18th 544.1.2

[JohnW2]

John you have recolections and may still have it somewhere and flameport your accusation that it was perhaps the NICEIC.

Yes, but as I said, my recollections definitely do not relate to anything 'official' or authoritative (regulations, Standards, guidelines from trade associations etc.) since I did not look at such things in those days.

As I've said, I must have read about is somewhere, since I believed that 'cross-bonding' was required and did it myself, but that will inevitably have been in books/articles directed at amateurs ('DIY manuals' etc.), and undoubtedly reflected the way in which some people (including the authors) were (I now realise probably incorrectly) interpreting the regulations.

I often quote a story I was told about 50 years ago by my Chemistry teacher. He drew our attention to an alleged chemical reaction which had first been 'described' in a 'trusted' textbook around 1900. By the 1960s, that reaction was described in virtually every chemistry textbook in existence, including the most respected and 'authoritative' ones. The only problem is that, at some point in the 60s, it was discovered that the reaction in question didn't actually happen, and never could have happened in the past! Sheep follow sheep!

Kind Regards, John

 

[JohnW2]

I shall still rely on the 'ALL' in 415.2.1.

Fair enough - but, even then, I personally still don't think it is totally clear (not the least because of the below).

As for A,B,C,D; I would say it applies to all of them. It would only NOT apply to one (or more) of them if it was not simultaneously accessible with any of the others.

You may well be right about the intention of the authors. However, I imagine you would probably agree that, electrically speaking, nothing is gained by 'bonding together' two things which can't be touched simultaneously - so it is presumably 'unnecessary'.

Kind Regards, John

 

[EFLImpudence]

You may well be right about the intention of the authors. However, I imagine you would probably agree that, electrically speaking, nothing is gained by 'bonding together' two things which can't be touched simultaneously - so it is presumably 'unnecessary'.

Ah, yes, I might not have fully realised your ABCD.

I now see you have two separate groups of bonded parts. I would then agree that joining the two groups would not be necessary even though ALL the parts are bonded.

 

[JohnW2]

Ah, yes, I might not have fully realised your ABCD. I now see you have two separate groups of bonded parts. I would then agree that joining the two groups would not be necessary even though ALL the parts are bonded.

Yes, but in terms of what makes electrical sense (i.e. 'necessary') it does not necessarily have to be ALL the parts that are bonded, does it? In addition to having two or more 'groups' which are bonded 'within groups' (but not 'between groups), there could also be parts that could not be touched simultaneously with any others (hence not requiring any bonding), couldn't there?

I suppose this brings us back to the question of what happens if there are no exposed-c-ps and one simply bonds two or more extraneous-c-ps together (i.e. 'cross-bonding'). Even if one thought that was something that was 'required', I don't even know how one would judge whether SB was necessary in that situation since attempting to apply "≤50/Ia" would beg the question as to what OPD's "Ia" one was going to use. I suppose the 'fail safe' answer would be to use the Ia of the highest rated OPD in the property, but that could well be 45A or 50A, leading for a very demanding SB requirement.

The simple solution would be to assume (as I think one probably can interpret from the regs) that SB is never required if there are no exposed-c-ps in the bathroom (which is a very common situation - I have a number of bathrooms, none of which have any exposed-c-ps other than, I suppose one could argue, the faceplate screws of plastic light switches and shaver sockets) - but, to turn my usual argument on its head, it is not impossible that two extraneous-c-ps could, under certain circumstances, have a dangerous pd between them.

Kind Regards, John

 

[EFLImpudence]

Yes, but in terms of what makes electrical sense (i.e. 'necessary') it does not necessarily have to be ALL the parts that are bonded, does it? In addition to having two or more 'groups' which are bonded 'within groups' (but not 'between groups), there could also be parts that could not be touched simultaneously with any others (hence not requiring any bonding), couldn't there?

Yes but I thought you meant A was bonded to B and C was bonded to D while A and B were not accessible from C and D. Therefore they are ALL bonded but not all bonded together.

I suppose this brings us back to the question of what happens if there are no exposed-c-ps and one simply bonds two or more extraneous-c-ps together (i.e. 'cross-bonding'). Even if one thought that was something that was 'required', I don't even know how one would judge whether SB was necessary in that situation since attempting to apply "≤50/Ia" would beg the question as to what OPD's "Ia" one was going to use. I suppose the 'fail safe' answer would be to use the Ia of the highest rated OPD in the property, but that could well be 45A or 50A, leading for a very demanding SB requirement.

True but a short piece of g/y would make it negligible if you wanted to do it. I think you are overthinking it.

The simple solution would be to assume (as I think one probably can interpret from the regs) that SB is never required if there are no exposed-c-ps in the bathroom (which is a very common situation - I have a number of bathrooms, none of which have any exposed-c-ps other than, I suppose one could argue, the faceplate screws of plastic light switches and shaver sockets) - but, to turn my usual argument on its head, it is not impossible that two extraneous-c-ps could, under certain circumstances, have a dangerous pd between them.

Perhaps the SB is NOT NEVER required then. It's up to someone who knows what they are doing, I suppose.

 

[JohnW2]

Yes but I thought you meant A was bonded to B and C was bonded to D while A and B were not accessible from C and D. Therefore they are ALL bonded but not all bonded together.

Yes - but, as I said, what if there is also an E, which is not 'simultaneosly touchable' with any of A, B, C and D? Does one simply ignore that one (because of the way the regs are worded), or what?

True but a short piece of g/y would make it negligible if you wanted to do it. I think you are overthinking it.

A short piece of G/Y would, indeed, make it negligible, so ....

Perhaps the SB is NOT NEVER required then.

IF extraneous-extraneous bonding (in the absence of any simultaneously touchable exposed-c-ps) IS required (and, as you know, I have yet to be convinced) then, yes, I agree that SB would 'NOT NEVER' be required (in fact, I think it would be more-or-less 'always required'), since, as I said, there is no prescribed 'test' (unless one uses 50/Ia, Ia relating to the highest-rated OPD in the installation - which would probably often/usually 'confirm' the need for SB).

However, I'm a little confused since, if that's what you think/believe, it would seem to suggest that you 'approve of' (indeed, seemingly think would be 'required') 'bonding together' all the extraneous-c-ps in a bathroom (if requirements for omitting SB are not satisfied), even if there are no exposed-c-ps in the room - which I didn't think was your view.

Kind Regards, John

 

[EFLImpudence]

Yes - but, as I said, what if there is also an E, which is not 'simultaneosly touchable' with any of A, B, C and D? Does one simply ignore that one (because of the way the regs are worded), or what?

I didn't think you mentioned E.
"Simultaneously accessible" is to which parts require bonding as "extraneous-conductive-parts" is to which parts require bonding.
If they are not that then ignore the rest of the regulations.

IF extraneous-extraneous bonding (in the absence of any simultaneously touchable exposed-c-ps) IS required (and, as you know, I have yet to be convinced) then, yes, I agree that SB would 'NOT NEVER' be required (in fact, I think it would be more-or-less 'always required'), since, as I said, there is no prescribed 'test' (unless one uses 50/Ia, Ia relating to the highest-rated OPD in the installation - which would probably often/usually 'confirm' the need for SB).

I don't know what they meant - it cannot be deduced from the wording - so, even if it is not required, you may still apply it you wish.

However, I'm a little confused since, if that's what you think/believe, it would seem to suggest that you 'approve of' (indeed, seemingly think would be 'required') 'bonding together' all the extraneous-c-ps in a bathroom (if requirements for omitting SB are not satisfied), even if there are no exposed-c-ps in the room - which I didn't think was your view.

I think you'll find I said right at the beginning that I have never been sure of the exact meaning of the wording.

I find a failing with the IET forum is that no one will ever say "Yes, we meant that when we wrote it".
Perhaps, as nothing is statutory, ambiguity is one of their means to CTAs.

 

[JohnW2]

I didn't think you mentioned E.

Not, initially, by 'name', no, but I very much 'mentioned' them ...

... In addition to having two or more 'groups' which are bonded 'within groups' (but not 'between groups), there could also be parts [i.e. "E] that could not be touched simultaneously with any others (hence not requiring any bonding), couldn't there?

"Simultaneously accessible" is to which parts require bonding as "extraneous-conductive-parts" is to which parts require bonding. If they are not that then ignore the rest of the regulations.

Yes but, as we've been discussing, I don't think either of us know for sure whether or not the wording means that two simultaneously accessible extraneous-c-ps (in the absence of any exposed-c-ps) require bonding.

I don't know what they meant - it cannot be deduced from the wording - so, even if it is not required, you may still apply it you wish.

As must be apparent, I don't know what they meant, either. However, the point is surely not that (as you rightly say) one may apply it "even if it is not required", but, rather, the question of whether or not it IS required - and, as above, neither of us seem to be sure.

I think you'll find I said right at the beginning that I have never been sure of the exact meaning of the wording.

You did, as did I. However, you seem to be as 'critical' as many others of those (plumbers etc.) who routinely just join pipes (which will often be 'simultaneously accessible/touchable') together with G/Y cables.

I find a failing with the IET forum is that no one will ever say "Yes, we meant that when we wrote it".

To be fair, although "the IET" must take partial responsibility for what BS7671 says, it is not the IET, as such, who "writes it", but, rather JPEL/64, which is an IET/BSI joint committee. Even in terms of that joint committee, it's worth remember that 'even Supreme Court Judges quite often disagree', so that it's far from impossible that, in relation to specific regs, even the IET representatives on the committee may disagree with what ends up in BS7671 - I don't think that they have any 'veto' or 'casting vote'!

Kind Regards, John

 

[EFLImpudence]

You did, as did I. However, you seem to be as 'critical' as many others of those (plumbers etc.) who routinely just join pipes (which will often be 'simultaneously accessible/touchable') together with G/Y cables.

That might be fair enough but unless the boiler is in the bathroom - no requirements for SB apply.

You're surely not saying that the plumber has worked out something and considers SB to be necessary even when the pipes are connected by the boiler itself.

 

[JohnW2]

That might be fair enough but unless the boiler is in the bathroom - no requirements for SB apply.

I wasn't contemplating any boiler in the bathroom. I was thinking about those plumbers who connect together (with G./Y) every 'simultaneously accessible' pipe that enters the bathroom. Is your argument that those pipes are not extraneous-c-ps.

Kind Regards, John

 

[EFLImpudence]

I thought you were referring to the 'cross' bonding blow the boiler which is usually the reason for criticising plumbers.

I was thinking about those plumbers who connect together (with G./Y) every 'simultaneously accessible' pipe that enters the bathroom.

Which plumbers are those?

Is your argument that those pipes are not extraneous-c-ps.

What are you on about? How can I tell?

They might be; they might not be.

 

[JohnW2]

I thought you were referring to the 'cross' bonding blow the boiler which is usually the reason for criticising plumbers.

No, I was referring to the 'cross bonding' that some plumbers do in bathrooms (and any/everywhere else!).

Which plumbers are those?

Well, the one who re-fitted my late mother;'s bathroom, for a start - if you looked under the bath, basis or loo, a lot of what you saw was G/Y cables! He even bonded the metal cradle which was supporting the plastic bath.

What are you on about? How can I tell? They might be; they might not be.

Quite - so what did you mean when you wrote...

.... but unless the boiler is in the bathroom - no requirements for SB apply.

Your interpretation of the regs seems to be that SB does apply to two or more 'simultaneously accessible' extraneous-c-ps (even if there are no exposed-c-ps), so I assumed that "no requirements for SB apply" meant that you were suggesting/implying that the piped weren't extraneous-c-ps.

Maybe you weren't th

Kind Regards, John

 

[EFLImpudence]

This will be my last reply. Your questions are getting silly.

No, I was referring to the 'cross bonding' that some plumbers do in bathrooms (and any/everywhere else!).

I think people only call the bonding under boilers 'cross bonding' although you have been using the phrase a lot for some reason to apply to normal supplementary bonding.

Well, the one who re-fitted my late mother;'s bathroom, for a start - if you looked under the bath, basis or loo, a lot of what you saw was G/Y cables!

Should I know that?

Quite - so what did you mean when you wrote...
Your interpretation of the regs seems to be that SB does apply to two or more 'simultaneously accessible' extraneous-c-ps (even if there are no exposed-c-ps), so I assumed that "no requirements for SB apply" meant that you were suggesting/implying that the piped weren't extraneous-c-ps.

I don't know why you are having such difficulty with this.
As I thought (as I have told you) you were talking about the bonding plumbers do below the boiler, then unless the boiler were in the bathroom SB would not even be considered.

 

[JohnW2]

I think people only call the bonding under boilers 'cross bonding' although you have been using the phrase a lot for some reason to apply to normal supplementary bonding. ... I don't know why you are having such difficulty with this. As I thought (as I have told you) you were talking about the bonding plumbers do below the boiler, then unless the boiler were in the bathroom SB would not even be considered.

Ah - in that case I think we have probably been talking at cross-purposes for at least the last few pages....

I can't speak for 'people' but I'm used to seeing the term 'cross-bonding' used to refer to all those situations in which I 'learned' (from books etc.) that one had to join pipes together with bits of G/Y - yes, common in the vicinity of boilers, but also in plenty of other places. I'm neither an electrician nor a plumber, but I have seen plenty of examples of such plethoras of GYs in bathrooms, kitchens, airing cupboards and in the vicinity of cold water storage tanks and expansion tanks, to name but a few. I was even brought to believe that this 'cross-bonding' was particularly important in the vicinity of plastic cold water and expansion tanks (plastic ones probably being a fairly 'new idea' in those days!), since the various pipes connected to them did not benefit from the electrical continuity between them which would arise if they were connected to a metal tank.

What now confuses me is why we have been talking so much about SB, if you thought the discussion all along had been only about pipes in the vicinity of boilers - since, as you have pointed out, boilers are very rarely in a location where SB is ever needed (certainly under current or recent regs).

Kind Regards, John

 

[AlanE]

Ah - in that case I think we have probably been talking at cross-purposes for at least the last few pages....

To be honest terminology has changed over the years and overall requirements of each seem to change and maybe different between the various trades.

This thread was started inorder debate what is and what is not required when talking of 'bonding'. In order to put my reasons forward, and at the same time try to prevent misunderstanding anything I refer to as bonding may need to be converted into your own 'Terminology/Phraseology'.

Sorry but by necessity need to split this into several parts because of time/schedule constraints here. This is Part 1.

To set scene, to save confusion.

Also considering a standard domestic property housing one single family. This property, is of standard brick walls solid flooring downstairs plasterboard ceilings wooden floor upstairs, has a single phase electrical suppy with earth terminal supplied by supply company - presumed PME Earth & Neutral linked, a gas supply fed to the house by means of a yellow MDPE pipe into an outside meter cupboard and finally into the property itself. A water supply supplied via blue MDPE pipe to the inside stop valve which feeds a copper piped internal system. Copper pipe is used for the central heating system using a standard gas (Not combination) boiler. Property has an unvented water cylinder (only since this requires a metalic, until very recently and also then only in certain areas, pipe outside, openended, the building that might terminate in a safe place (with regards VERY hot water/steam that might be above 100deg) whish might be open air, into a drain gulley or feed a soakaway in the ground outside.

There are currently various regulations covering the various services

Electricity Regs - Non statutory in their own right but used as reference for 'Competent Persons' schemes.

Water Regs - WRAS but nobody actually seems to inspect water installations. Is also a 'Competent Persons' scheme.

Gas Regs - Statutory

Electricity Supply Regulations - Statutory

Health & Safety at work - Statutory Just added

Quotes used will be srom several sources but electrical regs will be form Edition 17 (Yellow) cover and same with quotes from Onsite Guide.