Telecommunications Tech Blog August 2013
A bad ground can be very expensive in a lightning storm!
By Mike Sandman •
This has been a heck of a summer for storms!
If you have good lightning protection for your telephone
equipment, but your equipment continues to blow up after a storm, you probably
have no or a bad ground.
Since most lightning damage is caused by high voltage,
which a lightning protector sends to ground, if you don't have a good ground you
don't have lightning protection - even if you bought the best you could find
In a place like Chicago where there is ordinary dirt
almost everywhere a good ground is pretty easy to get. The electrician drives an
8 foot ground rod into the dirt right outside where the main circuit-breaker
panel is and runs a heavy gauge wire from the ground rod to the metal box for
The ground is then carried to all the outlets in the
building through the conduit attached to the metal circuit-breaker box, through
the green ground wire put in most conduits (usually not for light switches), and
on the ground wire in Romex when the local authorities don't require conduit.
Sometimes the electrician forgets to attach the big gauge
wire to the ground rod or to the metal box inside. If you're not sure, it's
worth going to look for your ground rod to see if the wire (or big braided wire)
is attached - or just hanging loose?
The real problem comes when the earth around a building
isn't just plain dirt. If it's rocks, gravel, sand or clay, those
materials don't conduct electricity as well as nice moist dirt - and you have a
A bad ground can get really expensive, and you really feel
stupid replacing the same equipment over and over!
for our full Tech Bulletin on Electrical Grounding
Click HERE to see
our various models of Lighting Protectors for Voice and Data