[amsat-bb] Re: Static Discharge Protection - location

[Franklin Antonio]

At 07:35 PM 9/13/2008, Alan wrote:
>I support there could be a potential between the service panel ground and
>the ground for my mast, but, I've never bothered to check this.

Yep.

The potential difference between these two grounds will arise when 
the lightning strike occurs.  Lightning provides high current, so 
even tho the resistance of the earth may be small, there could be a 
substantial voltage drop between the two grounds during the 
strike.  Perhaps several hundred volts.

That's why grounding for lightning protection should TRY to all go to 
one point.  At least you can say that one point will be at one 
potential.  Beyond that you can't say much.