[BC] thanks to the list re: grounding system advice.

[Ron Youvan]

Dave Dunsmoor wrote:

>      Initially, maybe. But even so, there isn't nearly as much surface area
> connectivity between the ground rod and the associated ground cable as with
> cadweld. Further, even though the points where the copper pieces are pressed
> tightly against each other and this constitutes a more or less "gas-tight"
> (oxygen free) zone, it will probably corrode to a point of degradation, or
> failure. Later, more likely than sooner though.

>> It really depends on the conditions. In a desert dry environment where
>> moisture is not present, possibly.  In a wet/dry or all wet environment,
>> unlikely. BTDT.  Nothing works like a molecular joined connection.
>> Exothermic welding is just that followed closely by brazing/silver
>> soldering.

   In West central Florida, few electricians that do cad welding recommend it for anything except 
where no other connection is suitable.  They say the mechanical connection is frail, jerk the cable 
or hit the weld and it breaks. (it is like a brass sponge 90% air. as I proved when I accidentally 
drove over a cable and tore the cable from the tower at the cad weld)

   They recommend and we have been using compression connectors designed for lighting installations 
and bolt on lugs.  They crimp a two bolt lug on the cable end and drill and tap two holes in the 
tower member, a gusset at the bottom flange) remove the galvanizing with a grinding wheel and apply 
Anti-Ox and bolt the lug to the steel.
   The compression connections are a copper piece about 3/8" thick (1.5 - 2" long) that has two 
holes, like a figure "8."  One hole goes over the rod and the cable goes through the other hole (on 
to the next rod) and a hydraulic tool squeezes the fitting until it is round and has dug into the 
copper of the rod and into the cable.  (a form of welding)  They say this can not be pulled apart.
   They had to cad weld the end of a cable to the domestic water well casing (6" diameter, to bond 
all grounds together) as no other procedure is as suitable.  They also use 5% silver brazing when it 
comes to copper strap and such and say it is highly effective and will last.  (I use Sil-Flow 5)

-- 
Ron KA4INM