Surge protection, lightning, grounding, modems
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From: w_tom <firstname.lastname@example.org> Subject: Re: WinModems Date: Wed, 29 Jan 2003 14:51:54 -0500 References: <email@example.com>
<firstname.lastname@example.org> As demonstrated by high school science, one must understand both theory and experimental evidence to have knowledge. Have you built surge protectors, seen them work or fail, and learned the underlying theory? I have even repaired modems by replacing components on the PC board - to learn how surges damage modems. I learned the circuit paths used by surges through modems by replacing the defective parts. Your friend used surge protectors and still lost modems. Of course. Was the surge protector at the service entrance and connected short to central earth ground? If not, then the surge protector many even have contributed to his modem damage. Just because it is called a surge protector does not mean it provides surge protection. That assumption is called junk science.
It is called 'whole house' surge protection. Principles were proven long before either you or I existed. A surge protector is only as effective as its earth ground - as even Ben Franklin demonstrated in 1752. To appreciate why surge protectors work successfully, one must understand the difference between impedance and resistance, AND must understand why that concept is appropriate to surge protection. These are 1st year EE concepts. Cited previously is a discussion in newsgroup misc.rural. Nothing technically advanced. But if simple concepts are not understood, then the reader does not have sufficient knowledge to know even what a surge protector does. Demonstrated is why plug-in surge protectors are not effective (safety ground wire does or doesn't exist) and why a surge protector must connect less than 10 foot to central earth ground. A tech support person should be familiar with why surge damage happens. Figure from an industry professional shows how effective surge protection is installed - the essential single point ground for each structure. Destructive surges can even enter on underground wires. Notice no plug-in surge protectors: http://www.erico.com/erico_public/pdf/fep/TechNotes/Tncr002.pdf A benchmark in surge protection is Polyphaser. Tech support should know that name. Polyphaser's application notes are considered legendary by industry professionals. What do they discuss? Earthing, because surge protection is about earthing a surge - not about surge protectors: http://www.polyphaser.com/ppc_technical.asp http://www.telebyteusa.com/primer/ch6.htm > Section 6.4: > Conceptually, lightning protection devices are switches to > ground. Once a threatening surge is detected, a lightning > protection device grounds the incoming signal connection point > of the equipment being protected. Thus, redirecting the > threatening surge on a path-of-least resistance (impedance) > to ground where it is absorbed. http://www.ipclp.com/html/aud_ho_faq.html > A properly installed lightning protection system intercepts > the lightning bolt between cloud and earth and harmlessly > conducts it to ground without damage. > Yes, in addition to the lightning protection system consisting > of air terminals, conductor cables, clamps, fasteners, 10 foot > grounds, etc., a secondary lightning suppressor is installed > on your electric service entrance panel to prevent current > fluctuations (called lightning surges) during a thunderstorm.
That secondary lightning suppressor is the 'whole house' surge protector. Does the surge enter on phone line, destroy a modem, then stop? Of course not. Surges are electricity. No surge damage occurs if a complete circuit does not exist. An incoming and outgoing path must exist through that modem to have surge damage. One does not have a clue how a surge damaged something until one first defines both that incoming (from cloud) and outgoing (to earth) circuit path. This was defined in the above cited discussions you were expected to read in misc.rural. Industry professionals learn underlying principles which is why both internal and external modems are exposed to same surge damage. Again, you don't have the real world experience. You have heard about 15 symptoms. But did you follow the complete circuit - incoming and outgoing through the building? Did you replace damaged components to make the modem work? Does you experience also demonstrate that destructive surges occur typically once every eight years? Did you first learn from IEEE papers that demonstrate that outlet safety ground wire, if used for surge protection, would induce surges on all other household wires? Read that sentence again. That ground wire bundled with other household wires would induce surges throughout the building if a surge was using that safety ground wire. Again, another reason why a surge protector to earth ground wire must be less than 10 feet - and other essential fundamentals defined in those misc.rural newsgroup discussions. Those posts in misc.rural were not read which explains so little knowledge about surge damage. Those who have both learned theory and have extensive experience know why 'whole house' surge protectors with a short connection to earth ground are critical. Don't response yet. First learn how much there is to know about surge protection AND how ineffective plug-in UPSes and surge protectors really are. You have many hours of reading in those two discussion in misc.rural. Many industry sources cited. The importance of this sentence will then be important: a surge protector is only as effective as its earth ground. Kirk Strauser wrote: > At 2003-01-29T03:32:52Z, w_tom <email@example.com> writes: > >> This poster demonstrates a lack of real world experience. > > By this, you mean "you"? > > Look, I'm not making this stuff up. As I said earlier, I've personally > talked to 15-20 people whose computers were burnt to a crisp via lightning > into an internal modem. I'm certain that not every single one of them lived > in old houses with ancient wiring. A good friend, for instance, lived in a > 10-year-old home, used surge protectors, and still lost hardware. > > I'm sure that you know something about the subject, but I've seen this > happen first-hand, and I'm not particularly interested in someone telling me > that it's either impossible or extremely unlikely. > > To re-iterate, when I worked in tech support, it was well-accepted that a > thunderstorm *would* result in one or two callers who were online during the > storm, and now can't boot their computers. Guaranteed, every time.
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