Equipontal Bonding - Water

I've been wading through the interent, trying to find the details of where the strap needs to go but can't seem to find it.

Does the strap need to be within 0.6 metres of the 15 copper pipe entering the house, and before the pipe has an elbow, t connector?
is it before or after the stop tap?

many ta's for any help.

Yes and after.

thanks 4 that, will get me screwdrivers out!

Within 600mm of point of entry to the property, on the consumers side of the stop cock and before any tee's. It doesn't matter if it's after bends / elbows etc.

or if that can not be done where practical and the location noted down on the test certificate.
But we have touched on this before but you don't seem to acknowledge this.
//www.diynot.com/forums/electrics/flippin-lost-off-with-bonding-earthing-etc.322565/

RF Lighting said:

Within 600mm of point of entry to the property, on the consumers side of the stop cock and before any tee's.

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Although that is often said, 544.1.2 doesn't actually say anything about 'within 600mm of point of entry' (it says 'as near as practicable to the point of entry'). As far as I can see, the only explicit reference to 600mm is in relation to the outlet union of an internal meter. Nor does 544.1.2 say anything about one side (or the other) of a stopcock. The OSG seems to say no more about these issues than does 544.1.2.

Kind Regards, John.

Absolutely John.

It makes no sense to put it on the consumer's side of the stopcock if you can put it on the supplier's side.

The whole point of main bonding is to connect the MET to any external metal service that penetrates the equipotential zone and then bring it to that potential ASAP.

Which is exactly what the regulations say ('as near as practicable to the point of entry' which you quoted).

But the reason behind main bonding is very poorly understood. I had an electrician (time served) tell me he didn't like to connect the earth to the water pipes as it would take any faulty electricity to the taps.

Very poorly understood.

So tebreak, stick the strap as close as possible to where the metal pipe enters the house. That way it is also less likely to be disconnected if some work is later done on your piping. eg stock cock replaced

chapeau said:

Absolutely John. It makes no sense to put it on the consumer's side of the stopcock if you can put it on the supplier's side.
The whole point of main bonding is to connect the MET to any external metal service that penetrates the equipotential zone and then bring it to that potential ASAP.
Which is exactly what the regulations say ('as near as practicable to the point of entry' which you quoted).

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Quite so, but ....

chapeau said:

But the reason behind main bonding is very poorly understood. I had an electrician (time served) tell me he didn't like to connect the earth to the water pipes as it would take any faulty electricity to the taps.
Very poorly understood.

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...this is where I think the regs themselves introduce confusion and potential lacks of understanding ... when they go on to talk about attaching main bonding on the consumer's side of 'an insulating section or insert' or meter (which may not provide electrical contnuity). Maybe I'm naive but, as far as I'm concerned, any such bonding is supplementary, not main, bonding.

Kind Regards, John.

Hasn't it been quiet lately.

JohnW2 said:

the regs themselves introduce confusion and potential lacks of understanding ... when they go on to talk about attaching main bonding on the consumer's side of 'an insulating section or insert' or meter (which may not provide electrical contnuity).

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Any thoughts on why this is the case?

Maybe I'm naive but, as far as I'm concerned, any such bonding is supplementary, not main, bonding.

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It would be futile to argue but I suppose it is main bonding because it is connected to the MET (even if it is connected to the water supply on the way)

and it's purpose is to reduce earth potential (though there is none) rather than potential difference between the pipework.

EFLImpudence said:

Hasn't it been quiet lately.

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Maybe for you, but quite the converse for me - which is why you haven't heard from me for a while

EFLImpudence said:

JohnW2 said:

the regs themselves introduce confusion and potential lacks of understanding ... when they go on to talk about attaching main bonding on the consumer's side of 'an insulating section or insert' or meter (which may not provide electrical contnuity).

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Any thoughts on why this is the case?

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We can all have our thoughts on the matter! One might speculate that, as well as wanting main equipotential/protective bonding, as a totally separate issue they also want the metal pipework within the premises to be 'earthed' (to the installation's MET). Main Equipotential bonding itself will always be most surely/safely achieved by bonding as close as possible to the point of entry into the premises, regardless of whether that is in electrical continuity with the premises' pipework - and, as has already been pointed out, that also minimises the risk of that main bonding being disrupted by plumbing work.

EFLImpudence said:

Maybe I'm naive but, as far as I'm concerned, any such bonding is supplementary, not main, bonding.

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It would be futile to argue but I suppose it is main bonding because it is connected to the MET (even if it is connected to the water supply on the way)

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I presume we can agree that the purpose of main (equipotential/ protective) bonding is to minimise any pd between the installation's MET (hence CPCs, extraneous-c-ps etc.) and any extraneous conductive part which 'is liable to introduce a potential (usually earth potential)'. If it is connected to consumer's pipework which is electriclly insulated from that extraneous-conductive-part (e.g. by an 'insulating section or insert'), it cannot literally fulfill that role. I suppose we really should not be debating whether (in that situation) it is main or supplementary bonding but, rather, whether it is really bonding at all (rather than 'earthing')

EFLImpudence said:

and it's purpose is to reduce earth potential (though there is none) rather than potential difference between the pipework.

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I'm not totally sure what you're saying here - but, as above, if the 'MPB' is not in electrical continuity with any extraneous-conductive-part, I would question whether it is really functioning as bonding (rather than 'earthing').

Kind Regards, John.

JohnW2 said:

We can all have our thoughts on the matter! One might speculate that, as well as wanting main equipotential/protective bonding, as a totally separate issue they also want the metal pipework within the premises to be 'earthed' (to the installation's MET). Main Equipotential bonding itself will always be most surely/safely achieved by bonding as close as possible to the point of entry into the premises, regardless of whether that is in electrical continuity with the premises' pipework - and, as has already been pointed out, that also minimises the risk of that main bonding being disrupted by plumbing work.

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That was my point in another thread -

that should the bonding be removed from the water supply, then the gas supply (although itself insulated from 'the earth') would become extraneous by being connected to the now unbonded water supply but this maybe a bit far-fetched.

I suppose we really should not be debating whether (in that situation) it is main or supplementary bonding but, rather, whether it is really bonding at all (rather than 'earthing')

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No. It's still bonding - i.e. to equalise potential - not to ensure operation of the cpd.

Also, the gas pipe may be distant from the water pipe so cannot be touched simultaneously, therefore supplementary bonding is not required.

EFLImpudence said:

and it's purpose is to reduce earth potential (though there is none) rather than potential difference between the pipework.

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I'm not totally sure what you're saying here - but, as above, if the 'MPB' is not in electrical continuity with any extraneous-conductive-part, I would question whether it is really functioning as bonding (rather than 'earthing').

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No. It's still bonding - although the gas pipe may not actually be extraneous if tested in isolation - i.e. before being connected to the boiler.

tebreak said:

Equipontal

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?

EFLImpudence said:

That was my point in another thread - that should the bonding be removed from the water supply, then the gas supply (although itself insulated from 'the earth') would become extraneous by being connected to the now unbonded water supply but this maybe a bit far-fetched.

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I don't really understand. Ther gas pipe is a separate issue. If, as is almost always the case, it enters the premises as an extraneous-c-p, then it needs main bonding in its own right, even if the premises doesn't have a water supply! Perhaps I'm missing something.

EFLImpudence said:

I suppose we really should not be debating whether (in that situation) it is main or supplementary bonding but, rather, whether it is really bonding at all (rather than 'earthing')

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No. It's still bonding - i.e. to equalise potential - not to ensure operation of the cpd.

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Equalise the potential between what and what, and why?

EFLImpudence said:

Also, the gas pipe may be distant from the water pipe so cannot be touched simultaneously, therefore supplementary bonding is not required. .... It's still bonding - although the gas pipe may not actually be extraneous if tested in isolation - i.e. before being connected to the boiler.

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I'm again a bit uncertain as to why you keep talking about gas pipes in relation to this discussion about the bonding of water pipes. In any event, I'm again confused. Even if one did have a gas supply which was not an extraneous-c-p (which, as above, I would think would be extremely rare), why would connecting it to a boiler (hence other pipework) suddenly make it an extraneous-c-p?

Kind Regards, John.

JohnW2 said:

EFLImpudence said:

That was my point in another thread - that should the bonding be removed from the water supply, then the gas supply (although itself insulated from 'the earth') would become extraneous by being connected to the now unbonded water supply but this maybe a bit far-fetched.

Click to expand...

I don't really understand. Ther gas pipe is a separate issue. If, as is almost always the case, it enters the premises as an extraneous-c-p, then it needs main bonding in its own right, even if the premises doesn't have a water supply! Perhaps I'm missing something.

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Nope that sounds correct to me.

EFLImpudence said:

I suppose we really should not be debating whether (in that situation) it is main or supplementary bonding but, rather, whether it is really bonding at all (rather than 'earthing')

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No. It's still bonding - i.e. to equalise potential - not to ensure operation of the cpd.

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Equalise the potential between what and what, and why?

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Between the suppliers earth / MET and anything extraneous as a PD could exist between these two points especially under fault conditions.

EFLImpudence said:

Also, the gas pipe may be distant from the water pipe so cannot be touched simultaneously, therefore supplementary bonding is not required. .... It's still bonding - although the gas pipe may not actually be extraneous if tested in isolation - i.e. before being connected to the boiler.

Click to expand...

I'm again a bit uncertain as to why you keep talking about gas pipes in relation to this discussion about the bonding of water pipes. In any event, I'm again confused. Even if one did have a gas supply which was not an extraneous-c-p (which, as above, I would think would be extremely rare), why would connecting it to a boiler (hence other pipework) suddenly make it an extraneous-c-p?

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It wouldn't

JohnW2 said:

EFLImpudence said:

That was my point in another thread - that should the bonding be removed from the water supply, then the gas supply (although itself insulated from 'the earth') would become extraneous by being connected to the now unbonded water supply but this maybe a bit far-fetched.

Click to expand...

I don't really understand. Ther gas pipe is a separate issue. If, as is almost always the case, it enters the premises as an extraneous-c-p, then it needs main bonding in its own right, even if the premises doesn't have a water supply! Perhaps I'm missing something.

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After you mentioned insulating sections I got a bit confused with this thread -

//www.diynot.com/forums/electrics/earth-for-gas-meter-question.322813/

JohnW2 said:

EFLImpudence said:

I suppose we really should not be debating whether (in that situation) it is main or supplementary bonding but, rather, whether it is really bonding at all (rather than 'earthing')

Click to expand...

No. It's still bonding - i.e. to equalise potential - not to ensure operation of the cpd.

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Equalise the potential between what and what, and why?

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Well, the MET and true earth and between other metalwork.
Earthing is to ensure the cpds operate and disconnect the electrical supply.

JohnW2 said:

EFLImpudence said:

Also, the gas pipe may be distant from the water pipe so cannot be touched simultaneously, therefore supplementary bonding is not required. .... It's still bonding - although the gas pipe may not actually be extraneous if tested in isolation - i.e. before being connected to the boiler.

Click to expand...

I'm again a bit uncertain as to why you keep talking about gas pipes in relation to this discussion about the bonding of water pipes. In any event, I'm again confused. Even if one did have a gas supply which was not an extraneous-c-p (which, as above, I would think would be extremely rare), why would connecting it to a boiler (hence other pipework) suddenly make it an extraneous-c-p?

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If the bonding should be removed from the water supply, for whatever reason, the gas supply would become extraneous because of its connection to the water pipe by the boiler.
As I said, this may be a bit far-fetched.

I am trying to discover why the regulations state that the gas supply should be main bonded even though it is supplied in plastic and so is not extraneous.