>From: Theresa Roth <theresaroth@xxxxxxxxxxxx> >Reply-To: muglo@xxxxxxxxxxxxx >To: MUGLO <muglo@xxxxxxxxxxxxx> >Subject: [muglo] Re: Storm Protection >Date: Sun, 13 Jun 2004 14:06:18 -0400 > > > Eric D wrote: > > > >> >You could also install lightning protection at the entry point to your > >> >house. It'll cost a bit more than a properly protected UPS but will >protect > >> all the electrical equipment in your house (and, if your insurance >doesn't > >> cover lightning damage, you might have to replace a TV, fridge, etc. in > >> addition to your computer in the event of a strike). > >Please tell me more about that. >Theresa <http://www.google.com/search?q=install+lightning+protection+at+the+entry+point+to+a+building&ie=UTF-8&oe=UTF-8> From one site: "Mains and Power Supply Protection Just because your radio and antenna are miles away from a lightning strike does not mean that you are protected. Lightning often strikes power lines and produces a large voltage surge or spike that can be transmitted for miles on the main power lines. Therefore, for maximum protection, all power line interfaces should include a transient voltage surge protector. These devices are becoming quite common and inexpensive. Again, there are simple protectors and those that may include additional protection with built-in line inductors. Just make sure that the surge protector is placed between the power lines and the equipment power supply." From another (I'm finding this interesting reading ;) <http://www.backwoodshome.com/articles/carlson37.html>: "These power surges, or transients (so called because they are short and powerful), can be handled by using a couple of strategies. The first is to use a surge protector on all of the electrical appliances in the house. Many commercial models are available at Radio Shack, building supply stores, and other electrical or computer supply houses. These detect surges and react in a very short time, usually from micro- (1/1,000,000) to nano- (1/1,000,000,000) seconds. You must manually reset the protector each time it is tripped. Costs range from $10 to $100 for five outlets on the strip. More electrically handy people put dual transorbs and metal oxide varistors (MOVs) between the power lines and the point of entry to the house. Note: Don?t attempt this yourself, unless you really know what you?re doing; otherwise, call in a professional. Transorbs are components that carry current after a certain voltage is exceeded. This is called the trip voltage. The transorb keeps the voltage between the two lines at a set voltage and won?t allow it to go any higher. This prevents your appliances from being damaged by the application of too great a voltage at their inputs. Transorbs can absorb a lot of current but turn on more slowly than MOVs. They are rated in the number of kilovolts that they can handle. Never use a smaller-rated unit than 1.5 kV. The 5kV units are good all around choices to maximize protection and minimize cost. Most power grids, or power distribution systems, have voltage variations of 10% - 20%. This means that a 110V grid can vary between 88V and 132V, so rate the trip voltage for the transorbs at least 30% above the nominal, or rated normal voltage, for your grid. Make sure that you use the type of transorbs for AC (alternating current) lines. MOVs react very quickly to surges but have the tendency to allow the voltage between power lines to get further apart. In other words, they don?t clamp well if the inputs vary slowly. Their operational characteristics specify the normal voltage applied to them. As with transorbs, specify the operational voltage at least 30% over the nominal grid voltage. MOVs and transorbs are placed between individual power lines. And it?s worth saying again: Don?t attempt this if you are unsure or unfamiliar with electricity. Remember always put SAFETY FIRST." _________________________________________________________________ MSN Toolbar provides one-click access to Hotmail from any Web page ? FREE download! http://toolbar.msn.click-url.com/go/onm00200413ave/direct/01/ _________________________________________________ For information concerning the MUGLO List just click on http://muglo.on.ca/Pages/joinus.html Don't forget to periodically check our web site at: http://muglo.on.ca/