Earth bonding on gas pipes.

[Ret.]

I've been handed a card by the National Grid stating that the earth bonding on my gas pipe does not comply with regs. It seems that where the bonding clamp is attached to the gas pipe, and connected to earth on my consumer unit, is too far from the gas meter. The bonding clamp, apparently, should be on the gas pipe no further than 600mm from the meter.

I'm a bit puzzled by this. Why should it make a difference if the earth bonding clamp is attached to the gas pipe close to the meter - or (in my case) about ten feet away? Surely, as long as the earth bonding clamp is clamped onto the pipe it shouldn't matter how far it is from the meter - the earthing continuity is there through the pipe.

There's no real problem - I'm just going to have to move the clamp and buy about 15 feet of earthing cable - but I'm puzzled as to why it should be necessary to do this.

Ret.

[tinnews]

I agree with you in principle but, presumably, there is a distance specified somewhere.

What I'm replying for though is to point out that the bonding cable must be a single piece with no joins. I'm not sure if your "about 15 feet" takes account of this.

[ARWadsworth]

Is the meter external?

If so then the bonding should be done within 600mm of the point of entry to the building.

To make matters worse there should be no tees or branches before the bonding point.

Adam

[Ret.]

Ah - I had intended to leave the existing bonding clamp in place - and simply link that to another bonding clamp located within the 600 mm range of the meter. I take it that I cannot do that then?

Ret.

[Ret.]

No it's located inside my attached garage (on the inside of the outer wall).

That's worth knowing. Thanks.

Ret.

[ARWadsworth]

You could crimp the two cables together.

Adam

[Ash]

Try

Ash

[Ginge]

I am confused. what is the bonding for? I have bonding fixed to my water pipes, is that for the same thing? Has all this got anything to do with a copper spike and a piece of copper strip that goes up the wall to somewhere. Ginge

[Andy Champ]

That sounds like a lightning conductor.

Andy

[tinnews]

I'm not even sure that that is allowed by he regulations.

[Ret.]

Thanks for the link Ash - very informative.

Ret.

[ARWadsworth]

Crimping or soldering both count as unbroken ie you would need to cut the

10mm cable with snips to break its continuity.

The reason an extension from another clamp is not allowed is that anyone with a screwdriver can just remove the clamp, eg a plumber replacing some pipe work.

Adam

[Ret.]

That sounds sensible. I'll just remove the existing clamp and move it to within 600 mm of the meter - and then attach a fresh length of cable and either crimp or solder it onto the 'tail' left after removal of the clamp from its original position.

Ret.

[ARWadsworth]

Buy a new clamp. They are virtually impossible to remove and refit.

Adam

[Ret.]

OK - will do. Off to B&Q shortly!

Ret.

[DavidM]

A subsidary question - my gas meter is on the outside of the front wall in a plastic box. The incoming gas pipe runs through the wall and then for about 30ft underneath the suspended timber ground floor before popping up in the kitchen. So where should it be bonded, where it first appears inside the kitchen, or by the wall in the underfloor space where it first enters the house (but of course will not be visible? Thanks, David

[ARWadsworth]

I would bond the gas pipe inside the meter box.

The bonding connection at the point of entry to the building is not accessible for inspection in your case and the point where the pipe become visible in the kitchen is more than 600mm from the point of entry.

HTH

Adam