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Who is responsible in a failure between meter and RCD?

Peter Francis

I appreciate that @aligarjon had already posed a question about the responsibility boundaries at cut-out and meter.

But I have a friend who recently suffered a small (fortunately contained) fire caused by a meter tail pulling out of the RCD on the feed side (downstream from the meter). The RCD had been installed by his solar PV installers and a couple of years later his meter was changed by EON, along with the meter tails to the RCD. The feed side terminals of the RCD are enclosed and not accessible by the consumer, as are the terminals to the meter and cut-out.

Notwithstanding the parallel problem of the energy company removing the incoming earth connection to the property when they changed a pole-mounted transformer without confirming that there was a local earth, which resulted in some interesting potential levels when the fault occurred, who is responsible for ensuring that the installation is in good order and is to a sound standard, if the consumer is not permitted access to inspect everything?

So far he is getting the expected runaround from the energy company, the supply company and OFGEM, possibly in the hope that he will go away and sort it all out for himself, but unfortunately this is not a guy who goes away quietly when he senses an injustice or wrongdoing, but he's also an engineer with a problem-solving mindset, so doesn't accept administrative brush-off.

I'd appreciate some guidance, thank you.

  • 0 in reply to Keir Stitt

    But it sounds like in this case, the RCD is not MOP or DNO property - or is it ?

    Normally consumer responsibility starts at the meter output.

    More confusingly, in a large building the cables between the DNO incomer and the meters are often the building owners responsibility - the so called BNO_ building network operator - which in the common areas of small flats is sometimes not really a legal entity  at all, but usually a harassed subcontractor to a property management company.

    I do agree its daft by the way, and that an isolator belonging to the DNO or the meter company that the consumer was permitted to use, would be  sensible, or even a means of removing the load side only terminal cover on the meter. There were a few meters made with a user operable switch inside for isolating the output, but that idea seems to have fallen by the wayside with smart meters.

    the whole issue of how things are isolated to work on and by who is an unnecessary minefield.

    Mike.

  • 0 in reply to mapj1
    mapj1 said:
    Stuff beyond the output side of the meter is not normally DNO sealed.

    The tails are in the meter and therefore can't be worked on without cutting seals on both the cutout and potentially the meter terminal cover.

    Therefore MOP on behalf of the supplier is technically responsible. Reg 24 ESQCR spells it out. If the tails leaving the meter are owned by the supplier [often the case up until e.g. the henley blocks or an isolator] then irrespective of the fact that these tails are also part of the consumers installation they are the MOPs responsiblity. Conversely where an isolator is fitted then anything downstream of that isolator is under the control of the consumer so even if the tails were technically in the ownership of the MOP they'd be exempt from Reg 24.

    Hence it's always preferable for all concerned that an isolator is installed. Then everyone can go about their business without silly arguments about who's responsible for what. In leu of this then [unless it's urgent] hold the supplier to their responsiblities. From what I gather the complaint here is that the opposite end of the tails are loose in a front end RCD, it would be trivial for the MOP to torque these up and re-seal everything - and they'd probably put an isolator given the trivial cost just to avoid having any future responsibility. If those tails are owned by the MOP then it's there responsibity to ensure they are installed and maintained to prevent danger - which must include terminations at both ends including the consumers end.

    www.legislation.gov.uk/.../made

  • 0 in reply to Peter Francis

    Stuff beyond the output side of the meter is not normally DNO sealed.
    It may be customer sealed (landlord's supplies to prevent tenant theft are an example or just as an anti- tamper precaution in buildings with  unknown users - our Scout hall does this for example - anyone can open the cabinet door to reset a breaker, but to open the box requires  seal to be cut.)
    The customer is at liberty to cut (and replace or not) seals on Henley blocks switches  so on that are downstream of the meter - and this is often done where there is a split to more than one CU for example.

    Mike.

  • 0 in reply to Peter Francis

    That would explain why the installation is fronted by an RCD - if the DNO decided they can't provide an earthing conductor.

    As I say, just get the supplier out. Worse thing that can happen is they take a look and say its not their's. But if there's no isolator then technically the MOP should be the one changing the tails to the meter anyway - even though most electicians will cut the seals and do it.

    Most suppliers will install an isolator for typically < £100 anyway. Then you know exactly where the demarcation is and your electician can work safely without needing to depend on cutting seals or waiting for DNO/MOP.

  • 0 in reply to Keir Stitt

    ESQCR is a good call because of the overhead power supply and some changes to the pole-mounted transformer earlier (this year, I think). It was suggested that the earthing system may have been changed at that point from TNC-S to TT. I haven't got any evidence myself, but if there was no good local earth, then that could throw a wobbler to the safety at the property!

  • 0 in reply to Chris Pearson

    I think the old tails were the wrong colours, so the meter installer replaced them, Anecdotally, it sounds like instead of leaving an s-bend to spring them into the RCD, they ended up much shorter.If the terminals were torqued correctly, it shouldn't have caused much of an issue, but since the device was an existing consumer one, they possibly made an assumption, or forgot.

  • 0

    What was wrong with the old meter tails? Too short?

    I think that they belong to the consumer. When I had a new supply installed, the "consumer's tails" (see OSG Chapter 2) were connected to my isolator, which made life easy for the supplier's installer.

    Be that as it may, as Andy has pointed out, whoever touched them last is responsible for the state of the connection by virtue of owing a duty of care. I also agree that it may be difficult to establish negligence - that is where experts (like JP) come in.

  • 0

    Ideally these days the supplier will provide an isolator after the meter - then the demarcation is simple.

    The tails leaving the meter are your suppliers and everything before the meter is your DNOs.

    If you can see missing insulation then telephone your supplier. If your supplier is being awkward then mention the ESQCR regulations because ultimately its their equipment and they are obliged to maintain it in a safe condition.

    In my experience once you tell them that uninsulated conductors are on show then you can expect the MOP to be visiting typically within 24 hours. So no point trying to DIY this or even paying an electrician to. The supplier is responsible, let them do it.

  • 0 in reply to AJJewsbury

    Andy

    Thanks for that.

    I do think that this long after the meter was replaced, it's going to be challenging to prove that the installation was at fault.

    I've suggested to the guy to gather as much evidence and information that he possibly can, along with the reviews from his electrcian and responses from the ministry (he never aims particularly low!) and presents the case as best he can, otherwise it's all down to him, and most organisations now seem to take the view that the buyer or consumer is the ultimate responsible party unless proven otherwise!


    Peter

  • +1

    if the consumer is not permitted access to inspect everything?

    I'm not sure that's quite the case. There's nothing (legally) stopping an owner picking up a screwdriver and opening up the enclosures. Even if sensibly it would be recommended that if the owner didn't possess suitable electrical skills, that the actual doing of it should delegated to to someone who does. DNO/supplier stuff would normally be sealed to (legally) prevent access by anyone else, but consumer owned equipment shouldn't be.

    On the other hand, if the problem was caused by the supplier's meter change causing the cables to be moved (or re-terminated) - so causing a loose connection in the consumer's equipment, I would have thought that the supplier would have failed in their general duty of care. This after all is a well known problem in the industry - some consumer unit manufacturers now include extra cable clamps to mitigate that very risk, so it would be reasonable for the supplier to take precautions to mitigate the risk - e.g. checking the tightness of consumer side terminals or even formally informing the domestic customer of the risk and recommending they engage an electrician to check the installation (like they sometimes do when they spot inadequate earthing).

    The problem of course would be proving that the meter swap was the root cause of problem and it wasn't the result of something else - e.g. a latent fault in the RCD itself, causing overheating, which then loosened the terminal; or even later tampering (by person or persons unknown). That's the sort of thing lawyers make their money out of.

    live and neutral were "inverted"

    That's a common enough condition. It can be seen even when the supply earth is perfectly good, if one of the lines gets connected to true Earth. The typical cause is a L-PE fault in a TT installation with a faulty RCD. In effect both LV conductors are connected to Earth (rather than just the N) so the potential to true Earth is then a tug of war between them with N (and hence supply PE) ending up being a long way from true Earth, with large step voltages around the both means of earthing.

       - Andy.

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