[W2CRA] Grounding Follow-Up

[Bill Powell]

Folks,

It just so happens that QST has a very good article on grounding beginning on P 37 of the current issue.

Some comments:
 - Yes, the wire sizes he quotes are "real", even if unaffordable.  He is specifying what the various codes and standards require - BUT - something is always better than nothing.  Just don't pinch pennies where you shouldn't.

As I mentioned at the meeting and as the article states, there are two main objectives in lightning grounding:
1) Shunt the stroke to ground,
2) Equalize the potential difference
Objective 1 REQUIRES short, multiple, FAT conductors to shunt as much of the strike to ground as possible.  DON'T scrimp here!  A ground ring of #2 or multiple #4 or #6 BARE copper spreads the current around the base to the multiple ground rods.  We want the reactance of the conductors between the tower and earth ground to be as low as we can afford it to be.
An entrance protector (PolyPhaser) will provide additional shunt at the entrance point, which should also be effectively grounded.

Objective 2 is centered on bonding everything in the shack to a single point ground, nominally the entrance panel.  Please note that, if occupied, the term "everything" should also include the operator and whatever he/she is holding onto.
Since other people's lives are involved, I'm taking the extra step in the new RACES room to install conductive flooring which will be connected to the room entrance / SPG with a 1' wide, 2' long copper sheet.  The SPG is, in turn, connected to the room and building halo with the mandated #4 copper wire.

My advice:  Read the article.
Stroll thru your shack, out the yard, around the tower if you have one, and by your antenna entrance point.  Pretend you are a lightning strike.  Where you gonna go?  
What is the easiest path to ground?  What can you do to make that path happen outside your shack?
Will that path handle 100,000 A long enough or will you be simply creating an improved Acme fuse and wire tester?

Bill - WB1GOT