ehsjr reads selectively. ehsjr ignores this phrase:
ehsjr repeatedly claimed an MOV absorbs all surge energy. No. MOVs only absorb a minor part just like wire is also not perfectly conductive. To make it easier for ehsjr to grasp the concept, these phrases were also used:
and
ehsjr repeatedly claimed MOVs absorb ALL surge energy. His reasoning was that MOVs are rated in joules, joules measure energy, therefore MOVs must stop surges by absorbing all surge joules.
Joules do not measure the energy of a surge. Joules are the ball park measurement for a protector's life expectancy. More joules means a more conductive MOV, long life expectancy, and less energy absorbed. ehsjr never understood that and repeatedly denied it.
Lurker may note how ehsjr cannot get over being wrong seven years ago.
Even >> MOVs don't stop, block, or absorb surges to keep them out of
MOVs do not absorb whatever amount of surge energy they are expose to. MOVs dissipate a small amount of energy while shunting (diverting, conducting, clamping) massive energy elsehwere - where that energy will not be destructive.. The majority of energy shunted by an MOV is dissipated in earth - not absorbed by the MOV. But even in May 2005, ehsjr was still claiming MOVs absorb all that energy.
And so we have the phrase "... as ehsjr repeatedly claims over so many years." Lurkers should appreciate the integrity of those who promote plug-in protectors as 'magic box' solutions. ehsjr has so little electrical grasp as to assume a shunt mode protector absorbed whateever energy they are exposed to. MOVs work by *shunting* that energy elsewhere; not by absorbing "the total surge energy".
Your response contains lies about what I have posted. You've gone over the line. I can no longer give you the benefit of the doubt that maybe you misunderstood what was said. There is no longer any doubt, and it demands the reponse below identifing lies in your post.
LIAR. You know damn well that I have never claimed that an MOV absorbs *all* energy.
LIAR.
So in May 2005 you said: "MOVs don't stop, block or absorb surges to keep them out of equipment."
And in August 2007 you say: " w_tom never said "MOVs do not absorb energy" "
So were you lying then, or are you lying now?
LIAR.
You want to lie about someone else, that's your affair. Stop lying about what I have posted.
According to the IEEE guide you cited, it is important to have *both* a hard-wired protector at the service entrance and a plug-in protector at the critical loads.
LIAR. You know damn well I have never said that. Cease and desist from lying about what I have said.
If you think the energy absorbed in the MOV is *all* the surge energy, you're no engineer.
I did not say *all* the surge energy is absorbed in the MOV. But Ed did.
In the newsgroup alt.engineering.electrical in a thread entitled "cut off power to computer" on 16 Dec 1999, Ed posted:
Then on 17 Dec 1999, Ed claims the MOV absorbs all of a surge:
Where is energy absorbed after being *shunted* by an MOV? Earth ground. Demonstrated in that thread was a 39 joule protector dissipating a little energy while shunting significantly more energy via that MOV. Massive more energy is shunted through MOV terminals to be absorbed (dissipated) elsewhere. Where is that elsewhere? What provides protection? Earth ground.
But Ed claimed on both 16 Dec and 17 Dec 1999 that the MOV protects by absorbing *all* surge energy. Ed said I lied? How does ehsjr explain his posts at:
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Ed, you were making this claim that MOVs protect by absorbing the entire surge for many years. Accurately posted was:
You deny your own 1999 claims? Ed, you claimed the MOV was the entire load; that it absorbs the entire surge.
Where is most of a surge absorbed when using an effective protector? Earth ground. Shunt mode protector with short (less than
10 foot) dedicated connection to earth ground is effective. What kind of protector has that dedicated earthing wire? A 'whole house' protector as sold by responsible manufacturers such as Square D, Siemens, Leviton, Cutler-Hammer, Intermatic, and GE. Where does a protector dissipate a surge if not properly earthed? Page 42 Figure 8 shows one example: 8000 volts destructively via an adjacent TV.
Ed used to claim a 100 joule protector absorbed 100 joules and would fail is the surge is larger. But a 100 joule protector shunts maybe tens of times more energy into earth. Why are effective protectors for lightning protection so small? Their function is not to absorb surges. Their function is to shunt (divert, connect, clamp) that surge to earth. No earth ground connection means no effective protection.
Meanwhile, who is lying? Ed claimed for years that the MOV protects by absorbing the entire surge. Ed also denied then and denies today the importance of earth ground.
What happens if a plug-in protector has no earth ground to earth to? One possibility is demonstrated on Page 42 Figure 8 where 8000 volts gets earthed destructively via an adjacent TV. Another possibility are these scary pictures:
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After all, if a protector does not shunt (divert) that energy into earth, then that energy must be dissipated somewhere. Essential to protection is a short ('less than 10 foot', no sharp bends, no splices, etc) earthing connection so that a most of a surge entering an MOV will be dissipated in earth.
And so again, the protector is only as effective as its earth ground. Why did Ed repeatedly deny the need for earthing? Ed once insisted the entire surge is absorbed (dissipated) by the MOV. But effective protectors have the dedicated earthing wire to shunt massively more energy into earth.
grizdog and others: the most critical component of any surge protection system - where the surge is dissipated - is earth ground. No earth ground means no effective protection. A surge must be shunted to earth either by a wire or by a shunt mode protector (such as MOVs). That is what MOVs do - shunt - become as conductive as possible to divert a surge to earth. How does a protector become more conductive? More joules.
It's not shunted by the MOV, it's absorbed elsewhere.
It's been explained to w_tom a dozen times. The function is simple enough for anyone with a basic understanding of electricity (like me).
The Metal Oxide Varistor (MOV) clamps the terminals of the circuit so that they are the same voltage. When two points are at the same voltage, there is no current flow and nothing gets destroyed, no matter what the voltage. All that's left is for the surge to subside.
--
w_tom\'s obsession is a result of being connected to a surge suppressor
is a small child (and it didn\'t work)
A surge is a current source. That means current must have a path to dissipate energy. Clamp everything to nothing. Page 42 Figure 8 is what happens. A surge then created a path destructively through adjacent appliances. A current source will increase voltages as necessary to create a conductive path. That energy must be dissipated somewhere. Clamping without an earthing connection accomplishes nothing useful AND may give that current more paths to find earth ground ... destructively through the adjacent TV. Or that energy may simply create 'scary pictures' - a potential house fire created by a plug-in protector.
If that surge current is not shunted (clamped) to earth before entering a building; if there is no place to dissipate energy; then a surge will create potentially destructive paths to earth. Page 42 Figure 8 with all wires shunted (clamped) - that surge then created an
8000 volts path destructively through adjacent TV. Energy must be dissipate somewhere. If not dissipated in earth, then clamping to nothing means surge damage inside a building is either in adjacent applai9nces or those 'scary pictures'.
Funny John Doe. You still believe a protector will somehow stop or absorb what three miles of sky could not - by clamping to nothing? If current is not shunted to earth ground, then voltages will increase as necessary so that less conductive materials conduct that surge inside the building. That surge will be as destructive as necessary to find earth ground. No protector will stop that by 'clamping to nothing'.
What is standard for protection in Air Force bases, radio and TV stations, and even Orange County's emergency response center?
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John Doe says they all waste time and money. He knows plug-in protectors are sufficient. But then he learned using retail store science - admits he has no electrical training. Meanwhile plug-in protectors are often banned from reliable locations. Plug-in protectors have even contributed to damage of adjacent and powered off computers in a network. John Doe who admits to no engineering training *knows* that cannot be true.
John did not know the telco installs a protector on all subscriber lines - for free. According to John Doe, the telco need not earth that protector. But the telco knows earthing is so critiical as to earth your phone line protector AND make that wire short. Shorter connection to earth means that protector is better. Why does the telco waste time and money earthing that protector when it can clamp to nothing - and provide protection? Clearly the telcos are also stupid - John Doe knows better.
Page 42 Figure 8 - adjacent TV damaged because the surge was earthed
8000 volts destructively via the TV. Surge was clamped to nothing; so surge was shunted to earth 8000 volts destructively through that TV. But that protector was expensive. It must do something.. It clamps to nothing - expensively and destructively. It does not even claim to provide protection. Oh. Did John Doe also forget that the manufacture also does not list surges and protection from those surges in spec sheets. How curious. Manufacturer spec sheets also don't support John Doe's assumption. Clamping to nothing provides ineffective protection. A protector is only as effective as its earth ground - when it has something to clamp (shunt) to.
Note that it says nothing about *all* the surge energy.
Note that it says nothing about *all* the surge energy, but clearly refers to energy dissipated in the MOV *and* the house wiring.
LIAR - as shown above.
Enough on that matter and the remainder of your post, which contains more of the same. Let's get back on topic:
You've typed a lot of words, but have yet to respond to the fact that the IEEE guide you cited recommends plug-in protectors, in addition to good earth ground. Did you have a response to that specific point? Do you agree with the IEEE guide you cited, or disagree?
Repeating: ?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. The guide explains earthing occurs elsewhere. (Read the guide starting pdf page 40).?
Francois Martzloff, who was the NIST guru on surges and 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." That is, a ?single point ground? with short interconnect wires.
Lie #1 repeated. According to hanford overheating was fixed in 1998. And the ?grossly undersized? red herring.
A lie. Where does either guide say that.
A lie. Where does either guide say that.
What a surprise! Telcos don?t use plug-in suppressors to protect high amp hard wired switches with thousands of signal wires that would have to go through the suppressor.
w_ has a fetish about tower antennas. If you plan on erecting a 280 foot lightning rod (aka. tower antenna) in your yard and connecting it to equipment in your building this may be relevant.
A lie. Where does either guide say that.
The IEEE Emerald book ("IEEE Recommended Practice for Powering and Grounding Sensitive Electronic Equipment"), an IEEE standard, recognizes plug-in suppressors as an effective protection device. This is the most appropriate IEEE standard for protecting electronics.
And the IEEE guide, which was published by the IEEE, says plug-in suppressors are effective.
Lie #2 repeated. A plug-in suppressor at TV1 improves the conditions at TV2, although that is not its job. A service panel suppressor would provide *no* protection to either TV.
Everyone is in favor of earthing. The only question is whether plug-in suppressors work. Both the IEEE and NIST guides say plug-in suppressors are effective. Read the sources.
But still no link to another lunatic that says plug-in suppressors are NOT effective. Why no links w_? Don?t the other lunatics agree with you?
And never any answers:
- 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 Emerald book include plug-in suppressors as an effective surge protection device.
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 others. Attempts to discredit opponents. w_ is a prevaricator and a purveyor of junk science.
Ed's entire defense is repeated use of "LIAR" rather than deal with technology. Demonstrated repeatedly is why MOVs are effective with a short connection to earth. Demonstrated is why effective MOV protectors have that earthing path. Demonstrated is where surge energy must be dissipated. Demonstrated is why protectors without earthing may simply disspated that energy destructively elsewhere - such as 8000 volts through an adjacent TV.
Ed's denials only demonstrate that he has repeatedly denied technical facts - how MOVs work. He previously claimed MOVs protect by absorbing all surges. They do not. MOVs work by shunting most all surge energy into earth. A protector without that earthing connection has no earth ground to dissipate surge energy. That's it - the bottom line.
Bud routinely misrepresents facts by selective posting. Even Martzloff said what Bud fears you might learn. A point so important that Martzloff makes this the very first point in his 1996 IEEE paper:
Point or use (plug-in) protectors can even contribute to damage of adjacent appliances. But then that reality was demonstrated here. Where does surge energy get dissipated when a point of use (plug-in) protector has no earthing connection? Inside adjacent appliances? Even Martzloff warns about what protectors without earthing may be.
No earth ground means no effective protection. But those protectors without earthing sell even for $100+ in Circuit City or Best Buy. Clearly they must do something because they cost so much more? Those who instead use science notice no dedicated earthing wire.
If the device has a 2 wire cord, no ground, and no other connections, is a earth ground really necessary for protection of that device? A point of use surge protector will limit the voltage going to the device. (The key is that there are no other electrical connections to the device.) Relative to ground, the device may see a large change, but since nothing on the device is referenced to ground, the device see no destructive voltages. (Any capacitative coupling is taken as insignificant in this case.)
Ben Franklin's lightning was also finding earth ground via something non-conductive - wooden church steeple. That same problem exists inside a home. Things such as some wall paints, and linoleum and concrete floors are even better conductors.
Why can a static electric discharge occur? Electric path is down an arm, through something on the table top, and somehow into the rug to charges beneath feet. How many of those items are wires? The house is chock full of conductive items when we discuss surges.
Once permitted inside a building, then the surge will find numerous paths to earth. Those many paths also explain why one appliance is damaged while an adjacent appliance is unharmed.
Do we locate every conductive path in a room and conductive materials inside walls? No. To create equipotential in one room, then carefully integrate walls, floors, air ducts, and pipes all into the protection system. No one will or is expected to do all that - especially when one 'whole house' protector makes all that work for every room unnecessary.
Make everything in the building equipotential. Create equipotential by using earth beneath the building. Now all conductive materials in the building are at near same voltages - no surge currents flow. Now protection inside all appliances is not overwhelmed.
Yes, devices with multiple utility connections (portable phone base station, cable modem, answering machine, dishwasher) are at greater risk. Makes no difference if power cord is two wire or three wire (or only one wire because switch is open). Anything that would protect on that power cord is already inside those appliances. So that protection inside all appliances is not overwhelmed, spend less money for significantly superior protection. Earth one 'whole house' protector, or earth cable TV and satellite dish wires using no protector. Significantly better protection for tens of times less money per appliance.
A surge approaching on a black wire is distributed to white and green wires by an adjacent plug-in protector. Surge on all (two or three) wires is still seeking earth ground. Incoming on AC electric black wire, given more paths into stereo on black and white wires by an adjacent protector, then out to earth ground via speaker wire touching baseboard heater. Another example of damage because the surge was permitted inside a building. The adjacent protector simply gave that surge more wires to find earth ground via the stereo.
A lot of words, but none respond to my comments. Sure, a whole house protector is a good idea, but that is not viable for everyone. (Think about apartment dwellers or those who rent their home.)
For some folks, point of use protectors may be sufficient.
Point of use protectors also have value where a whole house protector is being used.
Where does a 'point of use' protector make that short connection to earth? If a plug-in protector is protection, then your post makes sense. However the protector is not protection. It is only a connecting device to protection. Lots of word repeatedly demonstrate why plug-in protectors would appear to be a complete solution but don't even claim to be protection. It only claims to be a protector..
In an apartment, modify a plug-in protector to act more like an effective 'whole house' protector. First, cut its power cord as short as possible. Every foot on that power cord means diminished protection. Find a wall receptacle that is electrically closest to the breaker box - minimum number of splices, shortest distance, etc.. Plug that 'short power cord' protector into that receptacle. Hopefully a breaker box earth ground exists. What makes a protector better? Increased distance between the protector and electronics. Decrease a connection length to earth ground.
A protector without earth ground does nothing sufficient. It is only a protector - a connecting device to protection. A protector without connection to protection does nothing useful.
If a 'magic box' was sufficient, then it would claim such protection in spec sheets. Why no such claim? Why is a 'magic box' that does not even claim to provide protection also called sufficient? The plug- in protector without earthing is not sufficient for anyone. The protector is only as effective as its earth ground. Or do we know it is protection only because it is called a protector?
A MOV works by limiting the voltage between two nodes of a circuit. It does nothing else. It does not know about 'ground' or 'earth'. Devices connected to the nodes are protected from surges greater than the specifications of the MOV. If the device connects to 2,3, 4, or 5 nodes in the circuit, and all nodes are protected, then the device is protected. (Within the limitations of the protection device, of course.)
This does not provide useful protection as the protected nodes are where the protector is. Any wiring between the node to be protected and the protector defeats the protection. (As you appear to know.)
Absolutely false. Disctance between the protector and the protected device allows charge to be coupled into the connecting wire. What you suggest only applies to surgest that come from the supply side of the {house, breaker box, whatever].
This kind of a statement needs to be qualified w.r.t. the source of the surge for it to have meaning.
"Earth" is not protection. Numerous lightening victims connected to earth were not protected.
Protection is keeping the voltages seen by the protected device to a minimum.
"Earth" or "ground" becomes something else in the presense of a surge. "Ground" does not revpresen an infinite volume of zero-voltage space. Any grounding system is limited by the impedance to some arbitrary reference point. If lightening hits the power lines entering a structure ground potential can rise significantly inside the structure. However is all the devices inside the structure only see the potentials the protections devices allow to pass, damage is minimized.
A simple analogy is ESD packaging. Devices inside a sealed ESD bag are protected from ESD as they can not see what goes on outside the bag. A connection to "ground" is not required for this protection.
A surge has energy. If voltage is limited, then where is the energy dissipated? Do you really believe that 100 joule MOV is dissipating energy of a direct lightning strike? That energy must be dissipated somewhere. Where? Go back to Page 42 Figure 8. An MOV limited voltage. Therefore protector was at 8000 volts on all wires. Therefore protector earthed that 8000 volts destructively via adjacent appliances (what craigm ignored) as voltage between those wires was limited to something between 250 and 900 volts (what craigm defines as protection). Why does craigm only post a half fact? Why does craigm ignore where that energy was dissipated - 8000 volts destructively to adjacent appliances because energy must be dissipated in earth.
craigm, how many protector systems have you designed and actually seen the results? When you get to your third decade of experience, then let me know. You are simply speculating same myths we debunked decades ago by actually doing the work. You have even ignored the typically destructive type of surge by assuming all surges are the other typically non-destructive type. Your type of surge make irrelevant by 'voltage limiting' is also made irrelevant by circuits inside electronics.
MOV limits voltage between black, white and green wires (maybe to
500 volts). But the typically destructive surge entering on black wire and is shunted to white and green wire is still seeking earth ground. Its still seeking earth ground - simply has more wires to destructively find earth. Having shunted (clamped, connected, limited, diverted) that surge current to other wires means that surge current stop seeking earth ground? Of course not. But that is what you have claimed. Having shunted that surge current to other wires means the energy need not be dissipated? Of course not. But that is also what you have claimed.
A surge shunted from black wire to white and green wire (what you call voltage limiting) now has many times more paths to destructively seek earth ground via appliance. No way around that realty. If not via one adjacent TV, then destructively via another appliance: Page
42 Figure 8. Why do you even ignore the facts demonstrated on Page 42 Figure 8? You must to keep promoting the myths.
Two facts (and there are many more): both demonstrate why your reasoning is bogus. Why do you ignore both reasons; therefore promote myths? A surge protector does not do as you have claimed. Shunt mode protectors shunt surge energy to earth ground. Ineffective protector sold as massive profits with insufficient MOVs don't even have an earth ground. But you promoting ridiculous myths that even the manufacturer will not claim. Why does the protector manufacturer not make your protection claims in their numeric specs? They don't need to. They have you even pretending that surge energy completely disappears - need not be dissipated.
A protector without earth ground to shunt that energy into may instead dissipate that energy into adjacent appliances - Page 42 Figure 8. No earth ground means no effective protection. No wonder the responsible manufacturers make 'whole house' protector with that dedicated earthing wire. They don't need you to promote myths for them. Instead, protectors from responsible manufactures earth that surge before it can even enter the building.
Provided is how to kludge a completely ineffective plug-in protector into something that might earth a surge. You have no idea how a protector works. Telco switching computers everywhere in the world suffer surges from overhead wires all over town - and must never suffer damage. Critical is locating the protector distant from electronics - typically less than 50 meters. Important is for the surge to be earthed long before getting near to electronics. Telcos don't was money on what craigm recommends because it is ineffective - makes damage to electronics easier.
So which one of us designed, built, and tested these solutions as an engineer for many decades? Not you. Your have even assumed the non- destructive type of surge is the only type of surge. A protector is only as effective as its earth ground. Craigm denies what is well proven where people learned science - not promote half truths. Craigm even assumes the surge that typically does not do damage is the only surge. Craigm completely ignores where that surge energy must be dissipated.
The simple fact is that electrical energy gets converted to heat energy whenever there is current through resistance in the path 6the current takes, in accordance with P = I^2R.
The energy in the case of a point of use protector is what comes out of the panel and travels through the specific branch circuit wiring to the MOV, *not* the entire energy in the source outside of the house (presumably lightning), or even the entire energy that gets through the panel and splits among all the branch crcuits.
What the point of use protector is clamping is the let through voltage on the specific circuit, and the MOV doesn't "see" all of it while it is clamping - some is dropped in the wiring.
The energy is dissipated in the path from the panel to the MOV protector, the MOV itself, and the path from the MOV back to the panel. Electrical energy is converted to heat, in accordance with ohm's law:
-- I-->
| |----PathR(t)----+ S |P | | U--|A | MOVr R--|N | | G |E | | E |L |----PathR(b)----+ | | --
The energy will go to three places and be converted to heat in each place:
Some energy will be converted to heat in the top path as follows: I^2 * PathR(t) In conjunction with the energy going to heat, there will be a voltage drop in the path of V = I * PathR(t)
Some will be converted to heat in the MOV as follows: I^2 * MOVr In conjunction with the energy going to heat, there will be a voltage drop in the MOV of V = I * MOVr
Some will be converted to heat in the bottom path as follows: I^2 * PathR(b) In conjunction with the energy going to heat, there will be a voltage drop in the path of V = I * PathR(b)
The voltage across the MOV will be clamped by the MOV to some value much lower than the let through voltage, until the MOV dies or the let through voltage drops below the level that keeps the MOV in the low resistance state. 340 volts is a typical clamping voltage spec.
Some are claiming an MOV protector without earth ground is sufficient protection. Somehow all that surge energy will be absorbed by wires. And that current will stop seeking what it wants to connect to - earth ground. Effective protectors are sold on science. The energy is diverted to earth 1) so that the electrical path is via things not damaged, and 2) so that the energy is absorbed in earth. Wires and the MOV do not absorb all that energy as ehsjr claims.
In effective protection, little energy is absorbed by wires and MOV. Massive energy is absorbed in earth. Only with proper earthing is a little protector is so massively effective. That energy has to go elsewhere. Those promoting protectors without earthing simply pretend that energy it trivial or does not exist.
A protector is only as effective as its earth ground. Earth is where surge energy must be absorbed - not inside an MOV protector as ehsjr so often claims.
I gave a short answer where the energy goes in my post dated 9-4.
Among those that claim a plug-in suppressor is effective are the IEEE and NIST .
Somehow all that surge energy will be absorbed
The IEEE guide explains that earthing does not occur primarily through a plug-in suppressor. The IEEE guide explains earthing occurs elsewhere in the circuit.
Complete mischaracterization of what Ed said in his last post.
Those who say plug-in suppressors are effective include the IEEE and NIST. But poor w__ can?t figure out how they work because thry biolate his religious belief in earthing.
The required statement of religious belief in earthing. Everyone is in favor of earthing. The only question is whether plug-in suppressors work.
Both the IEEE and NIST guides say plug in suppressors are effective. Read the sources.
w_ has still never found another lunatic that says plug-in suppressors are NOT effective.
And w_ has still not 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?
- Why does the IEEE Emerald book include plug-in suppressors as an effective surge protection device.
- Why did Martzloff sayin his paper "One solution. illustrated in this paper, is the insertion of a properly designed surge reference equalizer [multiport plug-in surge suppressor]."
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 others - like Ed. Attempts to discredit opponents. w_ is a prevaricator and a purveyor of junk science.
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