[RFI] DirecTV to ground or not to ground

Jim Brown jim at audiosystemsgroup.com
Fri Dec 26 02:50:24 EST 2008


On Fri, 26 Dec 2008 01:21:24 -0500, Roger (K8RI) wrote:

>Although it's usually phrased this way, it's pretty much impossible to 
>have an entire building rise to the same potential at the same times due 
>to the dV/dT (rise and fall) for lightning strikes, BUT is it possible 
>with proper, single point grounding AND the proper routing of all wiring 
>going into any particular area in a building to have voltage rises that 
>are "close enough" within all of the rooms.

Exactly right. All of those interconnections have inductance and resistance, 
lightning will be closer to one point in the building than others. In 
addition, there's voltage and current magnetically induced in that 
interconnect. The key point is that the bussing specified by NEC applies 
good engineering practice to minimize those effects. 

73,

Jim Brown K9YC




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