[TCML] comments on designing a lightning protection system

[David Speck]

Adam,

I think that what is in the photo is actually correct practice.  Any 
large metal components in the structure get bonded to the lightning 
system ground path.  I don't believe that the railing is the only path 
to ground.  There must be direct paths to ground somewhere else. 

When the lightning guys installed the protection system at my house, 
even my garage door rails got bonded to the ground system, as well as 
the I-beam in the center of the basement, even though it's 40+ feet 
below the roof line, and sitting in the cement block walls at both 
ends.  They explained that in the event of a a nearby lightning strike, 
isolated metal pieces can develop high potentials at their ends by 
induction, which can cause arcs to other things, like people, so these 
big pieces get bonded to ground as well. 

Dave
> Here's what a "professional" did on my last project. This is not a gag photo. The lightning rod was really tied directly to a handrail.
>
> http://www.hot-streamer.com/adam/temp/IMG_0385.JPG
>
> Of course if you're holding onto this handrail, proper grounding wouldn't really matter much.
>
> Adam
>