What would you do about this one.

Client (local authority) want the consumer unit upgrading from a plastic one to the latest spec. I have also done a bit of repair work in the kitchen so it can be plastered. This is how the power gets from the street to the consumer unit.

firstly TNS with a looped supply into meter and isolator in a cupboard by the front door.





But out of the isolator it goes to a length of two core pyro with a bonding clamp on it for the earth. The pyro runs along the skirting board, under the bootom stair tread to the cupboard under the stairs where it feeds another cut out fuse with another bonding clamp on the other end of it.



The tails from the henley block go to the consumer unit which is on the other side of the wall to the henleys. The property was re-wired in 2016 with a dual RCD MEM plastic board. I can't work out whats gone on with it, looking at the wooden board to the right of the henleys it looks like the meter/fuse box used to be there at one point and its been moved to the front door but the supply cable at the front door looks as old as the hills anyway, house was built in about 1920 judging by the penny we found under the floorboards. So if the electric board have moved the meter at some point, who owns the pyro?

I know you cant use a bonding clamp as a main earth terminal but I've seen it done so many times on incomers, so what to do, insist I replace it with a piece of SWA along with a fused isolator, but there isn't any more room in the cupboard, run a separate 16mm earth. Plus the pyro ends are single insulated and there isn't a gland on either end of the pyro but I'll bet the entire street is done the same way. I know from experience that the councils send a bod round afterwards and their job is to make installers life as much of a misery as they can by inspecting everything with a microscope.

I would run a new distribution circuit in SWA, if its too tight to add switch fuse then replace the isolator for one.

7029 dave said:

I would run a new distribution circuit in SWA, if its too tight to add switch fuse then replace the isolator for one.

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That's what my mate said but the isolator is owned by the metering company and the top half is sealed, replace anyway? I could probably make it fit if I shuffled stuff around a bit inside the cupboard but that would still mean the seal fairy would have to pay a visit.

If you look at the sun and squint, there is no seal

The pyro is DNO property so not your responsibility. I have seen it a lot in flats.

bill01803 said:

The pyro is DNO property so not your responsibility. I have seen it a lot in flats.

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It's after the meter and on the outgoing side of the isolator.

I would tend to agree with Bill (Post #5), its the DNO responsibility. We cant see that it is after the meter.

Really need to see where Brown and Blue tails that go down between the meter and the Trilliant device go to as suspect they are split (maybe Henley Blocks?) below the meter (Move the paperwork and get photo).
One pair feeding meter the other pair looped around to top of isolator before terminating to the MICC! so still DNO.

DefyG said:

I would tend to agree with Bill (Post #5), its the DNO responsibility. We cant see that it is after the meter.

Really need to see where Brown and Blue tails that go down between the meter and the Trilliant device go to as suspect they are split (maybe Henley Blocks?) below the meter (Move the paperwork and get photo).
One pair feeding meter the other pair looped around to top of isolator before terminating to the MICC! so still DNO.

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Read the OP post again, he says the other end of the micc goes via Henley blocks to the CU. So it must be after the meter else it would be free vend. In one of the pics you can just about see tails blue brown on floor level my guess is the feed the top of the iso from the meter. Also the pic of the isolator if you expand it can see a blue tail run up towards the top of the isolator.

Yes the first bit is just standard wiring, TNS lead cable into cut-out, cut-out to meter, meter to DP isolator, top of isolator is sealed as per normal. From the unsealed output of the DP isolator it connects to the MICC cable which runs across the hall skirting board, under the stairs and feeds another cut-out fuse in the under stairs cupboard. This second cut-out then feeds the consumer unit via a couple of henleys.

the more I think about it the meter must have been under the stairs at some point looking at the short tails that come out of the second cut-out into the henleys, they look the perfect size to feed into a meter.

I'm wondering whether its anything to do with the looped supply, if you look at the first cut-out next to the meter there is a second cable which is a bit newer, you can see the copper earths from it twisted together, probably a split con cable although I didn't look too closely. Maybe the house next door's supply failed and they couldn't re-feed it from the middle of this house so dug the cable up at the front of the house and put a new cut out there where they could feed it from. Its all very strange.