On Oct 18, 6:18 am, TimR wrote:
That's a common misconception, based on the average 30,000 amp
estimate of a lightning strike and trying to figure wire size.
But it's not a steady state current. It's a sharply dampled sinusoid,
and #10 wire is more than adequate for any expected strike.

TimR has accurately defined why so little wire can conduct such
massive surges. Electrical Engineering Times has two articles
entitled "Protecting Electrical Devices from Lightning Transients" at:
http://www.planetanalog.com/showArti...leID=201807127
http://www.planetanalog.com/showArti...leID=201807830

This discussion is based in engineering principles and with
numbers. Notice how much current is carried by an 18 gauge wire? If
I remember, 61,000 amps. Wires used for AC power would have maybe
four times that capacity.

BTW, also notice everything defined for surge protection. Notice
the article never discusses plug-in protectors or a UPS. This
professional engineering trade rag is not selling hype and myth. Both
articles discuss the only thing required for surge protection -
earthing and connections to earthing.

What is a protector? A connecting device to earth ground. It must
*divert* a surge to earth. But earth ground defines that protection.
This engineer author discusses wire size to conduct lightning to
earth, how wires must be routed, why that connection must be so short,
AND of course the most important part of surge protection - the earth
ground electrode. Protection of electronics is defined by the most
critical component in any surge protection system - earth ground.
This engineering article on lightning protection discusses what most
important component? Earthing.