On Tue, 13 Sep 2005 22:49:27 -0500, "Joel" wrote:

I 'should' have the power entrance ground run over to the common ground.

Hi Joe,

Yes, you 'should,' but only if you find life worth living.

But it's over 90 feet away and the house has plastic water pipes.. Does it
make sense to run a copper wire or strap that far?

The 'should' of you 'should' is a requirement of code that is in place
to save your life. It is not there because it has to make sense as an
RF ground lead.

If so, should it be
berried all the way or run exposed. It seems to me the impedance would be so
high in the run, that it would be a waste of copper?

Buried wire will provide an excellent safety ground, but it cannot be
the only safety ground (again code dominates the implementation). And
again, impedance is immaterial to the discussion. If you want an
excellent RF ground, you lay radials, but you connect that ground to
the safety ground for other reasons.

One reason is a mighty big charge called lightning.

Another reason is ground differentials (which occur naturally with
sometimes lethal differences for normal weather, and in great
potential differences with lightning).

If you had two regions separately grounded, and their only
interconnect was a length of coax cable between them, the common being
on the shield, AND if there were a potential difference between the
sites (or a considerable current shunt presented by the coax); then
the first time you pulled the connection on that link you might get
electrocuted. If you want to be a system fuse, what you be rated for?

73's
Richard Clark, KB7QHC