Whole house surge protector?

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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. (-:
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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.
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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.
snipped-for-privacy@optonline.net wrote:

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snipped-for-privacy@optonline.net wrote:

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
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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:

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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 literature: a lot of it is available on the internet.
--
Larry
Email to rapp at lmr dot com
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L. M. Rappaport wrote:

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


CL Gilbert
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w_tom wrote:

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
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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:

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....

So you agree with me then?
--
Respectfully,


CL Gilbert
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On Tue, 12 Jul 2005 09:12:42 -0400, "CL (dnoyeB) Gilbert"

I think that most of the posters here are right. Surge protection is best done in layers of protection. It starts with the grounding system, then the entry protectors, all tied to the ground system, then protecting the equipment and all it's inputs to a common grounded point, then protecting any interconnecting paths. Where I live you can't have "too much" protection, but we have about 200 thunderstorms a year and I never unplug anything..
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w_tom wrote:

You lost me here. Lightning is electrostatically generated, no current flows until the breakdown voltage of the insulating medium is exceeded. I'm not arguing with you, I'm questioning; what is it that tells you lightning is a current source? I'd call it a voltage source with a high current capacity.
--
If John McCain gets the 2008 Republican Presidential nomination,
my vote for President will be a write-in for Jiang Zemin.
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Once the plasma 'wire' is constructed, then CG lightning goes into the next phase which is to connect charges in a cloud to charges located on earth. This discharge is a current source. That means voltage will increase anywhere as necessary to maintain that current flow. And that current from is not DC electricity. It is AC current in numerous frequencies.
But the important point is that lightning is a current source. Give lightning excellent conductors and it will do no damage - no high voltage. Further observations provided by snipped-for-privacy@wt.net entitled "lightning protection" in the newsgroup rec.radio.amateur.antenna on 20 July 2005 at: http://tinyurl.com/8kfnq
clifto wrote:

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w_tom wrote:

Voltage can only increase as high as the original 'source' voltage. If it were a so called, "current source" the voltage could increase infinitely. But of course this voltage was created due to the flow of electrons which can be considered a current.
Lets not argue about it because it will just get circular. Current source, voltage source is all flakey talk. Its an energy source.

--
Respectfully,


CL Gilbert
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Current source and voltage source are electrical engineering concepts we even use to describe power supplies. Obviously, things within reality have limits. But voltage limits for lightning are just too distant to be considered. Voltage down here (which is our perspective) will increase seemingly unlimited as necessary to make that current flow. Lightning is the classic example of a current source. A concept so important for understanding what protectors and protection are and are not effective.
"CL (dnoyeB) Gilbert" wrote:

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w_tom wrote:

OK. So your calling it a "Current Source", as opposed to a source of current. I don't think its fair to argue about it. Nobody can be right because they both represent ideal concepts which do not exist.
Its debateable whether or not introducing false concepts helps one to understand something. At some point you must understand the truth and let go of the crutch.
--
Respectfully,


CL Gilbert
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CL (dnoyeB) Gilbert wrote:

Actually, these days the distinction between voltage sources and current sources is quite important in engineering design. I can see how w_tom and others who deal with lightning see the need for the distinction. Some things actually DO work better when you design them for the correct choice of source.
--
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my vote for President will be a write-in for Jiang Zemin.
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clifto wrote:

Yes I had voltage and current sources, they were in the basic electricity. I don't see why its easier to say 'current source' than to saw 200MV, but to each his own...
--
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CL Gilbert
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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:

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===> Aha, kaners abound here too don't they? Don't go away mad, just go away.

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!
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