[TowerTalk] Grounding, Lightning & corona discharge
Alan NV8A (ex. AB2OS)
nv8a at att.net
Thu Jul 29 11:34:11 EDT 2004
Similar here, in a 30-yr-old ranch-style house in W Michigan: Elec. at
one end, gas and phone at the other, cable and dish at the back. I am
working on getting those grounds bonded together.
Alan NV8A
On 07/29/04 10:58 am Jim Brown put fingers to keyboard and launched the
following message into cyberspace:
>>Illustrative of the difficulties of doing the single-point ground thing
>>properly with an old house, our telephone and cable TV connections are 180
>>degrees around the house from the AC power entrance, grounded to a rod at
>>that point
> I have a similar problem in my 110 year old Chicago house -- telco on the northeast
> side of the house, power on the southeast.
>
> Last I looked, code says that all grounds must be bonded together. It is NOT legal
> (nor is it safe) to have things tied to separate rods (or ground electrodes) without
> bonding those electrodes together. Ideally those bonds need to be as short as
> possible and outside the building, but those two requirements can often be
> conflicting. If I ran the bond outside my building, it would need to be at least 100 ft
> long and require a lot of trenching. Inside the building ( basement) adjacent to the
> grounding blocks, it could be as short as about 30 ft. At 1 MHz (the approximate
> peak of lightning energy per IEEE) there's a big difference in the inductive
> reactance. What's a mother to do?
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