Surge / Ground / Lightning
in [Home Built PC]
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From: krw on 4 May 2008 22:53 In article <d4a62a8a-464b-461f-a297-b6bc581749c3 @l64g2000hse.googlegroups.com>, w_tom1(a)usa.net says... > On May 4, 9:57 pm, bud-- <remove.budn...(a)isp.com> wrote: > > Bud has provided 2 sources that directly contradict Phil. (Of course > > they are not as smart as Phil.) > > > > Phil has provided no sources to support Phil's Phantasy Physics. > > Every Bud citations contradicts Bud's claims. Don't be so stupid. > So Bud must do what > those without knowledge do - post insults. Anything truthful posted about you would be an insult to a normal person. > Bud claims his plug-in protectors provide complete protection. Bullshit. Either you're a goddamned liar or are denser than a concrete slab. He's repeatedly said there is *no* protection from a direct strike (except to be elsewhere). > Good. Bud can post those manufacture spec numbers that list each type > of surge and protection from that surge. Oh. 400 requests and Bud > still cannot provide any specs? So Bud must post insults. Ok, that answers it. You *are* a liar. > How to identify the liar - who does exactly what Rush Limbaugh > does? He posts no facts (no manufacturer spec numbers) and his posts > are only insults. Bud posts only insults. That says Bud lies (and > that he has not technical facts). But then profits are at risk. That > justifies anything. There goes W, doing what he claims others do; not only stupid, but a liar and hypocrite, to boot. -- Keith
From: w_tom on 4 May 2008 21:51 On May 4, 11:13 am, Tony Hwang <drago...(a)shaw.ca> wrote: > Prpbably wannabee ham came from CB crowd when Morse code > requirement was dropped. Technology cannot be challenged? So you attack the messenger? Rush Limbaugh would be proud. Same mockery also proved Saddam had WMDs. At what point do you learn from professional citations - ask questions about the science? Ham radio operators who actually know enough about electricity to understand surge protection also define protection in terms of earthing. How many QST articles did you ignore therefore not understand what Phil, et al post? Another ham who learned: Bill Otten in rec.radio.shortwave on 5 Aug 2005 entitled "grounding and surge": http://tinyurl.com/79xoa and http://home1.gte.net/res0958z/ Another station engineer who also says surge damage is avoidable - but then, unlike Tony Hwang, he did his job; learned from his experience: http://www.harvardrepeater.org/news/lightning.html > Well I assert, from personal and broadcast experience spanning > 30 years, that you can design a system that will handle *direct > lightning strikes* on a routine basis. It takes some planning and > careful layout, but it's not hard, nor is it overly expensive. At > WXIA-TV, my other job, we take direct lightning strikes nearly > every time there's a thunderstorm. Our downtime from such > strikes is almost non-existant. The last time we went down from a > strike, it was due to a strike on the power company's lines > knocking *them* out, ... > Since my disasterous strike, I've been campaigning vigorously > to educate amateurs that you *can* avoid damage from direct > strikes. The belief that there's no protection from direct strike > damage is *myth*. ... > The keys to effective lightning protection are surprisingly simple, > and surprisingly less than obvious. Of course you *must* have > a single point ground system that eliminates all ground loops. > And you must present a low *impedance* path for the energy to > go. That's most generally a low *inductance* path rather than just > a low ohm DC path. You claim to be a responsible station engineer. But you had a lightning strike that created building damage and communication equipment damage. No decent broadcasting engineer would have considered that acceptable. Only one who did not even learn from QST magazine would post foolishly blame Ufer grounds for making damage. Yes an Ufer ground can result in damage when installed by a layman who failed to learn the science. Rather than learn, Tony Hwang declares failure as acceptable. Why are Ufer ground used? Because Ufer grounding provided protection from direct strikes even to munitions storage lockers - without damage. How curious. Ufer ground work great where Tony Hwang is not in charge. Since Tony's facility was not properly constructed or properly maintained, then Tony considers damage acceptable. Failure is acceptable. Educated station managers know lightning damage need not ever cause damage. When damage does happen, then responsible station managers find and eliminate the mistake. Tony Hwang knows otherwise; damage is acceptable - that nothing can protect from lightning. So Tony Hwang posts mockery and insults - and no technical facts. How curious. Tony's peers learn from the damage, then eliminated it.
From: phil-news-nospam on 4 May 2008 14:55 In alt.engineering.electrical w_tom <w_tom1(a)usa.net> wrote: | Bud claims plug-in protectors provide a complete protection system - | can protect from all types of surges. A plug-in protector only | protects from surges that rarely damage appliances. As demonstrated | repeatedly in other posts, plug-in protectors have even earthed a | typically destructive type of surge through adjacent appliances. A | problem alleviated by earthing a 'whole house' protector. I don't agree with that assessment of the plug-in protector. If the appliance has its own MOVs to protect stuff, then this would be true. Not all do. Some appliances are more sensitive than others. It just depends on what kind of surge is arriving, and where from. If it is differential mode on the power wires, the plug-in protector can do some important protection. Even with whole house protection in place, you can have some energy get past it, and the surge can be induced into the building wiring. Usually the induced surge is common mode, which by itself is less of a problem. But if the appliance is connected to more than one wiring, such as a computer with modem, then induced surges can be more of a problem because of the difference between the wiring. If the plug-in surge protector has them all attached at one point, that should serve to equalize the voltage in most cases enough to avoid damage. | So that plug-in protectors do not compromise protection inside all | appliances, the typically destructive surge must be earthed BEFORE | entering a building. That solution is used everywhere professionals | install protection. Everywhere. Bud also denies this. The entrance protection, which works a lot better if earthed, is very important for the big surges arriving on the service wiring. Being earthed, it will sink most of the low frequency energy. That leaves a partial surge that can still propogate beyond that point, as well as induced surges which the entrance protection didn't even get a shot at. | If a destructive type surge is properly earthed, then one can spend | money on plug-in protectors to also protect from a typically non- | destructive surge. This is called "complete protection". However | better facilities make that whole house' protector even more effective | by enhancing earth ground. Where is money better spent? There is certainly a best "complete protection". I agreed that when Bud focuses on one type of protection and calls it effective, he is merely toying with the word "effective". It is better than nothing. It can even reduce the number of damaging incidents a lot. But it is not "complete effectiveness". But neither is "whole house" protection. What one needs for the best is "everywhere protection". | If not using a 'whole house' protector, well, even 'scary pictures' | created by typically undersized protectors now creates a hazard. There are tradeoffs. Bud is focusing on the low frequency energy and seems to think that is all there us because a lot of documents focus on it because more energy is in the low frequencies. Also, surges that come from a greater distance have the higher frequencies reduced. | Bud disputes this. Bud says if all wires connect to the same | protector, then surge energy somehow disappears. Obviously not true. | That surge energy must be dissipated harmlessly into earth. Just | another reason why plug-in protectors create problems when a 'whole | house' protector and (more important) proper earthing is not | installed. It depends. The surge consisting of primarly low frequency energy (under 1 MHz) gets distributed around more evenly. The advantage is that leaves less voltage differences between various wires. This is an advantage to devices connected to more than one wire, like a TV with cable. Without it, the surge arriving in common mode on power (the plug-in suppressor won't stop that) will go through the TV and on to the cable, generally zapping the tuner front end stage. But if the cable is connected in parallel to the plug-in protector, then the cable and power are at about the same voltage. The risk of damage is much less that way. This applies to low frequency energy, which is the more common. OTOH, if high frequency energy is coming in, such as a direct strike on the mast of the power service drop, with shorter branch circuit wires in the house, then the high frequency energy can cross over from the power to the cable and zap the front end stage just from the fast rising wavefront. It's a give and take. Adding the plug-in surge protector connected to all wires reduces certain surge effects, and increases others. The advantage is gained when what you decrease is more common than what you increase. Bud either does not understand the high frequency energy or just does not believe it can happen. All lightning strikes have it. It does get attenuated quickly on wiring that has inductance. When the surge is in common mode, as it will be in the wiring from most direct strikes, the inductance on the wire is substantial, and the high frequencies will be attenuated quickly. But, once _part_ of that energy is diverted to ground on _one_ of the wires (e.g. the neutral that is grounded), then _part_ of the surge is now differential (or transverse) mode, and that part can propogate high frequency energy further on wire _pairs_. One important way to protect against high frequency energy is to have inductive blockage. That's practical to do on power lines. It can be done on phone, but it has to be reduced if DSL is being used. There are special DSL-specific telephone surge protectors that have low pass filters to the service and high pass filters to ground with a cutoff frequency above the DSL level. Othewise they can do the cutoff way lower just above the voice level. | Others claim a plug-in protector will stop or magically absorb | surges. Obviously no protector stops lightning. Obviously (from so | many professional citations) lightning damage is routinely eliminated | by diverting typically destructive surges to earth ground "where it | will do no harm". Actually, it is possible to make an absorption-type protector. It is not a trivial thing, and you would never want to do so inside a house. I have built one. It consisted of a zig-zag phone wire running through a large 8 inch PVC pipe filled with steel wool. At one end going to the building, was a lot of inductance (the phone wire wrapped through half a dozen large ferrite cores). The whole thing was buried in the ground. It took a hit a few months later and was destroyed. The phone wire was burned up. The steel wool was gone. The pipe was shattered. The computer the phone line was connected to was undamaged. Oh, it did have some diversion, as well. A pair of #12 copper wires was run along inside the pipe, running into ground several feet on each end. Those wires survived the event. | Yes, plug-in protectors do have limited protective functions. But | the discussion is about the type of surge that typically does surge | damage ? that finds earth ground destructively through appliances. | Any protector located too close to appliances and too far from single | point ground cannot protect from that type of surge. So Bud invents | this magic plug-in protector that somehow makes surge energy disappear | and that, by itself, is a complete protection system. There are lot of different types of surges that cause damage. There is no one protection that can defeat them all. | Bud pretends that typically destructive surges don?t seek earth | ground. Even plug-in protectors need that properly earthed 'whole | house' protector so that plug-in protectors do not contribute to | adjacent appliance damage. Only then can a plug-in protector do what | it is designed to do - protect from a type of surge that typically | does not cause damage. He is partially right. The common mode does "seek ground" in the sense that the big difference is there. The differential mode is just propogating where it can (and it can go further). Both can consist of low (more often, and more energy) frequency and high frequency. Connect two TVs to an antenna. Connect the chassis of ONE of them to ground. The one with the ground connection will be more often damaged alone. But there are also times when the other one can be damaged alone. Often both will be damaged. It depends on things like whether the surge in the wire is induced or direct. It depends on if you have additional lightning arrestors on that wire (which can even change common mode to differential mode and change which TV will be damaged). The two of you are arguing entirely different aspects of surge issues that has some degree of overlap. And it seems both of you have an incomplete understanding of all the possible issues (or at least have only expressed point regarding said subsets). There is no simple answer to surge protection. There are some good practices. -- |WARNING: Due to extreme spam, I no longer see any articles originating from | | Google Groups. If you want your postings to be seen by more readers | | you will need to find a different place to post on Usenet. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |
From: phil-news-nospam on 4 May 2008 14:57 In alt.engineering.electrical Timothy Daniels <SpamBucket(a)nospamplease.biz> wrote: | As always, "w_tom" ignores that the high voltages that short out | "3 miles of sky" will short out the underground power lines which | enter my building and buildings all over America. Anything able to | leap "3 miles of sky" will leap the fraction of an inch between the | power lines and the earthed metal conduit. What is left will be a | much lower voltage spike that can be handled by the average | "plug-in protector". It does not always make the 2nd leap to ground. There is not always a metal conduit available. I've seen such strikes. -- |WARNING: Due to extreme spam, I no longer see any articles originating from | | Google Groups. If you want your postings to be seen by more readers | | you will need to find a different place to post on Usenet. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |
From: phil-news-nospam on 4 May 2008 15:06
In alt.engineering.electrical Michael A. Terrell <mike.terrell(a)earthlink.net> wrote: | | Tony Hwang wrote: |> |> Hmmm, |> Prpbably wannabee ham came from CB crowd when Morse code requirement was |> dropped. | | | Who knows? Wherever he came from, I don't see him on this computer. | All I know is that I finally kill filed him on this computer after I got | tired of reading his 'twilight zone' electrical & electronics babble. I | am a former radio & TV broadcast engineer, and if I followed his or Google for Michael A. Terrell's past posts and you will see he is more of a person with social problems that prefers to find ways to attack people at a personal level, rather that make his "disputes" with the specific points being presented. I don't cave in to such attacks and he apparently eventually realized that and figured that if he didn't read my posts at all, he would not be tempted to make more personal attacks. What he can't know is what would happen if he followed _any_ advice given on the net. Since he didn't, there was no such test. He is merely speculating. And he didn't seem to fully grasp all that was said, since his responses were sometimes in reference to things not actually said. Whether he misread what was said in those instances, or lacked the understanding needed, I do not know. -- |WARNING: Due to extreme spam, I no longer see any articles originating from | | Google Groups. If you want your postings to be seen by more readers | | you will need to find a different place to post on Usenet. | | Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) | |