Hi Attila, if I remember correctly, the issue is that the "ground" at the house is not a "real" ground when the earth is frozen, as the resistance of frozen earth goes up substantially over non-frozen earth. So it's like not having grounded the wires at all. This is a real issue for cables brought to the house (cable TV, telephone, etc etc) as those cables are grounded somewhere else on the other side, and thus there may be 1000's or even 10000's Volts between the two "grounds", even (or especially) for just a proximity strike. As mentioned by someone else, all bets are off anyway's for direct hits, not much will survive a direct hit. It's been a long time since I designed cable TV receivers, but the specs are here, and I think there are some explanations in there somewhere: _http://www.nordig.org/specifications.htm_ (http://www.nordig.org/specifications.htm) bye, Said In a message dated 4/12/2012 09:54:40 Pacific Daylight Time, att...@kinali.ch writes:
Hmm? That sounds interesting. In switzerland, and AFAIK in most european countries, power feeds have to be grounded at the entry of the house (ie the neutral conductor is grounded). This should protect the electrical equipment from such ground jumps as you discribe. Or do i miss something? Attila Kinali _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.