[TowerTalk] Hazards of low soil conductivity

[Richard (Rick) Karlquist]

On 1/9/2022 12:28 PM, David Gilbert wrote:
> 
> 
> That sounds like an urban legend.  A Google search for "Congo fatal 
> static charge" comes up with not a single reference.  The physics of the 
> 
> 73,
> Dave   AB7E
> 

I don't know about this specific thing being an urban legend, but what 
is not an urban legend is a phenomenon known as "stray voltage" having
to do with ground currents on farms producing voltage gradients in the 
ground that shock animals with their hooves touching the ground. 
Perhaps the worst risk for this is dairy cows connected to milking machines.

My QTH has three different electric service connections, which are truly 
different, being connected to different pole pig transformers, not just 
having separate meters.  The property also used to have several 
agricultural wells (separate from the domestic well for the houses), 
that ran on their own 480V 3 phase service.  Interestingly, this service 
was installed on a former "milk barn".  The property used to be a dairy 
farm!  We used to have have two houses on different electric feeds that 
had common galvanized pipe plumbing.  This was very problematical with 
respect to the use of cold water pipes as electrical grounds.

The grounds for these independent systems are subject to considerable 
voltage differences and will draw considerable current if you try to 
connect them together.  Note that for this purpose, "ground" and 
"neutral" are the same circuit.  I have been very careful to never make 
any connections between the respective islands of electricity, 
especially the ground wires.  Everything is protected by GFCI breakers 
as well, just in case.

The electric utility has a rule against having multiple electric 
services on the same property, but didn't follow their own rules in the 
past as this property was developed.  At this time, it is what it is.

Incidentally, my ground is the opposite of the Congo, being 100% clay, 
highly electrically conductive.

Rick N6RK