Surge Protectors

Sjouke Burry wrote in news:4c1d48fd$0$14115$ snipped-for-privacy@textnews.kpn.nl:

I never said it did. the MOV voltage rating is the voltage when it changes state and drops to a low resistance to shunt the surge to GROUND. Now,how low a resistance in the conducting state is another matter. that's dependent on the MOV design/ratings.

USAF PME School,1971.

yes,I said the MOV's dissipation would be "minimal",....compared to the total energy the MOV was passing to ground. what energy the MOV dissipates can easily be enough to blow it apart. I've seen it happen many times. But the MOV is not dissipating the total energy of the surge with it's suicide.

Of course,the fuse itself can arc over in a lightning strike,as it can exceed the typical 250v voltage rating of the fuse.

--
Jim Yanik
jyanik
at
localnet
dot com

A MOV is somewhat like two back-to-back Zener diodes. It is a voltage clamp. You do not pass energy to ground, you pass current to ground just like you do with any load. The energy is totally dissipated in the MOV.

David

So what is the point? John Dvorak wrote a story about surge supressors and how they worked with his Cumulus 386 laptop and his CompuAdd 486sx tower?

suppressors.

so.

supression

The point is that they were performing lab tests on the suppressors. These tests included determining the clamping voltage. (I don't remember if they were tested to destruction.) The tests were presumably performed in accordance with industry-accepted standards.

Poor westom just keeps repeating the same lies, just like Josef Goebbels.

If he had valid technical arguments he would not have to try to discredit those that expose his drivel.

My only association with surge suppressors is that I have 2 of them.

"Each type of surge" is more nonsense. SquareD, amongst others, does not have specs for "each type of surge".

I provided a link to the specs I have provided in many threads -always ignored by westom, just like he ignores anything that conflicts with his religious belief in earthing.

Apparently poor westom believes plug-in suppressors do not work, so he believes specs cannot possibly exist.

Poor westom's religious blinders prevent him from seeing what has been said in this thread, and numerous other threads.

For incoming power wires, at about 6kV there is arc over from service busbars to the enclosure. After the arc stabilized the arc is hundreds of volts. The enclosure is connected to the earthing electrodes, so this dumps the vast majority of the incoming surge energy to earth. The neutral (in the US) is also always tied to the system ground at the service, so energy coming in on the neutral is directly earthed. Apparently that is all magic for westom.

For a plug-in suppressor, the impedance of the branch circuit wiring greatly limits the current that can reach the suppressor. That greatly limits the energy that can reach the suppressor. NIST surge guru Martzloff looked at the energy that could reach the suppressor and was surprised that it was 35 joules or less. In most of his tests it was under 1 joule. That is with service surges up to the maximum that there is any reasonable probability of occurring.

As Sjouke wrote, the MOV dissipates an energy equal to the clamp voltage times the current times the time. For a plug-in suppressor the current is very limited by the branch circuit impedance. And the time is very short - well under 100 microseconds. Fuses or circuit breakers do not provide protection because they are nowhere near fast enough - they won't open during a surge.

Plug-in suppressors do not work primarily by earthing a surge - that reason poor westom believes they do not work. The IEEE surge guide explains how they work (starting pdf page40). They clamp the voltage on all wires to the ground at the suppressor. The voltage between all wires going to the protected equipment is safe for the protected equipment.

Service panel suppressors also work by clamping the voltage - from hot wires to ground/earthing electrode (and hot-to-hot). Because the current can be up to 10,000A per hot (essentially zero probability of higher current, at least for houses) they can dissipate significant energy. But the vast majority of the energy is dissipated in the earth by the service earth electrode connection. The largest surges (lightning) are under 100 microseconds. Suppressors are readily available that will provide protection. With thousands of amps to the earthing electrode, the potential of the building "ground" can rise far above "absolute" earth potential.

Neither service panel suppressors or plug-in suppressors protect by absorbing the surge energy. But in the process of protecting, some of the energy is absorbed.

MOVs are fast enough to protect from the fastest surge. And if there was an extremely fast rise time it would be lowered by the impedance of the source wiring.

All of the above is from NIST expert Martzloff, or other experts in the field.

westom ignores it all.

The lie repeated. Poor westom tries to make an example that explains protection say the opposite.

The plug-in suppressor in this IEEE surge guide example protects the TV connected to it. It lowers the surge voltage at a second TV, although its job is to protect the equipment connected to it. It is a lie that the suppressor at TV1 damages TV2.

The point of the illustration for the IEEE, and anyone who can think, is "to protect TV2, a second multiport protector located at TV2 is required."

In the IEEE example the surge comes in on the cable service, and high voltage results from a ground wire that is too long. westomn's favored service panel suppressor would provide absolutely *NO* protection. The IEEE says, for distant entrance points, that "the only effective way of protecting the equipment is to use a multiport [plug-in] protector."

westom's religious mantra protects him from conflicting thoughts (aka reality). westom is the poster child for cognitive dissonance.

Still never explained - why aren't flying airplanes crashing every day when they are hit by lightning?

The lie repeated.

But still never seen - any reliable source that agrees with westom that plug-in suppressors are NOT effective.

Still never seen - answers to simple questions:

- Why do the only 2 examples of protection in the IEEE guide use plug-in suppressors?

- Why does the NIST guide says plug-in suppressors are "the easiest solution"?

- Why does the NIST guide say "One effective solution is to have the consumer install" a multiport plug-in suppressor?

- How would a service panel suppressor provide any protection in the IEEE example, page 42?

- Why does the IEEE guide say for distant service points "the only effective way of protecting the equipment is to use a multiport [plug-in] protector"?

- Why did Martzloff say in his paper "One solution. illustrated in this paper, is the insertion of a properly designed [multiport plug-in surge suppressor]"?

- Why does Dr. Mansoor support multiport plug-in suppressors?

- Why does "responsible" manufacturer SquareD says "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use"?

- Why don?t favored SquareD service panel suppressors list "each type of surge"?

For real science read the IEEE and NIST surge guides. Both say plug-in suppressors are effective.

The IEEE guide, in particular, is really an excellent source of information from a reliable source. I really recommend anyone who is interested in surge protection read it.

--
bud--

Now do the numbers. How does that hundred joule MOV absorb energy that is hundreds of thousands of joules? You are reciting the myths promoted by plug-in protectors.

For example, how to get the protector to last longer? Increase its joules rating. Then the entire protector absorbs "LESS" energy. Protector that absorbs a surge is the urban myth promoted by those who never learned this stuff. This 100 years old technology.

So that energy dissipates harmlessly in earth - not inside the building - the protector must make a short ('less than 10 foot') connection to single point earth ground. No protector is protection. None. A protector is only a connecting device. Either it connects a

20,000 amp surge harmlessly to earth. Or it does nothing. A protector is only as effective as its earth ground - which those educated by advertising never learn.

e circuit breaker (or fusable parts) have time to

No surge protector is too slow. That wiring is why plug-in protectors are not earthed. And why Bud will not discuss wire impedance and earth ground.

bud's citation Page 42 Figure 8 shows a plug-in protecting earthing a surge 8000 volts destructively through a nearby TV. He hopes you do not grasp the point in his IEEE citation.

So let's put numbers to it. Let's say the plug-in protector and TV are 50 feet of wire from the breaker box. That means it is less than

0.2 ohms resistance. And maybe 120 ohms impedance. So that protector will earth a trivial 100 amp surge? 100 amps times 120 ohms means the protector and TV are at maybe 12,000 volts. Why did the protector earth that surge 8000 volts through the TV? AC electric wire impedance meant the surge had to obtain earth 8000 volts destructively through the TV.

Why do telcos all over the world not waste money on bud's plug-in protectors? Because telcos can suffer about 100 surges per thunderstorm. So telcos put a protector as close to earth ground as possible. And up to 50 meters separated from electronics. That separation means increases protection. Why? See numbers in that above paragraph.

Whereas an average homeowner suffers maybe one surge every seven years. A telco suffers at least 100 with each storm. So telcos do not locate protectors adjacent to electronics. Telcos always earth 'whole house' protectors for the same reasons it was done 100 year ago =96 a low impedance connection to single point ground. Protector must be as close to earth as possible (lowest impedance to single point ground) AND works best when distant from electronics.

Learn that no protector works by absorbing energy. That is why the protector too close to appliances and too far from earth ground can even earth that surge 8000 volts destructively through a nearby TV. A majority only believe the advertising myths - that protectors magically make hundreds of thousands of joules just magically disappear. That myth sells plug-in protectors. Any location that cannot have damage (ie munitions dumps) instead earths a 'whole house' protector. Then energy never enters a building. Then energy harmlessly dissipates outside the building in earth ground.

Protection is always about where energy dissipates. IOW a protector is only as effective as its earth ground. A reality that would harm bud's profit margins.

"David" wrote in news:hvjmsg$4v4$ snipped-for-privacy@news.eternal- september.org:

no,it's not. it does not "clamp" the voltage.

totally wrong. Wiki has a nice article on metal-oxide varistor,I suggest you read it.

--
Jim Yanik
jyanik
at
localnet
dot com

"William Sommerwerck" wrote in news:hvl00i$lma$ snipped-for-privacy@news.eternal-september.org:

"clamping" is a misuse of the word WRT surge protectors. It misleads people,as in "david" s post.

"trigger voltage" might more accurate.

--
Jim Yanik
jyanik
at
localnet
dot com

Jim, I am not going to get into a flame war over this topic. Maybe you should check this out:

David

Amazing coincidence that they act much like the old NE-2 neon bulb across the antenna leads of old receivers for protection.

They would conduct around 65 volts and suddenly go to near zero impedance, safely shunting what ever energy on the antenna line to ground.

And although most receiver inputs couldn't handle a steady state of 65 volts (or 130 vpp), they could handle them long enough for the neon bulb to conduct and then shunt them to ground.

Jeff

--
?Egotism is the anesthetic that dulls the pain of stupidity.?
Frank Leahy, Head coach, Notre Dame 1941-1954

http://www.stay-connect.com

Hi,

I've been following this thread, and I got to wondering are there any accepted methods to tell if a surge arrestor setup is still usable as such? I've got a couple industrial 3-phase units that I'd like to hook up to protect my incoming power, and though they pass the sniff test I haven't quite convinced myself to add them to the electrical panel yet. I only have single phase (in the US), but figure that gives me a spare module that would just be left disconnected.

Anyone have any recommendations or guidance to lend?

Thanks, Mike

"David" wrote in news:hvlq34$3ic$ snipped-for-privacy@news.eternal- september.org:

did you even READ the wiki article? it appears not.

--
Jim Yanik
jyanik
at
localnet
dot com

"David" wrote in news:hvlq34$3ic$ snipped-for-privacy@news.eternal- september.org:

Uh,"passing current to ground" IS passing energy to ground.

Varistors can absorb part of a surge. How much effect this has on risk to connected equipment depends on the equipment and details of the selected varistor. Varistors do not absorb a significant percentage of a lightning strike, as energy that must be conducted elsewhere is many orders of magnitude greater than what is absorbed by the small device.

--
Jim Yanik
jyanik
at
localnet
dot com

" A protector is only as effective as its earth ground. So bud wants to discuss airplanes to avoid reality. Where are those manufacturer specs that claim protection from each type of surge? NIST and IEEE say why bud cannot provide them. A protector is only as effective as its earth ground. "

Certain ignorant people here keep perpetuating this total LIE. I won't call them liars because I believe they are not doing it inttentionally, they just have no understanding of what they are talking about. This makes them very dangerous as they are spreading False information which may be read by someone who thinks it is actually true.

This is my final say on this topic. In the quote above, you assume the section saying that "... energy that must be conducted elsewhere ..." goes to ground through the MOV. This is where your error resides. The energy is going elsewhere but being dissipated somewhere else completely such as blowing up a transformer. The article should also use the term dissipated elsewhere to make things clearer.

You also assume that passing current is equivalent to dissipating energy. Current can *move* energy somewhere, but electrical energy is only dissipated when the current causes a voltage drop. A perfect ground will not have a voltage drop so that is not where the the energy is being dissipated.

David

"David" wrote in news:hvmjej$2ep$ snipped-for-privacy@news.eternal- september.org:

feel free to edit it.

No,that's what YOU assume I said. Wrongly.

HA,now you're talking about "perfect grounds".Sheesh. you don't know what you're talking about.

BTW,when a lightning strike hits a ground,it dissipates it's energy -in the ground-. literally.

It even makes a fulgurite.(fused earth)

--
Jim Yanik
jyanik
at
localnet
dot com

circuit breaker (or fusable parts) have time to

Poor westom's religious blinders prevent him from reading what gets written. I certainly have written about wire impedance in this thread.

But if westom was not hampered by religious blinders he would read in the IEEE surge guide that plug-in suppressors do not work primarily by earthing. They work primarily by clamping the voltage on all wires to the ground at the suppressor.

I hope everyone will "grasp the point" in the IEEE example.

- The TV connected to the plug-in suppressor is protected.

- "To protect TV2, a second multiport protector located at TV2 is required."

With minimal reading skills westom would have read that at about 6kV (US) there is arc-over at the service panel from bus to enclosure/ground

- which is connected to the earthing electrode and neutral. After the arc is established, the voltage is hundreds of volts. The same thing happens at receptacles. This is a well established action for people who are familiar with surge protection.

westom makes up a 100 amp surge on the branch circuit and 120 ohm impedance - won't happen together.

And the lie repeated - 5th time?

In the IEEE example - of how plug-in suppressors protect - the suppressor at TV1 causes absolutely NO damage to TV2.

Ho-hum - because telco switches are high amp, hard wired, and thousands of phone circuits would have to go through the plug-in suppressor.

True of service panel and plug-in suppressors (but they absorb some energy while protecting).

If you put a MOV across a relay coil, it protects by absorbing energy.

The lie repeated - 6th time?

In the IEEE example the surge comes in on the cable service. westom has not explained how his service panel suppressor would provide any protection. That is because it would provide absolutely NO protection.

With separated service entry points the IEEE guide says "the only effective way of protecting the equipment is to use a multiport [plug-in] protector."

Only magic if you suffer from willful stupidity.

Ho-hum - still never explained - why aren't flying airplanes crashing every day when they are hit by lightning? They must drag an earthing chain.

Still missing - any reliable source that agrees with westom that plug-in suppressors are NOT effective.

Still missing - answers to simple questions:

- Why do the only 2 examples of protection in the IEEE guide use plug-in suppressors?

- Why does the NIST guide says plug-in suppressors are "the easiest solution"?

- Why does the NIST guide say "One effective solution is to have the consumer install" a multiport plug-in suppressor?

- How would a service panel suppressor provide any protection in the IEEE example, page 42?

- Why does the IEEE guide say for distant service points "the only effective way of protecting the equipment is to use a multiport [plug-in] protector"?

- Why did Martzloff say in his paper "One solution. illustrated in this paper, is the insertion of a properly designed [multiport plug-in surge suppressor]"?

- Why does Dr. Mansoor support multiport plug-in suppressors?

- Why does "responsible" manufacturer SquareD says "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use"?

- Why don?t favored SquareD service panel suppressors list "each type of surge"?

For real science read the IEEE and NIST surge guides. Both say plug-in suppressors are effective.

--
bud--

I agree. The vast majority of energy in a lightning strike is passed on to the earth.

Assume a surge of 10,000A on a service wire (maximum that has a reasonable probability), a very good resistance to earth of 10 ohms and a duration of 100 microseconds. If I am multiplying right that is

100,000 joules dissipated in the earth.

If you had a service panel suppressor with UL let through voltage of

330V (measured at a specified current much lower than 10kA) the actual voltage across the MOV might be 500V and the energy dissipated for the same surge would be 500 joules.

Most of the energy that was available at the cloud is dissipated on the trip down - in heat, light, sound....

In about any lightning strike there are multiple paths to earth - multiple utility earthing points, multiple houses, ....

Nice example.