imperial size t&e and cu change

[BES]

help pls people
cu change. house built in 1968 all old imperial t&e. retired couple so cant afford a rewire. mem bs3036 board. ive not come across this old cable before and not quite sure how to proceed.maybe for assesment with elescsa or building control route (long story very boring).
1.does ths cable comply wth the regs for rating and vd
2.would you i&t and if all ok change board and make note on eic
3.cables need to be extended(adaptable box din rail and wago connector) i presume it is ok to extend imperial cable witn metrc as long as it is noted on eic.
4.do you think assessor or build control will be happy with cu without rewire.
5. what do you puy on eic for cable and cpc csa size.
thanks for your time
any help will be great

thanks neil

 

[Engineer54]

Well i can tell you that if your talking about PVC T&E, it will more than satisfy currant rating and VD. The cross sectional areas of 7/044, 7/029 and 3/029 are larger than the metric equivalents (6mm, 2.5mm 1.0mm) . Providing there has been no sustained overloading stresses on these cables they should last another 30 years or so!! lol!!!

 

[BES]

engineer54
cheers for quick reply
so no probs then with assessor or building control and i take it u just put the imperial sizes on eic.

 

[Engineer54]

No idea about assessor or the building control, i've never been involved with them ..sorry!!!

 

[BES]

ok mate thanks anyway

 

[Engineer54]

The only problem that i can think of is the CPC size, ....check on google, for 7/029 it will be a 3/029 CPC, for 3/029, it will have a 1/044 CPC. 7/044 will be 3/036 CPC.

 

[Richard Burns]

Should not be any problems if the existing cables are sound, except for the CPC csa.
building control and assessor should be happy with this so long as you have the readings showing that the circuits are not damaged or disconnected.
I tend to put the metric equivalent and write imperial beside it (as my form says mm2 at the top)
Joining to extend with metric is OK (so long as the circuit still complies) , but watch out for the current rating on wagos if you use them.View attachment imperial metric conversion 10.1.4.3.1.pdf

 

[topquark]

Also with regard to the cpcs, houses that old will probably have a couple of "main" junction boxes (one in the loft, one under the upstairs landing). You may find that the cpcs are not sleeved and are either just twisted together or in connector blocks. So don't be surprised if your R1+R2 is higher than you'd expect.

 

[telectrix]

and as it's been there since 1958, look out for Mr. Bodge-It DIY work and the dreaded shared neutral.

 

[Knobhead]

It’s still bloody good cable and so long as it not been abused, as sound as the day it was put in. Abuse modern cable and it will fail. It’s had 30 years out of a life expectancy of 80 years.
OK a bit of sleeveing on the CPC and you’re son will be looking at the rewire.

 

[BES]

thks for replys chaps
the couple have lived in house since new and ive been told he has never touched electrics only thing is a single way board for shower about 30 yrs old 30a 1361 wth 8.5kw shower wired in 6mm.and i presume landing light with borred neutral. at least lighting has cpc

 

[telectrix]

as long as the imperial cable is undamaged, even though 50+years old, it's better stuff than the crap we use now, and at least it's in the right colours. :biggrin5:

 

[Knobhead]

at least it's in the right colours. :biggrin5:

Don’t start me on that subject!