Fixing TT earthing problems and gas bonding for an EV charger

[JohnW2]

Surely unsatisfactory but functional bonding would be a C2 ....

As I've said, I personally think that to give it a C1 would be totally ridiculous since there is clearly no immediate danger.

considering it would only be dangerous if two faults were to occur (bonding conductor disconnected and a fault introducing voltage to the pipework)?

I imagine that nearly everyone would give the absence of bonding it a C2, but a non-continuous bonding conductor maybe even that is surely open to debate? Some might well not regard it as 'potentially dangerous' since, as you imply, no single fault would result in any danger.
Edit: Attempt at correcting the complete mess up in my mind!

 

[EFLImpudence]

That statement would be all veryt well were it not for the fact that the author of the guidance and the authors of the regulations are, at least 'officially', one and the same (namely "the IET").

I have written, and others have agreed, that the guidance is perfectly reasonable/sensible, but I don't think the IET should word it in a manner that will make many people think (incorrectly) that it is a regulatory requirement.

If they really thought that 'continuous' bonding conductors is essential, it would only have needed an additional sentence to make that a requirement of BS7671 - but they clearly didn't feel that was needed.

So - - - not much point discussing it, then.

 

[EFLImpudence]

As I've said, I personally think that to give it a C1 would be totally ridiculous since there is clearly no immediate danger.

I imagine that nearly everyone would give it a C2, but maybe even that is open to debate? Some might not regard it as 'potentially dangerous' since, as you imply, no single fault would result in any danger.

Are you saying conductors that can be disconnected are C2?

 

[pete01]

Surely unsatisfactory but functional bonding would be a C2 considering it would only be dangerous if two faults were to occur (bonding conductor disconnected and a fault introducing voltage to the pipework)?

No bonding at all would be a C2

 

[JohnW2]

So - - - not much point discussing it, then.

No, no point in 'discussing' - but (in my opinion) plenty of point in moaning about the fact that 'guidance' (maybe even 'personal opinions') are being presented in a potentially misleading manner that makes them sound like regulatory requirements. There is at least one of us here who tends to do that, but it is (in my opinion) far worse when the IET do it.

 

[JohnW2]

Are you saying conductors that can be disconnected are C2?

I messed that up - my mind was thinking of absent bonding - not non-continuous bonding conductors. Despite what that led me to write (I'll edit it), I can't see how a non-continuous bonding conductor could be given a C2, since, per se, it does not present a danger and nor is it non-compliant with BS7671

 

[SUNRAY]

As I've said, I personally think that to give it a C1 would be totally ridiculous since there is clearly no immediate danger.

I imagine that nearly everyone would give it a C2, but maybe even that is open to debate? Some might not regard it as 'potentially dangerous' since, as you imply, no single fault would result in any danger.

I agree but the thing is bonding wires do get removed or fail and because 'it doesn't do anything' it doesn't get noticed until the second fault appears several years later.

 

[JohnW2]

I agree but the thing is bonding wires do get removed or fail and because 'it doesn't do anything' it doesn't get noticed until the second fault appears several years later.

See recent posts. I did not mean to say that 'nearly everyone' would give a non-continuous bonding conductor a C". In fact, I doubt that many would, not the least because it is not non-compliant with BS7671.

 

[SUNRAY]

I messed that up - my mind was thinking of absent bonding - not non-continuous bonding conductors. Despite what that led me to write (I'll edit it), I can't see how a non-continuous bonding conductor could be given a C2, since, per se, it does not present a danger and nor is it non-compliant with BS7671

I agree but the thing is people do have knowledge of the 'continuous' requirement and they do give C1's when it's not there and if it's a rental property it does have to be corrected. Let's face it the actual cost of reterminating 2 wires into a single crimp once one is on site is 50p plus 2 nimutes of additional time.

See recent posts. I did not mean to say that 'nearly everyone' would give a non-continuous bonding conductor a C". In fact, I doubt that many would, not the least because it is not non-compliant with BS7671.

I do understand what you are saying.

 

[JohnW2]

I agree but the thing is people do have knowledge of the 'continuous' requirement and they do give C1's when it's not there and if it's a rental property it does have to be corrected.

Yes - except it is not 'a requirement'. I would say that anyone who gives a C1 is just plain wrong, and that even giving a C2 is very much open to debate.

As EFLI has implied, the same reasoning would suggest that any protective conductor 'which could be disconnected' ought to be a 'C2', but that would obviously be ridiculous/impossible - despite the fact that your argument would remain (i.e. that if such a conductor ever were disconnected, that could go unnoticed for many years before a second fault arose, creating a danger).

I find it hard to understand how anyone can give a C2 to something without being able to cite a regulation that is being contravened.

 

[EFLImpudence]

I find it hard to understand how anyone can give a C2 to something without being able to cite a regulation that is being contravened.

Someone wrote some guidance. Why?

 

[JohnW2]

Someone wrote some guidance. Why?

Good question.

Regardless of the individuals concerned, both BS7671 and the Guidance Notes are written 'in the name of' the IET.

Given that regulations are ('necessarily') often fairly vague (i.e. can't possibly be 'comprehensive') it's not unreasonable for an organisation like the IET to publish notes/guidance aimed at helping people to understand how the regs in ('their') BS7671 can be implemented - but, as I've said, I personally don't think that such documents should be 'recommending' practices that are not required to satisfy BS7671, particularly if written in a way which will probably fool many readers into thinking that they are regulatory requirements.

As I've said, if they feel that something is 'essential', it should surely be a requirement in the regs, not a 'recommendation' in a guidance document?

This has some similarities to some of the TV adverts for toothpastes that we see and which rather make me laugh. One usually has a dentist endorsing a product and saying that it is what they 'recommend to all their patients' - which is fair enough. However, they often go on to add, almost as an afterthought, something like ".... AND it's the one I use myself". It always strike me that it would be very odd indeed if they recommended to their patients something different from what they 'use themselves', and that has some similarities to the IET 'recommending' a practice which they have not included as a requirement in their regs

 

[StuB]

Yes, as Octopus have confirmed, bonding not required.

I've sent them some more pictures along with some other details just so they can confirm they're happy with my setup.

I've just heard back from Octopus and they're happy with the photos of the gas pipe provided and therefore that gas bonding is not required so hopefully that'll solve that problem.

Now I just need to improve the rod earthing.

 

[ericmark]

I remember using the C crimp

so the earth cable was not cut, but only with flameproof installations. The point is Octopus is doing the installation in such a way as they don't disturb the original installation. What is the point of doing that, if they want to lay down rules on how the original installation is wired?

Personally, earth bonding water pipes, no a problem. What ever current goes through the pipes, worse case scenario is a water leak. But with gas, we need to be very careful that the bonding is the correct side of any insulating block, should there be a loss of PEN, we do no want high current going through gas pipes, as if they melt there can be a big bang.

So telling anyone to run earth wires, one can be dicing with death, so easy to get them wrong side of insulation block. However, with TT that is not really a problem, as the earth rod can't conduct enough current to melt a gas pipe.

 

[Risteard]

This is it in a nutshell, they have a number of their own rules such as only using a separate CU regardless of what consumer unit is actually installed already.

As the charger is tied in with a car purchase we have to have Octopus install it hence trying to satisfy their requirements.

In fairness very, very few existing DBs would be suitable, and they would also be unlikely to stock all different types/makes of protective device. Many brands don't have double pole switching RCBOs in a single module, which will rule many boards out.