[TowerTalk] Tower grounding

[Grant Saviers]

Building codes now REQUIRE Ufer grounds in many jurisdictions for new 
foundations.  Codes also REQUIRE that rebar be covered with concrete, 
usually a minimum of 3" to prevent corrosion ingress along the rods.  So 
it is reasonable to extrapolate that ground wires connected to the rebar 
should not exit the concrete below grade and certainly ground rods into 
soils shouldn't be embedded in structural concrete below grade.  Per 
codes, buried connections need to be brazed or Cadweld.  Foundation 
Ufer's are connected to by bending the end of a 20' rebar to above top 
of the footing so the connecting ground wire isn't buried and the 
connection can be inspected.

I've read about some ground rods installed into concrete cylinders to 
increase the soil contact surface area, but don't know how widely this 
is used.

Grant KZ1W


On 7/17/2013 9:18 AM, Skip K3CC wrote:
> I'm not sure I understand the thread however,  NEVER EVER, ground 
> anything
> into the concrete base !!!!!!!    NEVER use any ground rods in 
> concrete !!!!
>
> If you would get a lightening strike, the current would carry into the 
> concrete
> and boil off the water.  When this happens the concrete will explode !!!
>
> If you must ground a tower base I use 4 rods spaced about 4 ft from 
> the base, Cad weld
> the wire onto the rod and make a physical connection to the tower on 
> all legs.  Bond
> the wire with at least 2 clamps onto the tower base using a conductive 
> paste .  Years ago I would pour Copper Sulfate
> around the tower to aid in the ground conductivity.  As a point check 
> the tightness of the
> clamps every few months
>
> it's not the best but who can afford the grounding system that works
> de Skip K3CC _______________________________________________
>
>
>
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