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