Good point, Don.
The ground potential, voltage on the ground wire, for the power company
may have risen during the strike because it (and your station ground
that was tied to the power company ground) was discharging the transient
from the strike. Lightning arrestors or surge suppressors on those
systems limited the voltage difference between power lines, feedlines,
and associated ground. Meanwhile, potential on the cable and phone
systems, not referenced to that same ground, didn't rise and a large
voltage difference developed between those systems and the power system
they connect to at appliances like the TV, phone modems, wireless
phones, etc.
This is a reason for tying all ground systems together and limiting the
voltage on all ungrounded lines with surge suppressors. If everything
is at the same potential, within normal limits, no damage will be done
even if the voltage references rises to thousands of volts, just short
of the level at which discharges to other systems like plumbing or
corona discharges to air occur. The eagle perches on the high voltage
transmission line but is not injured until it puts a foot or wind in
contact with a conductor at a different potential.
73 de WOØW
K4BEV@aol.com wrote:
>
> to tie their
>ground to the ground at the service entrance?
>Mine are not.
>Several months ago my tower took a lightning hit and everything tied to the
>phone and cable lines was *killed*. I wonder if not having their grounds tied
>into the power co's is the reason.
>
>73, Don - K4BEV
>
>
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