"chain" surge suppressers?

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"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:
http://members.aol.com/gfretwell/ufer.jpg
http://scott-inc.com/html/ufer.htm http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/UferGroundPsi~20030930.htm http://www.psihq.com/iread/ufergrnd.htm
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: http://www.cinergy.com/surge/ttip08.htm That 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: http://home1.gte.net/res0958z / Routine 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: http://www.psihq.com/AllCopper.htm http://www.copper.org/applications/electrical/pq/casestudy/nebraska.html

For more information about earthing, see an industry benchmark - Polyphaser's application notes such as: http://tinyurl.com/3y747k http://tinyurl.com/2rsdhj and other papers at: http://www.polyphaser.com/technical_notes.aspx
Meet post 1990 National Electrical Code requirements - then exceed them: http://www.eham.net/forums/Articles/40885 Welcome to an introduction to earthing - what provides the surge protection. http://www.citelprotection.com/citel/grounding.htm

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.
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w_tom wrote:

. 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 http://www.lightningsafety.com/nlsi_lhm/grounding_definitions.html "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.
--
bud--

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I had several components in my house protected by these local devices. One day lightning struck near by. I saw a flash behind my computer upstairs. My wife saw one at the TV downstairs. Both had surge suppressors. Everything still worked, but internet was down.
I checked later to see what happened. My cable modem was fried. My router was also fried. After I checked further I noticed the cable company did not ground the cable outside of my house. If it were today I would sue the for both the equipment and the hazard since I have pre-paid legal...
The came out and properly grounded the cable.
CL
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did they teach you that at big mac school?
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"Power surges on telephone exchange equipment meanwhile, affected a third of the Island. At 10.50 p.m. the surges resulted in a "main power failure" at Bermuda Telephone Company (BTC's) Paget Telephone Exchange, causing interruptions to 22,000 business and residential lines from Smiths to Dockyard.
Last night, 2,000 customers in the West End were still without service.
A BTC spokeswoman said: "The BTC staff will work very hard through the night to get everyone back on line. There are approximately 2,500 customers in the Devonshire South and Smiths South areas, feeding directly out of the Paget Exchange, who also continue to experience a service interruption."
Guess they should have paid attention to the expert.
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Not all surge protectors are created equal. One really good one is worth more than a dozen cheap ones. Just get one really good one and be happy. Generally the ones built into most UPS units are better than most. If you are in an area where it is a big problem, then I would suggest unplugging the devices. I would also suggest that you might want lightening rods for your home. We don't see many of them these days, but nothing has changed about lightening, they are still a good idea in lightning prone areas.
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On Jul 9, 6:14am, snipped-for-privacy@columbus.rr.com wrote:

What defines the good one verses bad one? Price? Hardly. How to identify an ineffective protection. 1) it has no dedicated earthing wire (no wire means no lightning protection). 2) Manufacturer avoids all discussion about earthing. No earth ground means no effective protection. This is why the resonsible manufacturers (GE, Square D, etc) sell the 'whole house' protector. Monster Cable does not.
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w_tom wrote:

. The required statement of religious belief in earthing. The IEEE guide explains, for those who can read, that plug-in suppressors work primarily by clamping, not earthing. The IEEE guide explains earthing occurs elsewhere. .

. The "responsible manufacturers" also sell plug-in suppressors. .

. w_ knows because he buys all his speaker wire from Monster Cable.
Never seen - a source that agrees with w_ that plug-in suppressors are NOT effective.
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."
For real science read the IEEE and NIST guides. Both say plug-in suppressors are effective.
--
bud--

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Every Bud citation says why plug-in protectors are ineffective. Each says the typically destructive surge must be earthed. Page 42 Figure 8 even shows how a protector too close to appliances and too far from earth ground can earth a surge *8000 volts destructively* through an adjacent TV. Bud calls that effective protection.
However if Buds sales promoted protectors were effective, then Bud would provide manufacturer spec numbers that list each protection. Bud refuses to provide the only relevant numbers. No plug-in protector can claim to provide that protection. Every Bud citation says why. From Buds NIST citation:

Protectors promoted by Bud are defined by the NIST (see above quote) as useless.
Nothing new here. Earthing protection has been a telco standard for over 100 years. Responsible facilities don't use Bud's 'easiest' solution. All put protectors as close as practicable to earth ground. All create a single point earth ground; what provides the surge protection. Reliable facilities dont use effective protection; not obscenely overprices products that Bud promotes.
Bud is not selling earth ground. Bud is promoting a $3 power strip with some ten cent parts for obscene profits: $25 or $150. The $10 grocery store protector also is his protector circuit. Admitting this would put profits at risk. Every Bud citation says why plug-in protectors are ineffective. Quoted above is the standard Bud myth. Bud still refuses to provide any manufacturer spec numbers. Honesty is not Bud. Profits are at risk. Where is that manufacturer spec for protection? Does not exist.
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w_tom wrote:

. Ho hum - 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."
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.
--
bud--

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Quoted from both Bud's citations are how plug-in protectors are ineffective. Bud simply cut and pastes the same replies everywhere to even deny what his own citations note.
If a plug-in protector provides that protection, then each type of surge is listed in its numeric specs - with numbers that claim protection. Why does Bud never post those numbers? Even the manufacturer does not claim that protection. Not only do plug-in protectors sometimes contribute to adjacent appliance damage. It does not even claim to provide protection. Why does Bud repost myths repeatedly? Bud is a sales promoter of plug-in protectors. He is so dishonest as to not even admit this conflict of interest.
Install one 'whole house' protector from other responsible companies. Eliminate surge threats to every appliance. Only more responsible companies market 'whole house' protectors - Siemens, Keison, Intermatic, Leviton, Cutler-Hammer, Square D, GE, etc. Profit margin on effective 'whole house' protectors is not obscene. Therefore APC, Belkin, Tripplite, and Monster Cable do not provide the effective 'whole house' protectors.
How to quickly identify ineffective protectors? 1) No dedicated earthing wire. 2) Manufacturer avoids all discussion about earthing. A protector is only as effective as its earth ground. That surge energy must be dissipated somewhere.
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w_tom wrote:

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.
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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.
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w_tom wrote:

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!?
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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.
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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.
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w_tom wrote:

. 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.
--
bud--

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w_tom wrote:

If the computer was off then there should be no current path through it. You mean it was in soft-off mode.
Furthermore, you gave your whole argument away when you introduced the phone line path to ground. most likely that is where it entered. A phone line does not provide a better path to ground than the house ground..
Sure the surge gets dumped from one wire (say black) into another wire in the suppressor. However, the other device is also connected to the black wire and it already has to deal with the surge with 0 protection. The devices are already parallel. So I fail to see how this adds anything to the other device being damaged.
Since we have 3 phase power, lets say the surge came in on 1 source wire. Then the surge was attempted to be dumped into ground/neutral. Some of that current can pass into adjacent device if ground/neutral cant sink all the load. So we are back to the question of the quality of the main path to ground vs. other paths. And the 3 phases should only mix in the fuse panel or at 220 devices.
I think you misinterpreted the example. Probably it was talking about surges entering on auxiliary lines like Cable and phone. I agree a cable/phone surge suppressor is going to potentially introduce components isolated from the phone/cable line to surges that came in on the phone/cable line. Again, to the degree the ground can't sink the load.
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> Protection is subverted when a protector is mislocated adjacent to

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:
http://teslamania.delete.org/frames/human_LF2.jpg
: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.
-- Bobby G.
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wrote:

Holy Crap!
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