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#11
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THe reason they don't operate fast enough is not really the problem it is
the fact that most of them don't. I think your comment about building grounding is misleading. At least in this country buildings are well enough grounded to be safe in most circumstances. In building design it is possible to reach a very high level of lightening and surge protection. the issue is one of cost mostly. PC are cheap relatively. My experience (5 years as telecom guy in a building with about 1000 networked pcs) suggest lightening or surges are very minor problems. From what I know of lightening protection engineering it is an art form to some degree. Sometimes the engineers get it right, sometimes despite the best of designs the stuff blows. As I said its the data thats important. BTW as I said $250 Can will buy you an 800 watt output battery inverter pack to run your Ipod or laptop on your "camping trip". That gets you one that plugs into the wall (110-120 here) and outputs to 2 sockets for a total of 800 watts AC on the other side. That's it said my piece "Paul" wrote in message ... In article , "notritenoteri" wrote: MOst surge protectors aren't much good they just don't operate fast enough. If U insist on protection a good UPS which convers AC to DC charges a battery pack then provides AC out the other side with an inverter is the best bet for my money. You can buy these in Canada where I am for about $200. They have to be maintained and the batteries do go after about 5 years. As to RAID 1 I think you really need 4 drives, controller that is smart and the software but maybe your definition is different than mine. At the risk of starting one of those whiny surge protector threads, the devices used can actually react fast enough. Some of them conduct in nanoseconds. The problem is with the physics - it is hard to get the dumped energy into the ground fast enough. Ground wiring is a secondary consideration in building construction, and even adding an extra extension cord to a surge protector can render it useless, due to the inductance of the cord preventing the dumped energy from getting to ground in time. (The Tripplite ISObar outlet has an insurance policy, that in invalidated if another extension cord is used with the product.) As for the UPS, the UPS acronym is used rather carelessly by the marketing people. Your typical cheap home UPS is actually an SPS. An SPS has no filtering capability to speak of, and uses a relay to switch operating modes. It looks like this: SPS - Normal operation SPS - Battery operation AC ---X---X----AC AC ---X X----AC / DC DC You can tell an SPS, because it remains stone cold to the touch while operating. After all, in normal operation, AC is just being passed through the device, via a relay. A real UPS looks like this, and the path stays the same all the time: AC -----DC------AC Such a UPS gets warm/hot, because the inverter on the output making the AC, dissipates energy just like the switcher inside your ATX power supply. A real UPS typical costs $1K (for no good reason that I can see). Paul "Mercury" wrote in message ... Everything man makes turns to dust right? I don't believe in tempting fate. There are plenty of low quality UPS and surge protectors out there. I will generalise and say most low cost consumer stuff is complete rubbish until I am proven otherwise.You can have a *good* surge protector for as little as $US30. Many surge protectors are only good for 1 surge!A good true online UPS for an average power computer can cost $US250 or less. RAID 1 costs 1 extra disc drive and a controller capable. It will protect you from drive failures. There is no replacement for quality proven backups kept off-site. This is most important. My sisters house got blown by lightning - oven, fax, x computers, TV's etc. The only thing that worked afterwards was the traction engine. Prevention is better than cure. "notritenoteri" wrote in message ... YOu want to worry about something? Worry about your data. Your MB is obsolete, Your OS is obselescent and going obsolete and the only thing that's of any value is your data. All the stuff about UPS's is theory. Are you running NASA and a lunar lander mission? If you are you should be shot for having only a single system. Given enough time EVERY piece of equipment will fail including $1000 UPS's. I power my system on and off all the time. I don't shut down when lightening storms are overhead and I never worry about the telephone lines or cable. But I live where the power wiring is fairly new ~15 years and its above ground. If lightening is going to get you its going to get you. I have heard claims that buried power and phone cables are susceptable to problems but I've never seen proof. "Paul" wrote in message ... In article URjEd.32449$3m6.5163@attbi_s51, "Travis King" wrote: What's probably the life expectancy of my A7V333 motherboard if I take good care of it? It has 2 years on it right now. I run the computer for the most part constantly except when I leave town or do something with the inside of the computer. Current MB temperature is at 30 C. If the case temp is not excessive, the electrolytic caps should be good for 10 years. Solder joints under stress, could be anyone's guess (more likely to happen with a P4 retail heatsink and its high clamping forces). In ten years, you can expect several PSU failures, and any one of those PSU failures could damage the motherboard. If you have a lot of lightning storms, or bad quality power, that could influence how long the mobo lasts. Look carefully at any modem, cable modem, ADSL wires etc, to see if there are any protection devices to take a (nearby) lightning hit, before it gets to the motherboard. For example, on a phone line, there may be a carbon block at the entry point, and you could enhance that by using a second protection device nearer the computer. For the really paranoid, a wireless network would reduce the wiring exposure to just the power lines. A real ($1K purchase price) UPS would reduce the risk of an AC power event from getting you, and would help protect the PSU from getting damaged. Cheap UPSes offer no protection at all, as they are actually SPS (standby power supplies) - they are a "straight wire" to power spikes, and the unit only cuts over to batteries if the AC power dies for enough milliseconds. On the motherboard itself, the Vcore circuit is the circuit under the most stress. If the MOSFETs are cool to the touch, that is a good sign. I've never read any MTBF estimates for switching regulators on motherboards, so don't know whether they are good for a 1 million hour MTBF or not. Large BGA packages also have a rating, for solder joint reliability. For example, a BGA with 750 pins, will last for about 10 years, with a certain daily temperature variation. From the Via web page: * 552-pin BGA VT8366A North Bridge * 376-pin BGA VT8233 South Bridge so you have little risk of a failure there (caps will fail first). Handling the processor a lot (removal, regrease, reposition heatsink) will cut into the life expectancy, if say the processor gets cracked, and it happens to overload the Vcore circuit. If the processor has the rubber bumpers on the top of the chip, that will cut that risk a bit. I would say your biggest exposure, is to external factors. Paul |
#12
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We still don't build as if the transistor exists.
Principles are well proven in telephone switching facilities. A massive improvement can be install in homes for about $1 per protected appliance. Effective protection is just not that expensive. But unfortunately, some spend many times more money for far less effective (plug-in) solutions. They purchase protectors that can even contribute to damage of an adjacent computer. Then rumors such as 'too slow' persist. Concepts requires comprehension of some basic principles. Fundamental to surge protection is why a Ben Franklin lightning rod works. Too many assume based upon what they see - that a lightning rod is protection. Wrong. The protection is and is defined by the quality of earth ground. That is the art - earthing. An art only because it is not intuitively obvious. Protectors are only as effective as the protection connected to. Protector and protection are two different components of a surge protection 'system'. Protection is earth ground. Sometimes earthing installed standard in most buildings (sufficient for human safety) is not sufficient for transistor safety. Human safety is mostly concerned with wire 'resistance'. Transistor safety is mostly concerned with wire impedance. Sometimes the earthing systems must be enhanced to also provide transistor protection. Even ineffective protectors operate plenty fast - as did the slower GDTs decades previous that operated so effectively. Problems understanding effective protection even causes one to confuse a wall receptacle safety ground (also called equipment ground) with something located elsewhere and completely different - earth ground. Why are they different? Wire has impedance. These concepts are introduced in a previous discussion entitled "Is it safe to use computer during lightning/thunder storm?" in the newsgroup sci.electronics.basics on 22 Sept 2004 at http://tinyurl.com/5fu8n Further details from same author (including figures from industry professionals) are in two posts that precede this above post. Protection is so easily installed and is so effective that damage is considered a human failure. One additional point. Destructive surges occur typically once every eight years. Five years with no damage proves little. Protection is only as effective as its earth ground which is why earthing is so important in telco buildings that must operate without interruption during every thunderstorm. notritenoteri wrote: THe reason they don't operate fast enough is not really the problem it is the fact that most of them don't. I think your comment about building grounding is misleading. At least in this country buildings are well enough grounded to be safe in most circumstances. In building design it is possible to reach a very high level of lightening and surge protection. the issue is one of cost mostly. PC are cheap relatively. My experience (5 years as telecom guy in a building with about 1000 networked pcs) suggest lightening or surges are very minor problems. From what I know of lightening protection engineering it is an art form to some degree. Sometimes the engineers get it right, sometimes despite the best of designs the stuff blows. As I said its the data thats important. BTW as I said $250 Can will buy you an 800 watt output battery inverter pack to run your Ipod or laptop on your "camping trip". That gets you one that plugs into the wall (110-120 here) and outputs to 2 sockets for a total of 800 watts AC on the other side. That's it said my piece |
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#14
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w_tom,
I read your referenced thread with great interest. The principles were clearly explained but some of the stuff about different types of surges was over my head (I'm a physician whose use and knowledge of electricity is pretty much limited to dc defibrillators). At my newly constructed home, I employed an electrician whose business is limited to surge protection to provide and install the whole-house suppressor. He put in an Eaton/Cutler Hammer CHSP Ultra that comes with a $100,000 warranty. He says he's never in his career seen a claim against Cutler Hammer for damage occurring in spite of this unit. I have faith in this electrician and his recommendations, but the whole-house suppressor was MUCH smaller than what I expected from my minuscule knowledge of electricity. Here's my question: This unit is mounted on the side of the circuit-breaker box, so where is it's connection to ground? It is very clearly within ten feet of the external earthing rod, but does it connect to this through the inside of the breaker box? Can you give me a brief explanation, of how this thing is wired to protect all the circuits in the house? Also, in one of your posts, you mentioned that phones and cable do not require separate protection because they have built-in surge suppression, and, yet, my guy installed a companion module (on the whole-house suppressor) for cable (not phone) connections. Is that superfluous? Thanks for all the time you take to provide us with these explanations. They're great. On Fri, 14 Jan 2005 02:38:02 -0500, w_tom wrote: We still don't build as if the transistor exists. Principles are well proven in telephone switching facilities. A massive improvement can be install in homes for about $1 per protected appliance. Effective protection is just not that expensive. But unfortunately, some spend many times more money for far less effective (plug-in) solutions. They purchase protectors that can even contribute to damage of an adjacent computer. Then rumors such as 'too slow' persist. Concepts requires comprehension of some basic principles. Fundamental to surge protection is why a Ben Franklin lightning rod works. Too many assume based upon what they see - that a lightning rod is protection. Wrong. The protection is and is defined by the quality of earth ground. That is the art - earthing. An art only because it is not intuitively obvious. Protectors are only as effective as the protection connected to. Protector and protection are two different components of a surge protection 'system'. Protection is earth ground. Sometimes earthing installed standard in most buildings (sufficient for human safety) is not sufficient for transistor safety. Human safety is mostly concerned with wire 'resistance'. Transistor safety is mostly concerned with wire impedance. Sometimes the earthing systems must be enhanced to also provide transistor protection. Even ineffective protectors operate plenty fast - as did the slower GDTs decades previous that operated so effectively. Problems understanding effective protection even causes one to confuse a wall receptacle safety ground (also called equipment ground) with something located elsewhere and completely different - earth ground. Why are they different? Wire has impedance. These concepts are introduced in a previous discussion entitled "Is it safe to use computer during lightning/thunder storm?" in the newsgroup sci.electronics.basics on 22 Sept 2004 at http://tinyurl.com/5fu8n Further details from same author (including figures from industry professionals) are in two posts that precede this above post. Protection is so easily installed and is so effective that damage is considered a human failure. One additional point. Destructive surges occur typically once every eight years. Five years with no damage proves little. Protection is only as effective as its earth ground which is why earthing is so important in telco buildings that must operate without interruption during every thunderstorm. notritenoteri wrote: THe reason they don't operate fast enough is not really the problem it is the fact that most of them don't. I think your comment about building grounding is misleading. At least in this country buildings are well enough grounded to be safe in most circumstances. In building design it is possible to reach a very high level of lightening and surge protection. the issue is one of cost mostly. PC are cheap relatively. My experience (5 years as telecom guy in a building with about 1000 networked pcs) suggest lightening or surges are very minor problems. From what I know of lightening protection engineering it is an art form to some degree. Sometimes the engineers get it right, sometimes despite the best of designs the stuff blows. As I said its the data thats important. BTW as I said $250 Can will buy you an 800 watt output battery inverter pack to run your Ipod or laptop on your "camping trip". That gets you one that plugs into the wall (110-120 here) and outputs to 2 sockets for a total of 800 watts AC on the other side. That's it said my piece Ron |
#15
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You're right 5 years with no damage doesn't prove anything but it does point
to the fact that the cost to take extraordinary precautions to protect against rare events is probably not worth it. On the other hand spending money on the best possible lightening protection for a radio antenna tower may be worthwhile. Your claim that protection is easily installed is somewhat misleading. The facts are "it depends" "w_tom" wrote in message ... We still don't build as if the transistor exists. Principles are well proven in telephone switching facilities. A massive improvement can be install in homes for about $1 per protected appliance. Effective protection is just not that expensive. But unfortunately, some spend many times more money for far less effective (plug-in) solutions. They purchase protectors that can even contribute to damage of an adjacent computer. Then rumors such as 'too slow' persist. Concepts requires comprehension of some basic principles. Fundamental to surge protection is why a Ben Franklin lightning rod works. Too many assume based upon what they see - that a lightning rod is protection. Wrong. The protection is and is defined by the quality of earth ground. That is the art - earthing. An art only because it is not intuitively obvious. Protectors are only as effective as the protection connected to. Protector and protection are two different components of a surge protection 'system'. Protection is earth ground. Sometimes earthing installed standard in most buildings (sufficient for human safety) is not sufficient for transistor safety. Human safety is mostly concerned with wire 'resistance'. Transistor safety is mostly concerned with wire impedance. Sometimes the earthing systems must be enhanced to also provide transistor protection. Even ineffective protectors operate plenty fast - as did the slower GDTs decades previous that operated so effectively. Problems understanding effective protection even causes one to confuse a wall receptacle safety ground (also called equipment ground) with something located elsewhere and completely different - earth ground. Why are they different? Wire has impedance. These concepts are introduced in a previous discussion entitled "Is it safe to use computer during lightning/thunder storm?" in the newsgroup sci.electronics.basics on 22 Sept 2004 at http://tinyurl.com/5fu8n Further details from same author (including figures from industry professionals) are in two posts that precede this above post. Protection is so easily installed and is so effective that damage is considered a human failure. One additional point. Destructive surges occur typically once every eight years. Five years with no damage proves little. Protection is only as effective as its earth ground which is why earthing is so important in telco buildings that must operate without interruption during every thunderstorm. notritenoteri wrote: THe reason they don't operate fast enough is not really the problem it is the fact that most of them don't. I think your comment about building grounding is misleading. At least in this country buildings are well enough grounded to be safe in most circumstances. In building design it is possible to reach a very high level of lightening and surge protection. the issue is one of cost mostly. PC are cheap relatively. My experience (5 years as telecom guy in a building with about 1000 networked pcs) suggest lightening or surges are very minor problems. From what I know of lightening protection engineering it is an art form to some degree. Sometimes the engineers get it right, sometimes despite the best of designs the stuff blows. As I said its the data thats important. BTW as I said $250 Can will buy you an 800 watt output battery inverter pack to run your Ipod or laptop on your "camping trip". That gets you one that plugs into the wall (110-120 here) and outputs to 2 sockets for a total of 800 watts AC on the other side. That's it said my piece |
#16
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notritenoteri wrote:
You're right 5 years with no damage doesn't prove anything but it does point to the fact that the cost to take extraordinary precautions to protect against rare events is probably not worth it. On the other hand spending money on the best possible lightening protection for a radio antenna tower may be worthwhile. Your claim that protection is easily installed is somewhat misleading. The facts are "it depends" And "easily installed" doesn't matter much to people like me. I live in a rental apartment and I have to deal as best I can with the existing wiring. Screwing around with the wiring is not an option for me. I - and many others like me - have to do the best I can with surge suppressors and UPSes. "w_tom" wrote in message ... We still don't build as if the transistor exists. Principles are well proven in telephone switching facilities. A massive improvement can be install in homes for about $1 per protected appliance. Effective protection is just not that expensive. But unfortunately, some spend many times more money for far less effective (plug-in) solutions. They purchase protectors that can even contribute to damage of an adjacent computer. Then rumors such as 'too slow' persist. Concepts requires comprehension of some basic principles. Fundamental to surge protection is why a Ben Franklin lightning rod works. Too many assume based upon what they see - that a lightning rod is protection. Wrong. The protection is and is defined by the quality of earth ground. That is the art - earthing. An art only because it is not intuitively obvious. Protectors are only as effective as the protection connected to. Protector and protection are two different components of a surge protection 'system'. Protection is earth ground. Sometimes earthing installed standard in most buildings (sufficient for human safety) is not sufficient for transistor safety. Human safety is mostly concerned with wire 'resistance'. Transistor safety is mostly concerned with wire impedance. Sometimes the earthing systems must be enhanced to also provide transistor protection. Even ineffective protectors operate plenty fast - as did the slower GDTs decades previous that operated so effectively. Problems understanding effective protection even causes one to confuse a wall receptacle safety ground (also called equipment ground) with something located elsewhere and completely different - earth ground. Why are they different? Wire has impedance. These concepts are introduced in a previous discussion entitled "Is it safe to use computer during lightning/thunder storm?" in the newsgroup sci.electronics.basics on 22 Sept 2004 at http://tinyurl.com/5fu8n Further details from same author (including figures from industry professionals) are in two posts that precede this above post. Protection is so easily installed and is so effective that damage is considered a human failure. One additional point. Destructive surges occur typically once every eight years. Five years with no damage proves little. Protection is only as effective as its earth ground which is why earthing is so important in telco buildings that must operate without interruption during every thunderstorm. notritenoteri wrote: THe reason they don't operate fast enough is not really the problem it is the fact that most of them don't. I think your comment about building grounding is misleading. At least in this country buildings are well enough grounded to be safe in most circumstances. In building design it is possible to reach a very high level of lightening and surge protection. the issue is one of cost mostly. PC are cheap relatively. My experience (5 years as telecom guy in a building with about 1000 networked pcs) suggest lightening or surges are very minor problems. From what I know of lightening protection engineering it is an art form to some degree. Sometimes the engineers get it right, sometimes despite the best of designs the stuff blows. As I said its the data thats important. BTW as I said $250 Can will buy you an 800 watt output battery inverter pack to run your Ipod or laptop on your "camping trip". That gets you one that plugs into the wall (110-120 here) and outputs to 2 sockets for a total of 800 watts AC on the other side. That's it said my piece |
#17
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What you describe as describe as "all SPSes include at least
as much separate surge protection on the mains supply line as a decent standalone surge protector would provide;" is really near zero protection for numerous reasons. Both the plug-in UPS and power strip protector have the same protector circuit. And both are typically so grossly undersized to be ineffective. Always start with the numbers. In this case joules. In another post and in those previously cited posts are examples of how joules define protection. Notice that so many plug-in protectors AND their plug-in UPS counterparts may be rated at 345 joules. As joules increase, the life expectancy of that protector increases exponentially. IOW if the plug-in protector is good for two same size surges, then the 1000 joule 'whole house' protector is good for something on the order of 300 of those same size surges. Then it continues farther. The plug-in protector has no earth ground. Therefore the manufacturer avoids the entire topic altogether. This is how one identified ineffective (and grossly overpriced - yes grossly overpriced) plug-in protectors. 1) No dedicated wire connection to earth ground AND 2) manufacturer avoids all discussion about earthing. Further details will be provided in response to Milleron. But the plug-in protectors are on the order of 10 and 50 times more expensive per protected appliance. So yes, what you are calling cheap protectors are really overpriced and expensive protectors that also are not effective. BTW, UPSes switch in milliseconds. (One must be careful to buy power supplies with numerical specs that read: Hold up time, full load: 16ms. typical). Surges do their damage and are done in microseconds. 300 consecutive surges could pass through a UPS before the UPS even considered switching to battery power. Plug-in UPSes have one function - data protection. They do not provide the hardware protection so often implied. You want a UPS that also provides hardware protection? That is typically the building wide UPS that also makes this all so important 'less than 10 foot' connection to earth ground. Plug-in UPSes are for data protection; not for hardware protection. "Peter R. Fletcher" wrote: On Sun, 09 Jan 2005 19:50:06 -0500, (Paul) wrote: ...... wiring exposure to just the power lines. A real ($1K purchase price) UPS would reduce the risk of an AC power event from getting you, and would help protect the PSU from getting damaged. Cheap UPSes offer no protection at all, as they are actually SPS (standby power supplies) - they are a "straight wire" to power spikes, and the unit only cuts over to batteries if the AC power dies for enough milliseconds. I think that you are being unduly negative about cheap "UPSes". You are absolutely correct that they are not true UPSes, since: a) they normally connect the mains power (effectively) straight through to the controlled devices, thus offering no _intrinsic_ protection from spikes; and b) they have to switch to inverter mode when the power fails, which takes finite time. However: a) almost all SPSes include at least as much separate surge protection on the mains supply line as a decent standalone surge protector would provide; and b) All except the cheapest, no-name, ones switch fast enough so that a normal computer system power supply does not "notice" the transient power loss (though network switches, hubs, and the like may "glitch"). For most home and SOHO users, an SPS will provide cost-effective protection against most of the data loss problems which might otherwise be caused by brownouts and/or power outages, while their built in (but unrelated) surge protection circuitry is a _lot_ better than nothing as insurance against damage from power line spikes. Please respond to the Newsgroup, so that others may benefit from the exchange. Peter R. Fletcher |
#18
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Plug in protectors claim to protect from one type of surge.
Do some punching. As one arm swings out, the other withdrawals. That 1-2 punching is an example of a surge that typically does not do damage. Now instead punch with both left and right arms simultaneously. That is the common mode surge that typically damages electronics. Lightning seeks earth ground. It comes down any and all 'arms', passes through punching bag, and exits out other side of punching bag. The plug-in protector does not stop, block, or absorb such destructive surges. IOW it does not sit between surge and the electronics - even though they hope you will assume that. And effective protector connects earlier where wires enter the building so that the 'surge down all wires simultaneously' all find the same earth ground. Lightning in 1752 found earth ground destructively via a church steeple. Franklin simply gave lightning a better path to earth. Lightning is the 'all arms moving forward at the same time" type of surge. You don't stop, block, or filter what miles of sky could not even stop. You 'shunt' lightning to earth ground. That is also what the 'whole house' protector does. It provides lightning with a short path to earth ground. You are surprised how small the Cutler Hammer unit is. It need not be large because it does not stop, block, or absorb the energy. Wire is also not massive because it too carry massive electrical energy and does not try to stop or block it. A surge protector is nothing more than a wire. A wire that conducts only during the rare and short transient. It can be small because the transient is only in microseconds. In a parallel example, try to push a common nail into wood. You cannot. It takes the force of a backhoe to drive that nail. However, we hit that nail with only a 20 oz hammer. Does the human arm have same energy as the backhoe? Of course not. People often confuse energy with power. The hammer has low energy but high power. Lightning has low energy but high power. The protector need not be monstrous because 1) it does not stop or absorb the energy, and 2) the energy is not as massive as urban myths portray. Too many only 'feel' that a lightning strike is high energy. The electrical circuit is best demonstrated by an NIST figure used in an example from: http://www.epri-peac.com/tutorials/sol01tut.html They demonstrate why a fax machine was damaged. Notice that the phone line was not 'earthed' less than 10 feet to the same single point ground as AC electric. Telephone line protector is inside the box labeled NID. The 'whole house' protector is located where 'Arrestor' is labeled. Notice that the destructive surge goes through Arrestor, then to earth ground. Since it need not pass through fax machine to get earth ground, then an AC electric surge does not damage fax machine. All electronic appliances contain effective protection. Anything that is going to work on the end of a power cord (those grossly overpriced plug-in protectors) is already inside electronics - as even required by industry standards. But we worry that internal electronics protection might be overwhelmed. So we install a 'whole house' protector on every incoming utility wire - to same earth ground. Demonstrated in various posts is the AC electric 'whole house' protector (such as the Cutler Hammer), the telco provided protector, and a ground block for cable wire (no protector required). All are only as effective as that earth ground. Now about earthing. Engineered discussed this in two discussions in the newsgroup misc.rural entitled: Storm and Lightning damage in the country 28 Jul 2002 Lightning Nightmares!! 10 Aug 2002 http://tinyurl.com/ghgv and http://tinyurl.com/ghgm Depending on the problem with transients, the earth ground may need be enhanced. Important is the neighborhood history. Also important is the geology. Does the ground tend to attract more CG lightning? For example, mid-west storms may be spectacular, but most of the lightning remains sky to sky. WV is a region with high numbers of CG (cloud to ground) strikes per thunderstorm. Those discussions also mention equipotential which is why Ufer grounds and halo grounds make the protector even more effective. Also is earth conductive or is it sand. I believe that previous discussion also tells a story of a house struck multiple times - and lightning rods did not work. Why? Lightning rods were earthed poorly in non-conductive sand. Bottom line - a surge protector is only as effective as its earth ground. In most locations, a single ground rod may provide massive increase in protection. A house that does not at least meet post 1990 National Electrical Code earthing requirements does not have the necessary earth ground. Also in that misc.rural discussion would be how wire must be routed. For example, no sharp bends and no splices. A ground wire bundled with other wires may only induce more surges on that other wire (which is but another reason why plug-in protectors have no effective earth ground). There is much to read. Come back with questions. The simple earthing of surges is surprisingly not intuitively obvious. In discussing this, I was amazed how many don't even know what a Ben Franklin air terminal (lightning rod) does - AND yet would recommend surge protectors. Many even argue pointed verse blunt lighting rods - when earth ground defines the effectiveness of that rod. A surge protector is only as effective as its earth ground. Milleron wrote: tom, I read your referenced thread with great interest. The principles were clearly explained but some of the stuff about different types of surges was over my head (I'm a physician whose use and knowledge of electricity is pretty much limited to dc defibrillators). At my newly constructed home, I employed an electrician whose business is limited to surge protection to provide and install the whole-house suppressor. He put in an Eaton/Cutler Hammer CHSP Ultra that comes with a $100,000 warranty. He says he's never in his career seen a claim against Cutler Hammer for damage occurring in spite of this unit. I have faith in this electrician and his recommendations, but the whole-house suppressor was MUCH smaller than what I expected from my minuscule knowledge of electricity. Here's my question: This unit is mounted on the side of the circuit-breaker box, so where is it's connection to ground? It is very clearly within ten feet of the external earthing rod, but does it connect to this through the inside of the breaker box? Can you give me a brief explanation, of how this thing is wired to protect all the circuits in the house? Also, in one of your posts, you mentioned that phones and cable do not require separate protection because they have built-in surge suppression, and, yet, my guy installed a companion module (on the whole-house suppressor) for cable (not phone) connections. Is that superfluous? Thanks for all the time you take to provide us with these explanations. They're great. |
#19
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Effective protection costs so little. For example, go to
Home Depot or Radio Shack from something called a grounding block for incoming cable TV line. It costs less than $2 retail. Connect this grounding block less than 10 feet using 12 AWG or heavier wire. Now the CATV line is fully surge protected. Yes, the cable line requires no surge protector. A surge protector is nothing more than a temporary connection to earth ground. BUT the ground block has already made that protection connection using a 12 AWG wire. Where is the big cost? Unfortunately we still don't build new homes for transistor safety. So effective protection often must be installed as an after thought. Sometimes, this means the incoming cable - improperly installed - must be moved. Now we are talking big bucks; and only because humans were the reasons for failure. I recently had this discussion with some cable installer who keep saying, "Is that what they were saying", or "That's right. They said something about that". Every incoming wire must connect to single point earth ground. That connection is either via a protector or hard wire. The telephone company even installs a 'whole house' protector .... for free. But again, it is only as effective as the earth ground provided by the home builder. I don't see where all this expense is. Many waste big bucks on plug in protectors that (quietly) don't even claim to provide effective protection. The missing information is that damning. IOW those expensive protectors also are ineffective solutions. The less expensive 'whole house' protector connected 'less than 10 feet' to protection is the less expensive and more effective solution. Which wire is most often struck? Wire highest on telephone pole. AC electric. This is a direct strike to the computer inside the house IF effective 'whole house' protectors do not connect to that all so essential single point earth ground. "It depends" is a discussion about the human who did or did not install effective protection - and what it takes to correct that mistake. There is no reason for any electronics to be damaged by surges. And some locations make protection far more essential. The need for earthed protection varies even with geology AND can vary significantly even within the same town. notritenoteri wrote: You're right 5 years with no damage doesn't prove anything but it does point to the fact that the cost to take extraordinary precautions to protect against rare events is probably not worth it. On the other hand spending money on the best possible lightening protection for a radio antenna tower may be worthwhile. Your claim that protection is easily installed is somewhat misleading. The facts are "it depends" |
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Equipment can be replaced data mostly can't . Any problem that can be fixed
by the application of money is not a problem, at most an inconvenience. Data is not one of those. Lost data is a problem. "Rob Stow" wrote in message news:AqUFd.78839$6l.50962@pd7tw2no... notritenoteri wrote: You're right 5 years with no damage doesn't prove anything but it does point to the fact that the cost to take extraordinary precautions to protect against rare events is probably not worth it. On the other hand spending money on the best possible lightening protection for a radio antenna tower may be worthwhile. Your claim that protection is easily installed is somewhat misleading. The facts are "it depends" And "easily installed" doesn't matter much to people like me. I live in a rental apartment and I have to deal as best I can with the existing wiring. Screwing around with the wiring is not an option for me. I - and many others like me - have to do the best I can with surge suppressors and UPSes. "w_tom" wrote in message ... We still don't build as if the transistor exists. Principles are well proven in telephone switching facilities. A massive improvement can be install in homes for about $1 per protected appliance. Effective protection is just not that expensive. But unfortunately, some spend many times more money for far less effective (plug-in) solutions. They purchase protectors that can even contribute to damage of an adjacent computer. Then rumors such as 'too slow' persist. Concepts requires comprehension of some basic principles. Fundamental to surge protection is why a Ben Franklin lightning rod works. Too many assume based upon what they see - that a lightning rod is protection. Wrong. The protection is and is defined by the quality of earth ground. That is the art - earthing. An art only because it is not intuitively obvious. Protectors are only as effective as the protection connected to. Protector and protection are two different components of a surge protection 'system'. Protection is earth ground. Sometimes earthing installed standard in most buildings (sufficient for human safety) is not sufficient for transistor safety. Human safety is mostly concerned with wire 'resistance'. Transistor safety is mostly concerned with wire impedance. Sometimes the earthing systems must be enhanced to also provide transistor protection. Even ineffective protectors operate plenty fast - as did the slower GDTs decades previous that operated so effectively. Problems understanding effective protection even causes one to confuse a wall receptacle safety ground (also called equipment ground) with something located elsewhere and completely different - earth ground. Why are they different? Wire has impedance. These concepts are introduced in a previous discussion entitled "Is it safe to use computer during lightning/thunder storm?" in the newsgroup sci.electronics.basics on 22 Sept 2004 at http://tinyurl.com/5fu8n Further details from same author (including figures from industry professionals) are in two posts that precede this above post. Protection is so easily installed and is so effective that damage is considered a human failure. One additional point. Destructive surges occur typically once every eight years. Five years with no damage proves little. Protection is only as effective as its earth ground which is why earthing is so important in telco buildings that must operate without interruption during every thunderstorm. notritenoteri wrote: THe reason they don't operate fast enough is not really the problem it is the fact that most of them don't. I think your comment about building grounding is misleading. At least in this country buildings are well enough grounded to be safe in most circumstances. In building design it is possible to reach a very high level of lightening and surge protection. the issue is one of cost mostly. PC are cheap relatively. My experience (5 years as telecom guy in a building with about 1000 networked pcs) suggest lightening or surges are very minor problems. From what I know of lightening protection engineering it is an art form to some degree. Sometimes the engineers get it right, sometimes despite the best of designs the stuff blows. As I said its the data thats important. BTW as I said $250 Can will buy you an 800 watt output battery inverter pack to run your Ipod or laptop on your "camping trip". That gets you one that plugs into the wall (110-120 here) and outputs to 2 sockets for a total of 800 watts AC on the other side. That's it said my piece |
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