[TowerTalk] Ground System

Jim Brown jim at audiosystemsgroup.com
Thu Aug 16 22:38:34 EDT 2007


On Thu, 16 Aug 2007 20:38:51 -0500, Gary Schafer wrote:

>A great deal of lightning energy is
>connected to earth by capacitance in any ground system. Yes a DC (bare wire)
>connection would be better and help more with the low frequency energy
>coupling.

You might want to do some calcs (on the capacitive reactance of a big radial 
system) before you say that a DC ground is BETTER. Having a DC connection in 
addition to the capacitive coupling IS better, and is, in fact, required by 
most building codes and common sense. But it is in parallel with the 
capacitance, and most electrode grounds have a lot more resistance to "earth" 
that you might think. Indeed, the inductance of the earth connection dominates 
the impedance at a surprisingly low frequency. 

73,

Jim Brown K9YC






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