[Elecraft] Lightning in New Mexico

[george fritkin]

Let's introduce some facts.  Lightning strikes can carry from 10K to over 50K amps.  That will vaporize #12 wire instantly.  Typical ham installations do not have adequate protection and in fact it is not affordable for the average ham.  When you are in the mist of a storm disconnect everything....I mean unplug and pray that nature spares your antenna.  Storms that are in the proximity may induce high voltage spikes on the power grid so it is hard to evaluate potential damage.
As I said unplug.  Switches, power strips, discharge tubes, are patch solutions.  For safety sake unplug!!
George, W6GF




--- On Tue, 3/29/11, Don Wilhelm <w3fpr at embarqmail.com> wrote:

From: Don Wilhelm <w3fpr at embarqmail.com>
Subject: Re: [Elecraft] Lightning in New Mexico
To: "Phil Townsend" <philji at mac.com>
Cc: "Elecraft Reflector" 
Date: Tuesday, March 29, 2011, 6:23 AM

  Phil,

Despite disconnecting your antennas, you still have to consider that the 
coax shields enter the house.

Yes, ground rod #2 (and #3 and all others) are to be bonded to the AC 
Electrical Entry ground rod.

I am not sure why that is counterintuitive to you.  Yes, there is a very 
real possibility that a lightning surge will be induced in the house 
wiring with or without the connection between the grounds.  But if there 
is a lightning surge on either the antennas or the house wiring, you 
want to keep both at the same potential.

Keeping everything at the same potential during a lightning surge event 
is what the bonding is all about.

A lightning surge traveling through the earth can create a very large 
difference in potential between ground rods that are not connected 
together, and that potential difference can cause fires and damage.  The 
soil has more resistance than a wire between the ground rods.

Look at the 2010 (or 2011) ARRL Handbook chapter on Safety - the fact 
that ALL ground rods should be connected together is clearly stated.

One other point on disconnecting your antennas - consider what happens 
when you re-connect them.  The PL-259 center conductor is connected 
first, and then the shell is attached.  If there is a charge on the coax 
center conductor, you can zap your equipment by the simple act of 
re-connecting it.  Short the center conductor to the grounded shell 
before connecting it to your equipment.  It is better to disconnect the 
antennas with a switch in the coax line and provide a DC path to ground 
across the common coax connector at that switch.

73,
Don W3FPR

On 3/29/2011 1:12 AM, Phil Townsend wrote:
> I have beat into the dirt another 8' foot ground rod(G.R. #2) next to the outside coax switch
> and have installed a Poly Phasor on the output coax that goes into the shack and poly phasors on each of the coax cables from the antennas.
> All the poly phasor's ground lugs are connected to ground rod #2. (Each Poly phasor has its own wire going to ground rod #2)
>
> This remote coax switch and ground rod #2 are about 12 feet from the AC mains.
>
> If I understand correctly, I should also bond this ground rod #2 to the the AC mains ground rod as well????
>
> But if I do that then those antennas will be connected to the grounds in the house via the AC mains ground rod?????
> This seems counterintuitive? I mean... now there will be the very real possibility of lightning in the house wiring???
>
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