UK Earthing Arrangement

[Tonychitty]

Can anyone help, i had a new combi boiler fitted last year and they used mainly plastic fittings to make there connections, i have attached a photo below my question is where should my 10mm earth bond go , the incoming water pipe is made of lead, do i simply bond the 10mm earth to the incoming water pipe with a suitable clamp and then bridge the plastic plumbing tee to the nearest copper pipe.
any feedback would be mostly appreciated

 

[telectrix]

looks like the plastic has eliminated the need for bonding. the only extraneous metal pipework appears to be the incoming up to the plastic. test any copper to MET. above 22k Ohms, not extraneous. if < a couple ohms, it's bonded elsewhere, e.g. to the gas at the bolier. and what's that torpedo above the stop. is it a filter?

 

[pc1966]

Assuming the existing bond is 10mm then yes, put a new clamp on to the lead pipe and run another bit of 10mm up to join the existing bonding cable. Ideally you should join them with a crimp or soldering so if any one screw loosens you don't have multiple bond wires separating.

Is there a separate bond wire to the gas meter already?

 

[davesparks]

looks like the plastic has eliminated the need for bonding. the only extraneous metal pipework appears to be the incoming up to the plastic. test any copper to MET. above 22k Ohms, not extraneous. if < a couple ohms, it's bonded elsewhere, e.g. to the gas at the bolier. and what's that torpedo above the stop. is it a filter?

The torpedo is a magnetic scale inhibitor, generally required by most manufacturers for their combi boilers
[automerge]1591442417[/automerge]

Assuming the existing bond is 10mm then yes, put a new clamp on to the lead pipe and run another bit of 10mm up to join the existing bonding cable. Ideally you should join them with a crimp or soldering so if any one screw loosens you don't have multiple bond wires separating.

Is there a separate bond wire to the gas meter already?

Why? That can be left exactly as it is, the bonding should be connected after the stopcock, not before it.
And I certainly wouldn't fit a pipe clamp to a soft lead pipe.

 

[Tonychitty]

Assuming the existing bond is 10mm then yes, put a new clamp on to the lead pipe and run another bit of 10mm up to join the existing bonding cable. Ideally you should join them with a crimp or soldering so if any one screw loosens you don't have multiple bond wires separating.

Is there a separate bond wire to the gas meter already?

Yes there is, can i not loop in and out with the 10mm earth bond with an ordinary bs951

 

[bill01803]

Replace the plastic tee with a compression - job done (presuming the filer is metal)

 

[Tonychitty]

Assuming the existing bond is 10mm then yes, put a new clamp on to the lead pipe and run another bit of 10mm up to join the existing bonding cable. Ideally you should join them with a crimp or soldering so if any one screw loosens you don't have multiple bond wires separating.

Is there a separate bond wire to the gas meter already?

yes there is
[automerge]1591443071[/automerge]

looks like the plastic has eliminated the need for bonding. the only extraneous metal pipework appears to be the incoming up to the plastic. test any copper to MET. above 22k Ohms, not extraneous. if < a couple ohms, it's bonded elsewhere, e.g. to the gas at the bolier. and what's that torpedo above the stop. is it a filter?

is a magnetic scale inhibitor,
Source URL: UK - Earthing Arrangement - https://www.electriciansforums.net/threads/earthing-arrangement.187131/#post-1633862

 

[Tonychitty]

looks like the plastic has eliminated the need for bonding. the only extraneous metal pipework appears to be the incoming up to the plastic. test any copper to MET. above 22k Ohms, not extraneous. if < a couple ohms, it's bonded elsewhere, e.g. to the gas at the bolier. and what's that torpedo above the stop. is it a filter?

is a magnetic scale inhibitor,
Source URL: UK - Earthing Arrangement - https://www.electriciansforums.net/threads/earthing-arrangement.187131/#post-1633862

 

[pc1966]

Why? That can be left exactly as it is, the bonding should be connected after the stopcock, not before it.

Really, why?

Normally I don't trust plumbing joints for electrical function even when they are all metal and should be good as I have seen oddities before.

And I certainly wouldn't fit a pipe clamp to a soft lead pipe.

That is fair enough. A strip of sandpaper cleaning up the painted copper pipe just before the stopcock would have enough for the clamp and be the best place in my opinion.

Other opinions are available, just wait...
[automerge]1591443635[/automerge]

Yes there is, can i not loop in and out with the 10mm earth bond with an ordinary bs951

If you have the cable to do it, yes.

Usually the "best practice" is to avoid breaks/screw connections in bonding wires, though it is not actually mentioned in the BS regulations, so a screw coming loose has less impact (a bit like the guidance for high leakage CPC arrangements). So if the wire is short then you could use a crimp joint to extend it, then loop round the existing far-end clamp to your new one.

You probably don't need the far-end clamp, but easiest to leave it and it won't upset the plumber who next comes to do maintenance.

 

[telectrix]

it won't upset the plumber who next comes to do maintenance.

where's the fun in that?

 

[Tonychitty]

looks like the plastic has eliminated the need for bonding. the only extraneous metal pipework appears to be the incoming up to the plastic. test any copper to MET. above 22k Ohms, not extraneous. if < a couple ohms, it's bonded elsewhere, e.g. to the gas at the bolier. and what's that torpedo above the stop. is it a filter?

What if the plastic tee in the future gets replaced with a metal one, should i not put a the option of a bonding clamp after the plastic tee

 

[pc1966]

What if the plastic tee in the future gets replaced with a metal one, should i not put a the option of a bonding clamp after the plastic tee

Sir, put down the plumbing and walk away solely...

Just add another clamp, extending wire as needed. Quick and easy to do, not worth the trouble of trying to re-use a clamp anyway, avoids complaints of anything else not being adequately bonded as a result. Sorted!

 

[radiohead]

Nothing there requires bonding, either leave it as it is or disconnect it entirely.

 

[pc1966]

Nothing there requires bonding, either leave it as it is or disconnect it entirely.

Not even the cold water pipe / stopcock / filter as an extraneous conductive part that is clearly within normal touch access?

You could argue the boiler water pipes are no longer part of such a system, but the cold pipe is still something I would bond.

Also you might just find it is like my flat where some muppet of a plumber has split the cold pipe below the floor and I have two stopcocks, one for bathroom and the other for the kitchen! So the plastic pipes visible in the shower/bath did not reflect on the electrical connectivity to the kitchen.

For years I could not find the 2nd stopcock and then when the gas board need to move the meter (no longer allowing central riser feed, had to go outside) they put it in my kitchen and cut through the back of the under sink cupboard for pipe access.

And lo! The missing stopcock was found!

Yes, folks the (possibly same) group that had built the kitchen had hidden the stopcock behind a permanent backing panel, oh FFS!

 

[Tonychitty]

Nothing there requires bonding, either leave it as it is or disconnect it entirely.

even though there is a metallic water pipe coming in from the outside, i do have the 10mm eath cable near by should i just connect it anyway.