Main bonding diagram (2)

[JohnW2]

The mods are clearly having to waste their time doing more work - it's tempting to suggest that the source of these recent problems should be 'removed'! Whatever, whilst the previous thread was being locked, I was typing the following ....

Anyway, latest version.

I didn't have enough time to get involved in this yesterday, but commend you on your efforts. A few initial observations:

Your Example 3 obviously raises an issue. As your note indicated, although this is 'correct' (electrical, in terms of the purpose of main boinding) it 'may be' (I would say "is" seemingly non-compliant with 544.1.2 (which nearly all of us believe is 'incorrect'). Given that there are people here of the view that one should comply with what regulations "actually say", even if we don't like it (e.g. because we don't think it is correct), is it appropriate that we should advise people to do what we believe to be 'correct', even if that makes it non-compliant with a regulation?

I realise that one of your aims is presumably to emphasise the point you often make (correctly) that 'isolated' bits of metal pipe do not need to be main bonded (and, arguably, 'should not' be main bonded). However, I wonder if, in your efforts to do this and to be 'comprehensive' are not making things over-complicated and hence potentially confusing. ...

... your Example 5 is virtually never going to be seen. It is hard to imagine a situation with entirely metal pipework without there being a connection, somewhere, to a CPC - essentially, it could only happen if there were no boiler, no immersion and no CH. Although not impossible when there is a mixture of plastic and metal pipework, even Examples 2 and 4 (which are essentially electrically the same) are going to be pretty rare - since one wonders what those bits of isolated pipe will be supplying that does not invoke a connection to a CPC.

If they are to be there, you could consider combining (2) and (4) into a single diagram, by having an 'insulating section' in both branches of the metal pipe.

It's probably the case that many of the questions about bonding relate to supplementary bonding in bathrooms, so it would perhaps be worthwhile considering corresponding diagram(s) for that. That could obviously be more complicated, since it will often be permissible to omit supplementary bonding , and there is the problem of defining what constitutes an extraneous-c-p (not simply a question of whether or not it is 'connected to true earth' as per your diagram).

Those are just my initial quick thoughts, to which you may wish to give some consideration. Keep up the good work!

Kind Regards, John

 

[ban-all-sheds]

Your Example 3 obviously raises an issue. As your note indicated, although this is 'correct' (electrical, in terms of the purpose of main boinding) it 'may be' (I would say "is" seemingly non-compliant with 544.1.2 (which nearly all of us believe is 'incorrect'). Given that there are people here of the view that one should comply with what regulations "actually say", even if we don't like it (e.g. because we don't think it is correct), is it appropriate that we should advise people to do what we believe to be 'correct', even if that makes it non-compliant with a regulation?

#3 is fine - it shows an incoming metal service bonded at the point of entry.

I always thought the problem with 544.1.2 is that it says you must do this:

Which would make #2 & #4 non-compliant.

I realise that one of your aims is presumably to emphasise the point you often make (correctly) that 'isolated' bits of metal pipe do not need to be main bonded (and, arguably, 'should not' be main bonded). However, I wonder if, in your efforts to do this and to be 'comprehensive' are not making things over-complicated and hence potentially confusing. ...

I fear that it is too confusing, as I said in the Other Place.

On the one hand (kicking the issue of 544.1.2 requiring bonding of non-ecps into the long grass for now), it is trivially simple: bond incoming metal pipes.

On the other it rapidly starts to get too complicated when you try to draw the distinction (ooh, I like that) between earthing and bonding.

The problem is that main bonding is unaffected by any of the branches, insulating sections, and cpc connections which happen after the pipe enters the building.

Supplementary bonding is (perhaps) affected by them.

Examples 2 and 4 (which are essentially electrically the same) are going to be pretty rare - since one wonders what those bits of isolated pipe will be supplying that does not invoke a connection to a CPC.

• Kitchen taps.
• WC washbasin taps.
• WC cisterns.
• Outdoor taps.
  
• Cold water storage cisterns (although one could argue that there would almost certainly be a cpc connection to another pipe from that)

 

[JohnW2]

It's a damn nuisance that the other thread got locked as a result of silly behaviour, since it means I'm having to jump back and forwards to refer to EFLI's diagram. I'm therefore re-posting his most recent version here ...

 

[JohnW2]

I always thought the problem with 544.1.2 is that it says you must do this: .... Which would make #2 & #4 non-compliant.

Yes, you're right. EFLI's 'warning' (about 'non-compliance') should relate to (2) and (4), not (3) as I suggested - but my question (now in relation to 2 and 4) still remains as to whether it is right to 'advise' those practices which we all feel are 'correct', even though seemingly non-compliant with the regulation (which we believe to be 'incorrect').

Kitchen taps. WC washbasin taps. WC cisterns. Outdoor taps. Cold water Storage cisterns

Indeed, but I wasn't really wondering what non-earthed things exist, and therefore could possibly be supplied by an isolated section of pipe but, rather, how likely it is that they should be supplied by isolated bits of pipe 'in the middle of' an installation with mixed pipes. It's not unusual to get 'plastic additions' to metal plumbing, but they would not usually be in the positions depicted in those diagrams.

Kind Regards, John

 

[EFLImpudence]

I've just got home so will study more later but am confused by the points made so a quick point -

#2 and #4 do not contradict 544.1.2.
In #2 and #4 none of the pipe work is an extaneous-c-p so does not need bonding anyway although, as stated, unnecessary bonding will not introduce a hazard because the pipes ar earthed by CPCs - the reason I think it important to show the CPCs

#3contradicts 544.1.2 because it (544) says to bond to the consumer side (not e-c-p) of insulating section instead of the incoming pipe which is the e-c-p.
That is just wrong - for whatever reason it is stated.

 

[JohnW2]

I've just got home so will study more later but am confused by the points made so a quick point -

Yes, you're right to be confused. BAS got me very confused! Now I have thought a bit more clearly ...

As for #3, what you have actually drawn surely is (despite what you say in this post and in the note on the diagram) compliant with 544.1.2, since it clearly was possible to bond to incoming metal pipe at/near the point of entry. The situation which does produces an issue with that reg is effectively the same as you illustrate in your #2, #4 & #5, since 'an insulating section at the point of entry' is effectively the same as a plastic pipe entering the property.

It therefore seems to follow that, although your #3 is compliant with 544.1.2, your #2, #4 and #5 are not, because they shown no bonding (since we know that it makes no sense to have any), whereas 544.1.2 would presumably say that there is an 'insulating section [the end of the plastic supply pipe] at the point of entry', so that main bonding should be applied to metal pipe on the consumer's side of that.

What the "... or there is a meter" bit actually means, we have never really worked out. Does it (irrationally) really apply even when there is no metal pipe upstream of the meter??

Kind Regards, John

 

[EFLImpudence]

No. (being polite)

544 does not address plastic supply pipes as then none of the pipes is an e-c-ps so 544 does not apply.

544.1.2 says MPB connections shall be made as near as practicable to the point of entry. [correct, but then says] Where there is an insulating section at that point, or there is a meter, the connection shall be made to the consumer's pipework.

This is wrong and bonds pipes which are not e-c-ps and leaves unbonded the incoming pipe which is - and incidentally is also not as close as practicable to the point of entry.


You have always stated this in the past so I do not know why you are having difficulty here and with my diagrams.

 

[JohnW2]

544 does not address plastic supply pipes as then none of the pipes is an e-c-ps so 544 does not apply.

Hmm. I struggle to understand how 'an insulating section at the point of entry' differs from a plastic supply pipe. Indeed, someone within the property could not tell the difference. We obviously agree that, even if you perceive a difference, neither of those situations requite main bonding - whereas 544.1.2 appears to be requiring it (even though, as you say, if there is an insulating section at the point of entry there cannot be any extraneous-c-p).

544.1.2 says MPB connections shall be made as near as practicable to the point of entry. [correct, but then says] Where there is an insulating section at that point, or there is a meter, the connection shall be made to the consumer's pipework. This is wrong ....

All correct. However, your #3 shows a situation in which, although there is an 'insulating section', it clearly has been possible to bond the incoming metal pipe "as near as practicable to the point of entry" - so there clearly is not an "insulating section at that point", so that the daft bit about bonding downstream of the insulating section does not apply. Hence, as I said, your #3 does appear to be compliant with the reg.

The silly situation arises if there is an insulating section at/near the point of entry which makes it impracticable or impossible to bond to metal upstream of the insulating section (clearly not the case in your #3), since it is then that the reg stupidly requires bonding to be applied downstream of the insulating section.

Do you not agree with that?

Kind Regards, John

 

[EFLImpudence]

Hmm. I struggle to understand how 'an insulating section at the point of entry' differs from a plastic supply pipe. Indeed, someone within the property could not tell the difference. We obviously agree that, even if you perceive a difference, neither of those situations requite main bonding - whereas 544.1.2 appears to be requiring it (even though, as you say, if there is an insulating section at the point of entry there cannot be any extraneous-c-p).

Well, it depends what is meant by án insulating section át point of entry'.
If, as you say, the insulating section starts outside the point of entry then there are no e-c-ps so 544 does not apply and bonding is moot.
What i have always assumed to be the case is that there is a metal supply pipe visible inside which then has an insulating section (as my #3, plus it says ór there is a meter so obviously the metal pipe comes in).
544.1.2 then says ignore this incoming pipe and bond the consumer's pipework which is NOT an e-c-p.

All correct. However, your #3 shows a situation in which, although there is an 'insulating section', it clearly has been possible to bond the incoming metal pipe "as near as practicable to the point of entry" - so there clearly is not an "insulating section at that point", so that the daft bit about bonding downstream of the insulating section does not apply. Hence, as I said, your #3 does appear to be compliant with the reg.

My #3 IS correct but I do not consider that is what is meant in 544.1.2
If what you are saying is the case and the insulating section goes outside then there is no need at all for that part of 544.1.2

The silly situation arises if there is an insulating section at/near the point of entry which makes it impracticable or impossible to bond to metal upstream of the insulating section (clearly not the case in your #3), since it is then that the reg stupidly requires bonding to be applied downstream of the insulating section.

Exactly. Either that IS the case or that part of 544.1.2 is not needed at all.

Do you not agree with that?

I think so.

 

[EFLImpudence]

Also, of course, there is 'a point of entry' on the outside of a wall as well.

Plus, if what you are saying is the true case, how would an 'insulating section at the point of entry' be positioned or fitted if the supply comes out of the ground?

 

[JohnW2]

If, as you say, the insulating section starts outside the point of entry then there are no e-c-ps so 544 does not apply and bonding is moot.

Whether the insulating section starts 'at' or 'outside' the 'point of entry', there will be no (at least, no appreciable or 'usable') visible (or touchable) metal supply pipe - so I suppose I have never made the same assumption as you - i.e.

What i have always assumed to be the case is that there is a metal supply pipe visible inside which then has an insulating section (as my #3...)

.... plus it says ór there is a meter so obviously the metal pipe comes in.

Yes, that's the definitely silly one (unless, I suppose, it is 'not practicable' to bond to that bit of incoming, necessarily metal, pipe)

.My #3 IS correct but I do not consider that is what is meant in 544.1.2 ...
If what you are saying is the case and the insulating section goes outside then there is no need at all for that part of 544.1.2

As above, it does not have to 'go outside' - it could just start AT 'the point of entry' (in which case I agree that there still would be no extraneous-c-p). What else could it mean when it says "When there is an insulating section AT that point [of entry]"?? What you are talking about is an insulating section 'which starts a little way from' the point of entry, hence clearly is not in existence AT the point of entry - which is surely different?

If you were to agree with my interpretations, I suppose it would slightly alter what we regard as being silly about the reg. As above, the 'meter' bit is probably always going to be silly (unless bonding the incoming pipe is 'impracticable'). However, as for insulating sections, we might now not be saying that the reg is telling us to bond on the wrong side of an insulating section but, rather, that it is telling us to bond the internal pipework when nothing needs bonding at all

Kind Regards, John

 

[JohnW2]

Also, of course, there is 'a point of entry' on the outside of a wall as well.

Yes, I've considered that - but have concluded that the nearest practicable point at which one could bond would probably be the point at which the pipe entered the (interior of the) building, even if one regarded the 'point of entry' as being that on the outside of the wall.

Mind you, if you really wanted to be mischievous, you might suggest that we are not told on which side of the point of entry one's 'nearest practicable bonding' has to be - so maybe it could be outside?!! [in fact, electrically speaking, I can see nothing particularly wrong with that ]

Plus, if what you are saying is the true case, how would an 'insulating section at the point of entry' be positioned or fitted if the supply comes out of the ground?

I don't think it really matters but I suppose, given the wording of the reg, I have always imagined it starting literally at, or extremely close to, the point of entry into the interior of the building.

Kind Regards, John

 

[EFLImpudence]

What you are talking about is an insulating section 'which starts a little way from' the point of entry, hence clearly is not in existence AT the point of entry - which is surely different?

Factually correct but is that what is meant?
I am at the window - how close?

If you were to agree with my interpretations, I suppose it would slightly alter what we regard as being silly about the reg. As above, the 'meter' bit is probably always going to be silly (unless bonding the incoming pipe is 'impracticable').

It would but because of the meter I don't think I can agree.

However, as for insulating sections, we might now not be saying that the reg is telling us to bond on the wrong side of an insulating section but, rather, that it is telling us to bond the internal pipework when nothing needs bonding at all

So, therefore is not needed at all.

 

[EFLImpudence]

Yes, I've considered that - but have concluded that the nearest practicable point at which one could bond would probably be the point at which the pipe entered the (interior of the) building, even if one regarded the 'point of entry' as being that on the outside of the wall. Mind you, if you really wanted to be mischievous, you might suggest that we are not told on which side of the point of entry one's 'nearest practicable bonding' has to be - so maybe it could be outside?!! [in fact, electrically speaking, I can see nothing particularly wrong with that ]

Of course nothing wrong with it, often possible to feed the cable through the hole from outside rather than get under the floorboards.

I don't think it really matters but I suppose, given the wording of the reg, I have always imagined it starting literally at, or extremely close to, the point of entry into the interior of the building.

I don't see how it could be fitted that close.

 

[JohnW2]

Factually correct but is that what is meant? I am at the window - how close?

You tell me. However, what id fairly clear is that there is enough visible/touchable metal pipe upstream of the insulating section for it to be 'practicable' to bond to it, then the daft requirement to bond downstream of the insularing section does not apply.

It would but because of the meter I don't think I can agree.

I'm not sure what you can't agree with.

So, therefore is not needed at all.

Quite probably not. Let's face it, this reg is silly, no matter how one interprets it - since, with either interpretation, it's telling us to bond downstream of an insulating section, which is daft.

Kind Regards, John