Conduit cabling sizes

[cliffed]

Helping out a fellow spark, 2nd fixing,nice school extension.
Have the regs changed,concerning cpc sizes with cables.
It’s all been specificed by consultant,the circuits are radials,which is a good thing.
Bit confused about the sizing of the cpc,obviously single cabling,4.0mm live & neutral,the strange thing is that the cpc is 2.5mm.
I always thought this should be 4.0mm,it this situation.

 

[Simonslimline]

Designers can't depend on the integrity of the installation nowadays and hence rightly specify separate CPC conductors.

The quality of kit available now is atrocious, brass bushes are paper thin and I'm comming across malleable boxes that are not threaded straight which is irksome for besa mounted lighting runs that you want perfectly lined up. I think most of this carp is now cast in China.

Absolutely agree.

 

[Flanders]

In SWA the cpc is always a different size, and a different material for that matter. It’s only if you use a cable with an extra core (eg 3 core for single phase) to use as a cpc that you get one the same size.

You can get 5 core swa i think the earth is the same size as the lives 5 core swa cable - https://www.electrical-trader.co.uk/cable/swa-cable/5-core-swa-cable

 

[Flanders]

In SWA the cpc is always a different size, and a different material for that matter. It’s only if you use a cable with an extra core (eg 3 core for single phase) to use as a cpc that you get one the same size.

You can get 5 core swa i think the earth is the same size as the lives 5 core swa cable - https://www.electrical-trader.co.uk/cable/swa-cable/5-core-swa-cable