[TowerTalk] grounding

[Jim Lux]

At 08:44 PM 1/19/2004 -0500, Glenn Noska wrote:
>     i'm an electrician in the surge capital of the world, Orlando ( did 
> lightning just hit that house?), Florida. the last three days were spent 
> devouring old towertalk threads on grounding, super informative! well, 
> surge protectors are pretty useless without a good ground and armed with 
> towertalk knowledge i was ready to give my customer's the best ground 
> their money could buy.
>     then, a really sharp engineer at Intermatic dropped this little 
> bombshell. if your ground is a lot better than the utility's ground at 
> the transformer then all the neighborhood's surges are coming for a 
> visit. and you might think they're just coming to your ground, but, as 
> they travel the common they induce surges in the two hots. So, you may 
> have dodged the big surge, and bought yourself a whole lot of little ones.
>      is this significant? do i need to put a big horkin MOV on the 
> neutral to the meter that'll add a couple dozen ohms and keep the 
> neighborhood's surges out? is there such a thing?
>     all kidding aside, i'm guaranteeing all appliances and electronics to 
> $10,000.00 or the homeowner's deductable (installing Intermatic 
> IG1300-4T-2C). please help.

Sounds to me like you need a big RF choke between the utility and you.  For 
these kinds of transients, it might as simple as running the wire through a 
section of steel pipe.  Are you concerned about differential or common mode 
transients?

Jim, W6RMK