Anyone seen this before

[jelliottelectrical]

Started a job yesterday and this cable runs from the above car crash, to the consumer unit at the other end of the house. Joint here is where the meter was moved, and will be sorting that out

I thought it initially was a 16mm twin and earth but actually appears to be a flat conduit with singles inside. Just wonder if anyone had come across it before and if there’s a name for it!

 

[pete01]

I didn't think anyone would find that....

 

[Murdochcat]

“Above car crash” ?

Think I would be looking to replace the tails end to end

 

[Scally-Ho]

I am somewhat surprised to see that in a domestic location. From what I can see in the photo, someone has used old down service PVC conduit that used to be used when connecting an overhead fed TT service down to the main cut out. House probably wired on the QT by a jointer or other linesman type employee. The ends still look in good condition so if all holds up under testing, I'd leave in situ. At a guess I'd expect to find 7/076" or7/044" conductors under the insulation.

 

[sparkwright]

Yes, it's a cable system used to put in walls and ceilings, typically on concrete blocks of flats and offices.
I think the advantage of it was you could put in straight in screed and plaster without further protection.
(Bit surprised to see it under a wooden floor, but then again, why not?)

 

[jelliottelectrical]

“Above car crash” ?

Think I would be looking to replace the tails end to end

Yep

This is the meter box

The tails run up the cavity and join to that cable under the floor, then under the floor approx 25 metres to the garage where the consumer unit is. The single insulated cables go via the submeter to feed an annexe. And there’s a 6mm swa feeding another barn, via only an RCD. House is being totally refurbed so now is the time to sort it

I’m fitting a switchfuse and I’m now looking to run an SWA to replace it

 

[securespark]

That's similar to something I saw in the 80s called Aercon.

Prewired flat conduit.

 

[Taylortwocities]

What limits the current on the tails/T&E? Tails longer than 3metres cannot rely on the service fuse for protection.
DNO rules IIRC.

PS Someone who comes to change the meter will just walk away again. that MK box with the RCD cannot be there.

 

[jelliottelectrical]

What limits the current on the tails/T&E? Tails longer than 3metres cannot rely on the service fuse for protection.
DNO rules IIRC.

PS Someone who comes to change the meter will just walk away again. that MK box with the RCD cannot be there.

Nothing at all!

No I know and it’s all going to be replaced

 

[JohnD]

PS Someone who comes to change the meter will just walk away again. that MK box with the RCD cannot be there.

I have a feeling it would fall out if you undid that screw.

 

[EFLImpudence]

What limits the current on the tails/T&E?

Nothing at all!

According to the picture; 80A (max) main fuse.

Tails longer than 3metres cannot rely on the service fuse for protection.
DNO rules IIRC.

Can the DNO alter physics to get you to install an identical fuse that will protect them?

 

[Taylortwocities]

Can the DNO alter physics to get you to install an identical fuse that will protect them?

Ye cannae change the laws of physics, Jim. But there's a logic to the requirement of 3 metres (2 in some areas) as specified by the DNOs. Its all buried HERE and HERE

 

[EFLImpudence]

Ye cannae change the laws of physics, Jim.

Q.E.D.

But there's a logic to the requirement of 3 metres (2 in some areas) as specified by the DNOs.

Is there?
There seems to be a significant lack of logic everywhere - except the regulations if read properly.
I must have missed the reason for the two metre variation.

Its all buried HERE and HERE

I think they all have misinterpreted the regulation; the same as Eric frequently does in stating that ring spurs similarly have a maximum length of three metres.

 

[jelliottelectrical]

Ye cannae change the laws of physics, Jim. But there's a logic to the requirement of 3 metres (2 in some areas) as specified by the DNOs. Its all buried HERE and HERE

From memory it was something like the DNOs don’t like you relying on their fuse for protection. I mean if I put an 80a fuse in the switchfuse I’m installing there is no discrimination between the two!

 

[JohnW2]

Ye cannae change the laws of physics, Jim. But there's a logic to the requirement of 3 metres (2 in some areas) as specified by the DNOs. Its all buried HERE and HERE

Don't they trust their own fuses?
It seems that they are perfectly happy with long 'tails' between cutout and CU being protected by a consumer's fuse of the same rating as theirs in the cutout.