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Marty[_2_] Marty[_2_] is offline
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First recorded activity by BoatBanter: Nov 2007
Posts: 713
Default Lightning Protection questions

Richard Casady wrote:


Sounds like BS. My house barn and corn crib all had half inch or so
braided copper cable connecting 1/2 inch pointed rods. The ground rods
are presumed to be the standard ones the electrical places all sell.
They were struck hundreds of times, they were on top of a hill.

I heard it was 20 000 amps, at a million volts.



Guess I should have included a tongue and a cheek,,,

However my point was rather that lightening is inherently unpredictable.
Our barn is "protected" the same as yours, still has the cool glass
globes at the base of the pointed rods, what the hell they are supposed
to do I don't know. As far as I know it's never been hit. I've seen a
neighbor's lightening system vaporized, fortunately it was raining hard
enough, and his roof was leaky enough that damage was limited to a some
singed hay and a couple of scorched boards.

I've been involved with ground protection systems for airports,
(counterpoises in the trade) and seen some absolutely whacky things,
like edge lighting halogen bulbs blown up, even though the feeder was
buried three feet below a 4 gauge bare copper ground wire just a few
inches below ground..... I've seen constant current power supplies that
feed the lighting fried but the lighting fixtures and transformers
remain unharmed.... lighting is funny stuff..

Cheers
Martin