Its not a protector its a suppressor. Probably for legal reasons since they will not protect from a direct power line or house strike. Neither will whole house models.
Obviously because "whole house" suppressors need to be installed by electricians and cost substantially more at first glance. Plug in suppressors are baked into devices that surge other purposes like adding ore outlets. They are bought "over the counter." These are two different markets.
A protector is only as effective as the earth ground it can provide vs. the ground provided through the device it is protecting. Please recognize the other 1/2 of that equation.
Yes, I did misspeak. I am used to saying it that way. In fact its this relative resistance division that makes local protectors just as good as remote ones.
The only thing worth mentioning is that the device protects everything downstream of it. So a fuse panel protector will protect a lot more devices. But it still wont protect the better.
Again, discuss wire impedance. Why do telcos routinely install protectors so close to earth ground and up to 50 meters distant from their computers? Because separation between protector and electronics increases protection. Impedance in that 50 meter separation means even more surge will not seek earth ground via electronics and will seek earth ground via the lowest impedance (ie 'less than 10 foot') earthing connection.
Protection is subverted when a protector is mislocated adjacent to appliances. A protector too far from earth ground and too close to appliances is why an adjacent TV, 8000 volts destructively, earthed a surge on Page 42 Figure 8. TV damaged because the protector was too close to appliances and too far from earth ground.
OK, and its your contention that the quality of the path through the electronics is irrelevant. Even if that path has infinite resistance, if the ground is not absolute 0 the device will still get hit with the surge.
I don't follow this example you keep giving. Seems like your saying a device adjacent to a protected device got damaged!?
I can help you out on that one. Anytime any electronic device is damaged by a surge, to comply with W-'s religious beliefs, the damage must be attributed to a plug-in surge protection, if one is present anywhere. If a computer was plugged into a surge protector and NOT damaged during an electrical storm, while a nearby TV, which had no surge protector was, Tom will come up with some convoluted explanation of how the surge protector at the computer CAUSED the damage at the TV.
Of course this requires the suspension of some electrical basics, common sense, and experience, but that clearly isn't an issue.
Power plant surges don't create consumer surges for numerous reasons. But lightning and other surges such as those created by utility switching may be destructive and do seek earth. Also install one 'whole house' protector for typically non-destructive surges. We install and earth one 'whole house' protector to protect from all types of surges. The word *all* does not apply to plug-in protectors.
Install only four plug-in protectors around the house. If a plug-in protector works as claimed, then we need maybe 100 plug-in protectors including one at the furnace, one at the dishwasher, and one for every far more critical appliance such as bathroom GFCIs and smoke detectors. That is the kind of protection obtained from one 'whole house' protector. Meanwhile, plug-in protectors do not even claim to protect from the typically destructive surge and can even provide that surge with more destructive paths through appliances (Page 42 Figure
8).
Instead of 100 plug-in protectors selling at $25 or $150, the informed consumer installs superior protection from all types of surges using only one properly earthed 'whole house' protector. Superior protection for only $1 per appliance. Yes, you agree. But this post is for many - not just you. Four protectors scatter around the house does not even approach being sufficient or effective. Four protectors - and not one provides a manufacturer spec for protection from typically destructive surges? What kind of protection is that? Profitable. Ineffective.
I don't know what your 'relevant impedance' is. But wire impedance is why effective protectors are located close to earth AND separated from appliances. Wire impedance for earthing concerns industry professionals. A 'top of the front page' article in Electrical Engineering Times entitled "Protecting Electrical Devices from Lightning Transients" discusses what is required for surge protection:
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Another aspect of impedance ... of a wire is predominately related to
The article is about surge protection. Therefore it describes what is essential - a low impedance earth connection. It is about effective protection. So it does not discuss plug-in protectors.
Any facility that requires effective protection earths surges at the service entrance, worries about connection impedance. and addresse grounding issues should damage not be averted. A plug-in protector cannot protect from typically destructive surges. Its manufacturer makes no such claims. Obvious: plug-in protectors are not used inside telephone switching centers where damage must not occur and therefore 'whole house' protectors are used.
Protection inside appliances makes most surges irrelevant. A typically destructive surge can overwhelm that existing protection. So we install and better earth one 'whole house' protector to make a typically destructive surge irrelevant AND to make other surges also irrelevant.
Where does the US Air Force demand that protectors be located? Not inside:
Why at the service entrance? Any surge that might be stopped or absorbed inside a building will simply find many other (some potentially destructive) paths inside that building. A surge earthed before entering the building means protection inside *all* (not just four) appliances is not overwhelmed. A surge earthed at the service entrance (ie breaker box) means a low impedance connection into earth AND a high impedance path to appliances. Essential to effective surge protection is that low impedance earth connection. Then surge energy gets dissipated in earth; not inside the building. Routine is to have direct lightning strikes and no damage.
A 'whole house' protector also makes that other typically non- destructive surge irrelevant for tens or 100 times more money.
Of course this is not 100% protection. From the IEEE Green Book entitled 'Static and Lightning Protection Grounding' :
Where does a plug-in protector costing tens or 100 times more money per appliance make any such claim? It doesn't. One glaring reason - no low impedance connection to earth.
Surge created by a high voltage transmission line falling onto local distribution is energy from the power plant (actually transformer that is sourcing power) seeking a path back to that power plant via earth. A surge so violent as to literally explode hundreds of electric meters 10 meters off buildings did not cause any appliance damage when one 'whole house' protector (and no plug-in protectors) was properly earthed.
A surge that entered a building of powered off and networked computers was simply earthed, destructively, by two plug-in protectors through those adjacent computers and through the network. We traced that surge by literally replacing ICs. What kind of protection from two plug-in protectors? Completely ineffective as demonstrated on Page 42 Figure 8 - 8000 volts earthed through the adjacent TV.
Why spend so much money on protectors that cannot and do not claim to protect from the typically destructive surge? Why waste money on plug-in protectors? Because it is the popular thing to do. Facilities that must have protection don't waste money on plug-in protectors. Instead 'whole house' protectors AND short (low impedance) connections to a single point earth ground are installed. Earthing is critical for protection from all typically destructive surges. Same protection 'system' also protects from all other surges. No plug-in protector can or does make that claim.
Effective protection protects from all types of surges =96 including the type that is typically destructive. Where does any plug-in manufacturer make that protection claim?
IEEE example on Page 42 Figure 8 shows a protector too far from earth ground. A surge was not earthed (energy diverted into earth) before entering the building. So the surge arrived at a plug-in surge protector. What do surge protectors do? Shunt (distribute, connect, clamp) that energy on all other wires. Well, that surge still must find earth ground. Since the wire back to the breaker box is maybe 50 feet long, then that surge voltage is so high as to find another path to earth: 8000 volts destructively through the adjacent TV.
In an obvious example, lightning incoming on AC electric was shunted to all other wires by two plug-in protectors. Surge on the black wire was shunted to the green wire, into two adjacent, powered off computers, out via NIC cards, into a third powered off computer, and to earth via modem and telephone line. We literally located and replaced every IC that conducted the surge to make all computers functional. Surge not earthed at a service entrance (no 'whole house' protector) means a surge is inside the building finding other paths to earth. In this case, surge found earth ground via three powered off computers because the plug-in protector connected an AC hot (black) wire surge directly into computer motherboards.
Permit me to shoehorn this thread into the OT Joe Horn thread: a surge is like a burglar or a vandal. You want to stop them at the perimeter, where there's likely to be very little collateral damage. Since surges come in through the power line (or phone line or CATV copper cable) the best place to offload those excessive currents is where they enter. Using a protector deep within the house allows the surge to enter a lot of the household wiring that a protector placed at the wiring entrance *might* not.
Even though the common wisdom says to wait until a burglar is inside before you shoot them., that advice usually comes from people who've never had to clean up all that blood. (-: Unless you've seen it, you can't believe how much blood a shot burglar can leave around while wriggling and writhing around in pain, or worse yet, trying to escape. To add even more insult to injury, your house becomes a crime scene and you can't wash away the blood while it's still wet (which is about the only time you can ever wash blood away).
But I digress. The point we are both trying to make (me via black humor!) is that threats are best dealt with at or outside the permimeter of the protected area, not within. If you're going to surge protect your home, it makes a lot more sense to do it at the point where the wires (and the surges) enter the building. That way, the surges don't dance around your house like that shot burglar, ruining a lot of things that could have been saved had the threat been stopped at the perimeter.
For those with a love of the weird, here's a lightning bolt burn on a man's back:
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:Lightning goes where it wants, when it wants to, and the best hope there is to lessen its damage is to keep it out of the house by offering a more attractive (groan) path to the ground. The proper place for that "offer" is right where the wires enter the house, not at some appliance located deep within the house wiring.
LA302R is called a single phase protector. That means it connects one AC hot wire to earth. The other phase would not have protection. However it also uses the number 125/250 and phrase 'per pole' implying this is really a two phase protector.
First, joules define a protector's life expectancy. As joules increase, a protector's life expectancy increases exponentially. This protector has an above average life expectancy. Being larger, it would also earth more surge energy - absorb less. For others, this protector to protect maybe 100 household appliances is listed at $42 or about $0.42 per protected appliance. Compare that to $150 per appliance for Monster Cable plug-in protector that does not even claim to provide this protection.
Above is about protector life expectancy - a long duration consideration measured in years. Another consideration involves short duration operation - what the protector does during microseconds. This is defined by how that protector connects to and the quality of earthing. A protector is as effective as its earthing. Nothing in that Delta spec will provide information on its short term quality - how well it will earth a surge.
For example, does the breaker box wire go up over the foundation, then down to an earth ground rod? How to make that Delta protector even better? Reroute that earthing wire through the foundation and down to a single point earthing electrode. Having made a shorter wire with less bends, now the Delta is an even better protector. If that rerouted ground wire is separated from other wires, protection further improves. Not only should that earthing wire be as short as possible, no sharp bends, no splices, etc. It must also attach to the same earth ground used by telephone, cable, and satellite dish. Another factor that makes that Delta protector and equivalent protectors more effective.
Delta's specs only discuss something long term - life expectancy. What determines how well the Delta will perform during microseconds of surge? Well, the Delta has above average joules meaning it is conductive. But what really determines its short term performance is how the Delta is earthed.
Whereas a plug-in protector would be promoted as a complete solution; effective protection is a 'system'. The Delta is only one 'system' component. Only component always required in a protection 'system' is the earthing electrode. How good is that earthing electrode and connections to that electrode? Earthing is a defining parameter for Delta effectiveness. A protector is only as effective as its earth ground.
Above discusses a 'secondary' protection system. Also inspect your 'primary' protection system:
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notice what defines whether that protection layer will be effective. I cannot stress how often utility install grounding is left compromised as if it was never needed. After all, the lights work. Therefore earth ground for the primary protection layer also is not required?
The Delta protector appears to have specs significantly above minimum. How effective is it? Well does its earthing meet and exceed post 1990 code requirements?
And no one here is disagreeing that a whole house surge protector, properly installed, is the best first line defense for surge protection. Of course it's best to deal with the surge before it gets into the house.
The problem is, W_, with his religious beliefs, denies and rants that plug-ins can't offer any protection and in fact, actual create damage. Plug-ins can offer protection by clamping voltages coming into a protected appliance. And how about people who can't install a whole house protector? For example, those living in a rental property or an apartment? Clearly using plug-ins can be effective. Everyone here seems to agree, except W_, who's stuck on his religious beliefs.
"Measuring" earthing is not practical. Although we can measure earth resistance, still, that does not determine quality of that earthing 'system'.
In many cases, a single 10 foot earth ground rod is more than sufficient if soil is conductive and moist. In simple terms, fine soil tends to be more conductive. Sandy soil is typically less conductive. Current habit is to install two ten foot ground rods separated by more than 6 feet to make that single point ground more conductive.
We earth to achieve a more conductive connection. But that connection can never be sufficient. So we single point earth to make earth beneath the building more equipotential. But we can never create sufficient equipotential. So we make the earthing electrodes more conductive.
If in sandy soil, other techniques include a halo (loop) ground buried around and outside the building. In FL, with more lightning and sandy soil, also standard is Ufer grounds. Effective because concrete is an electrical conductor:
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Ufer grounding means surge protection is installed when footings are poured - not when the electrician arrives to install wires. Meanwhile a utility offers suggestions on how to fix defectively installed earthing:
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buried interconnection wire converts multiple earthing electrodes into single point earth ground while increasing conductivity.
Unfortunately we don't always know what is in the earth. For example, one building was adjacent to a vein of graphite. Or a transcontinental pipeline is buried nearby. Surge instead ignored service entrance ground, passed through the building, to obtain earth via more conductive graphite. Solution was to surround that building with a buried conductor (halo ground) so as to make earth beneath the building into a big single point ground - create equipotential. Surge that traveled underground around and outside a building need not enter the building (see Faraday shielding to appreciate the concept).
In another case, lightning would repeatedly strike an exterior bathroom wall. They installed lightning rods. Lightning struck that bathroom wall again. Why? Plumbing inside that wall connected to deeper and more conductive limestone. Lightning rods were only earthed 10 feet in sand. The bathroom wall, not lightning rods, made a better connection to earth borne charges.
Make earthing as best as practicable. Then if damage does occur, learn why that earthing (or connections to it) was not sufficient. No good way to lest earthing without an actual lightning strike. Best we can do is install earthing correctly using what has been well learned the past 100 years.
Many assume a cold water pipe makes a best earth ground. Well, it is conductive but it does not necessary provide equipotential. Also it may be too far away (ie more than 10 feet). Pipe joints (ie solder) may also compromise protection.
Another problem is a water well. Lightning may pass destructively through a building to obtain earth via that well pump. Just another reason why we want the service entrance ground to be a most conductive earth ground AND why all incoming wires (overhead or buried) enter a building connected short to the single point earth ground.
Described previously were factors that can increase wire impedance and compromise surge protection. That earthing connection must be short ('less than 10 feet'), no sharp bends, separated from all other non-ground wires, not pass through or inside metallic conduit or sheets, no splices, and all ground wire routed separately to meet at the earthing electrode (single point earth ground).
One cannot have too much earthing. However most locations with conductive soils have massive and probably sufficient earthing with only one 10 foot ground rod. Every addition to the earthing system has a diminishing return. But many facilities install massive earthing system to obtain just a little better earthing. Ham radio operators who learned this stuff will install better earthing systems:
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is to have direct lightning strikes without damage. But if damage does occur, then plug-in protectors are not a solution. Instead the earthing system is reevaluated for defects or automatically upgraded:
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In one memorable instance at KROA, lightning ignored
For more information about earthing, see an industry benchmark - Polyphaser's application notes such as:
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other papers at:
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Meet post 1990 National Electrical Code requirements - then exceed them:
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to an introduction to earthing - what provides the surge protection.
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A protection system with a poor ground is the same as having no protectio= n at all.
So we do what has been proven effective elsewhere for the past 100 years. Then we learn from the experience. On average, typically destructive surges occur once every seven years. However that number can vary significantly (due to geology and other factors) even within the same town.
w_tom never said what trader only assumes. Plug-in protectors provide ineffective protection at massively high prices. Plug-in protectors do protect from one type of surge - that is typically not destructive. Internal appliance protection makes that surge irrelevant. Plug-in protectors offer no protection from the type of surge that typically causes appliance damage. The other destructive surge overwhelms protection inside appliances.
If a protector shunts (connects, clamps) wires together during a surge, well, one wire short to earth ground means protection. However if none of those wires are connected short to single point earth ground, then the surge voltage is same on all wires; surge is now provided more paths to find earth ground. Page 42 Figure 8.
Every responsible citation is quite blunt about what a protector must do - divert surge energy into earth. Surges that don't enter a building don't create damage. Surges that do enter a building find all kinds of destructive paths to earth.
Meanwhile, the surge that a plug-in protector might protect from? That surge is also made irrelevant by a ''whole house' protector.
What does the plug-in protector do? A $3 power strip with some ten cent parts does protect from a surge made irrelevant by protection inside appliances, and by one 'whole house' protector. What does that plug-in protector accomplish? Higher profits.
trader already read a kludge solution for apartment dwellers whose landlord will not install a tenant provided 'whole house' protector. Take a power strip of maximum joules. Cut off its six foot power cord as short as practicable since every foot of wire only subverts protection. Plug that protector into an outlet closest to the breaker box. Hopefully that protector will have some (obviously inferior) earthing. Now an ineffective plug-in protector is kludged
- attempts to do what effective 'whole house' protectors accomplish. To be effective, the protector must divert the typically destructive surge into earth. Furthermore, move electronic equipment to outlets farthest from the breaker box. That separation also increases electronics protection.
Even a kludge solution puts a protector as close as possible to earth ground and distant from electronics. However a far superior solution (a 'whole house' protector and better earthing) is also tens or 100 times less money. Money wasted on plug-in protectors is better spent upgrading the earthing. A protector is only as effective as its earthing.
Yes, plug-in protectors can protect from one type of surge - that typically is not destructive. You would recommend spending tens or
100 times more money for a protector that does not protect from the other and typically destructive type surge?
Why does a plug-in protector not list protection in numerical specs? Plug-in protectors do not protect from the type of surge that typically causes damage. If does protect from a type of surge made irrelevant by protection inside appliances and made irrelevant by the 'whole house' protector. trader has been too busy insulting rather than read what was posted. As another notes, effective protection (that also costs massively less money) means keeping surge currents out of every building and dissipiated in earth. A protector is only as effective as its earth ground.
. Poor w_?s religious blinders prevent him from reading what the IEEE guide says.
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.
Without the plug-in suppressor the surge voltage at TV2 is 10,000V. With the suppressor at TV1 the voltage at TV2 is 8,000V. It is simply a *lie* that the plug-in suppressor at TV1 in any way contributes to the damage at TV2.
The point of the illustration for the IEEE, and anyone who can think, is "to protect TV2, a second multiport protector located at TV2 is required."
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. The IEEE guide says in that case "the only effective way of protecting the equipment is to use a multiport protector."
Because plug-in suppressors violate w_'s religious belief in earthing he has to twist what the IEEE guide says about them.
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"? ? Why does SquareD say "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use."
- Why does the IEEE guide says in its example "the only effective way of protecting the equipment is to use a multiport protector"?
- How would a service panel suppressor provide any protection in the IEEE guide example?
Still never seen - a source that agrees with w_ that plug-in suppressors are NOT effective.
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
. The NIST guide cites US insurance information that indicates equipment most likely to be damaged by lightning is computers with modem connection and TV/related equipment - presumably with cable connection. All can be damaged by high voltage between signal and power wires.
If a surge comes in on power wires and produces 1000A to earth through a very good 10 ohm impedance to earth, the 'ground' at the service panel rises 10,000V above 'absolute' ground potential. Equipment connected only to power can float above 'absolute' ground. The only way to protect equipment with both power and phone/cable connection is to make sure the phone and cable 'ground' potential is the same as the power 'ground'. That requires a *short* connection from phone/cable entrance protectors to the power system 'ground'.
An example of a cable protector 'ground' wire that is too long is in the IEEE guide starting pdf page 40. .
From
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"Halo 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." Perhaps w_ could learn the right name (ground ring). .
. Ufer grounds are required for most new construction, and are good ground electrodes. .
. The buried interconnection wire (Figure 2 "right") is unlikely to keep power/phone/cable grounds at the same potential. Figure 2 "preferred" is correct. .
. Running phone and cable 'ground' wires to the earthing electrode will almost certainly make the power-signal interconnection distance longer, increasing the voltage between power/phone/cable 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."
Often the phone or cable entry protectors are distant from the power service. In that case the IEEE guide says "the only effective way of protecting the equipment is to use a multiport [plug-in] protector." .
Ham radio operators are likely to have a direct lightning strike on their antennas. Surge amps are far higher than can be conducted in on power/cable/phone wires. For protection from a direct strike you need lightning rods.
The IEEE guide explains, for anyone who can think, that 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. The guide explains that earthing occurs elsewhere in the system.
Still never seen - a source 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"? ? Why does SquareD say "electronic equipment may need additional protection by installing plug-in [suppressors] at the point of use."
- Why does the IEEE guide says in its example "the only effective way of protecting the equipment is to use a multiport protector"?
- How would a service panel suppressor provide any protection in the IEEE guide example?
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
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