Surface area counts ten for lightning protection. Down conductor braid , copper pipe or strap 2-3" wide has the most conductivity. Coiling Coax in a 3" diameter at the base of the tower and placing a separate ground strap on the coax before the coil to strip off the lightning currents will off some degree of protection. For ideas and knowledge visit http://www.protectiongroup.com/Home
Art, KC6UQH
-----Original Message----- From: amsat-bb-bounces@amsat.org [mailto:amsat-bb-bounces@amsat.org] On Behalf Of K5OE Sent: Wednesday, October 16, 2013 11:45 PM To: amsat-bb@amsat.org Subject: [amsat-bb] Re: Lightning protection
K9STH wrote:
Sorry, but NFPA NEC (National Electrical Code) definitely requires that
ALL
grounding electrodes MUST be connected together! There are VERY good
reasons
for doing this...
Yeah, this is a requirement that has vexed designers of complex electrical systems for years. One solution, generally meeting this requirement, is to go ahead an utilize separate ground rods and tie the rods together with a (large) grounding cable--usually pvc insulated cable for corrosion protection. In industrial installations these connections are often made so they can be disconnected in the event of differential currents flowing and causing problems with communication/signal systems.
Much like K8BL's recommendations, I too have used #10 AWG for the ground from the rotor/mast to the ground rod, and hoped and prayed the lightning liked it (if ever needed). This is especially important for a non-earthed installation like a tripod on a roof. I have been fortunate to never having to find out...
73, Jerry, M0GOE _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb