Question about MOV's

[Richard Freeman]

"w_tom" <w_tom1@hotmail.com> wrote in message
news:3F4ADCAC.4AEF6C4F@hotmail.com...

1) I don't work for any surge protector manufacturer nor sell
these products. If I did sell protectors, then why do I
recommend so many competitor products? Clearly wild
speculation based upon no facts has no merit.

Hmm let see Someone who appears to use Google to search out postings with
the words 'surge', 'Lightning' etc in them and then visits NGs he does not
otherwise post in to sing the praises of 'whole house protection' despite
having his errors pointed out time and time again. I am afraid the only
other explantions for this kind of behaviour are less reptuable than having
a vested commercial interest.
I also note that you merely claim not to sell these products or work for a
surge protection Manufacturer these two claims hardly discount all the
potential forms of commercial self interest you could have. Maybe if you
stated what you did and what you used to do for a living we might believe
you.

2) Minimally effective 'whole house' protectors of greater
than 1000 joules sell for less than $50. That is less than $1
per effectively protected appliance.

Like I said effective Earthing costs more in the order of $10,000 - and I am
talking earthing here I am not talking about cheap shitty MOVs which handle
a monstrous 2000A for the 2.5nS they survive for, I am talking effective
Earthing. The EPR on a typical single Earth stake during a Lightning strike
IS in excess of 50,000 Volts - hardly an effective earth.

3) In many locations, a single 3 meter ground rod is been
demonstrated sufficient for effective earthing of a direct
strike - about $9 for the rod. Of course better grounding
means even better protection. Surge protection is that easily
installed. Damage demonstrates how little effective surge
protection is actually installed.

BS a single 3 meter Earth stake in the event of a Direct strike is woefully
inadequate suffering an EPR in a typical installation in excess of 50,000
Volts in fact in the event of an indirect near strike on say a lightning rod
etc the EPR can travel up the protective earth and look fo rthe far superior
MEN Earth blowing the crap out of any appliance in its path

4) Where damage has been experienced and especially where
lightning damage occurs repeatedly, the human requires
technical assistance in the art of earthing - because direct
lightning strike damage is routinely avoided. There are many
humans who cry "woe is me". As quitters, they get the
lightning damage they deserve.

usually at great cost being multiple earth stakes bonded together and spread
out over an area of 1/4 of an Acre or more.

Richard Freeman wrote:
It F'ing well is as you would well know if you worked with a Telco for
any
length of Time I have seen Sites that are blown to kingdom come just
about
every time a Thunderstorm rolls into Town - DESPITE the best efforts of
the
Telco I worked with to provide Lightning protection
...

Ahh but you forget or are unaware that mr w_tom makes his living from
selling 'whole house Surge arrestors' and he conveniently forgets to
mention that for effective Earthing to cost $1 per appliance assumes you
have around 10,000 appliances in the house - or by the time you take
into
account the cost of land in say Sydney it assumes you have around
300,000
appliances. And will still fail to protect appliances in the event of
the
most common form of surge - Lightning entry via other than power cables
but
only in an extremely rare event - that of lightning damage via Power
mains.

 

[Rod Speed]

Richard Freeman <deletemerichard@atps.net> wrote in
message news:3f4b030e$1_1@news.iprimus.com.au...

w_tom <w_tom1@hotmail.com> wrote

1) I don't work for any surge protector manufacturer
nor sell these products. If I did sell protectors, then
why do I recommend so many competitor products?
Clearly wild speculation based upon no facts has no merit.

Hmm let see Someone who appears to use Google to
search out postings with the words 'surge', 'Lightning' etc
in them and then visits NGs he does not otherwise post in
to sing the praises of 'whole house protection' despite having
his errors pointed out time and time again. I am afraid the
only other explantions for this kind of behaviour are less
reptuable than having a vested commercial interest.

Or he's just got one hell of a bee in his bonnet about 'whole house protection'

Rather pathetic, really.

He's also mindless obsessive about
brand name power supplys for PCs too.

Everything points to a substantial problem between the ears.

I also note that you merely claim not to sell these products
or work for a surge protection Manufacturer these two
claims hardly discount all the potential forms of commercial
self interest you could have. Maybe if you stated what you
did and what you used to do for a living we might believe you.

It appears to do nothing but comb usenet for those mentions.

Maybe from its padded cell etc.

 

[Mainlander]

In article <pan.2003.08.22.20.10.33.186975@susie.linux.au>,
noah@susie.linux.au says...

Probably a stupid question, but why aren't MOV's standard in all
electrical appliances like amplifiers and computer PSUs?
They are found in most power boards these days to obviously protect
equipment from being destroyed.

To get a reasonable amount of protection against all possible line
conditions you need to spend up to a couple of hundred dollars. That
would add to the cost of all such power supplies. Anyway some people
would still rather have a UPS which is better still.

 

[Richard Freeman]

"The real Andy" <ihatehifitrolls@yahoo.com.au> wrote in message
news:3f4b2fc4$0$6529$afc38c87@news.optusnet.com.au...

"Brian Goldsmith" <brian.goldsmith@nospamecho1.com.au> wrote in message
news:ONn2b.62088$bo1.50224@news-server.bigpond.net.au...

"The real Andy" <ihatehifitrolls@yahoo.com.au> wrote

Lightning strikes are a different story. For decent protection against
lightning stikes you will need to invest significant cash, which is
not
viable for consumer products. I think these days the telco industries
doesn't even try to arrest surges, rather they let the gear float up

**** Answer the question ,moron!Do you seriously believe that the POTS
"floats" up to the MVs of a lightning strike?
Brian Goldsmith.


Read the post cocksucker. If their is a piece of copper going into your
house (which I never said) then it will be a different story. And in case
you are to old and stupid to read my post, may I point out that i
mentioned
the words "I think" not 'I know'. Just for the record, i was thinking
about
something other than copper PSTN lines going into your house, i was
thinking
of a slighly more modern (more lightning prone) piece of equipment.

Find me a Correctly installed Telco installation that is not earthed .....
Rims,Optomuxes,Remote exchanges,Main exchanges etc all are Earthed.

 

[The real Andy]

"Richard Freeman" <deletemerichard@atps.net> wrote in message
news:3f4be8a7$1_1@news.iprimus.com.au...

"The real Andy" <ihatehifitrolls@yahoo.com.au> wrote in message
news:3f4b2fc4$0$6529$afc38c87@news.optusnet.com.au...
"Brian Goldsmith" <brian.goldsmith@nospamecho1.com.au> wrote in message
news:ONn2b.62088$bo1.50224@news-server.bigpond.net.au...

"The real Andy" <ihatehifitrolls@yahoo.com.au> wrote

Lightning strikes are a different story. For decent protection
against
lightning stikes you will need to invest significant cash, which is
not
viable for consumer products. I think these days the telco
industries
doesn't even try to arrest surges, rather they let the gear float up


**** Answer the question ,moron!Do you seriously believe that the POTS
"floats" up to the MVs of a lightning strike?
Brian Goldsmith.


Read the post cocksucker. If their is a piece of copper going into your
house (which I never said) then it will be a different story. And in
case
you are to old and stupid to read my post, may I point out that i
mentioned
the words "I think" not 'I know'. Just for the record, i was thinking
about
something other than copper PSTN lines going into your house, i was
thinking
of a slighly more modern (more lightning prone) piece of equipment.


Find me a Correctly installed Telco installation that is not earthed .....
Rims,Optomuxes,Remote exchanges,Main exchanges etc all are Earthed.

Microwave repeaters perched upon hills!! ;-) I don't know if this is done
here in Oz, but I know it's done in a few overseas countries. They still use
an isolated lightning arrestor thingy, you know those big gold balls that
are supposed to discharge the clouds, the ones that start to squeal when
there is a storm nearby!!

 

[The real Andy]

"Brian Goldsmith" <brian.goldsmith@nospamecho1.com.au> wrote in message
news:%NH2b.64635$bo1.57198@news-server.bigpond.net.au...

*** What on Earth is all this tripe about?
Do you have the slightest idea of what a dogs breakfast you have
written?

Nope, neither do you.

How are we supposed to know precisely what you are thinking?

Your so fucken clever, you tell me.

You are worse than a moron,they don't pretend to know anything!!

I know more than you..

And I see you hide behind a psuedonym!Why might that be so?

I did once use Andy, but then someone else started using that name here, so
I changed to the real Andy and prompltly let the imposter know that he stole
my name. PS, my real name is Andy Pearson, which most people here know.

Perhaps you are so ashamed of your real name and the possibilty that
some one who knows you might connect you with the mindless moronic
babblings as written above.

Perhaps you stole your name from an 80's pornstar so you sound more popular
than you are.

Brian Goldsmith.

Andy Pearson

 

[Brian Goldsmith]

"The real Andy" <ihatehifitrolls@yahoo.com.au> wrote

Find me a Correctly installed Telco installation that is not earthed
......
Rims,Optomuxes,Remote exchanges,Main exchanges etc all are Earthed.

Microwave repeaters perched upon hills!! ;-) I don't know if this is
done
here in Oz, but I know it's done in a few overseas countries. They still
use
an isolated lightning arrestor thingy, you know those big gold balls
that
are supposed to discharge the clouds, the ones that start to squeal when
there is a storm nearby!!


**** Is this moron for real????
Brian Goldsmith.

 

[w_tom]

Clearly never bothering to learn the science before
criticizing it. Read MOV datasheets. Learn before
speculating. Only the ill informed says that the joules
rating is absorbing all energy of lightning. MOVs don't
absorb energy just like wire does not absorb energy. Yes,
both absorb some energy because they are not perfect. But
absorbing energy is not their function. Very few joules in an
MOV or copper wire will shunt massive electrical power.

Trend is quite simple. Greater the joules rating means even
less energy is absorbed during a transient. Meaning that the
surge protector life expectancy increases - exponentially.
You are left to do the homework; to learn what those numbers
are really measuring instead of just wildly speculating. All
those posted kilojoules without first learning how joules
measure MOVs. Learn from datasheets the whys and the
relationships that make MOVs effective surge protectors - if
properly sized and properly earthed.

In the meantime, for residential AC electric, a minimally
effective 'whole house' surge protector starts at about 1000
joules. That would be about 3000 joules to be equivalent in a
plug-in surge protector. A plug-in surge protector that would
still not be effective without a short connection to single
point earth ground.

If one did not learn the simple science of MOVs, then how
could one even hope to understand the art of earthing - what
is and is not effective? We have long understood that a surge
protector is only as effective as its earth ground. MOVs (and
the quality of a surge protector) are measured in joules.
Earthing determines that surge protector's effectiveness. All
so well understood that damage from a direct lightning strike
is directly traceable to human failure.


Richard Freeman wrote:

"w_tom" <w_tom1@hotmail.com> wrote in message
news:3F4ADCAC.4AEF6C4F@hotmail.com...
1) I don't work for any surge protector manufacturer nor sell
these products. If I did sell protectors, then why do I
recommend so many competitor products? Clearly wild
speculation based upon no facts has no merit.

2) Minimally effective 'whole house' protectors of greater
than 1000 joules sell for less than $50. That is less than $1
per effectively protected appliance.

Now so far in my answers I have been highlighting the fact that an
effective Earth System is costly but of course this silly statement
from the mysterious w_tom should not be allowed to pass without a
bit more amusement. Mate even weight watchers dont bother talking
in Joules but find that measurement of energy to small and instead
tend to talk about Kilo Joules (KJ) as a few minor points of
reference 1000 Joules (hereby referred to as 1kJ) and to bring
things into perspective:

1kJ is not enough energy to bring 1 Litre of water to the boil but is
enough to make 1 Litre of water approx 1/4 deg C warmer
1kJ is the food energy in 1/2 a Gram of carrot
1kJ is the energy in 0.4 Grams of lettuce
1kJ is the energy in 1.42 Grams of celery

1kJ is bugger all of a Lightning strike it is not a pinch of S..t in
a snowstorm compared to a Lightning strike which is in the order of
1,000,000 kJ to 10,000,000 kJ - in other words assuming your house
is not hit directly but rather cops a near strike and the wiring of
your house picks up 0.01% of a small strike this $50 1kJ protector
is going to cop lets see... 100 times its energy rating - no wonder
the ones I see on phone lines after Lightning strikes were usually
Black, Charred and open circuit.........................

 

[Richard Freeman]

"w_tom" <w_tom1@hotmail.com> wrote in message
news:3F4CB81A.FBF9B778@hotmail.com...

Clearly never bothering to learn the science before
criticizing it.

Nope unlike you I have often seen the charred and smoking remains left after
a Lightning strike

Read MOV datasheets. Learn before
speculating. Only the ill informed says that the joules
rating is absorbing all energy of lightning.

Never said it had to

MOVs don't
absorb energy just like wire does not absorb energy. Yes,
both absorb some energy because they are not perfect. But
absorbing energy is not their function. Very few joules in an
MOV or copper wire will shunt massive electrical power.

Nope you are dead right they do not absorb energy they are not Capacitors
instead they turn it into heat.

Trend is quite simple. Greater the joules rating means even
less energy is absorbed during a transient.

Sorry no energy is Absorbed by a MOV it aint a Capacitor.

Meaning that the
surge protector life expectancy increases - exponentially.
You are left to do the homework; to learn what those numbers
are really measuring instead of just wildly speculating.

It wasnt Speculation it was based on Facts and Figures very very easily
found from the web

All
those posted kilojoules without first learning how joules
measure MOVs.

I posted those Figures to get things into perspective and to show how
ridiculous it is to even think that a device designed to handle a max of
1000 Joules of energy is going to even begin to be effective during a
Lightning strike

Learn from datasheets the whys and the
relationships that make MOVs effective surge protectors - if
properly sized and properly earthed.

Sorry but they dont - no theory here but long experience - the regular sight
of charred and smoking installations that foolishly thought a MOV was of any
more use than a pinch of shite in a snow storm.

In the meantime, for residential AC electric, a minimally
effective 'whole house' surge protector starts at about 1000
joules.

Residential AC does not need Surge protection I have never seen Lightning
damage come in via the AC mains it just does not happen that way. there are
a number of reasons for this but I have gone over them all with you before
and you still choose ignorance of Fact as you continue in your quest...

That would be about 3000 joules to be equivalent in a
plug-in surge protector. A plug-in surge protector that would
still not be effective without a short connection to single
point earth ground.

A surge arrestor installed in a Switchboard is only a waste of money against
Lightning, And a single Earth stake is woefully inadequate Earthing if being
used to protect against Lightning. As you would be aware if you bothered
taking time to figure out causes of Surge Damage you would soon realise that
although a plug in surge arrestor has slightly more trouble shunt the
Lightning/surge to an inadequate earth it does mean that being close to the
equipment it is likely to be far more effective. In fact the MOVs built into
a lot of equipment are going to be th most effective of all.

If one did not learn the simple science of MOVs, then how
could one even hope to understand the art of earthing - what
is and is not effective? We have long understood that a surge
protector is only as effective as its earth ground.

You dont seem to understand the simple Science of Earthing either with your
insistance that a single Earth stake is an effective Earth in fact come to
think of it you also appear to have problems with what a MOV can and cant
protect against.

MOVs (and
the quality of a surge protector) are measured in joules.
Earthing determines that surge protector's effectiveness. All
so well understood that damage from a direct lightning strike
is directly traceable to human failure.

In point of fact I see that the IEEE, NEMA and IEC all Recommend AGAINST
using Joule ratings when either specifying or comparing Surge arrestors

but I agree in Failure to take reasonable precautions against Lightning,
Failure of people with undisclosed vested interests in 'whole house
protection' to point out the shortcomings of their 'surge arrestors' and
finally failure of people who track down mentions of the words 'Lightning'
and 'Surge' to take the time to discover the facts about the normal Paths
taken by Lightning when causing damage.

I have seen too much Lightning damage over the years to believe a word you
say about Lightning

I note your lack of explanation about what you real interests are with surge
arrestors

Also note the Adavantage of not Top posting you can respond to points raised
more clearly .... but then maybe you do not want that

Richard Freeman wrote:
"w_tom" <w_tom1@hotmail.com> wrote in message
news:3F4ADCAC.4AEF6C4F@hotmail.com...
1) I don't work for any surge protector manufacturer nor sell
these products. If I did sell protectors, then why do I
recommend so many competitor products? Clearly wild
speculation based upon no facts has no merit.

2) Minimally effective 'whole house' protectors of greater
than 1000 joules sell for less than $50. That is less than $1
per effectively protected appliance.

Now so far in my answers I have been highlighting the fact that an
effective Earth System is costly but of course this silly statement
from the mysterious w_tom should not be allowed to pass without a
bit more amusement. Mate even weight watchers dont bother talking
in Joules but find that measurement of energy to small and instead
tend to talk about Kilo Joules (KJ) as a few minor points of
reference 1000 Joules (hereby referred to as 1kJ) and to bring
things into perspective:

1kJ is not enough energy to bring 1 Litre of water to the boil but is
enough to make 1 Litre of water approx 1/4 deg C warmer
1kJ is the food energy in 1/2 a Gram of carrot
1kJ is the energy in 0.4 Grams of lettuce
1kJ is the energy in 1.42 Grams of celery

1kJ is bugger all of a Lightning strike it is not a pinch of S..t in
a snowstorm compared to a Lightning strike which is in the order of
1,000,000 kJ to 10,000,000 kJ - in other words assuming your house
is not hit directly but rather cops a near strike and the wiring of
your house picks up 0.01% of a small strike this $50 1kJ protector
is going to cop lets see... 100 times its energy rating - no wonder
the ones I see on phone lines after Lightning strikes were usually
Black, Charred and open circuit.........................

 

[w_tom]

Richard Freeman wrote:

I note your lack of explanation about what you real interests
are with surge arrestors.

I learned this stuff many decades ago by reading theory from
so many sources (including the legendary GE Application Notes
on MOVs, AND doing many experiments. Have had spectacular
successes and one (still) puzzling failure. I have repaired
multiple networked computers by tracing the surge, incoming on
AC electric, through the network, and out to earth ground via
one computer's modem. Identified the damaged ICs, replaced
them, and the entire system was restored. These experiences,
education, research papers, and testimony from industry
professionals are why I know how surges damage AND why AC
electric is a most common source of direct lightning surge
damage.

However I am appalled that so many posters so hate humanity
as to promote junk science and outright lies. If for no other
reason because they cannot bother to first learn basic
electrical principals. You have demonstrated the problem.
Insufficient understanding of fundamentals. Just a charred
MOV and outright lies from the web. On this flimsy
information, one would make recommendations to others? That
is absolutely unacceptable behavior by a human being.
Irresponsible to let such outright lies stand unmolested.

Surge damage is so avoidable since before WWII as to be
considered human failure. MOVs, properly earthed and sized,
will make surge damage unnecessary. But MOVs typically are
not effective for this type of surge when inside the appliance
or inside a plug-in surge protector.

With so many junk scientists, many humans waste good money
on ineffective surge protectors. How shameful for one human
to do that to another.

 

[Rod Speed]

w_tom <w_tom1@hotmail.com> wrote in message
news:3F4D643E.9740BFD8@hotmail.com...

I learned this stuff many decades ago by reading theory
from so many sources (including the legendary GE
Application Notes on MOVs, AND doing many experiments.

And are now pathetically senile and a pathological liar.

Have had spectacular successes

Obvious lie.

and one (still) puzzling failure.

No viable brain cells left now.

I have repaired multiple networked computers by tracing the
surge, incoming on AC electric, through the network, and out to
earth ground via one computer's modem. Identified the damaged
ICs, replaced them, and the entire system was restored.

Well whoopy bloody do. Plenty of
us have done plenty of that stuff.

Soorree, you dont even qualify for this funky leather medal.

These experiences, education, research papers, and
testimony from industry professionals are why I know
how surges damage AND why AC electric is a most
common source of direct lightning surge damage.

Easy to claim...

However I am appalled that so many posters so hate
humanity as to promote junk science and outright lies.

Best set fire to yourself in 'protest' or something.

If for no other reason because they cannot
bother to first learn basic electrical principals.

Then there's pathetically senile silly old fools like you...

You have demonstrated the problem. Insufficient
understanding of fundamentals. Just a charred MOV
and outright lies from the web. On this flimsy information,
one would make recommendations to others? That
is absolutely unacceptable behavior by a human being.

Best set fire to yourself in 'protest' or something.

Irresponsible to let such outright lies stand unmolested.

So you're an admitted molester too eh ?

Surge damage is so avoidable since before WWII

And here you flaunt your terminal pig ignorance.
What is cost effective with devices that dont use
semiconductors aint necessarily with those that do.
In spades with domestic situations where it makes
a hell of a lot more sense to ensure that your
home contents policy covers the very unlikely
possibility of a direct or close lightning strike
when all electronic devices that arent complete
pieces of sit have MOVs used in the design.

as to be considered human failure.

Describes you to a T.

MOVs, properly earthed and sized,
will make surge damage unnecessary.

All electronic devices that arent complete
pieces of sit have MOVs used in the design.

Where they work very well for the common spikes etc seen.

But MOVs typically are not effective for this type of surge
when inside the appliance or inside a plug-in surge protector.

They aint intended to protect against that sort of surge, fool.

With so many junk scientists, many humans waste
good money on ineffective surge protectors.

And fools like you waste good money on 'whole
house protection' when they should just ensure
that your home contents policy covers the very
unlikely possibility of a direct or close lightning strike

How shameful for one human to do that to another.

Wota fucking wanker...

 

[Richard Freeman]

"w_tom" <w_tom1@hotmail.com> wrote in message
news:3F4D605B.BC0FD9E0@hotmail.com...

The web is full of outright lies about surge protectors.
You believed them due to lack of basic EE training. One
classic example of numerous, outright, erroneous facts is:
http://www.howstuffworks.com/surge-protector1.htm

Indeed as are most of the sources you appear to work from in point of fact

This probable English major is taken by layman to be an
expert only because it is posted on the web! That site also
lies about how MOVs work. It also says that MOVs absorb
(absorb by converting to heat) the entire energy of a surge.
How foolish. Basic circuit theory demonstrates 'absorbing' is
not possible. To absorb, the MOV must be in series with the
protected device. Instead MOVs are in parallel. A parallel
device cannot absorb the transient. MOV manufacturers don't
even claim to absorb that energy. Obvious due to simple
circuit theory.

I have never said the MOV absorbs the Surge (a point I have already made in
my previous post but by Top posting you get to pretend I have not already
made that point) however any Component or Circuit that carries current
dissipates heat and in the event of a MOV during a Lightning strike when
even joints in cables burn out this is a shit load of Heat.

I fear this has gotten too complex since your sources are
the web rather than IEEE papers, manufacturer datasheets, and
basic education on electrical fundamentals.

In other words you are having a little trouble coping with : Experience,
Education and Information

Try using numbers
for the 2V250 MOV in this datasheet:
http://www.nteinc.com/Web_pgs/MOV.html

Damn good Idea Lets see now.....

A 70 joule device can shunt 4500 amps direct strike - and on
leads only 1 mm diameter. This without charring.

Provided the strike lasts less than 20uS !!!! and the peak current of a
Lightning strike can and often does last in excess of 5 times this long and
exceed 200KA with a trailer running around 4-5000 Amps for another 0.25 S or
so ( all info available in Text books as well as the web) - in a direct
strike your MOV is toast. even in a Near strike the MOV is likely to be
toast - Believe me they often are I have seen toasted Movs often enough to
know that MOVs do not survive Lightning strikes Even the engineering and
Maths tells you that.
Lets look a bit further through the Data hmmm Power dissipation 0.6W ???
wonder what the 'On clamp' Voltage across the device is ? ( it is usually
lower than the clamp voltage but higher than the rated Voltage - Do the math
figure out what current the MOV can handle at say 240V ).

If you have
sufficient electrical knowledge to do simple circuit analysis,
then numbers from this data sheet make it obvious. MOVs don't
absorb the energy of a surge - as wildly speculated.

Just did it and your MOV is fried.....

Datasheet demonstrates why a 1000 joule surge protectors can
earth a direct strike - without damage.

Where ?? I have done the Math and your MOV is Toast

But then we have been
doing this, successfully and without damage, for
generations. Experience proven even before WWII.

Nope wrong ! Experience has instead shown that surges from 240V mains are so
rare from Lightning that MOVs on commercial Mains (for Lightning Protection)
are generally a waste of time and Money as the MEN System and Cabling are
usually more than adeqaute to cope with Lightning.
Of course the MOVs I have seen are all on Telephone and Data Links which are
prone to Lightning so unlike you I have had plenty of opportunity to look at
and analyse failures of Surge arrestors (including MOVs).

All you
have is a grossly undersized MOV that is charred

BS how would you know ? I have seen 1000J Movs (note the Plural) that were
incinerated following a Lightning strike. but then again as the IEEE, IEC
and NEMA all reccomend against basing MOV ratings on Joules.

- and not
enough fundamental (theoretical) knowledge to understand why
it is charred. Without specific or ball park numbers, then
you have no idea (other than junk science reasoning) why it is
charred. You have criticized the science before learning it
or learning the numbers. Classic example of junk science
reasoning.

You are pushing a protection System that is inadequate to cope with what you
claim but Fortunately for you the MEN power system ensures that your MOVs
dont have to. Despite your pontificating to the contrary you have little
knowledge about Lightning Protection which is highlighted by your
assumptions about the effectiveness of single point (stake) Earthing.

Answering the original poster's question again: MOVs shunt
a direct strike less than 3 meters to an effective earth
ground. But the MOVs will only be as effective as that earth
ground.

and a single earth stake is woefully inadequate as you would well know if
you had any real practical knowledge in this field.

 

[Richard Freeman]

"w_tom" <w_tom1@hotmail.com> wrote in message
news:3F4D643E.9740BFD8@hotmail.com...

Richard Freeman wrote:
I note your lack of explanation about what you real interests
are with surge arrestors.

I learned this stuff many decades ago by reading theory from
so many sources (including the legendary GE Application Notes
on MOVs,

GE right who had a vested interest in whipping up hysteria and selling MOVs
without exposing themselves to liability Right !

AND doing many experiments. Have had spectacular

successes and one (still) puzzling failure. I have repaired
multiple networked computers by tracing the surge, incoming on
AC electric, through the network, and out to earth ground via
one computer's modem.

Bullshit what sort of Network is only grounded via a modem?????
ohh hang on I missed the obvious the modem was charred right?
equipment only plugged into AC mains ( and not the Network or modem) was O.K
right?
and so you followed the trail of destruction to the Modem and assumed that
was the way the Lightning went huh ?
WRONG ! the lightning would have come in via the phone line, Bounced around
the Network a bit and slowly dissipated into the MEN Mains earth. I have
seen this far too often - obviously a hell of a lot more often than you. If
you are lucky I might write up some of my Lightning tales and add them to
the Techy Tales thread.

Identified the damaged ICs, replaced
them,

but the modem was beyond repair and had to be completely replaced right ?

and the entire system was restored. These experiences,
education, research papers, and testimony from industry
professionals are why I know how surges damage AND why AC
electric is a most common source of direct lightning surge
damage.

Utter Utter Utter Bullshit which only serves to highlight your complete Lack
of experience in the Field I have seen plenty of Lightning Damage but never
a case where the Lightning came in through the AC mains your advice is only
going to cause more damage.

However I am appalled that so many posters so hate humanity
as to promote junk science and outright lies.

Why are you posting your lies then ?

If for no other
reason because they cannot bother to first learn basic
electrical principals.

it seems I know them much better than you ...

You have demonstrated the problem.
Insufficient understanding of fundamentals. Just a charred
MOV and outright lies from the web.

Far far more than just one .........

On this flimsy
information, one would make recommendations to others? That
is absolutely unacceptable behavior by a human being.
Irresponsible to let such outright lies stand unmolested.

A heap more information and experience than you it seems

Surge damage is so avoidable since before WWII as to be
considered human failure. MOVs, properly earthed and sized,
will make surge damage unnecessary. But MOVs typically are
not effective for this type of surge when inside the appliance
or inside a plug-in surge protector.

not the smoking ruins I have seen

With so many junk scientists, many humans waste good money
on ineffective surge protectors. How shameful for one human
to do that to another.

You are the proponent of people wasting their money on unneccasary surge
protection not me hang your head in shame then.

Besides all this still fails to explain your pathalogical pursuit if the
words 'Lightning' and 'Surge' on the newsgroups ....

 

[Richard Freeman]

"w_tom" <w_tom1@hotmail.com> wrote in message
news:3F4F6DE6.D50AF6F6@hotmail.com...

Clearly the manufacturer must have put up MOV data that
cannot work - that would only result in fried MOVs. Reality.
It does work.

Movs on Power lines rarely get fried Because the MEN Power system absorbs
most if not all the strike and in fact MOVs on power lines are generally a
complete waste of time and money.
Lightning 'surges' tend to come in from other sources such as : Phone lines,
Data Lines, unearthed sections of metal building frame Aerials, etc etc etc

And destructive surges for lightning are
typically on the order of 8/20 usecond events.

The peak current surge for a lightning Strike is generally in the order of
100-200uS with a tail which typically lasts 250 mSec or more. Spin crap as
much as you like wishful thinking will not change the nature of Lightning.
You are confusing a standard dreamt up by some 'Comittee' with reality. Yes
that may be the standard way of measuring a MOVs current capacity but that
does not mean it matches with reality.

The MOV shunts
direct strikes without damage as has been standard since
before WWII - no matter how you twist those numbers.

More blatent lies from w_tom. twist the facts all you like burt the fact
remains that in a Near or Direct strike the MOV is toast ...... I have seen
fried MOVs in installations which had MOVs within 1 - 2 Meters of the earth
stake (yes with nice thick earth wire and nice big MOVs) far too often to
believe otherwise.

but the
MOV protector must be properly earthed and properly sized.

Properly earthed means more than the paltry single earth stake installations
you keep claiming are adequate. As for adequately sized ..... well your 1000
Joule claim is way to small for a Near / Direct strike.

The real Danger with claims like w_tom makes is that people end up believing
them and fail to take sensible precautions when a Thunderstorm is looming
one thing is True Lightning damage is often due to people failing to take
reasonable precautions these include disconnecting phone lines etc from
modems - This is by far the most common cause of Lightning damage that I
have seen. Choosing an external modem over an internal one also helps keep
Lightning damage at arms length in the event you forget to unplug the phone
line when Lightning calls.

 

[Richard Freeman]

one minor correction ......

"Richard Freeman" <deletemerichard@atps.net> wrote in message
news:3f5282e7$1_1@news.iprimus.com.au...

"w_tom" <w_tom1@hotmail.com> wrote in message
news:3F4F6DE6.D50AF6F6@hotmail.com...
Clearly the manufacturer must have put up MOV data that
cannot work - that would only result in fried MOVs. Reality.
It does work.

Movs on Power lines rarely get fried Because the MEN Power system absorbs
Or rides out.

most if not all the strike and in fact MOVs on power lines are generally a
complete waste of time and money.
Lightning 'surges' tend to come in from other sources such as : Phone
lines,
Data Lines, unearthed sections of metal building frame Aerials, etc etc
etc

And destructive surges for lightning are
typically on the order of 8/20 usecond events.

The peak current surge for a lightning Strike is generally in the order of
100-200uS with a tail which typically lasts 250 mSec or more. Spin crap as
much as you like wishful thinking will not change the nature of Lightning.
You are confusing a standard dreamt up by some 'Comittee' with reality.
Yes
that may be the standard way of measuring a MOVs current capacity but that
does not mean it matches with reality.

The MOV shunts
direct strikes without damage as has been standard since
before WWII - no matter how you twist those numbers.

More blatent lies from w_tom. twist the facts all you like burt the fact
remains that in a Near or Direct strike the MOV is toast ...... I have
seen
fried MOVs in installations which had MOVs within 1 - 2 Meters of the
earth
stake (yes with nice thick earth wire and nice big MOVs) far too often to
believe otherwise.

but the
MOV protector must be properly earthed and properly sized.

Properly earthed means more than the paltry single earth stake
installations
you keep claiming are adequate. As for adequately sized ..... well your
1000
Joule claim is way to small for a Near / Direct strike.

The real Danger with claims like w_tom makes is that people end up
believing
them and fail to take sensible precautions when a Thunderstorm is looming
one thing is True Lightning damage is often due to people failing to take
reasonable precautions these include disconnecting phone lines etc from
modems - This is by far the most common cause of Lightning damage that I
have seen. Choosing an external modem over an internal one also helps keep
Lightning damage at arms length in the event you forget to unplug the
phone
line when Lightning calls.