Is this earth wire a problem?

[EFLImpudence]

I have witnessed many a gas engineer condemning such a thing, where he has expected it to be in the gas meter box.

...and many plumbers who want their "cross bonding" under a boiler.

Equally misguided and irrelevant.

 

[JohnW2]

Well, yes because you were rephrasing the rest of the regulation (after the first sentence) to try and make it apply to an external meter. ... Bearing in mind what the first sentence says, then it is obvious that the subsequent wording only applies to internal meters.

I'm not so sure about that - "as near as practicable to the point of entry of that part into the premises" does not, in itself, mean that either the meter or the 'point of bonding' necessarily has to be within the property, does it? Without thinking very hard, I can think of at least one house I know in which the point (for bonding) "as near as practicable to the point of entry of that part into the premises" is definitely outside of the property (near the external meter).

If one does bond the pipe (to the MET of the property's electrical installation), then the pipe entering the property presumably ceases to be an extraneous-c-p, and therefore presumably does not require any bonding within the property?

Kind Regards, John

 

[EFLImpudence]

I'm not so sure about that - "as near as practicable to the point of entry of that part into the premises" does not, in itself, mean that either the meter or the 'point of bonding' necessarily has to be within the property, does it?

Maybe not, but then it renders the regulation ridiculous (albeit not a first).

In the case of gas, there is never not a meter, so are you saying you think the bond must be connected within 600mm. of the meter outlet - wherever the meter is and not "as near as practicable to the point of entry"?

Plus, as I mentioned, for water it will have to be connected (in many cases) under the pavement.

Without thinking very hard, I can think of at least one house I know in which the point (for bonding) "as near as practicable to the point of entry of that part into the premises" is definitely outside of the property (near the external meter).

So what? The picture I posted in post #5 shows exactly that.

The point though is: what if the meter (in the picture) was a distance from the point of entry?
Assuming the meter and pipe run were easily accessible, would you then bond it at the point of entry or within 600mm. of the meter outlet?
I realise it does not matter electrically but we are discussing the regulation requirement.

If one does bond the pipe (to the MET of the property's electrical installation), then the pipe entering the property presumably ceases to be an extraneous-c-p, and therefore presumably does not require any bonding within the property?

Do you mean it doesn't require bonding because it is bonded, or
it ceases to be an e-c-p when it is bonded so it doesn't actually require bonding unless the bonding is removed?


I still maintain I am correct because the only occasion where it is necessary to mention the meter at all is when it is inside because the gas company does not want the bond connected to the supply pipe (even though it makes no difference when there is continuity through the meter joints).
As I know you agree, when inside the incoming supply pipe is the e-c-p and the meter outlet pipe might not be electrically connected to it but the regulation still states that the bond must not be connected to this actual e-c-p.

Also, the only reason for the "as near as practicable to the point of entry" is precisely because that is the e-c-p and subsequently internal pipes might be altered thus disconnecting this e-c-p from the MET - otherwise connecting the bond anywhere would achieve the desired result.

 

[JohnW2]

Maybe not, but then it renders the regulation ridiculous (albeit not a first).

I think that we have always agreed that there are big problems with the way that the reg is written (fractionally more in the past). Also, in addition to the uncertainties/ambiguities we are discussing (due to the poor wording of the reg), it seems that many readers of the reg have misinterpreted it because they have not 'noticed' that it applies only to extraneous-c-ps.

If, as a consequence of a plastic supply pipe and/or the absence of electrical continuity there is no electrical continuity between pipework on the consumer's side of the meter and 'the outside world' ('true earth'), then that pipework is not an extraneous-c-p - which (as you've said, because of the first part of the first sentence) means that none of 544.1.2 (including the bits about the consumer's side of the meter) applies - since there is no requirement for it to be main bonded anywhere.

In the case of gas, there is never not a meter, so are you saying you think the bond must be connected within 600mm. of the meter outlet - wherever the meter is and not "as near as practicable to the point of entry"?

Not at all. In the case of an external meter, the 'practicable point' closest to the 'point of entry' will very commonly (probably nearly always) be inside the building. It is very commonly possible to bond (inside the building) within an inch or three of the true 'point of entry', whereas bonding 'outside' would be at least the thickness of the wall away from the 'point of entry'.

In any event, as you go on to say, all this business about 'where to bond' is actually (common sense, not necessarily regs!) irrelevant 'in normal service'. Since the pipe is very conductive, so long as the pipe remains intact it does not matter one iota whether one bonds it 'at the point of entry' or 20 metres away (e.g. at the boiler). Only if the pipe is 'cut' does the 'point of bonding' matter - since that cutting could leave a length of unbonded extraneous-c-p (if that's what it was!) upstream of the cut.

... So what? The picture I posted in post #5 shows exactly that. The point though is: what if the meter (in the picture) was a distance from the point of entry?

As above, if one had (internal) access to a point close to 'the point of entry', then to do as in your picture would be ('common sense') daft. Furthermore, also as above, if the supply pipe were plastic and/or there was no electrical continuity across the meter, then there would be no need for bonding of anything, anywhere.

Do you mean it doesn't require bonding because it is bonded, or it ceases to be an e-c-p when it is bonded so it doesn't actually require bonding unless the bonding is removed?

I meant the latter, but I'm not sure that teh former is really materially different. As you know, an extraneous-c-p is defined as "A conductive part liable to introduce a potential, generally Earth potential, and not forming part of the electrical installation." ... and I would hope that we might agree that they are talking about 'a potential' which is different from the potential of the installation's MET? If one accepts that, then it obviously cannot be an extraneous-c-p if it is already bonded (before it even enters the building) to the building's MET.

I still maintain I am correct because the only occasion where it is necessary to mention the meter at all is when it is inside because the gas company does not want the bond connected to the supply pipe (even though it makes no difference when there is continuity through the meter joints).

I don't think we really disagree. Most, perhaps all, of what the reg says about meters is seemingly irrelevant. All that matters is that anything which IS an extraneous-c-p should be bonded to the MET, and anything which is not an extraneous-c-p does not require bonding, no matter where it is relative to the meter.

However, as above, there may be occasions on which the closest 'practicable' point to the 'point of entry' (at which to bond IF it really is an extraneous-c-p) may be outside of the building - but that's nothing to do with the meter, per se. I would be saying exactly the same if an underground metal pipe entered the building and then travelled a distance to an internal meter. The pipe between 'point of entry' and the meter would then need to be bonded 'as close as possible to the point of entry - and, in fairly unusual circumstances, that 'nearest point' might be 'on the other side of the wall' (i.e. external to the property).

As I know you agree, when inside the incoming supply pipe is the e-c-p and the meter outlet pipe might not be electrically connected to it but the regulation still states that the bond must not be connected to this actual e-c-p.

Yes, ridiculous.

You and I cannot be alone. Common sense, coupled with an understanding of the nature of extraneous-c-ps and the reason for bonding them, could surely do a lot better than this reg which has been worded very badly (with only slight semi-recent 'improvements') for decades ?!

Kind Regards, John

 

[EFLImpudence]

I think that we have always agreed that there are big problems with the way that the reg is written (fractionally more in the past). Also, in addition to the uncertainties/ambiguities we are discussing (due to the poor wording of the reg), it seems that many readers of the reg have misinterpreted it because they have not 'noticed' that it applies only to extraneous-c-ps.

If, as a consequence of a plastic supply pipe and/or the absence of electrical continuity there is no electrical continuity between pipework on the consumer's side of the meter and 'the outside world' ('true earth'), then that pipework is not an extraneous-c-p - which (as you've said, because of the first part of the first sentence) means that none of 544.1.2 (including the bits about the consumer's side of the meter) applies - since there is no requirement for it to be main bonded anywhere.

Agreed but I don't really think that relates to what I have been saying - namely, the meter requirements in the regulation only refers to internal meters.
I have not been talking about where there is a plastic supply pipe.

Not at all.

That means you agree with what I have been saying.

In the case of an external meter, the 'practicable point' closest to the 'point of entry' will very commonly (probably nearly always) be inside the building. It is very commonly possible to bond (inside the building) within an inch or three of the true 'point of entry', whereas bonding 'outside' would be at least the thickness of the wall away from the 'point of entry'.

I don't see how that is relevant.

In any event, as you go on to say, all this business about 'where to bond' is actually (common sense, not necessarily regs!) irrelevant 'in normal service'. Since the pipe is very conductive, so long as the pipe remains intact it does not matter one iota whether one bonds it 'at the point of entry' or 20 metres away (e.g. at the boiler). Only if the pipe is 'cut' does the 'point of bonding' matter - since that cutting could leave a length of unbonded extraneous-c-p (if that's what it was!) upstream of the cut.

Agreed.

As above, if one had (internal) access to a point close to 'the point of entry', then to do as in your picture would be ('common sense') daft.

I don't see why.
If the MET is on the inside of the wall to the left then doing as in the picture might avoid considerable disruption inside the premises.

Furthermore, also as above, if the supply pipe were plastic and/or there was no electrical continuity across the meter, then there would be no need for bonding of anything, anywhere.

Obviously but again not relevant to the question.

However, as above, there may be occasions on which the closest 'practicable' point to the 'point of entry' (at which to bond IF it really is an extraneous-c-p) may be outside of the building - but that's nothing to do with the meter, per se.
I would be saying exactly the same if an underground metal pipe entered the building and then travelled a distance to an internal meter. The pipe between 'point of entry' and the meter would then need to be bonded 'as close as possible to the point of entry - and, in fairly unusual circumstances, that 'nearest point' might be 'on the other side of the wall' (i.e. external to the property).

Agreed but the regulation states that is not acceptable when the meter is inside.

Yes, ridiculous.

Agreed but that is what the regulation states.

You and I cannot be alone.

You definitely were alone regarding the supplementary bonding requirements.

Common sense, coupled with an understanding of the nature of extraneous-c-ps and the reason for bonding them, could surely do a lot better than this reg which has been worded very badly (with only slight semi-recent 'improvements') for decades ?!

Puzzling indeed.

 

[JohnW2]

Agreed but I don't really think that relates to what I have been saying - namely, the meter requirements in the regulation only refers to internal meters.

As I've said, I think the wording is sufficiently unclear that we cannot be sure what it is trying to refer to.

In any event, as I've also said, in terms of electrical common sense (which the reg in question doesn't seem to understand) the meter and its location are irrelevant. All that matters (in terms of electrical common sense) is that anything entering the building which actually is an extraneous-c-p should be bonded as close as possible to the point of entry into the building (which point, as I've said, might occasionally be outside of the building) - and all that regardless of where the meter is located.

I don't see how that is relevant.

As I said, it's relevant in the (probably very uncommon) situation in which the closest point at which one can 'practically bond' an incoming extraneous-c-p is actually outside of the building. Of course, that depends upon one's view of 'practicable'- some would probably argue that a person with hammers, chisels, wrecking bars etc. could always gain access to, at bond at, the actual 'point of entry'.

I don't see why. If the MET is on the inside of the wall to the left then doing as in the picture might avoid considerable disruption inside the premises.

Very true. However, I probably thought it was fairly clear that when I wrote:

"As above, if one had (internal) access to a point close to 'the point of entry', then to do as in your picture would be ('common sense') daft."​

... I actually meant ...

"As above, if one had easy (internal) access to a point close to 'the point of entry', then to do as in your picture would be ('common sense') daft.​

... and I would say that "easy access" excludes the situation in which internal bonding would involve "considerable disruption inside the premises"

Agreed but the regulation states that is not acceptable when the meter is inside. Agreed but that is what the regulation states.

I think that we have always agreed that a lot of this reg, and/or interpretations of its unclear wording, makes little sense, but in the absence of any words such as "inside"/"outside" or "internal"/"external", I don't really know how you can be sure what it is trying to say about the location of the meter!

You definitely were alone regarding the supplementary bonding requirements.

That's obviously a totally different matter, but I continue to hold the view (based on electrical principles) that what a lot of people (and probably the regs) seem to believe about Supplementary Bonding is simply not true/correct!

Kind Regards, John

 

[EFLImpudence]

... and I would say that "easy access" excludes the situation in which internal bonding would involve "considerable disruption inside the premises"

Fair enough.

I think that we have always agreed that a lot of this reg, and/or interpretations of its unclear wording, makes little sense, but in the absence of any words such as "inside"/"outside" or "internal"/"external", I don't really know how you can be sure what it is trying to say about the location of the meter!

...because what it says (sensible or not) cannot apply to an external meter.
Everyone seems to be only thinking of the meter outside as just on the other side of the wall (not elsewhere farther away) but even in this case there is no point even mentioning the meter as it has no effect on the situation.

That's obviously a totally different matter, but I continue to hold the view (based on electrical principles) that what a lot of people (and probably the regs) seem to believe about Supplementary Bonding is simply not true/correct!

Yes, I now agree with you but it was only you who realised it.

 

[JohnW2]

...because what it says (sensible or not) cannot apply to an external meter.

So you believe, but since what it says doesn't make (electrical) sense even with an internal meter, I don't know what we can be sure about ... As you say ...

Everyone seems to be only thinking of the meter outside as just on the other side of the wall (not elsewhere farther away) but even in this case there is no point even mentioning the meter as it has no effect on the situation.

I'm glad we agree - we've now both said that the meter is irrelevant!

Yes, I now agree with you but it was only you who realised it.

.. but that only makes two of us, one of whom has no 'electrical credentials'.

In many senses I wish someone could prove me wrong, since it worries me that, if I am right, many people (and the regs) seem to think that in some situations it is 'safe' to omit SB, whereas it seems to me that, if there are simultaneously-touchable exposed- and extraneous-c-ps, a theoretical danger will always exist unless there is local SB.

Kind Regards, John

 

[denso13]

The rest of it qualifies that because of the gas people not wanting the bonding conductor in the correct place on the supply pipe

This is all the gas regs say about the matter, nothing more...

Safe use of pipes
18.—(1) No person shall install any installation pipework in any position in which it cannot be used with safety having regard to the position of other pipes, pipe supports, drains, sewers, cables, conduits and electrical apparatus and to any parts of the structure of any premises in which it is installed which might affect its safe use.

(2) Any person who connects any installation pipework to a primary meter shall, in any case where electrical equipotential bonding may be necessary, inform the responsible person that such bonding should be carried out by a competent person.

 

[denso13]

In the case of gas, there is never not a meter

There actually can be "no meter". An outhouse can be fed from a main building, underground, with no meter as the one in the main building will do the metering.

I only point that out to see what difference it makes to what you are discussing as I really don't know. Or does the outhouse pipework not matter as the main house pipework will be bonded?

 

[EFLImpudence]

This is all the gas regs say about the matter, nothing more...

Maybe it is just another urban myth.

I don't know - but I have read (somewhere) that the gas people do not want voltages on the supply pipe so prevent the bonding conductor being connected to it, although, unless there is an insulating joint on the meter, there is nothing they can do to prevent it.
If there is an insulating joint then bonding is not required [EDIT] on the internal pipes but is still required on a metal supply pipe.

Perhaps there is another reason for the incorrect electrical regulation.

 

[EFLImpudence]

There actually can be "no meter". An outhouse can be fed from a main building, underground, with no meter as the one in the main building will do the metering.

So - there is a meter - somewhere.

That is exactly the point being discussed if people think the regulation means outside meters and bonding should only be connected 600mm. from the meter outlet - even if outside the premises.

I only point that out to see what difference it makes to what you are discussing as I really don't know. Or does the outhouse pipework not matter as the main house pipework will be bonded?

It would depend what exactly and what else in in the outhouse.

A water pipe may be used as a bonding conductor therefore, in effect, negating the need for bonding as such between the buildings.

A gas pipe may not be so used.

 

[EFLImpudence]

Please see edit on post #41.

 

[denso13]

So - there is a meter - somewhere.

Ok, I misunderstood.

If (a big if probably) there was a scenario where gas supply was yellow MDPE (an external box) and the water was blue MDPE then the internal main gas and water would not need bonding, if I understand correctly.

The supplies carry on through the main house around 10m then 10m underground to an outbuilding. The water is again blue MDPE but the gas is copper as fitting yellow MDPE is not usually an option for "normal" installers.

So the metal service entering the outhouse from underground would need bonding I presume, but where? Back at the meter to comply with the within 600mm rule?

 

[JohnW2]

There actually can be "no meter". An outhouse can be fed from a main building, underground, with no meter as the one in the main building will do the metering. ... I only point that out to see what difference it makes to what you are discussing as I really don't know. Or does the outhouse pipework not matter as the main house pipework will be bonded?

As both EFLI and myself have said, despite the confusion created by BS7671, the presence/absence and/or location of a meter is (electrically) irrelevant.

IF something metal enters the outhouse from underground (whether gas pipe, water pipe, structural metal or anything else) then it must be bonded to the earthing system used in the outhouse. If that earthing system is the one exported from the main house, then that bonding has to be back to the MET of the house, and, say, the armour of SWA feeding the outhouse may (but might not) be adequate as the bonding conductor. If the outhouse has its own TT earthing system, and is 'isolated' from the house's earth, then the bonding must be to the local TT system/electrode.

Kind Regards, John