Earth from cutout to MET - who is responsible?

[JohnD]

in the absence of the isolator those tails would usually have gone straight to the Main Switch of a CU, access to which would obviously not have been prevented by a DNO/supplier seal

and that's surely the point of the isolator as main switch; so that you can safely work on downstream parts of the installation, even if (say) the tails are loose in a metal CU

 

[JohnW2]

and that's surely the point of the isolator as main switch; so that you can safely work on downstream parts of the installation, even if (say) the tails are loose in a metal CU

That's all true, as far as it goes, but it still doesn't answer my question ...

... why do they feel a need to put on an 'official seal' to prevent/discourage access to the supply-side terminals of an external isolator, when they obviously don't (couldn't) do anything to prevent/discourage such access when the same tails (always live, unless cutout fuse is pulled) are connected to the supply-side terminals of an isolator within the CU?

Kind Regards, John

 

[EFLImpudence]

I suspect you are attributing thinking to where there was none. They just do.

 

[JohnW2]

I suspect you are attributing thinking to where there was none. They just do.

I suspect the same as you, hence my question (which, I suppose, was therefore semi-rhetorical, although someone may have come up with a rational/credible actual answer)!

Kind Regards, John

 

[flameport]

Seals exist for one purpose - to allocate blame in the very rare event of some major problem.
Other than that, they are generally useless items and are ignored by most.

 

[JohnW2]

Seals exist for one purpose - to allocate blame in the very rare event of some major problem. ... Other than that, they are generally useless items and are ignored by most.

I can't disagree with any of that, but I'm not sure that even that explains the plastic seal (if that's what it is) on the cover over the load-side terminals of my isolator. I haven't bothered to examine it closely, but I'm not convinced that it (bottom-right in photo below) actually is a seal - is it perhaps some sort of 'clip' that can be removed without having to cut it? ...

 

[ban-all-sheds]

I suspect you are attributing thinking to where there was none. They just do.

Which, of course, is an utterly indefensible position.

People die all the time because others don't think, and therefore the practice of not thinking rightly deserves condemnation, no matter how trivial the subject, because it is the whole idea of not thinking which should be eradicated from society.

 

[JohnD]

is it perhaps some sort of 'clip' that can be removed without having to cut it? …

I think it's a "tamper-evident" seal - very easy to remove, but shows when it has been. They are sometimes like a plastic padlock with a locking loop having barbs on it (like a cable tie) so they can be pushed in but not pulled out. Sometimes they have serial numbers, or have company initials moulded in. It is not unknown for people to cut them with great care and glue back together after.

and that's surely the point of the isolator as main switch; so that you can safely work on downstream parts of the installation, even if (say) the tails are loose in a metal CU

so I think an isolator adds safety. In a domestic installation it will be used approximately never, so is unlikely to wear out or go wrong.

Mine was customer-supplied and has no seals on it.

 

[securespark]

I agree with EFLI, with that cutout, the DNO have to attend to access it. But there is nothing to stop you fitting a length of 16mm² an earth block adjacent, or taking a length to the earth terminal in the CU.

 

[JohnW2]

I think it's a "tamper-evident" seal - very easy to remove, but shows when it has been. They are sometimes like a plastic padlock with a locking loop having barbs on it (like a cable tie) so they can be pushed in but not pulled out.

Yes, that's what it looks like, but I was wondering whether it might not even have the barbs. I'll have a closer look sometime!

However, it still begs the question as to whose 'tampering' one wants to be 'evident'. Why would there be a perceived need for 'tamper-evident' seals at that end of the pair of conductors but not at the CU end?

... so I think an isolator adds safety. In a domestic installation it will be used approximately never, so is unlikely to wear out or go wrong.

I don't think anyone has suggested otherwise. This discussion has been about the seals, not the merits (or otherwise) of having an isolator. As you imply, once in a blue moon they may be a small convenience in a domestic installation. The only person I can ever recall having expressed a fairly 'anti' opinion was the late-lamented westie, who often observed that DNOs not infrequently got called out because of overheating of the cable terminations in poorly-installed (by supplier or meter operator) isolators.

Kind Regards, John

 

[jg321]

Is this a knock-out?

I can confirm this was a knockout - and despite it not being obvious in the original photos it looks to have been knocked out quite some time ago

Thanks guys.

 

[JohnW2]

I can confirm this was a knockout - and despite it not being obvious in the original photos it looks to have been knocked out quite some time ago

"not being obvious" would seem to be somewhat of an understatement! Are you saying that it had previously been 'knocked out' and then somehow 'knocked back in' again? Do I take it you're saying that you can get to the terminal screws through it?

Kind Regards, John

 

[plugwash]

I may just be seeing things, but when I look very carefully at the photo (and clean the area of my monitor) I can barely see what look like two small circular features on the recessed area that seem to line up with the terminals. I guess these are holes allowing access to the terminal screws.

 

[jg321]

"not being obvious" would seem to be somewhat of an understatement! Are you saying that it had previously been 'knocked out' and then somehow 'knocked back in' again? Do I take it you're saying that you can get to the terminal screws through it?

Yep, and it just fell out when I brushed past it, odd isn't it. I can confirm that it is now possible to reach the terminal screws.

 

[JohnW2]

I may just be seeing things, but when I look very carefully at the photo (and clean the area of my monitor) I can barely see what look like two small circular features on the recessed area that seem to line up with the terminals. I guess these are holes allowing access to the terminal screws.

Your eyesight must be a lot better than mine (or your screen much cleaner!) ...

Kind Regards, John