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| Aerial+LNB
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Aerials Bargains
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rod Leads
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 When an electrical storm is imminent it is essential to disconnect all cables from telephone sockets and TV aerial sockets. It's also advisable to disconnect all plugs from mains 230v sockets and to disconnect LNB feeds. In addition, move leads away from the sockets because lightning can jump huge gaps! Lightning struck the TV aerial mast of a house not far from here (in a valley!) It blew the aerial mast off the wall, travelled down the coaxial cable into a linen cupboard and arced across from the TV aerial socket into the mains power socket ten centimetres below. (In doing so, it set fire to sheets in the cupboard). It travelled down the mains and aerial cables, blowing sockets off the walls and dislodging several ceiling lights before reaching the garage and damaging the electronic circuitry of the boiler. It also killed the TV, DVD player and audio Hi-Fi unit. Curiously, the satellite dish on the roof was undamaged and the satellite receiver was also undamaged. As you can see from the photo, they were very lucky that the curtain didn't go up in flames. Keep curtains and furnishings away from sockets and wiring. You can reduce the risk of damage by looping external cables down to the ground, then up to enter the house. Lightning goes for the easiest path to ground, so much of the charge will go to earth at the loop, thus minimising the power that enters the house. There will still be damage but it will be less than would occur if the full power of the strike entered the house. You might further reduce the damage by running your aerial or satellite cable through an earthing bar at the bottom of the loop (or before it enters the house if you can't provide a ground loop). The earthing bar is connected by a stout cable* to an earthing rod, which is buried in the ground. This provides an easier path to ground, making it less likely that a large amount of energy will enter the house. Whatever you use is likely to vaporize very quickly in a strike! However, that doesn't matter if the distance is short (and it must be) because the ionised air will continue to carry the current for the microseconds duration of the lightning strike. Obviously, it doesn't have to be insulated (but insulation will protect it from the effects of bad weather). You could use multistrand copper cable but anything thick enough will be very expensive and available only in long lengths. Here are some suggestions: Protect it from corrosion by applying a thick coat or two of outdoor paint. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
