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.

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.

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.

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

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.

mapj1 said:

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

If the issue is with the termination of the MOP's tails into the consumers RCD, then as those terminations are part of the installation of the tails themselves it would naturally follow that it's within scope of reg 24(1)(b) irresepective of who owns the RCD.

By contrast the outgoing terminals of the RCD would not be in the scope of reg 24 even if it is owned by the MOP/DNO - because presuming it's suitable for isolation then it's under the control of the consumer.

but - in this case it sounds like it is "under the control of" the customer - its not locked  behind a DNO key is it, and if so, its the customers RCD, surely - why would it belong to anyone else ?

I'm not being funny, I'm struggling to see what makes it appear that  this RCD belongs to anyone but the customer - After all the tails that leave the meter are the customers to cut into and re-route if they wish - as very commonly happens to add a second CU for a car charger, larger shower or whatever. The fact that the addition of a single pole henley blocks into the  tails might mean it has ben cut in live without removing the DNO fuse is a detail - they are the customer's tails.

I'm still seeing this as no different to the terminals at the incomer switch of a CU when there is no RCD - it is just the first thing on the free end of the meter tails.

Now, the MOP technicians may have caused to to cook by half pulling its wires out, but equally they may argue, and it would be quite hard to prove one way or the other, that that means the original installers did up the terminals or clamped the tails in a substandard way - UK meter tail is notoriously wilful and imposes very large forces on a cage clamp terminal if pulled by the average installation monkey. The seal is irrelevant, it is post-meter.

and the MOP often does not 'have' any tails.

Mike.

but - in this case it sounds like it is "under the control of" the customer - its not locked  behind a DNO key is it, and if so, its the customers RCD, surely - why would it belong to anyone else ?

I'm not being funny, I'm struggling to see what makes it appear that  this RCD belongs to anyone but the customer - After all the tails that leave the meter are the customers to cut into and re-route if they wish - as very commonly happens to add a second CU for a car charger, larger shower or whatever. The fact that the addition of a single pole henley blocks into the  tails might mean it has ben cut in live without removing the DNO fuse is a detail - they are the customer's tails.

I'm still seeing this as no different to the terminals at the incomer switch of a CU when there is no RCD - it is just the first thing on the free end of the meter tails.

Now, the MOP technicians may have caused to to cook by half pulling its wires out, but equally they may argue, and it would be quite hard to prove one way or the other, that that means the original installers did up the terminals or clamped the tails in a substandard way - UK meter tail is notoriously wilful and imposes very large forces on a cage clamp terminal if pulled by the average installation monkey. The seal is irrelevant, it is post-meter.

and the MOP often does not 'have' any tails.

Mike.