Is my new consumer unit 17th edition compliant?

[PrenticeBoyofDerry]

or main stop valve, as not all water is metered with respect to the consumer's side! And to my knowledge, with regards to the installation and popularity of water meters, they also seems to be section of the population having them taken out.
This thread now seems to becoming a war of attrition!

 

[JohnW2]

[main stop valve, as not all water is metered with respect to the consumer's side!

I agree that the regs also refer to the consumer's side of a stop valve or insert, but I don't really understand the rest of that statement. Anyway, talking about "the consumer's side" (of meter, stop valve or insert) surely means just what it says - it is simply defining a side of the object in question, regardless of where the "consumer's side of the water installation" starts. By analogy, if an electrical installation had the outgoing meter tails 'split', it would be perfecly reasonable, and meaningful, to talk about "the consumer's side of the Henley block, but that would not alter, or have anything to do with, the fact that "the consumer's side of the electrical installation" still commenced at the output terminals of the meter.

And to my knowledge, with regards to the installation and popularity of water meters, they also seems to be section of the population having them taken out.

I suspect that it will change (for 'environmental reasons') eventually but, yes, one can (at least with my water supplier) currently opt to revert to paying for water on an un-metered basis (at least, within the first 2 years of having a meter fitted). However, my water supplier (and I suspect others) make it clear that if one does this, the meter will be physically left in place (to avoid work in removing it, and so that it remains available for future householders), so people making this choice do not reduce the number of water meters that are 'out there'.

However, all these discussions about details are obscuring the underlying issue, and I share with EFLI a lack of real understanding of what you were getting at when you started all this.

I agree with you totally that many people are under the false impression that "the consumer's side of the water service" (hence their responsibility for maintenance/repair of pipework) starts at the internal stopcock, whereas the truth is that ('legally') it often starts outside of the house, near to the property boundary. However, in terms of the question of bonding, I have to ask "So what?". You presumably were not suggesting that one would bond to the pipe outside of the house - so what was your point? In other words, how does the the point of commencement of "the consumer's side of the water service" influence where one can/should bond the water service?

Kind Regards, John

 

[jabuzzard]

Here is a question, what do you do if the water mains coming into the house is plastic, goes under the living room floor before emerging in the kitchen where it is then turned into copper?

Clearly there is no point in bonding it where it enters the property as it's plastic and it travels several metres before it becomes copper and shortly afterwards has a stopcock. I added bonding to it as soon as it turned to copper but reading through the thread it would appear nothing I could do would be compliant.

 

[JohnW2]

Here is a question, what do you do if the water mains coming into the house is plastic, goes under the living room floor before emerging in the kitchen where it is then turned into copper? Clearly there is no point in bonding it where it enters the property as it's plastic and it travels several metres before it becomes copper and shortly afterwards has a stopcock. I added bonding to it as soon as it turned to copper but reading through the thread it would appear nothing I could do would be compliant.

Despite your fears, I think this is straightforward. If the pipe enters the house as plastic, then there is NO need or requirement (either in terms of common sense or the regulations) for any main bonding.

Some people would argue that to do as you have done, and to 'unnecessarily' bond your house's internal metal pipework introduces an unnecessary hazard, but that is controversial. In fact, IMO, it's not really a valid argument - since in virtually any house, the internal metal pipework will already be connected to earth (via the wiring of immersion heaters, central heating pumps, valves and boilers etc.), so to 'bond' it doesn't really introduce any additional'hazard'.

Kind Regards, John.

 

[jabuzzard]

Despite your fears, I think this is straightforward. If the pipe enters the house as plastic, then there is NO need or requirement (either in terms of common sense or the regulations) for any main bonding.

Other than the resistance to earth of the copper pipe work was rather more than I was happy with. It was in the region of 28-30 Ohms. Either it should be millions of Ohms or close to zero, certainly less than one Ohm.

Some people would argue that to do as you have done, and to 'unnecessarily' bond your house's internal metal pipework introduces an unnecessary hazard, but that is controversial. In fact, IMO, it's not really a valid argument - since in virtually any house, the internal metal pipework will already be connected to earth (via the wiring of immersion heaters, central heating pumps, valves and boilers etc.), so to 'bond' it doesn't really introduce any additional'hazard'.

I am not sure I buy that argument either. I would have said from an electrical point of view if the pipe emerges into the house in metal pipe work then it is by definition grounded and the potential for a dangerous situation to arise is minimal.

On the other hand by coming in on a plastic pipe and thus have a none zero resistance to earth means that should any part of the pipe work come into contact with the electricity supply there would be a potential to earth that could carry a lethal current should one touch it.

 

[JohnW2]

Other than the resistance to earth of the copper pipe work was rather more than I was happy with. It was in the region of 28-30 Ohms. Either it should be millions of Ohms or close to zero, certainly less than one Ohm.

That is, indeed, difficult to understand, and to some extent worrying. If you have any electrial items (immersion heaters, central heating components etc.) attached to the pipework then one would, as you suggest, expect that the wiring of those items would result in a low resistance (almost certainly less than 1 ohm) between the pipework and the house's earthing system. However, when you say 'resistance to earth', what 'earth' were you measuring to? In any event ....

I am not sure I buy that argument either. I would have said from an electrical point of view if the pipe emerges into the house in metal pipe work then it is by definition grounded and the potential for a dangerous situation to arise is minimal.
On the other hand by coming in on a plastic pipe and thus have a none zero resistance to earth means that should any part of the pipe work come into contact with the electricity supply there would be a potential to earth that could carry a lethal current should one touch it.

... I think you are misunderstanding the reason for main bonding, and confusing it with 'earthing'. The hazard which main bonding seeks to minimise is that which arises if a metal pipe at true earth potential enters a house. Although that pipe is at true earth potential, there are (fault) situations in which the potential of the 'earthing system' of the house could rise to a dangerous potential relative to earth. Provided that everything in the house is connected to the house's 'earthing system' that is not a hazard, because a person could not touch that andalso anything which was not at that same potential. However, if there is also something in the house (like an incoming water pipe) which is at true earth potential, someone touching something connected to that (e.g. a pipe/tap) at the same time as touching something connected to the house's earthing system (e.g. a metal electric kettle) could receive a shock. Main bonding joins any incoming path to true earth with the house's earthing system, thereby preventing any significant potential differences existing between the two, and thus fremove that risk of shock.

I hope that's fairly clear!

Kind Regards, John

 

[jabuzzard]

Main bonding joins any incoming path to true earth with the house's earthing system, thereby preventing any significant potential differences existing between the two, and thus fremove that risk of shock.

As I outlined a supply coming in in plastic pipe which then turns to copper, then the copper has no direct route to earth, thus could be at anything up to line voltage if it comes into contact with the electricity supply depending on the resistance to earth. There is now a nasty potential difference between the copper pipe and the houses earth and/or true earth and could be lethal should someone touch and connected exposed part. By bonding the copper pipe I have eliminated that risk. It's back to front to the risk you outline but just as real.

My 28-30 Ohms was the copper pipe to houses earth. Now admittedly it was at the point of testing not connected to very much and not connected to the boiler as the kitchen pipe work was being redone for a new kitchen, and what went before was such a mess I started again. I figure the modern plastic pipe clips don't provide any grounding points unlike old fashioned copper and brass ones. I suspect connecting it to the combi boiler would have reduced this as of course the gas pipe is both bonded and connected to true earth. However relying on bonding through the boiler seems dubious to me.

 

[JohnW2]

As I outlined a supply coming in in plastic pipe which then turns to copper, then the copper has no direct route to earth, thus could be at anything up to line voltage if it comes into contact with the electricity supply depending on the resistance to earth. There is now a nasty potential difference between the copper pipe and the houses earth and/or true earth and could be lethal should someone touch and connected exposed part. By bonding the copper pipe I have eliminated that risk. It's back to front to the risk you outline but just as real.

I explained to you the purpose of (required by regulations) 'main protective bonding' of metal pipes which enter the house - you are talking about something different (which is not required by regulations). The reality is that the chance of 'floating' ('unearthed') pipework ever coming into contact with electricity is very remote - the only way I can think of it happening is if someone dropped a live wire onto the pipework. If there are any things like boilers, pumps, valves, immersion heaters etc connected to the pipework which could, under fault conditions, 'connect electricity to the pipe', those very same things would also connect the pipework to the house's earthing system - so the pipe would not be 'floating'. That's why I said that, if with an such things connected to the pipework, the pipe does not have a low resistance path to the house's earthing system, that would be a cause for concern.

Anyway, as I said, despite what some people say, I don't personally believe that what you have done is any problem, even though the regulations do not require it - not the least because there is virtually no house which doesn't already have the sort of 'incidental' connections from pipework to the house's earth taht I have described.

My 28-30 Ohms was the copper pipe to houses earth. Now admittedly it was at the point of testing not connected to very much and not connected to the boiler as the kitchen pipe work was being redone for a new kitchen, and what went before was such a mess I started again.

Fair enough, but I still find it odd. As you said yourself, one would expect the resistance to either be extremely high (if 'floating') or else very low (if connected to the house's earth via any wiring of electrical components) - 28Ω-30Ω is neither one thing nor the other, and begs the question as to what was resulting in that sort-of path to the earthing system.

I figure the modern plastic pipe clips don't provide any grounding points unlike old fashioned copper and brass ones.

I very much doubt that metal pipe clips, attached to wood or masonry, would ever have provided any significant path to truth earth. Ironically, if they did, the regulations would probably require them to have main protective bonding!

Kind Regards, John

 

[EFLImpudence]

I am not sure I buy that argument either.

Nevertheless it is correct.

As I outlined a supply coming in in plastic pipe which then turns to copper, then the copper has no direct route to earth,

Your 28-30Ω is indirect, then.

thus could be at anything up to line voltage if it comes into contact with the electricity supply

How will it do that?
That is not the purpose of bonding.

There is now a nasty potential difference between the copper pipe and the houses earth

That is why it should be bonded.

It's back to front to the risk you outline but just as real.

It is you who is back to front.

My 28-30 Ohms was the copper pipe to houses earth. Now admittedly it was at the point of testing not connected to very much and not connected to the boiler

Still not >23kΩ or any where near infinite.

I suspect connecting it to the combi boiler would have reduced this as of course the gas pipe is both bonded and connected to true earth.

It will.

However relying on bonding through the boiler seems dubious to me.

Why? It's a big chunk of metal.

Measure it again when finished.

 

[JohnW2]

I am not sure I buy that argument either.

Nevertheless it is correct.

I agree that the argument would be correct if the alternative were to have the internal metal pipework 'floating'. However, when did you last see a house in which there was not at least one CPC connected to the metal pipework somewhere? (a house with non-electrically-controlled, and non-pumped, water and space heating, and no back-up immersion, might conceivably do it, I suppose!). Once there is such a connection, adding another connection to the MET will surely not increase any hazard, will it?

Kind Regards, John

 

[EFLImpudence]

I meant you were correct and

jabuzzard not buying into it was wrong.


Did I get too many negatives the wrong way round?

 

[JohnW2]

I meant you were correct and jabuzzard not buying into it was wrong. Did I get too many negatives the wrong way round?

Ah My understanding was that jabuzzard was agreeing with me - i.e. saying that he 'did not buy into' the same thing that I didn't buy into, namely the argument that to unnecessarily 'bond' (actually earth) metal pipework which was not an extraneous-c-p created a hazard!! As I've just written, I would buy into that argument only if the pipework were truly floating - which would be extremely unusual.

Kind Regards, John

 

[PrenticeBoyofDerry]

and I share with EFLI a lack of real understanding of what you were getting at when you started all this.

I was pointing out that the consumer side of the water services, does not start at the location of the internal stop tap, which was relevant to the opening posts of this topic, which as below you have expressed an agreement with me over. I have only offered what I believe and still do, to be the correct information, with reference to my learning/understanding and info within the water regs, OSG and GN8.
So obscuring what exactly? I was quite clear!
"wake up and smell the coffee my friend" this thread has matured and died a death and still no clarity! But you seem to insist on the pursuit of keeping it alive.

I agree with you totally that many people are under the false impression that "the consumer's side of the water service" (hence their responsibility for maintenance/repair of pipework) starts at the internal stopcock, whereas the truth is that ('legally') it often starts outside of the house, near to the property boundary. However, in terms of the question of bonding, I have to ask "So what?". You presumably were not suggesting that one would bond to the pipe outside of the house - so what was your point? In other words, how does the the point of commencement of "the consumer's side of the water service" influence where one can/should bond the water service?

As well you know the requirements state on entering the property, so why would I suggest external bonding. But just to add as a side note, it is not a water regulation that a stop tap/valve is actually located within the property.

So to make my point again and explain with example, for clarity, and hopefully an understanding can then be made of my reasoning behind making what I thought was an informed and constructive post.
It is possible that the water services pipework will enter the property for a distance (lets say greater than 600mm), before the internal stop tap/valve is fitted to this service.
If this was the case, it could be thought that the consumer side is at the point at where the internal stop tap/valve is located, therefore from that point, it is where the requirements should be applied.
Which is not true!
You ask why is this relevant? I can hear you!
Well it could well be the case, that the uninformed, then believe that the fixing of the MEB is required at a point after the internal tap/valve and it also could be that this tap/valve is located in a position where bonding immediately after the tap/valve (or within 600mm, consumer side) is not possible and further beyond that point is going to extremely difficult, without major upheaval. But the actual requirement in reality, allows the pipework to be bonded before the insertion of the internal stop tap/valve. This could then therefore allow the installation of MEB to the water service pipe at a point between entering the property and the internal tap/valve and this may mean that the installation can be done much easier with less upheaval.
That was my point...... I therefore commit my further contributions to his thread, to the ground; earth to earth, bonding to bonding, pipework to pipework; The End!

 

[JohnW2]

OK. Let's try to tidy this up and put it to bed, lest any remaining readers get even more confused!

I was pointing out that the consumer side of the water services, does not start at the location of the internal stop tap ... which as below you have expressed an agreement with me over.

Yes, I have always agreed with you about that and, indeed, have also agreed with you that very many people probably misunderstand this.

I think I now understand your point, but it really relates to people who have not read 544.1.2 properly, regardless of whether or not they have a correct understanding of where "the consumer's side of the water service" starts.

The first sentence of 544.1.2 makes it very clear that the pipe should be bonded as near as practicable to the point of entry of the service into the premises, without any mention of whether that point is on the "supplier's side" or "consumer's side" of the service. Anyone who has read and understood that first sentence should bond in the correct place, even if they think (usually incorrectly) that "the consumer's side of the service" doesn't start until the internal stopcock.

The rest of 544.1.2 is all about what one should do if there is an insulating section or meter at that point (the point of entry into the premises), and does not alter what I've said above. In that situation, anyone who has read and understood 544.1.2 should still bond in the required place, regardless of their understanding of where "the consumer's side of the service" starts.

Lest any readers be confused by what you've written, compliance with the first sentence of 544.1.2, when possible, is required, not an option. You wrote:

Well it could well be the case, that the uninformed, then believe that the fixing of the MEB is required at a point after the internal tap/valve and it also could be that this tap/valve is located in a position where bonding immediately after the tap/valve (or within 600mm, consumer side) is not possible and further beyond that point is going to extremely difficult, without major upheaval. But the actual requirement in reality, allows the pipework to be bonded before the insertion of the internal stop tap/valve.

The regs don't just 'allow' this - the require it, if (as per your example) it is practicable. As I've said, in the absence of complications which invoke the remainder of 544.1.2, the first sentence should always be complied with. In fact, that would actually still be true if, due to some local legal quirk, the "consumer's side of the service" in the premises did not start until the internal stopcock (i.e. if the bonding was being done on the "supplier's side") - BS7671 does not care whether the pipe bonded is on the "supplier's side" or "consumer's side" of the service, only that it complies with 544.1.2.

Is it perhaps possible for us to agree on the above?

Kind Regards, John