[TowerTalk] What is a single point ground (again)

[Michael Tope]

I don't know if it would provide anything more than psychological 
comfort, but for a second floor installation you could run all the 
cables to an SPG at ground level and then run them through a metal 
conduit to the second floor and bring them out a second SPG panel that 
was bonded just to the conduit.

73, Mike W4EF............


On 8/5/2010 8:14 PM, Gary Schafer wrote:
> Hi Pete,
>
> Yes you have it right. It of course is not the ideal setup but sometimes we
> can not do any better. Polyphaser makes such a box. I can't remember the
> designation but it is basically an extension cord with an outlet box on one
> end. It has power protection devices in it and it is designed to mount on
> the SPG panel. As I remember it has gas tubes in it. I assume that you have
> all other lines bonded to the SPG panel.
>
> Being on the second floor has its problem with getting the SPG panel
> grounded to the ground  system because of the distance to earth. You will
> have a rather high impedance in the ground lead from the panel because of
> its length.
>
> It may be better to place the SPG panel at ground level and then run the
> lines up to the second floor after they enter the house. But then you have
> the problem of the possibility of induced currents, from nearby strikes,
> into the portion of the lines between the SPG panel and the equipment. But
> you can obtain a much better connection to earth with the panel mounted near
> ground level.
>
> Either way you at least have ALL lines, including power, referenced to one
> point this way with near zero impedance/resistance between all at that
> point.
>
> 73
> Gary  K4FMX
>
>    
>> -----Original Message-----
>> From: Pete Smith [mailto:n4zr at contesting.com]
>> Sent: Thursday, August 05, 2010 6:29 AM
>> To: garyschafer at comcast.net
>> Cc: TowerTalk at contesting.com
>> Subject: Re: [TowerTalk] What is a single point ground (again)
>>
>> Gary, are you saying that I can achieve the SPG objective in my second
>> floor shack simply by running a short 3-wire extension cord conductor
>> from a wall outlet, through a protective device on the SPG, and then
>> powering all the shack equipment (which is already bonded to the SPG)
>> from outlets off that line?  Other well-known and respected people, in
>> response to the same question, have said that you must bring the power
>> from the breaker panel, up a dedicated line to the SPG, and thence to
>> the equipment.  Obviously, your solution would be far easier, but is it
>> code?
>>
>> What sort of protective device is needed at the SPG for this power
>> circuit, whichever way it is wired?
>>
>> 73, Pete N4ZR
>>
>> The World Contest Station Database, updated daily at
>> www.conteststations.com
>> The Reverse Beacon Network at http://reversebeacon.net, blog at
>> reversebeacon.blogspot.com,
>> spots at telnet.reversebeacon.net, port 7000
>>
>>
>> On 8/4/2010 11:32 PM, Gary Schafer wrote:
>>      
>>> If the utility power is more than a few feet away from the SPG panel,
>>>        
>> the
>>      
>>> most practical way to maintain a single point ground system is to  run a
>>> power line over to the SPG panel and put a protection device for that
>>>        
>> power
>>      
>>> line directly on the SPG panel, bonded to the SPG panel, and then power
>>>        
>> the
>>      
>>> equipment only from that power line, after it has gone thru the SPG
>>> protector.
>>>
>>>        
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