[R-390] Grounds

[Dave or Debbie Metz]

Following this thread, I have a further question.  It is my 
understanding that all ground rods per the NEC need to be connected so 
that a danger situation does not develop.  The specific example is the 
ground rod (term used VERY loosely) that the cable company drives 
outside your house at the entry point on one side of the house and your 
ground rod at the opposite side of the house where the electric panel is 
situated is not connected but that indiscretion is a major danger in 
lightning protection.  As near as I can recall, the NEC requires ALL 
ground rods to be connected to maintain no possible potential 
difference. The danger as I understand is that the cable entrance has a 
ground, your TV is grounded to the "other" ground via the house wiring. 
  So,.... my question is: if we have additional grounds for our 
equipment, are we safer or more in danger if we do not connect them to 
the service entrance ground. Perhaps this is beyond the scope of this 
reflector but it seems like we have some engineers lurking in the 
background and I would really appreciate the science of this anomaly 
when talking about grounds to the entire group.

73's
Dave
Kj4JX



rbethman wrote:
> I'd suggest that you NOT have a lightning arrestor between the roof and 
> the ground braid.
> 
> The metal roof will, at the top of the second story, tend to be a 
> lightning attractant.  Gounds for use to dissipate lightning strikes 
> SHOULD have any necessary bends be a SMOOTH radius.
> 
> Standard electrical ground rods are indeed at LEAST 8 feet long, steel 
> cored copper, brand named originally COPPERWELD.  The strrel core is to 
> allow driving the rod into soils that aren't always easy to drive into - 
> like the clay and shale here in Virginia.
> 
> Minimum of four ground rods, preferably ALL bonded together below the 
> surface of the soil with at least 1/4" copper conductor.
> 
> In a power plant or substation we ALWAYS used a "grid" of 500 MCM bare 
> copper between all grounds.
> 
> This will provide a Great counterpoise AND a very good ground for the 
> home itself.
> 
> Bob - N0DGN
>> I'm not in that position at the moment, thank goodness, but I'd think
>> that the more copper straps or braids you could put down to ground rods,
>> the better. All of them loop-and-bend-free, of course, to keep the
>> inductance as low as possible.
>>
>> Do please let us know what your results are, as you continue in this
>> investigation. 
>>
>>   
> 
> 
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