Ufer grounds are bare solid copper wire buried in the first 3 inches of a
concrete pour with the tail brought above the surface to tie into whatever you
need to ground. The NEC (National Electrical Code) requires a minimum of 20
feet and a wire size of #2 solid bare copper. This method usually is cheaper
than copper clad ground rods or even galvanized pipes when you consider the
cost of connecting wire and approved clamps. The concrete enhances the contact
with earth and makes the best ground per area covered. Be sure to clamp the
wire to the rebar cage with a approved clamp. This is all required by the code
so be sure to do this if you are going to have any electrical inspections. In
the case of a 9' by 9' base I would run the #2 Cu 3" in from edge of perimeter
of the square and 3" from the bottom of the pour. Then take the tail up and out
the top of pour for connection to tower and tuners etc., with no splices in
slab. For your base it would take about 40' for #2 solid
and one clamp. I'm sure that would be cheaper than four rods, five clamps
counting the rebar one, and interconnecting rods. Anyone considering a new
house or shack remote from house electrical grounds would benefit from this
type of ground system. Just be sure to get it in before concrete foundation
pour and have inspected before covering and you'll make your inspector very
happy.
Good luck,
Nick WB7PEK
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