On Friday, May 20, 2016 at 11:13:56 AM UTC-5, wrote:
On Fri, 20 May 2016 10:48:10 -0600, bud-- wrote:

A surge expert at the NIST has written "the impedance of the grounding
system to `true earth' is far less important than the integrity of the
bonding of the various parts of the grounding system."


That was our experience. In places with very long data lines, we
actually bonded the cases of the machines together with a large wire
that was significantly shorter than the signal wire. You can use
ferrite beads to essentially "lengthen" the signal wire but we also
looped up some extra data cable through the ferrite. That stopped the
problem of losing POS terminals in pool bars every time it rained.

"Ground" is a misnomer anyway. We have documented several volts
difference between the electrode systems of buildings that were less
than 100' apart. That causes it's own problems. You also have the
problem that in why distribution, the PoCo is using earth as a
parallel return path to that little neutral wire they have in the
distribution system. There is a significant amount of current in those
8ga wires you see going down the pole from a transformer. There is no
rod at the end of that wire. it is just tacked to the bottom of the
pole before they set it.
There is almost 3 amps on this one. (on the single phase distribution
line)
http://gfretwell.com/electrical/First%20xfmr.jpg

This one is where the 3 phases of the distribution split out. (less
than an amp)
http://gfretwell.com/electrical/dist...20braodway.jpg

When I worked as an electrician out in The Marshall Islands for a construction company building the mission control center for The SDI test program, we drove ground rods 10 feet apart around the building, bonded them together and to a ground grid under the raised computer floor where there were ground rods driven through holes in the slab under the raised flooring. It was what The Army Corps of Engineers wanted. It was a giant ground plane/grid that all the electronics including the Cray supercomputer and peripherals were grounded to. That was in the late 1980's. There is no telling WTF is out there now. Part of the replacement for The Space Fence is or is being built out there now. ^_^

[8~{} Uncle Space Monster