[Elecraft] Lightning in New Mexico

[Don Wilhelm]

  Dave,

I believe you would get the opposite answer from a qualified electrician 
or your county inspector.  Maybe one with the proper credentials will 
answer on this list.

73,
Don W3FPR

On 3/29/2011 12:20 PM, Dave, W8OV wrote:
> These posts on lightning protection served to get me considering my
> shack, etc.  I had solar panels installed last summer, and on the side
> of the house opposite the electrical entrance panel the installers ran a
> wire from the PV panels, inverters, etc., down to a ground rod they put
> in.  So I asked them yesterday if there was any bonding of that rod to
> the ground on the entrance panel side of the house.  The response was
> "They are not bonded.  That ground rod is not a system ground and does
> not need to be bonded to the existing grounding system.  It is purely
> for lightning protection."
>
> --Dave, W8OV
>
> On 3/29/2011 8:23 AM, Don Wilhelm wrote:
>>     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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