Earthing Armour with BS951 clamps?

I was replacing a socket that had a cracked face and as I took said socket off I noticed the armour was earthed by using BS951 clamps. I wasn’t expecting to see any earthing of the armour as the SWA was in a conduit drop to the socket.

I’ve never seen it done like that before but now I walk around the factory and automatically assume every SWA I see entering a conduit drop will have the armour earthed with the clamps. Never been referenced on any EICRs we’ve had done in the past.

I don’t like it as the SWA hasn’t been glanded, just been shoved down the conduit.

I took the conduit drops away and glanded the SWA appropriately with the use of Earth Nuts.

Is the use of BS951 clamps acceptable practice for the earthing of armour?

Certainly not good practice, and I’m surprised whoever did this didn’t think the earth terminal in the bottom right of a plastic box needed earthed too.

littlespark said:

Certainly not good practice, and I’m surprised whoever did this didn’t think the earth terminal in the bottom right of a plastic box needed earthed too.

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I have found a couple of those BG sockets with an earthed plastic box in the factory!

Luckily it's only one area that has the SWA dropped in conduit so I think I'll be amending those.

Cheers littlespark.

MaintenanceSpark said:

I was replacing a socket that had a cracked face and as I took said socket off I noticed the armour was earthed by using BS951 clamps. I wasn’t expecting to see any earthing of the armour as the SWA was in a conduit drop to the socket.

I’ve never seen it done like that before but now I walk around the factory and automatically assume every SWA I see entering a conduit drop will have the armour earthed with the clamps. Never been referenced on any EICRs we’ve had done in the past.

I don’t like it as the SWA hasn’t been glanded, just been shoved down the conduit.

I took the conduit drops away and glanded the SWA appropriately with the use of Earth Nuts.

Is the use of BS951 clamps acceptable practice for the earthing of armour?

View attachment 117685

Click to expand...

BS 951 states that clamps to this standard are not intended for connection to the armour or sheath of a cable and requires the packaging of the clamp to include the warning “Not intended for use on the sheath or armour of a cable

littlespark said:

I’m surprised whoever did this didn’t think the earth terminal in the bottom right of a plastic box needed earthed too.

Click to expand...

Does it ?

mainline said:

Does it ?

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Agree.
Why does it? ........Unless it's a pee taking comment!
And also agree about the bad practice.
Sadly, seem to come across this more these days. It's not a solid earth connection.

yes it was a pee-take...

I was commenting if someone was dumb enough to use earth clamps on armour, they might just be dumb enough to earth a plastic box.