Current Earth Bonding Regulations

[JohnW2]

Yes, but you are proposing to describe as 'supplementary bonding' the connection you propose to install (just connecting two pipes) in order to allow (other) supplementary bonding to be omitted. Are you saying that there are two types of 'supplementary bonding', one which does, and the other which doesn't, require a connection to CPCs?

No, the CPCs will be within the 50/Ia limit and will not require supplementary bonding.

CPCs will (hopefully) always "be within 50/Ia and will not require supplementary bonding". It's when something (e.g. a pipe) does require supplementary bonding that BS7671 requires connection of that bonding to the CPC (even though the CPC itself will not require bonding).

Fair enough - but, as I've said, if this "IS" supplementary bonding, why is it immune from the requirement that it should be connected to "the terminals of the protective conductor" of each circuit in the room?

But that only applies IF the item requires supplementary bonding.

Fair enough. So, given that you are calling it 'supplementary bonding' even when supplementary bonding is not required, are you saying that there two variants of 'supplementary bonding' - (a) that which is 'required', and therefore which also has to have the BS7671-specified connection to CPCs and (b) that which is 'not required', and therefore does not have to have the specified connection to CPCs?

This whole discussion arises because you are insisting on calling your connection between two pipes (and nothing else) as 'supplementary bonding'. If you called it something else, I think we would probably be totally in agreement

What else is there to call it? It is additional; that is all supplementary means.

I don't really know what one should call it but, as above, you seem to have created two variants of supplementary bonding - one of which does, and the other of which doesn't, have to be connected to CPC terminals in the room. Is that not the case?

Kind Regards, John

 

[westie101]

but how do you apply that laudable view to the above?

Without it getting "messy" I'm niot even going to attempt to.

But having just discussed it with a number of colleagues some of whom are specifically trained on BS7671 we all agree that the view of no bond to mettallic pipework, no supply.

You commented about the Faraday cage, that was made of conductive metal, Bricks, mortar & plaster are NOT conductive so could not be energised at the 230V.
A kettle that has it's outer case energised and sat near a sink in your scenario would see a possible 230V difference and potentially kill someone. Oh sorry I'm aware of a number if incidents and reports of shocks when a fault occured on a PME syatem and the bonding was not adequate!

I'm, out of this discussion!

 

[JohnW2]

but how do you apply that laudable view to the above?

Without it getting "messy" I'm niot even going to attempt to. ... But having just discussed it with a number of colleagues some of whom are specifically trained on BS7671 we all agree that the view of no bond to mettallic pipework, no supply.

Fair enough - but I can but repeat my view that to requiring bonding of pipework within a building that has no electrical connection with anything outside of the building is (a) electrically crazy, (b) not required by BS7671 and (c) no different from requiring bonding of a metal handrail on the stairs.

You commented about the Faraday cage, that was made of conductive metal, Bricks, mortar & plaster are NOT conductive so could not be energised at the 230V.

It was you who mentioned a Faraday cage, and I thought you were merely using it to refer to an equipotential zone. There clearly is no need to bond together anything within an equipotential zone - since if it really is an equipotential zone, then everything within it is, by definition, already equipotential.

Something is very wrong (at least electrically) with the way in which you and your colleagues are interpreting regulations, and I find it hard to believe that all DNOs and DNO personnel think similarly.

Kind Regards, John

 

[JohnW2]

... we all agree that the view of no bond to mettallic pipework, no supply.

BTW, even when bonding is sensibly required, that is NOT what your regulation says. It does not say "no bond = no supply" - it says "no bond = no provision of a PME earth terminal".

Kind Regards, John

 

[EFLImpudence]

Last reply. I am quite confident that my replies are correct and your questions are becoming more and more inane.

Yes, but you are proposing to describe as 'supplementary bonding' the connection you propose to install (just connecting two pipes) in order to allow (other) supplementary bonding to be omitted. Are you saying that there are two types of 'supplementary bonding', one which does, and the other which doesn't, require a connection to CPCs?

No, the CPCs will be within the 50/Ia limit and will not require supplementary bonding.

CPCs will (hopefully) always "be within 50/Ia and will not require supplementary bonding". It's when something (e.g. a pipe) does require supplementary bonding that BS7671 requires connection of that bonding to the CPC (even though the CPC itself will not require bonding).

No, as far as the subject being discussed is concerned the 'offending' pipe should be made 'effectively connected to the PEB'.
You may do this with one piece of supplementary bonding.

Fair enough - but, as I've said, if this "IS" supplementary bonding, why is it immune from the requirement that it should be connected to "the terminals of the protective conductor" of each circuit in the room?

But that only applies IF the item requires supplementary bonding.

Fair enough. So, given that you are calling it 'supplementary bonding' even when supplementary bonding is not required, are you saying that there two variants of 'supplementary bonding' - (a) that which is 'required', and therefore which also has to have the BS7671-specified connection to CPCs and (b) that which is 'not required', and therefore does not have to have the specified connection to CPCs?

This is getting sillier.
Your BS7671 specified condition is in the same position when supplementary bonding is not required.

This whole discussion arises because you are insisting on calling your connection between two pipes (and nothing else) as 'supplementary bonding'. If you called it something else, I think we would probably be totally in agreement

What else is there to call it? It is additional; that is all supplementary means.

I don't really know what one should call it but, as above, you seem to have created two variants of supplementary bonding - one of which does, and the other of which doesn't, have to be connected to CPC terminals in the room. Is that not the case?

I have no idea.

 

[JohnW2]

Last reply. I am quite confident that my replies are correct and your questions are becoming more and more inane.

Fair enough - as I said, I've been getting confused by your responses. As I also have said, I think we are actually totally agreed, other than that you are using the term 'supplementary bonding' (a term effectively defined in BS7671) to refer to the (perfectly reasonable) connecting together of two pipes (and nothing else) so as to ensure that both are 'effectively connected to the MEB' - in order to satisfy one of the four conditions for omission of supplementary bonding.

More importantly, I think, is to address the things that westie is now saying! ... I presume that I'm not the only person to have some difficulty with what he is saying?

Kind Regards, John