plasma wire and lightning current does
not destroy the transformer. What comes next is more
spectacular. Lightning does not have high energy. But
electricity from the utility does. Now we have a short
circuit from primary voltages (2K, 4K, or 13Kv) to secondary
voltages (120, 240). Higher energy electricity from the
utility then uses the same plasma connection to literally
connect, for a short period, the 2K or 13K voltage into your
house. Then the transformer explodes.

Transformer was exploded by energy from a higher energy
source - the utility 2K or 13K volt electricity.

Same is true of protection inside the computer. Galvanic
isolation provided by transformers inside a power supply can
provide 1000 or 2000 volt isolation. These numbers required
even by Intel specs. But once that existing protection inside
the computer is overwhelmed - once a common mode transient
exceeds the 2000 volt breakdown voltage, then internal power
supply protection has been compromised.

Yes, a transformer is effective protection when it performs
galvanic isolation - acts like a dam. However dams without
spillways (the earth ground wire) will fail catastrophically.

Internal appliance protection can be overwhelmed if the
typically destructive transient either is not earthed before
entering a building (secondary protection), or is not earthed
at the pole transformer (primary protection). Once voltage
exceeds a transformer's breakdown voltage, then that
transformer no longer mellows a surge.

Effective protection is about earthing a transient before
that transient can overwhelm protection already inside an
appliance. That means earthing so that a transient does not
build a plasma wire inside the transformer. Once a
transformer's breakdown voltage is exceeded, a transformer no
longer mellows. And so we say, protection is only as
effective as its earth ground.

"CL (dnoyeB) Gilbert" wrote:
...
Transformers have a way of mellowing out a surge. A surge typically
has to pass through a couple of transformers before it reaches a
damageable component.
...