This is one of the correct types of ground clamps designed for use on a ground rod (electrode). It is usually called an "Acorn" and it can be directly buried in the earth, and in concrete in a concrete encased electrode (Ufer Ground). See the words "Direct Burial" on the clamp.
PS: Make sure the (GEC) Grounding Electrode Conductor is positioned as shown, and not secured under the bolt.
Originally Posted By: Scott Vickrey This post was automatically imported from our archived forum.
It’s the wrong clamp. I’m sure that clamp is not listed for use on a ground rod. What’s going to happen to this connection when that steel all thread rusts to crumbs? I can’t tell if that’s copper-clad aluminum wire or not but if it is it’s in violation too. because aluminum and copper-clad aluminum shouldn’t be within 18" of the earth(big ball). Per 2002 NEC Section 250.64(A)
Originally Posted By: jpeck This post was automatically imported from our archived forum.
Joe, Scott,
It's the right clamp (well, one of the right types of clamps), however, the installer apparently did not know that the back piece of the clamp gets turned around for smaller diameter ground rods, and left like it is for larger diameter pipes.
If you don't know how to install something, there is a p-r-e-t-t-y g-o-o-d c-h-a-n-c-e that you should not be the one installing it. 
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
jpeck wrote:
Joe, Scott,
It's the right clamp (well, one of the right types of clamps), however, the installer apparently did not know that the back piece of the clamp gets turned around for smaller diameter ground rods, and left like it is for larger diameter pipes.
If you don't know how to install something, there is a p-r-e-t-t-y g-o-o-d c-h-a-n-c-e that you should not be the one installing it. 
NOTE: The reversed (smaller) position of the water pipe type of clamp is not designed for use on ground rod electrode, it is designed to be used on "Water Tubing" See the words here: "Copper Water Tubing"
Originally Posted By: jmyers This post was automatically imported from our archived forum.
Joe T.
I am confused.
While working for an electrical distributor for over 5 years, we sold the acorns for 5/8 ground rods and the larger clamps which you have shown for 3/4 ground rods. I had the understanding that the acorn style clamps would not fit on the 3/4 ground rods.
If I am reading your post correctly, the clamp that you have shown is not allowed to be used on ground rods.
While I did not know they were not allowed to be used on ground rods, my question would be is what clamp is used for the 3/4 ground rod?
I know this clamp was used for bonding the panel to the water pipes, but I also had the understanding it was ok to be used on the larger diameter ground rods.
As a matter of point, when I purchased my first home, I installed a new 200 amp CH series panel with a 3/4 X 10 copper ground rod. Since I could not use the acorn clamp, I used one of these. The inspector that inspected the service did not say anything to me when he saw it, and I know he saw it, it was directly below the electric meter and above the ground, since they are not rated for direct burial.
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
Quote:
Clamps are intended for use with rod and/or pipe electrodes in accordance
with the NEC and are marked with the size of electrode and electrode
grounding conductor with which the clamp is intended to be used.
Clamps suitable for use on copper water tubing are marked for such use.
Originally Posted By: jtedesco This post was automatically imported from our archived forum.
No that’s not what I am saying! The 3/4 inch “Acorn” is available and the clamp in the first picture is not to be used on a rod, it is for a Water Pipe!
Originally Posted By: jpeck This post was automatically imported from our archived forum.
jtedesco wrote:
NOTE: The reversed (smaller) position of the water pipe type of clamp is not designed for use on ground rod electrode, it is designed to be used on "Water Tubing" See the words here: "Copper Water Tubing"
Note these are shown for use on "Water Pipe" - "1/2 to 1 inch", "Galv. Steel" - "5/8 to 1 inch", and "Copper Clad" - well, copper clad shows "N/A" for size.
I will have to look closer next time I see one, but some apparently are rated and approved for ground rod use, apparently, some may not be rated or approved for that use. Or are they just approved for that in Canada and not the US?
