Start with datasheets from MOV manufacturers to understand any surge
protector. Thihs will be long - chock full of tech specs and
concepts.

If the MOV fails catastrophically, then the MOV operates completely
outside "Absolute Maximum Parameters". Its datasheet is quite blunt.
MOVs do not blow like fuses. In fact fuses and MOVs perform two
completely different functions. But those who never learned how plug-
in protectors work will often assume the protector acts like a fuse -
as trader4 has just assumed.

Trader4 implies a protector will disconnect an appliance to stop a
surge. That surge could not be stopped by three miles of sky. How
does an MOV or fuse then stop or limit it? It only does when one (ie
trader4) has no idea what these components do. As in previous posts,
trader4 will cite no spec numbers, no citations, and cannot even say
how a protector works. This post will be chock full of engineering
sources, numbers, and quotes because plug-in protectors do not claim
to provide protection AND because one effective 'whole house'
protector with earthing provides massive protection - at tens of times
less money.

How good is protection inside appliances? Trader4 denies this
protection exist, but forgets to provide numbers. Industry standards
even in 1970 defined 600 volt transients without damage. Computers
defined in Intel specs must withstand AC electric voltages in the
thousands of volts without damage. If trader4 has learned the
technology, then he knew these well known standards.

How many volts much the NIC (network) withstand without damage?
Again, rated for thousands of volts. trader4 calls that minimal
protection? Fine. It is the protection inside electronics that can
be overwhelmed if the surge is not earthed where the surge enters a
building. Internal protection that can be overwhelmed if an adjacent
plug-in protector earths a surge destructively through that
appliance. Protection that means no appliance damaged because surges
are earthed before entering the building. Appliance internal
protection that makes daily (trivial) transients completely
irrelevant.

Trader would have us believe no such protection exists? Many who
know without first learning the numbers make those claims. Industry
standard for 120 volt computer equipment. It must withstand
transients up to 600 volts without damage. Intel demands even higher
voltages computers. That is the internal protection standard in
electronic appliances. What protects dimmer switches and GFCI from
household generated surges? They all have internal protection.
Protection that may be overwhelmed if the typically destructive surge
is permitted inside the building. One 'whole house' protector properly
earthed means no surge damage.

Bud's citation says protectors work IF there is an earth ground to
divert to. Bud's citations also say a protector too close to
appliances and too far from earth ground may earth a surge .... 8000
volts destructively ... through the adjacent electronics. This is
effective protection? Page 42 Figure 8. Does Trader4 deny that
figure? The adjacent protector earths the surge through TV2 - and
that is effective protection? Either the surge is earthed before
entering the building (effective protection) or the surge is earthed
destructively where? ... 8000 volts through an adjacent TV?

If plug-in protectors are so effective as Trader4 says, then where
does the manufacture claim that in numeric specs? Why no listing for
each type of surge AND no protection from that surge? Well, the plug-
in protector may protect from a surge made irrelevant by protection
already inside the appliance. What type of surge does it not protect
from? One that seeks earth ground.

Every responsible source including IEEE and all of Bud's citations
say that the protector works by earthing. How does the plug-in
protector work without an earth connection? That is the point of
Bud's citations. That is the point of Page 42 Figure 8. No earth
ground connection. So it earths a surge 8000 volts through the TV.

Where does the IEEE make recommendations? Not in pamphlets. IEEE
makes recommendation in standards. What does the IEEE Standard 141
(Red Book) say?
In actual practice, lightning protection is achieve by the
process of interception of lightning produced surges,
diverting them to ground, and by altering their
associated wave shapes.

Other IEEE Standards also make similar demands for earthing.
Earthing provides the protection. Even the NIST document (quoted
earlier) says the effective protector works by *diverting* a surge to
earth ground. If a dedicated connection to earth ground does not
exist? Page 42 Figure 8. An 8000 volt surge gets earthed
destructively through the adjacent TV.

As trader4 said, a protector might "limits the differential between
hot-neutral, neutral to ground, hot to ground". Fine. The
typically destructive type of surge is still seeking earth ground.
The protector has distributed (shunted, diverted, connected, clamped)
the surge onto all three wires ... and still seeking earth ground.
Trader4 - stop denying Page 42 Figure 8. The surge is shunted to
other wires. Therefore the surge now has more wires to find earth
ground, 8000 volts destructively, through the adjacent TV.

Why do I know this? We have traced surges doing just that. In one
case study, plug-in protectors on some networked computers earthed a
surge into those adjacent computers. The surge passed through network
cards to enter other computers - the path to earth ground. We
literally replaced each damaged IC - traced the path of that surge.
We made network cards and computers functional again because we
learned how surges actually do damage. Protectors did connect the
surge "differential between hot-neutral, neutral to ground, hot to
ground" - as trader4 says. That gave the surge plenty of paths into
the adjacent computers, through the network, and out to earth ground
destructively via another computer. Again, damage occurred because
the protector was too far from earth ground AND too close to
electronics.

Only one of us has learned this stuff over many decades by even
designing protectors AND by tracing out resulting failures - or
complete protection. That engineering knowledge is not displayed by
trader4. Trader4 has only posted what retail store salesmen claim.

I asked how a protector earths a surge without that short connection
to earth. Trader4 said, "Take it up with the IEEE." I did long ago.
And I quoted repeatedly from the IEEE. In every case, effective
protection is defined by earthing as the IEEE says.

But then I went farther - and with numbers. Why does the telco
switching computer connected to overhead wires all over town not
suffer damage? Why does a typical thunderstorm send hundreds of
surges to that switching computer - and no damage? Because every
protector is earthed were wires enter the building AND up to 50 meters
away from electronics. Why do telcos not use plug-in protectors that
trader4 and Bud recommend? They learned 100 years ago what provides
the protection. An earthed protector was even patented in the 1890s.
Earthing. They want protectors that don't create those "scary
pictures".

Then trader4 asks:
So, I can take any size/rating MOV and pass any size current
through it and if it fails, it violates the manufacturer's spec?

Obviously not. But then plug-in protectors often have that problem
- too few MOVs (are so grossly undersized). A surge strikes protector
and computer simultaneously (see how the protector is wired).
Protection inside a computer is so robust that the computer is
unharmed. But the protector inside a power strip is so grossly
undersized as to fail - as trader4 says "blown out". The naive claim
a protector sacrificed itself to save the computer. Reality:
computer saved itself. That same trivial surge destroyed a grossly
undersized protector. This failure promotes sales.

What happens when the same surge is earthed by a properly sized
'whole house' protector? Surge is earthed. Protectors remains
functional. Human never even knows the surge existed. That is
effective protection. But that does not get the naive to promote more
sales of grossly overpriced plug-in protectors - including $150 models
from Monster Cable.

Grossly undersized plug-in protectors sometimes create these scary
pictures:
http://www.hanford.gov/rl/?page=556&parent=554
http://www.westwhitelandfire.com/Art...Protectors.pdf
http://www.ddxg.net/old/surge_protectors.htm
http://www.zerosurge.com/HTML/movs.html :
http://tinyurl.com/3x73ol or
http://www.esdjournal.com/techpapr/P...OR%20FIRES.doc
http://www3.cw56.com/news/articles/local/BO63312/

So who makes 'whole house' protectors? Responsible companies such
as GE, Siemens, Intermatic, Cutler-Hammer, Square D, Leviton, and
others. Notice names missing such as Tripplite, Belkin, APC, and
especially Monster Cable. Let's see. Take a $3 power strip. Apply
some expensive paint. Install some $0.10 protector components. Sell
it for $150. No wonder plug-in protector need people such as Bud to
promote their products. Profits may be at risk. And then those
"scary pictures". Don't put too many MOV inside. That would harm
profits. An undersized (failing) power strip will have the naive
assume, "My protector sacrificed itself to save my computer".

Tell us trader4. If the plug-in protector magically protects by
""limits the differential between ...", then were does all that energy
get dissipated? You claim the surge is dissipated by the MOV "between
hot-neutral, neutral to ground," etc. So where does all that energy
get dissipated? Inside a tiny MOV that is doing the limiting? If the
MOV is doing limiting, then the MOV is absorbing all that energy. But
even MOV manufacturers say that is not the purpose of the MOV. Well
if the MOV absorbs too much energy, then it will fail - promote more
sales. That energy must be dissipated somewhere. Tell us trader4 -
since you deny so often and never provide facts - tell us where that
energy is dissipated?

No earth ground means energy cannot be dissipated in earth. So
where is that energy dissipated? In the MOV? Or on Page 42 Figure 8
- 8000 volts dissipates energy across the adjacent TV? The energy
must be dissipated somewhere. How curious that IEEE Standards, all
Bud's citations, any responsible source list where energy is
dissipated. Either destructively in the building OR earthed
harmlessly by a 'whole house' protector.

Let's see. Electrical Engineering Times just published two front
page articles entitled "Protecting Electrical Devices from Lightning
Transients". What does an engineer define for effective surge
protection? Protectors? Of course not. He discusses what provides
the protection - where all that energy is dissipated. Read it
yourself. From the 1 Oct and 8 Oct 2007 issues of EE Times:
http://www.planetanalog.com/showArti...leID=201807127
http://www.planetanalog.com/showArti...leID=201807830

Earthing provides the protection. Those articles don't even discuss
protectors. But important for protection is the wire length to earth;
it must be short for lowest possible impedance. Why does Kaufmann
discuss earthing and short connections to earth? No earth ground
means no effective protection. No earth ground means trader4 must
claim energy is absorbed (or blocked) by the MOV. But that is not
what an MOV does. As the NIST says on page 6 (Adobe page 8 of 24) of
http://www.nist.gov/public_affairs/p.../surgesfnl.pdf
You cannot really suppress a surge altogether, nor "arrest"
it. What these protective devices do is neither suppress nor
arrest a surge, but simply divert it to ground, where it can do
no harm.

What does a plug-in protector do without that low impedance
connection to earth ground? If may shunt that energy 8000 volts
destructively through the adjacent TV (Page 42 Figure 8) or it may
shunt that energy through computer network (our analysis).

Trader4 - when will you tell us how the adjacent protector works?
By limiting (your really mean shunted or diverting) that current, it
simply gave the surge more paths to find earth ground destructively
through adjacent appliances.

No wonder the telco puts their protectors up to 50 meters distant
from their switching computer. No wonder the telco earths their
protector so short. No wonder the telco can suffer 100 surges during
each storm - and no damage. No wonder the telco does not use
undersized and grossly overpriced ($15) plug-in protector. No wonder
telcos do not use the same protectors selling for $150 in Radio Shack,
Circuit City, et al. They want protection; not to enrich the
manufacturer.


How much grasp of electronic design do you have? I said appliances
contain effective protection. I did not say they contain MOVs as
trader4 assumes. Trader4 asks:
why do manufacturers put surge protection into electronic eqpt

They don't. Apple II once had MOVs inside. All electronic
equipment contains internal protection. Nothing said it is provided
by surge protectors. Apple no longer used MOVs in their equipment
because MOVs located too far from earth ground do nothing effective.
But again, trader4 did not first learn the industry numbers. Again
trader4 made assumptions because he does not know how such equipment
is designed. He denies everything about effective surge protection,
somehow magically knows a grossly overpriced protector must provide
protection, but does not even know how electronics routinely contain
protection.

Trader4, take a walk through semiconductor databooks. Interface
semiconductors. Why does the datasheet cite 15,000 volt protection?
And without MOVs? And why is that protection defined by IEC1000-4-2
standards? Oh. Such internal protection is that high and that
standard. Trader4 did not even know this? Which one of us is posting
because he has learned the technology? I provided the voltage
numbers. I provided the standards number. I quote what the IEEE Red
book (and other IEEE Standards) require for protection. I provided
the EE Times article that discussed earth ground for protection. I
quoted same in all of Bud's citations. What does Trader4 know? Only
what he was told by the retail store salesman. What kind of citation
is that?

Trader4 provides only one thing. Denial.

No earth ground means no effective protection. One 'whole house'
protector, properly earthed, is what dissipated the direct lightning
strike harmlessly in earth. What does trader4 paraphrase? Bud who
promotes for plug-in protector manufacturers.

w_tom took it up with the IEEE and learned what is required for
effective protection long ago. w_tom built surge protectors to learn
what does and does not work. w_tom traced direct lightning strikes
to learn why damage occurred. w_tom has seen what is also
demonstrated on Page 42 Figure 8 - the protector that earthed a surge
8000 volts through an adjacent TV.

Who should we believe? Trader4 who has yet to cite a technical
fact. Of this poster who is citing numbers, standards, energy, and
concepts repeatedly. How curious that manufacturers with far better
reputations - Square D, Leviton, Intermatic, Cutler- Hammer, Siemens,
and GE - all make protectors with that dedicated earthing connection.
Why would more responsible manufacturers do that when Trader4 says it
is not necessary? Why would everyone's telco also install only
properly earthed protection. Could it be that a protector without
earthing is profitable rather than effective?

When does trader4 quote manufacturer numeric specs that claim
protection? He cannot. Plug-in protectors do not even claim such
protection. How to identify an ineffective protector? 1) No
dedicated earthing wire. 2) Manufacturer will not discuss earthing.
No earth ground means no effective protection. But don't worry. Page
42 Figure 8 - it may earth that surge 8000 volts destructively through
the nearby TV. When that happens, the plug-in protector does exactly
what trader4 says it does.

On Nov 11, 9:16 pm, wrote:
On Nov 11, 2:01 pm, w_tom wrote:
On Nov 11, 7:49 am, wrote:
...
If the MOV is blown out,
then it provided no protection. Nada. Effective protectors MUST
earth a surge and remain functional.

Following that logic, a blown fuse offers no protection either. It's
certainly possible for a MOV inside a plug-in surge protector to have
taken the biggest part of the surge, blowing it out, and the
protection inside the electronic appliance, acting in parallel, to
have also taken some of the surge, but not be destroyed.

...
LOL. Let me get this straight. According to you, the minimal
protection inside electronic eqpt or an appliance is supposed to be
perfectly capable of stopping a surge, yet components capable of
disipating a similar or larger surge in a plug-in protector are
useless?

Plug-in protectors will even earth surges destructively through
adjacent appliances. Review Bud's citations.

Bud's citations say that plug-ins work.

A protector must earth a surge - not absorb it.

No, in the case of a plug-in protector, as Bud outlined, the device
limits the differential between hot-neutral, neutral to ground, hot to
ground.

How does a plug-in protector earth without
a 'less than 10 foot' dedicated earthing wire? It does not. But then
it does not even claim such protection in its own numeric specs. Its
purpose is profits; not protection.
Take that up with the IEEE.

Learn why plug-in protectors may even earth surges destructively
through appliances. The surge must be earthed somewhere. Page 42
Figure 8 in
http://omegaps.com/Lightning%20Guide...ion_May051.pdf
A plug-in protector too close to an appliance has earthed a surge
*8000 volts destructively* through an adjacent TV. Where is the
protection? That protector - earthing a surge through the TV - has
done what its manufacture claims. It does not claim to protect from
the type of surge that typically causes damage. By being grossly
undersized (ineffective), you have assumed a blown out protector
provided protection? A blown out protector even violates every MOV
manufacturer spec. Acceptable MOV failure means never vaporizing. But
vaporizing gets the naive to promote more profits - recommend those
grossly undersized protectors.

So, I can take any size/rating MOV and pass any size current through
it and if it fails, it violates the manufacturer's spec? What are
they, a miracle device?

A 'blown out' MOV is even a safety hazard - completely unacceptable.

Do you really believe it will absorb the energy from three miles of
lightning? They need you to 'feel' that one inch part stops or
absorbs what three miles of sky could not stop. Show me a single MOV
designed to do that - and good luck. Bud needs you to 'feel' it
protects by absorbing the entire surge - sacrificing itself.

You are the only one here talking about surge protectors "absorbing"
anything. You brought up the term.

How is it that disaster results only from plug-in surge protectors and
not from similar protection that you crow about that is built into
electronic devices/appliances and located 4 ft away? Hmmm, neither
one has a close by earth ground, do they?

MOVs are no longer inside appliances because MOVs adjacent to the
appliance (on power cord or inside) are not effective. All appliances
have long contained internal protection - and no MOVs. MOVs must be
AT earth ground. Bud's citation even defines the effective
protector. From page 6 (Adobe page 8 of 24) of
http://www.nist.gov/public_affairs/p.../surgesfnl.pdf
You cannot really suppress a surge altogether, nor "arrest"
it. What these protective devices do is neither suppress nor
arrest a surge, but simply divert it to ground, where it can do
no harm. So a name that makes sense would be "surge
diverter" but it was not picked. So, for the rest of this booklet,
we will stick to the most popular "surge protector".

Where does it say anything about absorbing energy to be 'blown
out'? It does not. It *diverts* - and it remains functional. Blown
out is how to promote more sales of protectors that don't even claim
to provide protection.

Again, only you are talking about absorbing energy. I never said
that. Bud didn't either. And to blow out a MOV all you need to do
is hit it with current beyond what it is rated for. You apparently
aren't aware that they have specs for max current and maximum energy
disipation. It's a semiconductor, not an infinite current shunt.



Divert it to where? Where is surge energy dissipated? Earth
ground. With a 6 foot power cord on a plug-in protector, how will it
make a 'less than 10 foot' connection?

Then why do manufacturers put surge protection into electronic eqpt
and appliances that work under the same conditions? No, wait! They
are even farther from earth ground by the length of the appiance power
cord of about 4 ft.

Wire length (not diameter) mostly determines wire impedance. The
effective surge protector must have a low impedance connection to
earth. That means 'less than 10 feet'. A plug-in protector too far
from earth ground is for profits; not protection. Does not even
claim to provide protection. View it yourself. Its numeric specs do
not even list or claim to protection from the typically destructive type
of surge. Bud will never post that number because the number does
not exist. A $15 plug-in protector (or same one sold in Circuit City
or Radio Shack for $150) does not even claim to provide that protection.
...