Clothes Dryer Moisture Sensor

. The illustration in the IEEE guide has a surge coming in on a cable service. There are 2 TVs, one is on a plug-in suppressor. The plug-in suppressor protects TV1, connected to it.
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." What a radical idea.
w_ says suppressors must only be at the service panel. In this example a service panel protector would provide absolutely *NO* protection. The problem is the wire connecting the cable entry block to the power service ?ground? is too long (not a "single point ground"). The IEEE guide says in that case "the only effective way of protecting the equipment is to use a multiport protector." This is the same as what is quoted from me at the top. .
. w_ has a religious belief (immune from challenge) that surge protection must use earthing. Thus in his 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). .
. I promote only accurate information. w_ promotes religious dogma. .
. From
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Grounded Ring: A grounded No. 2 wire, installed around all four walls inside a small building, at an elevation of approx. six inches below the ceiling. They are used around transmitter equipment. How would a halo ground help? Perhaps w_ could learn the proper term.
Both the IEEE and NIST (below) guides say equipotential of the ground references for power, telephone, cable requires a ?*short* connection from the phone and cable entrance protectors to the earthing wire at the power service.
Everyone agrees earthing is a good idea. The question is whether plug-in suppressors work. The IEEE guide says plug-in suppressors are effective.
So does an NST guide (written by Martzzloff but aimed at the unwashed masses) at:
formatting link
the sources.
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.
Simple questions never answered: - 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?
Reply to
bud--
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|> |> |> |> |> | snipped-for-privacy@ipal.net wrote: |> |> |> |> |> |> |> |> |> |> |> |> | Martzloff has also written "In fact, the major cause of TVSS [surge |> |> |> | suppressor] failures is a temporary overvoltage, rather than an |> |> |> | unusually large surge." |> |> |> |> |> |> And these would not damage the TV? |> |> | |> |> | |> |> | No. Why do you think it would? if the surge suppresser clips at a |> |> | safe voltage to protect from spikes, it won't go any higher with a |> |> | overvoltage condition, but the MOV or other protection device quickly |> |> | overheats as it tries to maintain the proper voltage. If the line |> |> | voltage is high enough, it will trip the Breaker, or blow the fuse for |> |> | that AC circuit. The protective device can only dissipate a small |> |> | amount of heat before it self destructs. |> |> |> |> This was a discussion about a suggestion tha the MOV condunction voltage |> |> should be higher than now used (330V for 120V systems). He wants to |> |> raise that voltage to avoid certain situations causing TVSS failure so |> |> the protection against spikes (above 800V) is maintained longer. My |> |> position is that the swells as high as 565V RMS could in fact cause |> |> damage to the TV. Under his proposal, these would be be suppressed. |> |> I think that is a bad idea because these voltage swells really can do |> |> damage. |> | . |> | Surge suppressors are intended to protect against surges. Raising the |> | clamp voltage is to lower unnecessary suppressor exposure to surges that |> | do not damage connected equipment. |> |> The last 7 words are the part we do not agree on. | . | You are disagreeing with Martzloff, who has done a lot of research on | surge protection an has numerous published papers. The same immunity has | also appeared elsewhere such as a PCMagazine review of plug-in suppressors.
Yes, I am disagreeing with him. I believe he has an agenda of some kind. What we have now works. I don't believe he has shown justification to make a change.
|> | Surge suppressors are not intended to protect against longer duration |> | swells or even longer duration overvoltage. Martzloff's comment above is |> | that the major cause of failure is overvoltage, which suppressors are |> | not intended to protect against. |> |> I've read discussions and online pages to the contrary. If you have put |> forth your theory ahead of time, I could have recorded the locations for |> you. | . | Contrary - overvoltage is the major cause of failure? - you are again | disagreeing with Martzloff. | | Contrary - not intended to protect against swells and overvoltage? - | provide a source that says plug-in suppressors are intended to protect | against swells and overvoltage. Like maybe specs from few manufacturers | that Ed asked for.
Yes, I still disagree with him. The "suppressors are not intended to protect against" is the point. BUT NOTE THIS VERY CAREFULLY ... I do not say he is wrong ... I say he has a twisted agenda in that regard. While they may not have been _intended_ to protect against overvoltage, they do have that capability and for many people, they have an expectation to do such protection. That's why I say leave things as they are.
| "Put forth your theory ahead of time" - apparently a new newsgroup | requirement?
It's not a requirement to post URLs of things read in the past if there was no expectation to need them. I save many URLs of many interesting things. But I can't save them all.
|> | If you keep the clamp voltage low, you are likely not increasing |> | protection from swells because a swell may well kill the MOV anyway. To |> | protect against overvoltage get a suppressor that disconnects on |> | overvoltage. |> |> The surge suppressor already does this. Sure, it can _die_ while doing |> this. The MOV shorts across, causing an increase in current that trips |> the supplementary breaker in the strip (usually integrated in the switch). |> There, appliance protected by one low cost device. | . | By the time current reached well over 15A required to trip a 15A breaker | in a short time, the MOV would be toast. UL has required since 1998 that | thermal disconnects be provided to disconnect overheating MOVs. Or fuses | as Greg suggests, but selected by the manufacturer which can have | operating characteristics closely matched to the MOVs, may also open. It | is unlikely that protection would come from a breaker.
So what if the MOV is toast. It's still the cost effective way to provide the protection. It's a rare event.
| Repeating: | "The IEEE guide goes on a length how the protected load can be connected | across the MOVs or connected to the incoming line. If connected across | the MOVs, the protected load will be disconnected when overheating MOVs | are disconnected on failure." Similar comments are in the NIST guide. | | Your response was "And you are saying what?"
Maybe if you had included an analysis, I would not have had to ask.
| What: that is the probable protection route indicated in both guides if | a plug-in suppressor can provide protection from overvoltage. Both | guides make clear not all plug-in suppressors are wired to disconnect | the protected load with the MOVs.
Those that don't have the disconnect need to have that added. That is a lot less expensive than adding a complex overvoltage protection system.
|> Maybe what should have proposed was that we use a more expensive device |> that integrates higher level MOVs with overvoltage sensors. | . | Repeating: | "To protect against overvoltage get a suppressor that disconnects on | overvoltage." They disconnect the load and MOVs.
Or get one that disconnects on MOV overcurrent that is the result of overvoltage. This latter idea will be lower in cost even when considering that each event requires replacing the protection device (because these events are rare). Martzloff does not appear to be considering the statistical economics. Maybe he has an agenda, like trying to sell more of some other kind of protection.
|> If he can |> show that such a MORE EXPENSIVE device is worth the extra cost in the |> longer term, he wins. But I think he cannot. | . | "He"? Is "he" Martzloff? I have never seen Martzloff indicate a MOV | based surge suppressor should protect against swells or overvoltage.
Maybe he doesn't want them to for some reason.
| The "IEEE Recommended Practice for Powering and Grounding Sensitive | Electronic Equipment" (Emerald book) does not indicate plug-in | suppressors are an effective means of protecting against swells or | overvoltage. | | Perhaps you could use a plug-in suppressor with overvoltage protection | built in, as above.
Can you point out a LOW COST ONE? My understanding is they have quite a high cost. But if you can point to one or two low cost ones, then I would be wrong.
| If you want to use failure of MOVs to protect your equipment I would | suggest a suppressor from a reputable manufacturer where the | manufacturer says the suppressor will protect from swells and | overvoltage. Given hype, I suggest using a device where the manufacturer | also has a warrantee on protected equipment. | | Saying plug-in suppressors should protect against swells and overvoltage | they are not designed for does not make them effective.
What something is designed for, and what it can do in certain cases, are not always the same thing. Then when manufacturers find out that their product already cheaply does what customers want that could have been done in a more expensive way to drive more revenue, they realise the golden goose has escaped the pen and are trying to round it back in.
| Or perhaps you could use a device the Emerald book indicates might be | effective. For houses that would be a UPS. But make sure the | manufacturer says the UPS will protect against swells and overvoltage.
This is exactly what I am describing. They want to sell something that is way more expensive, rather than admit that something cheap can do the same thing (though self-destructively).
Reply to
phil-news-nospam
|> |> |> |> |> |> |> |> |> | snipped-for-privacy@ipal.net wrote: |> |> |> |> |> |> |> |> |> |> |> |> |> |> |> |> | Martzloff has also written "In fact, the major cause of TVSS [surge |> |> |> |> | suppressor] failures is a temporary overvoltage, rather than an |> |> |> |> | unusually large surge." |> |> |> |> |> |> |> |> And these would not damage the TV? |> |> |> | |> |> |> | |> |> |> | No. Why do you think it would? if the surge suppresser clips at a |> |> |> | safe voltage to protect from spikes, it won't go any higher with a |> |> |> | overvoltage condition, but the MOV or other protection device quickly |> |> |> | overheats as it tries to maintain the proper voltage. If the line |> |> |> | voltage is high enough, it will trip the Breaker, or blow the fuse for |> |> |> | that AC circuit. The protective device can only dissipate a small |> |> |> | amount of heat before it self destructs. |> |> |> |> |> |> This was a discussion about a suggestion tha the MOV condunction voltage |> |> |> should be higher than now used (330V for 120V systems). He wants to |> |> |> raise that voltage to avoid certain situations causing TVSS failure so |> |> |> the protection against spikes (above 800V) is maintained longer. My |> |> |> position is that the swells as high as 565V RMS could in fact cause |> |> |> damage to the TV. Under his proposal, these would be be suppressed. |> |> |> I think that is a bad idea because these voltage swells really can do |> |> |> damage. |> |> |> |> |> | |> |> | But what you are doing in the discussion is force fitting |> |> | the MOV TVSS into protecting against events that it was not |> |> | designed for. It's like insisting that your umbrella |> |> | protect against the rain in a hurricane. It might keep |> |> | the rain off briefly, before the wind blows it apart. |> |> |> |> That's a poor analogy. |> |> |> |> The MOV based TVSS is most like to short circuit in a damaging event and |> |> cause the incoming breaker (the switch in the power strip, for example) |> |> to trip. The power strip might now be a usless hunk of metal and plastic, |> |> but the appliance to be protected is still protected for the duration. |> |> |> | |> | Ok, what specific TVSS models claim to be designed to do |> | what you stated: protect against the overvoltage in the |> | damaging event? Or are you just trolling? |> |> Apparently most all of them ... either designed that way or just happen to |> operate that way. Otherwise the previously mentioned paper would not have |> needed to be written. |> | | I asked for specific models. Your answer does not | contain a specific model. So you are trolling after all.
Since you asked a trick question, I had to give a trick answer.
I detected the trick question. I just didn't admit it so I could see how far you would go with the answer I gave.
They don't CLAIM to provide such protection. So no, I cannot list a mode that CLAIMS this. They just HAPPEN to do so because of the fact that the MOV breakdown voltage is relatively low. So ultimately, it is your trick question that is the troll.
Reply to
phil-news-nospam
| UL listed suppressors have MOVs from H-G, N-G, H-N. That is all | combinations and all possible surge modes. w_ has never explained how a | common mode surge coming in on a power service gets past the N-G bond | required at all US services. Past the service the surge is transverse mode.
The surge does not pick a specific direction to take when it comes to a fork in the path. The N-G bond is such a fork. The two paths of the fork are 1: go over to G ... 2: continue with N. What it really does is take both paths. So now you have less surge going past the N, but some does. The part of the surge on H is still at full strength because there is no H-G bond. Now is it partially common mode (at the level of N) and partially differential mode (at the level of H minus N).
What will help to make sure more of the surge goes via G instead of staying on N is to ensure that G has the lowest _characteristic_ impedance right at the point of the bond. That means things like less inductance and less skin effect. An increase of impedance on the continue-N path could also help. Then you get more than half of the surge going over G instead of N. Maybe you can get a lot.
Fortunately, as N continues on, there is a lot more impedance in the form of inductance at the high frequency leading edge of the surge. But the closer the start of that higher impedance is to the N-G bond, the more that can be reflected back to go down the N-G bond.
Reply to
phil-news-nospam
Typical troll bullshit.
Reply to
Michael A. Terrell
| w_ has a religious belief (immune from challenge) that surge protection | must use earthing. Thus in his 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).
If the cable wire comes in through that plug in suppressor, then it can have some effect at reducing the surge. Just how much will depend on the impedance of the ground it is attached to. The circuit ground wire is a path to ground (assume the system is installed right). But it is not that great of one for a high rise surge. If it had direct earthing it could do better, depending on the characteristic impedance of that path.
| Everyone agrees earthing is a good idea. The question is whether plug-in | suppressors work. The IEEE guide says plug-in suppressors are effective.
They do provide better protection than not having one, whether one has any of the other protections or not. But one must not be fooled into the false sense of protection by having one alone. Bringing all wires in at a common entrance and protecting them all with solid low impedance paths to ground is a very important level of protection to also have. None of the protections are 100%.
Reply to
phil-news-nospam
. So you assault the character of an electrical engineer that is an established authority on surges. And your assault occurs in an electrical engineering forum. Apparently Martzloff even fooled the IEEE which published his papers. And international conferences that also published his papers. Too bad they aren?t as smart as you. .
Again impugning the integrity of an electrical engineer that is a recognized expert. .
. Gee. you forgot the specs from a few manufacturers. What a surprise. .
. "Put forth your theory ahead of time" is one of the stupidest comments I have seen in a newsgroup. .
. The point of this paragraph, which should be clear to anyone who can read, is that circuit breakers are not likely to trip. The point was not toast. .
Maybe if you had any interest in what other people write you would have understood. .
. Another outrageous slander. .
. You have not pointed to a plug-in suppressor that the manufacturer says is effective on swells and overvoltage. Maybe you are wrong. .
. Yea, those manufacturers are really stupid. Just like Martzloff. And the IEEE. And the NIST. .
. You dismiss UPSs, which the IEEE Emerald book says may be effective, for plug-in suppressors which the Emerlad book does not recommend.
You attack an electrical engineer that is a recognized expert.
You ignore what I post.
There isn?t much point in responding further.
Reply to
bud--
. The panel 'ground' and neutral are bonded. They are at the same potential. The hot is raised with respect to H & N. To everyone I know that is a transverse mode surge.
Seems to me in the past you said it was a common mode surge because N is raised with respect to ?absolute? ground potential. Then everything is common mode. In my office all I can see is the hot rising and the neutral staying at ground wire potential. They taught me in school that was transverse mode. But maybe ?they? had a hidden agenda.
There seems to be no science in common for a conversation.
Reply to
bud--
. You obviously have not read the IEEE guide starting pdf page 40. My explanation - clamping to the common ground at the suppressor - is exactly what is described. The TV sees wires that have safe voltages with respect to each other. Plug-in suppressors do NOT work primarily by earthing.
But maybe the IEEE has a hidden agenda.
You ignore what I write. You ignore sources. In ham circles you are a monologuist.
Reply to
bud--
The problem is that "Ground" is not the same everywhere in a surge condition. I have seen 35v between 2 ground electrode systems less than 100' apart. That can spike quite a bit higher in a surge condition. If your cable or phone connection is not bonded to your local ground the service is using you can see significant transients between the cable and power. The other place you get in trouble is when you have a non-bonded connection between buildings (services) like a CAT5 LAN. At a big motel here we had 3 buildings that got connected together via LAN and we couldn't keep LAN cards in the PCs until we ran bonding conductors between them.
Reply to
gfretwell
|> |> |> |> |> |> |> |> |> | snipped-for-privacy@ipal.net wrote: |> |> |> |> |> |> |> |> |> |> |> |> |> |> |> |> | Martzloff has also written "In fact, the major cause of TVSS [surge |> |> |> |> | suppressor] failures is a temporary overvoltage, rather than an |> |> |> |> | unusually large surge." |> |> |> |> |> |> |> |> And these would not damage the TV? |> |> |> | |> |> |> | |> |> |> | No. Why do you think it would? if the surge suppresser clips at a |> |> |> | safe voltage to protect from spikes, it won't go any higher with a |> |> |> | overvoltage condition, but the MOV or other protection device quickly |> |> |> | overheats as it tries to maintain the proper voltage. If the line |> |> |> | voltage is high enough, it will trip the Breaker, or blow the fuse for |> |> |> | that AC circuit. The protective device can only dissipate a small |> |> |> | amount of heat before it self destructs. |> |> |> |> |> |> This was a discussion about a suggestion tha the MOV condunction voltage |> |> |> should be higher than now used (330V for 120V systems). He wants to |> |> |> raise that voltage to avoid certain situations causing TVSS failure so |> |> |> the protection against spikes (above 800V) is maintained longer. My |> |> |> position is that the swells as high as 565V RMS could in fact cause |> |> |> damage to the TV. Under his proposal, these would be be suppressed. |> |> |> I think that is a bad idea because these voltage swells really can do |> |> |> damage. |> |> | . |> |> | Surge suppressors are intended to protect against surges. Raising the |> |> | clamp voltage is to lower unnecessary suppressor exposure to surges that |> |> | do not damage connected equipment. |> |> |> |> The last 7 words are the part we do not agree on. |> | . |> | You are disagreeing with Martzloff, who has done a lot of research on |> | surge protection an has numerous published papers. The same immunity has |> | also appeared elsewhere such as a PCMagazine review of plug-in suppressors. |> |> Yes, I am disagreeing with him. I believe he has an agenda of some kind. |> What we have now works. I don't believe he has shown justification to |> make a change. | . | So you assault the character of an electrical engineer that is an | established authority on surges. And your assault occurs in an | electrical engineering forum. Apparently Martzloff even fooled the IEEE | which published his papers. And international conferences that also | published his papers. Too bad they aren?t as smart as you.
I am not being critical of specific statements he makes. From an engineering perspective, he is correct that by using a higher voltage MOV, surge suppressors would last longer. That is not in dispute.
What is in dispute is the worthiness of bothering to do this. He has not supported why this should be done. If MOV voltages go up, then the cost of full protection goes up because additional protection at the lower level is then needed.
|> Yes, I still disagree with him. The "suppressors are not intended to |> protect against" is the point. BUT NOTE THIS VERY CAREFULLY ... I do not |> say he is wrong ... I say he has a twisted agenda in that regard. | . | Again impugning the integrity of an electrical engineer that is a | recognized expert.
Being an expert in engineering has nothing to do with the applicable economics.
|> While |> they may not have been _intended_ to protect against overvoltage, they do |> have that capability and for many people, they have an expectation to do |> such protection. That's why I say leave things as they are. | . | Gee. you forgot the specs from a few manufacturers. What a surprise.
Show me _ANY_ manufacturer that publishes complete specs on what their products _CAN_ do (as opposed to what they merely market them to do).
|> |> | If you keep the clamp voltage low, you are likely not increasing |> |> | protection from swells because a swell may well kill the MOV anyway. To |> |> | protect against overvoltage get a suppressor that disconnects on |> |> | overvoltage. |> |> |> |> The surge suppressor already does this. Sure, it can _die_ while doing |> |> this. The MOV shorts across, causing an increase in current that trips |> |> the supplementary breaker in the strip (usually integrated in the switch). |> |> There, appliance protected by one low cost device. |> | . |> | By the time current reached well over 15A required to trip a 15A breaker |> | in a short time, the MOV would be toast. UL has required since 1998 that |> | thermal disconnects be provided to disconnect overheating MOVs. Or fuses |> | as Greg suggests, but selected by the manufacturer which can have |> | operating characteristics closely matched to the MOVs, may also open. It |> | is unlikely that protection would come from a breaker. |> |> So what if the MOV is toast. It's still the cost effective way to provide |> the protection. It's a rare event. | . | The point of this paragraph, which should be clear to anyone who can | read, is that circuit breakers are not likely to trip. The point was not | toast.
So you think that if an MOV begins a runaway conduction because the peak of an overvoltage causes it to fail, that this won't trip a breaker within a couple cycles?
Maybe the MOV will just clamp for the duration of the cycle peak, and not go into runaway conduction. Then don't worry. See above for the other case.
|> | Repeating: |> | "The IEEE guide goes on a length how the protected load can be connected |> | across the MOVs or connected to the incoming line. If connected across |> | the MOVs, the protected load will be disconnected when overheating MOVs |> | are disconnected on failure." Similar comments are in the NIST guide. |> | |> | Your response was "And you are saying what?" |> |> Maybe if you had included an analysis, I would not have had to ask. | . | Maybe if you had any interest in what other people write you would have | understood.
Well I sure have no interest (anymore) in what you write.
|> Martzloff does not appear to be considering the |> statistical economics. Maybe he has an agenda, like trying to sell more |> of some other kind of protection. | . | Another outrageous slander.
I accuse an engineer of not being an economist ... is a slander? That's very creative.
|> | The "IEEE Recommended Practice for Powering and Grounding Sensitive |> | Electronic Equipment" (Emerald book) does not indicate plug-in |> | suppressors are an effective means of protecting against swells or |> | overvoltage. |> | |> | Perhaps you could use a plug-in suppressor with overvoltage protection |> | built in, as above. |> |> Can you point out a LOW COST ONE? My understanding is they have quite |> a high cost. But if you can point to one or two low cost ones, then I |> would be wrong. | . | You have not pointed to a plug-in suppressor that the manufacturer says | is effective on swells and overvoltage. Maybe you are wrong.
Or maybe the manufacturer is hiding this so they can sell other stuff to unwitting people.
|> | If you want to use failure of MOVs to protect your equipment I would |> | suggest a suppressor from a reputable manufacturer where the |> | manufacturer says the suppressor will protect from swells and |> | overvoltage. Given hype, I suggest using a device where the manufacturer |> | also has a warrantee on protected equipment. |> | |> | Saying plug-in suppressors should protect against swells and overvoltage |> | they are not designed for does not make them effective. |> |> What something is designed for, and what it can do in certain cases, are |> not always the same thing. Then when manufacturers find out that their |> product already cheaply does what customers want that could have been done |> in a more expensive way to drive more revenue, they realise the golden |> goose has escaped the pen and are trying to round it back in. | . | Yea, those manufacturers are really stupid. Just like Martzloff. And the | IEEE. And the NIST.
I have not accused any of them of being stupid. I have accused them of possibly having an alternative agenda.
|> | Or perhaps you could use a device the Emerald book indicates might be |> | effective. For houses that would be a UPS. But make sure the |> | manufacturer says the UPS will protect against swells and overvoltage. |> |> This is exactly what I am describing. They want to sell something that |> is way more expensive, rather than admit that something cheap can do the |> same thing (though self-destructively). | . | You dismiss UPSs, which the IEEE Emerald book says may be effective, for | plug-in suppressors which the Emerlad book does not recommend.
This is the expensive "solution".
| You attack an electrical engineer that is a recognized expert.
... for his economic claims.
| You ignore what I post.
... because it is trash ... because you apparently don't even understand what it is I have said, since your responses don't even address what I was saying.
| There isn?t much point in responding further.
... I guess not.
Reply to
phil-news-nospam
|> They don't CLAIM to provide such protection. So no, I cannot list a mode |> that CLAIMS this. They just HAPPEN to do so because of the fact that the |> MOV breakdown voltage is relatively low. So ultimately, it is your trick |> question that is the troll. | | | Typical troll bullshit.
This from someone that never directly addresses the technical issues when it is so much easier to just make a personal attack.
Reply to
phil-news-nospam
|> |> |> | UL listed suppressors have MOVs from H-G, N-G, H-N. That is all |> | combinations and all possible surge modes. w_ has never explained how a |> | common mode surge coming in on a power service gets past the N-G bond |> | required at all US services. Past the service the surge is transverse mode. |> |> The surge does not pick a specific direction to take when it comes to a |> fork in the path. The N-G bond is such a fork. The two paths of the fork |> are 1: go over to G ... 2: continue with N. What it really does is take |> both paths. So now you have less surge going past the N, but some does. |> The part of the surge on H is still at full strength because there is no |> H-G bond. Now is it partially common mode (at the level of N) and partially |> differential mode (at the level of H minus N). | . | The panel 'ground' and neutral are bonded. They are at the same | potential. The hot is raised with respect to H & N. To everyone I know | that is a transverse mode surge.
And you think _ALL_ of the energy component on the neutral will go to ground over the bond?
| Seems to me in the past you said it was a common mode surge because N is | raised with respect to ?absolute? ground potential. Then everything is | common mode. In my office all I can see is the hot rising and the | neutral staying at ground wire potential. They taught me in school that | was transverse mode. But maybe ?they? had a hidden agenda.
You didn't even read what I said correctly. Or maybe you are intentionally trying to just twist it.
One of the following you do not understand (maybe even both):
1. A surge can have a high voltage rise time that makes part of its energy behave more like RF, even extending into the microwave range. Not all do, but a close direct strike often does.
2. A surge with RF character does not "stay at ground potential" just because there is a ground present. The energy is in propogation. It cannot just "disappear" because a wire is grounded.
| There seems to be no science in common for a conversation.
Apparently not. See #1 and #2 above.
Reply to
phil-news-nospam
|> |> |> | w_ has a religious belief (immune from challenge) that surge protection |> | must use earthing. Thus in his 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). |> |> If the cable wire comes in through that plug in suppressor, then it can |> have some effect at reducing the surge. Just how much will depend on |> the impedance of the ground it is attached to. The circuit ground wire |> is a path to ground (assume the system is installed right). But it is |> not that great of one for a high rise surge. If it had direct earthing |> it could do better, depending on the characteristic impedance of that |> path. | . | You obviously have not read the IEEE guide starting pdf page 40. My | explanation - clamping to the common ground at the suppressor - is | exactly what is described. The TV sees wires that have safe voltages | with respect to each other. Plug-in suppressors do NOT work primarily | by earthing.
This depends on the energy mode, common mode vs. differential (traversal) mode. You can have either or both situations. You can choose to have a surge suppressor ungrounded, grounded via the ground wire, or earthed directly on its own.
| But maybe the IEEE has a hidden agenda.
Or maybe you just don't grok the full range of possible surges and how high rise time energy propogates.
| You ignore what I write. You ignore sources. In ham circles you are a | monologuist.
The monologuist ignores everyone. You are not everyone. Your logic fails.
Reply to
phil-news-nospam
What do you call your post other than an attack?
Reply to
Michael A. Terrell
Bud distorts to protect profits. Bud says protection is 'clamping to nothing'. Every responsible source including NIST, IEEE, and the many organizations that 'need protection that works' all say clamping must be to earth ground. Conservation of energy. Where is energy dissipated? According to Bud, that energy is dissipated inside the protector by "clamping to nothing" or magically disappears. According to responsible professionals: energy must be dissipated in earth. No earth ground means no effective protection.
Both articles from Electrical Engineering Times are titled "Protecting Electrical Devices from Lightning Transients". Engineers define protection. Will they discuss Bud's protectors? Of course not. The article is about protection; not about myths. EE Times discusses real world protection in two front page articles on 1 Oct and 8 Oct 2007:
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What provides protection? Earth ground. Wire impedance is why 'clamping' to earth must be short, no splices, no sharp bends, etc. "Clamping to nothing"? Of course not. The article is about real world protection: clamping (also called shunting, connecting, diverting) to earth ground. "Clamping to nothing' is the scam.
Bud will reply again. Bud must post until he has the last reply. Then you will believe him rather than every responsible industry professional.
As I do repeatedly, just another professional defines effective protection: Kenneth Schneider PhD Telebyte USA:
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Conceptually, lightning protection devices are switches
Bud says protection is "clamping to nothing". Somehow surge energy will magically disappear? Yes, according to every Bud post. Every source cited by Bud has contradicted what Bud claims. Even Bud's Page 40 citation contradicts him: on Page 42 Figure 8. No earth ground means no effective protection.
An effective protector earths a direct lightning strike - without damage. The effective protector must remain functional after every surge. Is that surge protector damaged by a surge? Then it may be the grossly undersized and obscenely profitable protector promoted by Bud.
Reply to
w_tom
Bud must admit that different types of transients exist. Why do his plug-in protectors not list each surge in numeric specs? To be honest, a plug-in protector must list each type of transient AND admit that a plug-in protector does not protect from the typically destructive type of surge. Page 42 Figure 8.
Panel ground and neutral are bonded. Bud forgets to provide numbers. That common connection is too far away. Same point (provided with numbers) was made in both front page articles in Electrical Engineering Times entitled "Protecting Electrical Devices from Lightning Transients". Unlike Bud, the articles also provides numbers. The typically destructive surge seeks earth ground. That means a 'less than 10 foot' connection to earth. How long is that connection from protector to breaker box? 50 feet? 50 feet means Bud's protectors do not have effective earthing AND that bonding is irrelevant. No wonder Bud never discusses numbers; never even provides a manufacturer spec. How much impedance in that 50 foot wire? Add more impedance for splices and sharp bends. Problems made worse because earthing wires are bundled with other wires. More reasons why that 'bonding' is irrelevant when discussing surge transients.
And the protector must dissipate a typically destructive type of surge in earth. Bud's plug-in protectors will not claim to provide protection. That high impedance connection to breaker box is just one reason why Bud pretends "clamping to nothing" is protection. Type of surge that typically overwhelms protection inside appliances - Bud's protectors cannot provide that protection. No 'less than 10 foot' earthing connection. Bud says "clamping to nothing" will dissipate that surge energy. That bonding inside a breaker box is irrelevant once we apply the numbers as even listed in both EE Times articles.
Surge energy must be dissipated harmlessly in earth ground. Wires that bond neutral and safety ground together are too long. The numbers: assume that plug-in protector is confronted by a tiny 100 amp surge. 100 amp earthed via AC electric wire means protectors to AC breaker box voltage would be something less than 12,000 volts. Why is the adjacent TV damages by a surge through the plug-in protector? Wire to breaker box is too long - 12,000 volts too long. Surge takes a shorter path to earth - 8000 volts destructively through a TV - Page 42 Figure 8. That excessive wire impedance is a major point in EE Times "Protecting Electrical Devices from Lightning Transients"; two front page articles on 1 Oct and 8 Oct 2007 at:
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Since plug-in protectors have all but no earth ground, then plug-in protectors do not protect from the typically destructive type of surge. They hope you will assume "clamping to nothing" is protection. Why do plug-in protectors never list protection from each type of surge? No earth ground means no effective protection. Best is to be quite; provide no spec numbers; let Bud promote myths. Bud intentionally ignores the numbers. Excessive wire impedance is why properly earthed protectors have a 'less than 10 foot connection. Typ[iocally destructive surges are RF. Make that earthing connection even shorter for better protection. Protector is only as effective as its earth ground.
Bud pretends that wire impedance does not exist. He avoid numbers that expose the myths in his assumptions. Bud even claims "clamping to nothing" will make surge energy disappear. A protector is only as effective as its earth ground.
Reply to
w_tom
. Why does w_?s favored service panel supplier SquareD ?not list each surge in numeric specs?? Because it is bullcrap. Both service panel and plug-in suppressors have MOVs clamping the voltage between all wires. That suppresses all surge modes. Lacking valid technical arguments w_ invents ?issues?. .
. They aren't my protectors.
If w_ was not impaired by religious blinders he could understand the IEEE guide. Clearly explained - plug-in suppressors work primarily by CLAMPING the voltage on all wires (power and signal) to the common ground at the suppressor. They do not work primarily by earthing. Read the source starting pdf pg 40. .
. If w_ could read he would find in the IEEE guide example (pdf pg 40) that "the vast majority of the incoming lightning surge current flows through" the ?ground? wire from the cable ground block to the power service. And the guide says that is "as the NEC/CEC writers intended." The surge is earthed. But not primarily through the plug-in suppressor.
w_ could also read that when the signal protector is too far from the power service, common in many houses, "the only effective way of protecting the equipment is to use a multiport protector." .
. And the required statements of religious belief in earthing.
Everyone agrees earthing is a good idea. The question is whether plug-in suppressors work. Both the IEEE and NIST guides says plug-in suppressors are effective.
w_ still has not found another lunatic that says plug-in suppressors are NOT effective. There is only his opinion based on his religious belief in earthing.
w_ has still never answered 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"? - How would a service panel suppressor provide any protection in the IEEE example, pdf page 42?
Bizarre claim - plug-in surge suppressors don't work Never any sources that say plug-in suppressors are NOT effective. Twists opposing sources to say the opposite of what they really say. Invents opinions and attributes them to opponents. Attempts to discredit opponents. w_ is a purveyor of junk science.
Reply to
bud--
. I agree with all of that. I commonly write ?ground? in quotes to try to emphasize they aren?t all the same. In previous posts I wrote about not only bonding signal entry protectors to the ?ground? at the power service but the necessity of a *short* connection to limit the voltage developed between signal and power wires. Surge produced voltage between cable and power because of a long ?ground? connection is the IEEE example I keep citing (staring pdf pg 40). Voltage between signal and power wires appears to be the major cause of damage to equipment. Martzloff 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." (But he probably has a hidden agenda.)
The comments questioned above were only whether a common mode surge coming in on power wires can get past the N-G bond in US services. And it is a side issue because plug?in suppressors will protect from both common and transverse mode surges.
Reply to
bud--
| snipped-for-privacy@ipal.net wrote: |> |> |> |> |> They don't CLAIM to provide such protection. So no, I cannot list a mode |> |> that CLAIMS this. They just HAPPEN to do so because of the fact that the |> |> MOV breakdown voltage is relatively low. So ultimately, it is your trick |> |> question that is the troll. |> | |> | |> | Typical troll bullshit. |> |> This from someone that never directly addresses the technical issues when |> it is so much easier to just make a personal attack. | | | What do you call your post other than an attack?
A defense.
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phil-news-nospam

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