chemical ground rod

Status
Not open for further replies.
ceb58

ceb58

Senior Member
Location
Raeford, NC
Any one ever install/maintain chemical ground rods? We are looking at installing some at some of our sites that are rocky and cannot get under 5 ohms (required by the specks) with the traditional ground rods. Looking for the pros and cons and the PITA factor for installing.
 
ceb58 said:
Any one ever install/maintain chemical ground rods? We are looking at installing some at some of our sites that are rocky and cannot get under 5 ohms (required by the specks) with the traditional ground rods. Looking for the pros and cons and the PITA factor for installing.
Click to expand...

PITA, just install a small grid. How are you measuring your ground resistance?
 
"Enhanced ground rods are UL Listed and designed to last over 35 years. If for some reason the salts would become depleted xxx will provide additional salts free of charge." seems to say that periodic testing is advisable.

Can it poison the ground water?
 
Last edited:
zog said:
PITA, just install a small grid. How are you measuring your ground resistance?
Click to expand...
Grid is there it is an old site and due to other communication buildings that have been brought in there is no room to add to the grid. We are measuring resistance with FOP test.
 
It seems to give you only a local area of low resistance.

"One can visualize the effective radius, or earth shell, of a ground rod as a
buried hemisphere with a radius equal to the rod length. If two rods are spaced closer than their
length, the hemispheres overlap. The resistance will be less than that of a single rod but will not
be one half the resistance of a single rod: it will be more.

Conductive-cement rods and electrolytic rods have larger earth shells and should be spaced
farther apart, at least twice the rod length. "

So your rod system is isolated from the wider area more than rods buried in more conductive soil.
 
I worked on a job where they hired n outside contractor to install those chemical rods. They used gas powered post hole diggers that dig 10' since the rods are 10' long. The hole is much larger than the 2" copper pipe used so once the pipe is in the hole they fill the hole with bentonite, basically a clay, and add water. This will harder nicely. The rods gets filled with salt and then a cap is installed on the top with a 4/0 gec.

These units are $600- basically a 2" x 10' copper pipe with small holes drill around the circumference every foot of length. This is where the salt escapes. The clay keeps the soil moist and the salt increases the conductivity. How often it needs to be refilled is dependent on how wet the area stays. It is not a gaurantee around here to get under 5 ohms. In fact, the installer said they would guarantee something like 5 ohms but they added a few of these rods around the perimeter of the house. Not sure what readings they got. I got 13 ohms with just the rebar (CEE) connection so I am not sure it is worth it.
 
Status
Not open for further replies.
Top