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From: fuller@mcnc.UUCP (Bill Fuller)
Newsgroups: net.dcom
Subject: Re: lightning, PACXs and computers
Message-ID: <646@mcnc.mcnc.UUCP>
Date: Fri, 26-Jul-85 09:41:25 EDT
Article-I.D.: mcnc.646
Posted: Fri Jul 26 09:41:25 1985
Date-Received: Sun, 28-Jul-85 07:40:14 EDT
References: <1397@islenet.UUCP>
Reply-To: fuller@mcnc.UUCP (Bill Fuller)
Distribution: net
Organization: Microelectronics Center of NC; RTP, NC
Lines: 23

This was certainly one of the most devastating lightning strikes I've 
heard of, and I was wondering if you could perhaps fill us in on a few
details that weren't mentioned in your note.  In particular I wonder
if your communications lines are above or below ground?  What about 
your power lines?  Are they above or below ground? Secondly, do your 
communications lines have any type lightning or surge protection?  
Were any of the affected lines shielded?  Do you have surge protection
on your power lines?  

We are in a lightning prone area, and I have been attempting to
understand the intricacies of lightning protection recently.  I
confess that the more I hear the more confused I get.  I have
concentrated on power protection, but your problems seem to have resulted
from a communications line hit.  I wouldn't have thought that such a
hit would spread to so many machines, unless you had a tremendous
earth current transient that affected buried lines in a wide area,
or were unlucky enough to get a hit on some central distribution
point.  Am I wrong in this evaluation?  Is there some other way such
a strike could get into a widespread communications network?  How
does one go about protecting such a network from lightning?

			Bill Fuller
			{decvax,akgua}!mcnc!fuller