Just had a thought about surge suppressors...

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bud-- wrote:

Nothing here was up to snuff when I got here (previous owner was a power line janitor). I have since replaced the crappy Stab-Loc panel with a proper QO panel, installed two new ground rods (pounding them in did a number on my carpal tunnel), installed ground blocks and the inline suppressers on the cable feeds. The ground blocks are connected to the first ground rod with a 1' long jumper so the grounds are about as close together as possible. I also cleaned up the phone lines and upgraded/replaced the power feed and sub panel in the shop as well.
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I tend to err towards massive overkill when it comes to surge suppression. I do have a ground block at the entry point of the cable, bonded to the breaker box ground, and also a whole house surge suppressor at the panel. However, even with that in place, I still lost a circuit board in my dishwasher, a couple surge strips, and a power supply for my whole house air filter last year during a storm. (I've since added some small point of use surge protectors at several places throughout the house, although I'm not sure what I really could do about the dishwasher or other hardwired appliances like the stove.) There is no antenna currently installed, hence my question. I would certainly ground the antenna lead similarly to the cable should I install one, but I still am using surge strips with coax connections at both my cable box and my cable modem.
nate
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Those "couplesurgestrips" did what no protector must do - failed. Undersized surge strips fail, gets the naive to recommend more, and can even create a potential fire problem. Most every fire department has seen this danger: http://www.hanford.gov/rl/?page=556&parent=554 http://www.westwhitelandfire.com/Articles/Surge%20Protectors.pdf http://www.ddxg.net/old/surge_protectors.htm http://tinyurl.com/3x73ol or http://www3.cw56.com/news/articles/local/BO63312 /
A surge found earth ground destructively via dishwasher, furnace filter, etc. What provides protection? Not any protector - whole house or power strip. Protection is the building earthing electrode. If that earthing electrode is insufficient, then a surge will find other paths to earth, destructively, inside the house.
Protection has always been to earth before surges can enter a building. That means a connection from each incoming wire to earth must be short (ie 'less than 10 feet'), no sharp bends, no splices, not inside metallic conduit, and all connection are to the same earthing electrode. What is critical for that wire connection to earth? Not wire diameter. More critical are shorter length, no sharp bends, etc.
For example, if a ground wire from breaker box to electrode goes up over the foundation and down to earth, then the wire is too long, is probably bundled with other non-ground wires, and has too many sharp bends. How a surge connects to earth determines whether the surge will stay outside a building. That breaker box wire must go through foundation and down to earth ground rod.
Reason for furnace filter and dishwasher damage is a surge that found a better (destructive) path to earth. No 'point of use' protector will avert that problem (as even its specs note). A protector is only as effective as its earth ground. Apparently your earthing electrode (or connection to that electrode) is insufficient. Learn from what was damaged. 1) Upgrade your earthing or connections to that earthing. 2) Notice that the couplesurgestrip" was damaged; was grossly undersized; may have even been a fire threat.
Learn from the damage. A protector is only as effective as its earth ground.
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w_tom wrote:

. Excellent information on surges and surge protection is in an IEEE guide at: <http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf And one from the NIST at: http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf
Surprisingly w_ did not recommend a service panel suppressor. The are effective on equipment connected to just to power. Adding connections for phone and cable can be more complicated. .

. To w_, plug-in suppressors have minuscule ratings. In fact high ratings are readily available.
Both the IEEE and NIST guides say plug-in suppressors are effective. .

. w_ can't understand his own hanford link. It is about "some older model" power strips and says overheating was fixed with a revision to UL1449 that required thermal disconnects. That was 1998. There is no reason to believe, from any of these links, that there is a problem with suppressors produced under the UL standard that has been in effect since 1998. None of the links even say a damaged suppressor had a UL label. .

. w_ has a religious belief (immune from challenge) that surge protection must use earthing. In w_s view plug-in suppressors (which are not well earthed) can not possibly work. The IEEE guide explains plug-in suppressors work by CLAMPING the voltage on all wires (signal and power) to the common ground at the suppressor. Plug-in suppressors do not work primarily by earthing (or stopping or absorbing). The guide explains earthing occurs elsewhere. (Read the guide starting pdf page 40). .

. For cable and phone entry protectors you want a short ground connection to the ground at the power service. You want to minimize the voltage between power and signal wires. The author of the NIST guide has written "the impedance of the grounding system to 'true earth' is far less important than the integrity of the bonding of the various parts of the grounding system." .

. The statement of religious belief in earthing.
-_ bud--
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Both citations state why plug-in protectors make no protection claims from typically destructive surges. Bud will never provide a manufacturer spec that claims such protection. Bud will ignore request for facts because Bud is a sales promoter of plug-in protectors. No plug-in protectors will provide numerical specs for protection.
The first citation demonstrates how a plug-in protector earths a surge, 8000 volts destructively, through an adjacent TV. That is effective protection? A surge not earthed before entering a building MUST find earth ground inside the building. That plug-in protection on Page 42 Figure 8: the surge is earthed 8000 volts destructively through an adjacent TV. A protector without a short (ie 'less than 10 foot') connection to earth must earth that surge somewhere: 8000 volts destructively through the adjacent TV - Page 42 Figure 8.
Second citation is just as blunt. Surge energy does not just disappear. A protector does not magically absorb that surge. Surge energy must be dissipated somewhere. Therefore the NIST says on page 6 (Adobe page 8 of 24):

Where does the effective protector divert surges? To earth ground. Same NIST guide is even blunter. On page 17 (Adobe page 19 of 24):

Either surge energy gets dissipated (absorbed) harmlessly by earth OR that surge is diverted (8000 volts destructively) through adjacent appliances. A protector is only as effective as its earth ground. NIST, IEEE, and other professional organizations make that statement repeatedly in guides and in Standards.
Will Bud's tiny protector absorb a surge? Of course not. Even the cable company recommended removing ineffective (and massively profitable) plug-in protectors. An effective protector absorbs almost no energy while diverting massive surge energy into earth. Why does one effective 'whole house' protector remain functional after direct lightning strikes AND protect everything inside the building? Effective protection also costs tens or 100 times less money.
Essential to surge protection is the quality of earth ground. An example demonstrates the concept: A FL couple had an exterior bathroom wall struck repeatedly. Lightning rods were installed and connected to eight foot earthing rods. Lightning again struck the bathroom wall. Why? Lightning took the better connection to earth. Bathroom pipes connected to deeper, more conductive limestone. Lightning rods were only earthed in sand. Another example of why protection is only as effective as the earthing. The surge found the better path to earth via bathroom pipes not via eight foot ground rods.
Any surge will seek a best connection to earthborne charges located miles away. Any utility wire surge that finds a best path to earth before entering a building need not enter that building. Where surge damage occurs (ie a nuclear hardened maritime radio station), the informed professional learned from the damage and corrected a defective earthing system: "Reliable Protection of Electronics Against Lightning: Some Practical Applications" by van der Laan and van Deursen on 4 Nov 1998.
Where does surge energy get dissipated? Destructively inside a building? Will a protector rated at a trivial hundred or thousand joules dissipate hundreds of thousands of joules? Of course not. Will an in-line coax protector stop what three miles of sky could not? Obviously not. More reasons why surges must be dissipated in earth. OP's solution means single point earth ground, coax wire properly earthed by a ground block, and a 'whole house' protector on incoming AC wires. That's what professionals recommend, what those two citations demonstrate, and what a plug-in protector sales promoter will not recommend.
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w_tom wrote:

. Provided often and ignored. For example a few months ago on this newsgroup when w_ posted his drivel. http://tinyurl.com/6alnza .

. To quote w_ "It is an old political trick. When facts cannot be challenged technically, then attack the messenger." My only association with surge protectors is I have some.
With no technical arguments, w_ has to discredit those that oppose him. .

. If poor w_ could only read and think he could discover what the IEEE guide says in this example:
- A plug-in suppressor protects the TV connected to it. - "To protect TV2, a second multiport protector located at TV2 is required." - In the example a surge comes in on a cable service with the ground wire from cable entry ground block to the power service ground that is too long. In that case the IEEE guide says "the only effective way of protecting the equipment is to use a multiport [plug-in] protector." - w_'s favored power service suppressor would provide absolutely NO protection.
It is simply a lie that the plug-in suppressor in the IEEE example damages the second TV.
But with no valid technical arguments, w_ tries to twist what the IEEE guide says. .

. What does the NIST guide really say about plug-in suppressors? They are the "easiest solution".
With no valid technical arguments, w_ tries to twist what the NIST guide says. .

. The required statement of religious belief in earthing. Everyone is for earthing. The question is whether plug-in suppressors are effective. .

. Of course not. No one talks about absorbing surges except w_. The IEEE guide explains, for those who can think, that plug-in suppressors work primarily by clamping. .

. A service panel suppressor is a good idea.
What does the NIST guide say? "Q - Will a surge protector installed at the service entrance be sufficient for the whole house? A - There are two answers to than question: Yes for one-link appliances [electronic equipment], No for two-link appliances [equipment connected to power AND phone or cable or....]. Since most homes today have some kind of two-link appliances, the prudent answer to the question would be NO - but that does not mean that a surge protector installed at the service entrance is useless."
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
There are 98,615,938 other web sites, including 13,843,032 by lunatics, and w_ can't find another lunatic that says plug-in suppressors are NOT effective. All you have is w_'s opinions based on his religious belief in earthing.
Never answered - embarrassing 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"? - How would a service panel suppressor provide any protection in the IEEE example, pdf page 42? - Why does the IEEE guide say in that example "the only effective way of protecting the equipment is to use a multiport [plugin] protector"?
--
bud--

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Bud could have posted manufacturer specifications that claim protection from each type of surge. But Bud is promoting protectors that provide no such protection. So Bud does here what Bud does everywhere - post insults.
Every responsible source says surge energy must be dissipated someplace. Either inside the building or harmlessly in earth. Will hundreds of thousands of joules be absorbed - made irrelevant - by a tiny hundred joule protector? Of course not. Even protector manufacturers that don't have an *always required earthing wire* will not claim to provide that protection. Bud promotes ineffective (unearthed) plug-in protectors. Instead of providing manufacturer specs, Bud will always resort to mockery and insult. Sales are at risk.
A protector is only as effective as its earth ground. Therefore every facility that routinely suffers surges - and no damage - is very careful about what provides that protection. Single point earth ground. Where massive surge energy gets harmlessly dissipated.
No earth ground means no effective protection.
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wrote:

For anyone who has never seen posts by w_tom before, be forewarned. He's a usenet kook, who has been known to post advice that could kill you if followed. His rants about surge suppression are just that - rants of a lunatic. Bud performs a valuable service by rebutting W_Tom to make sure the unwary are not fooled, and possible put at risk.
Bud has truth on his side, as well as documentation from the agencies that are in charge of Electrical safety codes. They all disagree with W_Tom. He's truly a sicko. You'll rarely see him post, except in threads pertaining to surge suppression or lightning. I believe he scans even groups he doesn't normally follow for any mention fo certain key words like surge or lightning.
I'm sure he'll respond to this post with an attack on me. That's okay. As long as nobody follows W_Tom's advice and gets hurt, it's well worth any abuse he wants to lay on me.
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w_tom wrote:

. "Each type of surge" is nonsense. Plug-in suppressors have protection elements from H-G, N-G, H-N. That is all possible combinations and all possible surge modes. . > But Bud is promoting protectors

. I promote only accurate information to counter w_'s religious dogma. .

. Poor w_ is insulted by reality. .

. The required statement of religious belief in earthing.
w_ is evangelical in his belief in earthing, and trolls google-groups for "surge" to spread his religious tract to the heathens. Even the sewing machine newsgroups must be saved from the evils of plug-in suppressors. .

. w_'s religious mantra protects him from disturbing thoughts (aka reality).
Still no link to another lunatic that agrees with w_ that plug-in suppressors are NOT effective.
Still never answered - embarrassing 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"? - How would a service panel suppressor provide any protection in the IEEE example, pdf page 42? - Why does the IEEE guide say in that example "the only effective way of protecting the equipment is to use a multiport [plugin] protector"?
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
--
bud--



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I "fail" to see how that is bad - apparently an overvoltage got through my whole house protector (according to the power company, in their nice "GFY" form letter, a high voltage line was knocked into a low voltage one by a falling tree, neatly bypassing the transformer, so it must have been a big jolt) and the surge strips shut themselves down rather than pass through the overvoltage to the equipment connected to them. The more recent surge strips that I've purchased (I don't ever buy simple power strips; I figure if I need a power strip I'm probably going to have enough stuff plugged into it that surge protection might be a good idea, esp. for interconnected appliances like a rack of stereo equipment, computer peripherals, etc.) have a warranty where if you keep all your paperwork the mfgr. will replace the strip if this happens; as it was the ones that failed were all ancient (one had a date code in the late 90's) and still and all I'd rather spend $30 or so on a new one rather than have to replace the equipment connected to it. If I see a storm developing I do go around and switch off and/or unplug all the surge strips that aren't powering "mission critical" equipment as well, but in this case the incident happened at the very beginning of a storm, while I was away from home, so I didn't have the chance to do that.
nate
(BTW I have no idea what happened to the spaces in my previous message...)
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A surge does not enter the home like a wave on the ocean. Electricity does not work that way. A surge first flowed through *anything* in that path to earth. Long after that surge is flowing, then something fails.
No surge protector works by stopping or blocking a surge. If a surge protector failed, it simply abandoned appliances to the surge. To provide protection, the protector must remain functional. Ineffective protectors even fail as fast as possible to avoid these scary pictures: http://www.hanford.gov/rl/?pageU6&parentU4 http://www.westwhitelandfire.com/Articles/Surge%20Protectors.pdf http://www.ddxg.net/old/surge_protectors.htm http://www.zerosurge.com/HTML/movs.html http://tinyurl.com/3x73ol or http://www3.cw56.com/news/articles/local/BO63312 /
Observe the protector in pictures from zerosurge.com. Pprotector components were removed and its light still said the protector is OK. Why? Because a power strip protector is not electrically between the surge and appliance as N8N has assumed. Protector components only work when conducting; when diverting; when condcting and not absorbing a surge. If power strip varistors disconnect, then an appliance is still connected directly to AC mains and the surge. The appliance must protect itself. Fortunately, all appliance already contain protection internally.
How to sell power strip protectors to the naive? A surge too small to overwhelm protection inside the computer easily destroyed the power strip protector. Now the naive will recommend more power strip protectors .... using assumption rather than knowledge. The power strip protector was grossly undersized. Therefore a surge too small to harm the computer destroyed that power strip AND got the naive to recommend more.
No surge gets "through" anything. A surge can go left through the protector or right through appliances. Appliances are connected directly to AC mains even when plugged into a power strip protector. Nothing does, nothing claims to, and nothing can block a surge. But grossly undersizing a strip protector gets the naive to buy more.
Will a silly little varistor inside that power strip stop or absorb what three miles of sky could not stop? Of course not. Assumption is that a power strip will somehow block what three miles of sky could not. Reality: a protector is only as effective as its earth ground. Power strip protectors without earth ground do not even claim to provide that protection in numeric specifications. A failed power strip did not provide protection. Burn out is even a complete violation of varistor manufacturer specs. A protector that failed did nothing and sometimes will create those scary pictures.
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My understanding is that there are generally three MOVs in a typical AC-only surge protector, H-N, N-G, H-G. If any of those MOVs fail they generally fail shorted rather than open, directly either shorting a current-carrying conductor to ground or else shorting hot to neutral. This causes an internal fuse or circuit breaker to open, completely disconnecting the load from the line. Thus this *does* protect the load from a surge, unless the overvoltage is such that it can actually cross the gap in the fuse/breaker.
Or am I missing something?
nate
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wrote:

You are missing W_Tom's long and erroneous posting history.
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Errors upon errors. But you are correct. Those are popular myths promoted by the electrically naive (ie salty@dog) and protector sales promoters (bud).
First, if any MOV vaporizes, then it has violated Absolute Maximum Parameters listed at the top of every datasheet from every MOV manufacturer. Only acceptable MOV failure mode is to degrade. Degrade means its voltage changes 10% AND the MOV is not burned, shorted, open, or vaporized. Because the naive observe grossly undersized protectors burn, then the naive *know* vaporization, et al is a normal failure mode.
Scary pictures show what can happen when MOVs fail by shorting, vaporizing, etc: http://www.hanford.gov/rl/?page=556&parent=554 http://www.westwhitelandfire.com/Articles/Surge%20Protectors.pdf http://www.ddxg.net/old/surge_protectors.htm http://www.zerosurge.com/HTML/movs.html http://tinyurl.com/3x73ol http://www3.cw56.com/news/articles/local/BO63312 / Most every fire department has seen these totally unacceptable events. Only the nave say this is acceptable.
Read any MOV manufacturer datasheet. Voltage, current, or energy necessary to create a shorted or vaporized MOV is well beyond where chart lines end ... because that failure mode is unacceptable and a threat to human safety.
Second, this MOV failure mode does not disconnect any load. To disconnect a grossly undersized protector even faster, its thermal fuse is tiny. A thermal fuse only disconnects MOVs. And that surge may be even smaller. An even smaller surge will blow that thermal fuse so that MOVs do not vaporize. Again, it gets the naive to promote that protector.
Third, you have assumed an open fuse will stop what three miles of sky cannot. Read the numbers on any fuse. Typically rated for x amperes and 250 volts. Why 250 volts? Because electricity at higher voltage will continue to flow through that blown fuse. Assume your assumption is correct: that a fuse blows to disconnect the appliance. Suddenly that fuse rated at only 250 volts will stop 6000 volts? Of course not. The blowing fuse maintains a plasma path that continues to conduct that surge until the surge terminates. Fuses never open to disconnect a surge.
Surges are current mode events. Voltage will rise as high as necessary to conduct or arc through whatever tries to stop it. Any protector that would stop or disconnect from a surge is a myth. Protection is always about diverting surges as even Bud's citations bluntly state.
Assumed is that a fuse will blow fast enough. It could not stop voltage. It also cannot open fast enough. Surge current flows simultaneously through everything in that path to earth - including the appliance. A fuse takes tens or hundreds of milliseconds to blow. But a surge has already done damage and terminated in microseconds. 300 consecutive surges could pass through that fuse before a fuse (or circuit breaker) even thinks about blowing. Junk science does not provide numbers. This post says why AND includes numbers.
Summary so far: Why is a surge never blocked - especially by a fuse? a) Surge flows through everything long before a fuse sees that surge. b) 250 volt fuse cannot stop surges. c) Fuses take maybe 1000 times too long to open. d) Fuse only tries to protect MOVs; does not disconnect the appliance. Now move on to other myths that promote plug-in protectors.
Fourth: what does every Bud citation and every citation from me state? From the NIST on page 17 (Adobe page 19):

A surge is not stopped or absorbed by any protector. NIST states exactly where that surge energy must be diverted to: earth ground. Previously discussed was wire impedance. An effective protector makes a 'less than 10 foot' connection to earth ground. Why? Too much impedance (not resistance) means the surge finds earth ground, instead, inside the building. What happens when a plug-in protector is adjacent to the appliance (obviously something like 120 ohms impedance from the breaker box)? The plug-in protector with all but no earthing connection diverts the surge, 8000 volts destructively, to earth via an adjacent TV. That is Bud's other citation: Page 42 Figure 8.
We engineers have seen this repeatedly when tracing surge damage. The plug-in protector provides the surge even with more potentially destructive paths to earth via appliances.
How to identify the ineffective protector? 1) It has no dedicated earthing wire. 2) Manufacturer will not even discuss earthing. Industry benchmarks in surge protection such as Polyphaser discuss earthing extensively: http://www.polyphaser.com/technical_notes.aspx
Fifth: what do MOVs H-G, H-N, and N-G do? MOVs do not stop or absorb surges. The surge seeking earth is simply distributed (diverted, shunted, bonded, connected) from one wire to all wires. Now that surge has even more paths to destructively find earth ground. One classic example is Page 42 Figure 8. A surge exceeding 8000 volts puts 8000 volts destructively inside that TV. What did the plug-in protector do? Exactly what its manufacturer specs claim. Protector did nothing but give the surge a path to earth via the adjacent TV.
N8N has accurately described what so many believe (assume). How many errors and outright myths promote plug-in protectors? At least nine have been identified in this post. MOVs must degrade - must never vaporize or open. Every MOV manufacturer says this. Nothing stops or blocks surges - especially fuses. Fuses voltage is woefully too low; response time is 1000 times too long. Thermal fuse is for MOV protection - never protects or disconnects the load. If a thermal fuse - the emergency backup protection circuit - does not open fast enough, then scary pictures can result. Every responsible source describes what provides protection. Not a protector. Protection is earth ground. Surge energy can never be blocked or absorbed. Surge energy must be dissipated harmlessly in earth.
What does the effective protector have? Typically the 'less than 10 feet', no sharp bends, etc. connection to earth.
A $3 power strip with some ten cent parts sells for $25 or $150. Why do APC, Tripplite, Belkin, Monster Cable, etc not sell 'whole house' protectors? Profit margin on plug-in protectors is obscene. Only responsible companies sell 'whole house' protectors. Unlike APC, et al, responsible companies have names that everyone should recognize: Siemens, Intermatic, Cutler-Hammer, Square D, Keison, Leviton, GE, and others.
Learn what the professionals do. Your telco's switching computer is connected by overhead wires everywhere in town. It can suffer typically 100 surges during every thunderstorm. How often have you been without phone service for five days as they replace that computer? Never. Telcos use a 'whole house' protector on every incoming wire of every cable - connected as close to earth ground as is practicable. Separation between protector and electronics increases protection contrary to what plug-in promoters claim. Telco wants their protector up to 50 meters separated from electronics to increase protection. Telco does not waste money on plug-in protectors. The telco has same surge problems as a homeowner - just more of them. So that telephone service works just fine during every thunderstorm, telcos use better earthing, 'whole house' protectors, and no plug-in protectors. Telco does not install protectors that would open or vaporize to provide protection. And telcos have been doing this (not using plug-in protectors) for the past 100+ years.
Reality cannot be explained in a sound byte. Plug-in protectors (ie what you were told) is sound byte logic (junk science reasoning). However, a sound byte can summarize the above: No earth ground means no effective protection. Surge energy must be dissipated where? Harmlessly in earth ground. A protector is only as effective as its earth ground.
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. w_ is so pathetic. .

. Nobody talked about vaporization. w_ is hallucinating again. .

. The lie repeated. w_ should read his own sources. .

. What is required by UL is a thermal protector that disconnects an overheating MOV. The thermal protector may or may not be a fuse. The thermal protector opens after the MOV conducts at normal voltage. That is after the surge. Previous to that the MOV has clamped the voltage. .

. The thermal protector opens after the surge. (It may not work for overvoltage as both nate and I said.) .

. The thermal protector opens after the surge. .

. Covered in a previous post citing extensive discussion in the IEEE guide. In most good plug-in suppressors, the protected load is connected across the MOV so it is disconnected with the MOV. .

. Repeating: What does the NIST guide really say about plug-in suppressors? They are the easiest solution. .

. If poor w_ did not have religious blinders he could read in the IEEE guide that plug-in suppressors work primarily by clamping the voltage on all wires to the common ground at the suppressor. .

. The lie repeated. .

. w_ is so blind. The MOVs limit the voltage going to the protected equipment to a voltage safe for the protected equipment. .

. What nate wrote was accurate.
w_ still apparently hasnt figured out nates event was overvoltage, not a surge.
Plug-in suppressors with very high ratings are readily available for low cost. They are very unlikely to fail (except for overvoltage which will also rapidly destroy service panel suppressors.) .

. One of the MOVs in a plug-in suppressor I recently bought has a rating of 75,000A and 1475Joules. Provide a source for that MOV for $0.10. .

. All these responsible companies except SquareD make plug-in suppressors.
For its best service panel suppressor SquareD says "electronic equipment may need additional protection by installing plug-in [surge suppressor] devices at the point of use." .

. Like no earth ground means no effective protection. .

. The required religious sound byte.
But still no link to another lunatic that agrees with w_ that plug-in suppressors are NOT effective.
And still never answered - embarrassing 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"? - How would a service panel suppressor provide any protection in the IEEE example, pdf page 42? - Why does the IEEE guide say in that example "the only effective way of protecting the equipment is to use a multiport [plugin] protector"? - Why does responsible manufacturer SquareD says "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use." - Where is the link to a 75,000A and 1475Joule rated MOV for $0.10.
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
-- bud--
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w_tom wrote:

. Surge suppressors that can handle thousands of amps for a surge of less than a millisecond are rapidly destroyed by "overvoltage" (which is not a "surge"). That applies to both plugin suppressors and service panel suppressors. The author of the NIST guide has written "in fact, the major cause of [surge suppressor] failures is a temporary overvoltage, rather than an unusually large surge."
A few plug-in suppressors have circuits that disconnect on overvoltage.
For plug-in suppressors, the IEEE guide explains at length that the protected load can be connected across the MOV, so it will be disconnected with a damaged MOV - or connected so it stays live when MOVs are disconnected. A good suppressor should have the protected load across the MOV. (For overvoltage that does not guarantee the protection can clear on high voltage.) .

. w_ can't understand his own hanford link. It is about "some older model" power strips and says overheating was fixed with a revision to UL1449 that required thermal disconnects. That was 1998. There is no reason to believe, from any of these links, that there is a problem with suppressors produced under the UL standard that has been in effect since 1998. None of the sources even say a damaged suppressor had a UL label.
But with no valid technical arguments all w_ has is pathetic scare tactics. .

. This is indeed a serious problem if you live in an area where thieves steal MOVs out of surge suppressors. Check with your local police to see if a MOV theft ring is active in your area.
As N8N wrote, MOVs normally fail in high current mode. That produces heat which causes a UL required thermal disconnect to remove the MOV from the circuit. .

. Poor w_ refuses to understand how plug-in suppressors work. Clearly explained in the IEEE guide.
Poor w_ also ignores that N8Ns event was "overvoltge", not a "surge". .

. Reality: w_ is a religious fanatic.
Still no link to another lunatic that agrees with w_ that plug-in suppressors are NOT effective.
Still never answered - embarrassing 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"? - How would a service panel suppressor provide any protection in the IEEE example, pdf page 42? - Why does the IEEE guide say in that example "the only effective way of protecting the equipment is to use a multiport [plugin] protector"?
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
--
bud--

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I've seen you make this claim many times. Could you please give a reference to a manufacturer's data sheet on a common appliance (TV, computer, stereo) with surge protection data? Thanks, Doug
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If seeking "surge protection data", then you are asking the wrong question. Industry standards define how much surge an appliances should withstand without damage. A 1970 industry standard defined 600 volts without damage for 120 volt electronic appliances. Those old standards existed long before PCs even existed.
Other standards: For example, Ethernet ports must withstand 2000 volts.
Even low voltage interface ICs now contain 2000 or 15,000 volt internal protection as even required by an IEC standard. A USB interface chip datasheet demonstrates that standard: http://datasheets.maxim-ic.com/en/ds/MAX3349EA.pdf
Telco standards require phone appliances to withstand a metallic voltage of 800 V max and a longitudinal voltage of 1500 V max. I believe may be from FCC Part 68. The point: so many standards define internal protection that I am only grabbing random examples.
One ATX power supply spec (sorry - forgotten which one) said:

All appliances contain some protection. Those who never learned this stuff will then deny when a varistor or avalanche diode cannot be found. Protection is integrated into every design including dimmer switches. If a manufacturer is being honest, those numbers appear in manufacturer specifications (a reference to power supplies marketed to the electrically challenged such as A+ Certified computer techs). Since surge protection myths are so widespread, most do not even know that every appliance contains internal protection. If this was known, then many would start asking embarrassing questions that plug-in protector manufacturers do not want to answer.
How to sell power supplies to the electrically challenged? Provide no manufacturer specs. Sell a power supply that is missing essential functions (ie to A+ Certified Computer techs) at lower price and higher profits. When an inferior supply fails, then blame a surge; not the missing internal protection and not the electrically naive computer assembler.
So widespread is technical ignorance that most people also do not know phone lines have protection installed free by the telco at every subscriber interface.
Requested were sources for protection inside every appliance. Provided are examples of industry standards that only the few electrically knowledgeable would know. With so many electrically naive consumers (who don't even know that all appliances contain some protection), then the market is also ripe for selling a $3 power strip with some ten cent parts for $150.
All appliances contain internal protection. Why can this 120 volt computer grade UPS output 200 volt square waves with a spike of up to 270 volts between those square waves? This UPS output may even harm some small electric motors and power strip protectors. But protection in all computers makes this dirty 'modified sine wave' irrelevant (cause no damage). Why does that dirty UPS output not harm computers? Because all computers are required (by industry standards) to contain protection that makes 'dirty' UPS electricity irrelevant. Just another example of protection routinely installed in all appliances.
Enough examples? Furthermore, the examples also came with numbers. Those who only speculate also don't provide numbers. Why numerous examples when a clear majority did not know of protection routinely in electronics? Well, the majority also knew Saddam had WMDs. A typical example explains why technical knowledge is so rare: A + Certified computer techs need not know anything about electricity to be certified.
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. w_ is either stupid or dishonest (probably both). Read the data sheet. The 15,000V is for ESD protection - Electrostatic Discharge. As in shuffle across the rug and touch the wire. The source resistance is very high -1 megohm - and current is very limited - 15mA, and short period. The IC does not "see" 15,000V.
This has no similarity to what the IC would "see" from a surge.
15,000V can arc across about 3/4"9. .

. Provided were vague references to standards with no name and no links from a delusional source. .

. People with real world experience have challenged w_ on this. Just one example: <http://groups.google.com/group/comp.sys.hp.hardware/browse_frm/thread / e2275d3a21dadd68/01f94595de2e9a60?hl=en&lnk=st&q=#01f94595de2e9a60> or http://tinyurl.com/3w4h2v
-- bud--
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And the current from a surge is also very limited inside a building once surges are properly earthed. Of course Bud selected isolated examples. Why were maybe nine examples provided? Plug-in protector promoters fear an informed public. All appliances contain surge protection. Protection that is overwhelmed if the typically destructive surge is not earthed before entering the building.
Meanwhile Bud again forgets to include all those facts. 15 ma if continuous. Massive amperes if the 15,000 volts is only a very short term, microseconds transient. Bottom line remains. All appliance contain surge protection. Protection that is effective IF the typically destructive surge is earthed before entering a building.
Notice that Bud also posts insults and other disparaging remarks. He is promoting myths. Attack the messenger because Bud cannot dispute the facts.
Meanwhile, where is that plug-in manufacturer spec that even claims surge protection. Oh. Again, the sales promoter just cannot seem to find those spec numbers. Why? Even the plug-in manufacturer does not claim the protection that Bud is promoting. Again, Bud still cannot provide specs that claim protection because those specs do not exist.
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