Earth rod clamp not tight

[dave_104]

Hi

I've installed a 5/8" earth rod but the clamp isn't fitting very tightly, am I missing something? - see my picture.
Cable is 16mm if that matters and the clamp is a Unistrand brand for 5/8" rods - the original Screwfix clamp sheared in half without my knowledge
I tightened the bolt up as much as I physically could, not sure if it's wise to think about sleeving the rod with a bit of 15mm copper pipe or something else??

Thanks,
Dave

 

[ericmark]

The chances of that tightening on both rod and eye are slim, this

is the type of clamp for use with an eye.

 

[dave_104]

Thanks Eric, that's the kind I used but on an inspection (when I changed the temporarily wrapped wires to a proper crimp) I noticed mine had sheared in half on the bend and was loosely sitting there. Maybe a random manufacturing fault possibly as I didn't need to overbend it when fitting as the top of my rod wasn't burred over by hammering down (I'd used a spare coupler to hit).

 

[ericmark]

You knocked it in by hand? Well done, I used a paddies motor cycle, mind you I was fitting between 4 and 9 rods until reading down to 8 ohm.

 

[plugwash]

The problem is you have one bolt, but two things to clamp. If the bolt is short enough to properly clamp the lug then it's unlikely to properly clamp the rod is long enough to clamp the rod it's unlikely to properly clamp the lug.

as I see if you have two options.

1. Get a better designed clamp.
2. Use a long bolt in conjunction with a nut. The bolt can be used to tighten against the rod, then the nut can be used to clamp the lug.

 

[SUNRAY]

The problem is you have one bolt, but two things to clamp. If the bolt is short enough to properly clamp the lug then it's unlikely to properly clamp the rod is long enough to clamp the rod it's unlikely to properly clamp the lug.

as I see if you have two options.

1. Get a better designed clamp.
2. Use a long bolt in conjunction with a nut. The bolt can be used to tighten against the rod, then the nut can be used to clamp the lug.

Nothing wrong with those clamps, although being honest I dont like them. One only has to clamp the wire in the right place, shown green:

 

[dave_104]

Ahhh yes Sunray, I see now! These clamps only seem to make 2 points of contact with the rod and a wide gap all around, probably enough to take a decent current though.
I think the general opinion is to go back to the solid brass clamps as others have mentioned above as I guess even with the one I've used if one side was to shear then the whole lot would drop off anyway. I know the solid ones have been used for years and maybe I'd got one that someone else overbent and returned to store. I'll go and buy another today.
The rod is installed about 3M away from a river, and should be below the water table, so I'm hoping for a lovely low resistance on that

Thanks everyone for your inputs!

 

[SUNRAY]

Ahhh yes Sunray, I see now! These clamps only seem to make 2 points of contact with the rod and a wide gap all around, probably enough to take a decent current though.
I think the general opinion is to go back to the solid brass clamps as others have mentioned above as I guess even with the one I've used if one side was to shear then the whole lot would drop off anyway. I know the solid ones have been used for years and maybe I'd got one that someone else overbent and returned to store. I'll go and buy another today.
The rod is installed about 3M away from a river, and should be below the water table, so I'm hoping for a lovely low resistance on that

Thanks everyone for your inputs!

I woudn't change it for the sake of changing it, now it's there I'd just reconfigure.