Grounding - was: Thicknet/10base5 Test Segment: The Cable is In!

[Chuck Guzis]

If anyone's wondering, here's a 1975 Bell System treatise on grounding
and protection.   Note that carbon-block protection was standard practice:

http://bellsystempractices.org/500-/518-/518-010-105-i02_1975-09-01.pdf

Note also, that the standard practice dictated that grounding at the
dmarc should be tied to the power system ground, but that the grounding
not use the power system ground (i.e. independent connection).

Note also, if equipment frame/chassis grounds varied, bonding to a
common ground e was recommended.

This has loosened up quite a bit since the old days.  On my home, built
in 1980, the network interface box is tied to the old demarc box ground,
which ran out to the pad-mounted transformer in the side yard.  When the
local utility moved the transformer pad to the front yard, they simply
disconnected the telco ground and didn't tell anyone.

When a tree in the side yard became uprooted during an ice storm a
couple of years ago, it pulled up the old telco ground cable.   I took
out a service ticket for the incident and was told not to bother.  When
I asked why, I was told that buried subscriber lines are no longer
required to be grounded.   They didn't seem to be too perturbed about
it, so I just coiled the cable up and buried it when I filled in the
hole left by the tree.

But yes, I remember the old Bell System 232 hookups--DB-25 connectors
with phenolic backshells.  I think I've still got a couple of those in
my junkbox.

--Chuck