Quote:
Originally Posted by DonnaNi4os
About a year ago my neighbor’s ac was struck by lightning, knocking out the electric items in the garage. Surprisingly the house next door was unaffected by a surge. Another person in our neighborhood had her fountain struck and it damaged the front of her house. Surprisingly it did not hit the highest point of either home. That is baffling to me as I always thought that lightning hit the tallest things. As far as I can see, only one neighbor has a lightning rod installed but there are many flag poles which I would imagine attract lightning. Hmmm
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In reading about this topic when it came up last year, I came across a description of LPS design that used the concept of a rolling ball. The idea is that lightning doesn't come from the clouds directly to the ground in one arc, instead it makes several jumps of about 50m until it reaches ground.
At some point it will have reached close to the ground. From there, it will "look" for the easiest path to the ground that is 50m-100m away. If the top of the flagpole is closer than the fountain then it will go to the fountain. If the tree in the front yard is closer than the peak of the house then it will go to the tree. It doesn't go to the tallest thing around, it goes to the tallest thing within 50m to 100m.
Rather than thinking of flagpoles and lightning rods as things that attract lightning, think of them as the highest points within 50m. One flagpole in front of the house will not protect the back of the house. One lightning rod on the roof will not protect the entire roof. That's why an LPS system will have several rods on the peaks of a house.