That's a different situation, of course, but certainly very true. I bet
lots of people have multiple grounds connected to their homes, and most
don't realize they do or the potential effect of it. I've seen internet
providers stake their own ground because the egress for their equipment
was too distant from the utility service entrance. Then you get TVs and
computers connected to different ground potentials in the case of nearby
lightning hits.
73,
Dave AB7E
On 1/9/2022 4:26 PM, Richard (Rick) Karlquist wrote:
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
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