Multiple Conductors

[chloebear]

Whats the situation regarding the regs etc for using 2x 10mm single conductors bunched together for one circuit - let me explain the situation:-
I have a site that has an existing 4 core 10mm U/G SWA (+seperate earth) that is feeding a single phase sub main (small CU) and I need to increase the load to the CU. Curently as it is a 4 core only 2 of the cores are being used leaving 2 free. Options are dig up the existing route (heavy concreate - not desirable) or bunch the cores (I hate that term).
I understand that in the best practice the way to go is to upgrade the cable, but is there a practical or regulatory reason why the cores could not be bunched together??????

 

[bugsy]

Not that I'm aware of, I assume that the protective conductor is 10mm can ypou give more details regarding instalation ,load etc

 

[cornburn]

It specifically states in the regs that this is fine, can't be bothered to get the book out and check exactly what it says but have a look in the index should be pretty easy to find. I think it says same size conductors are preferred but that's what you have anyway. As above you need to check the armour CSA if you're using that as the CPC and make sure that's still up to the job

 

[pennywise]

With split concentric you have to combine multiple cores of equal size to make up the neutral so why not

 

[AEC]

433.4, 434.4, 523.8 and Appendix 10.

Good night time reading.

 

[chloebear]

Thanks all for the replies - just to confirm, the cores of the SWA are 10mm and I will be connecting this up to a 16mm further down the line, so by combining 2x 10mm cores in the SWA it will more than cover the 16mm requirement. The earth is a seperate 16mm.