2.5mm and 4mm in same ring - acceptable?

[Stormflex]

As per the title.

And if so, what would you put on the schedule of test results? (One end of the ring is 2.5mm and the other 4mm - so it is obvious at the CCU).

I am assuming it is 4mm. It is old colours (black and red) and the conductors are stranded so I'm thinking it's not 2.5mm. The other end of the ring is harmonised colours.

Thanks

Rich

 

[Sintra]

Older 2.5mm T&E was stranded.

 

[telectrix]

usaed to be called 7/029. recommend further investigation. is it def. one ring or 2 radials. have you got end/end continuity on all 3 conductors. suggest checking it's not some bodge somewhere on the install.

 

[Stormflex]

sintra, in that case perhaps it is 2.5mm - I hate trying to identify cable sizes. I'm sure I'll get better at it in time...

telectrix, have continuity. New cable run from socket #1 on the ring back to the CCU (less than 2m). The rest of the ring is old colours.

As I say, perhaps what I have thought is 4mm is in fact 2.5mm

 

[nickblake]

Ill back sintra on this one the old stranded cable very common till the early to mid 70's , and the outer sheathing can look very large and can be msleading the chances are it is 2.5 mm

 

[Stormflex]

Sounds good to me

It does indeed look chunkier than current 2.5mm.

But, as the house was built in 1969 (if I remember rightly) then that would tally up.

 

[telectrix]

sounds right. remember 4mm is almost twice the csa of 2.5. get a look at some 4mm next time in wholesalers. compare with what you've got. does look mlike socket 1 is a recent extension of the old ring final.

 

[nickblake]

definatly would

 

[Deleted member 9648]

You should note on the observations section if it is old imperial cable,something like...."existing ring circuit partially imperial CSA PVC cable,appears servicable and tests satisfactory"....on the schedule I normally write 2.5(imp)...

 

[SirKit Breaker]

I came across the exact same thing today. And stranded does look a lot bigger than single. There were 3 lines into one fuse, 2 single and 1 stranded. I guessed the 2 singles were the ring, and was wrong, got end to end between L, N, and CPC of both cables, one stranded and one single, the other single went off to some bodge job. Anyway IR was well down at a bit under 3Mohm, so advised rewire downstairs sockets. Thats my job for friday. i know it is in spec, but in a fortnight there is a new kitchen going in. So i told her do it now before it gets worse, and we wont be ripping the kitchen out in the future.

Cheers.........Howard

Cheers.........Howard