[TowerTalk] Grounding, Lightning & corona discharge

[Jim Lux]

At 07:46 AM 7/29/2004 +0000, you wrote:
>Just curious, how is the telco connection done in the states ? What is
>there to connect to a single point ground?
>
>Here in SM it is just two wires coming to the house from the telephone
>pole, no screened cable to ground and no ground connection allowed on any
>of the incoming wires.
>
>73/Peter SM2CEW
>www.qsl.net/sm2cew
At the "point of demarcation" there's usually some form of lightning 
arrestor/transient suppressor with a wire to the ground.  The wire comes 
from the pole (or conduit, for underground service) to the demarc/arrestor, 
then the house wiring plugs into the demarc.  IT serves a dual purpose of 
delineating whose wire it is (on the utility side or the homeowner side) 
and providing lightning protection.  Bear in mind that the utility doesn't 
care about protecting YOUR equipment though.  They're protecting their side 
(the drop, the cables, etc.)

Their goal and requirements for the device might be different from the 
consumers... hence the popularity of aftermarket protective devices... the 
phone company doesn't have a very complex system on their side of the line 
(wires, cables, splices, not much electronics until you get to the Central 
Office, and I'll bet the transient suppression on that end is a LOT better 
than at my end)