use a twin and earth as a three core

Good point UN, the cpc is surrounded by insulation but its not the same as the LN conductors which in effect have two layers .
Under fault conditions the cpc will be in as onerous situation as the LN
I am sure it might be changed on a whim in the near future.
RS

 

Not only that, it would save a lot of faffing having to sleeve it; prevent DIY'ers not bothering to sleeve it and provide some basic protection should an idiot decide to use it as a live conductor. Flex and SWA has no bare copper inside it so quite why 6242Y has is odd. It can't be that difficult to include it in the manufacturing process surely?

 

Same with 6243Y, something that has also mystifiy me for decades.

 

Me too!

 

Cores in SWA were never really designed for use as a CPC, the armour was. We have just adopted (sensibly) to use a core to supplement. That's why its Brown/Black/Grey and not Brown/Blue/GreenYellow (although if you want to pay the premium, it is available, as is 5 core).

I think it is likely down to cost. It would make the cable that much wider and heavier too. It also makes it easy to strip, lol.

 

I'm surprised that this post ever got off the ground let alone create so much response, surely anyone with the slightest bit of electrical knowledge knows that an earth conductor should never be used as a live conductor. (except plumbers when installing room stats etc.!)

 

So we're all agreed then, give it a go. What's the worst that can happen?

 

A fire ??

 

Hmm. What's the worst that can happen. Hmm. Best not answer that one, eh Cliffy.

 

No, not a fire. Fire is breathed by dragons. No its not fire.

 

The worst thing that could happen i'd say is that someone could get a belt from what they thought was an earth connection!

 

It would most certainly NOT be a grey area. The cpc in T&E is UNINSULATED. The sheath is mechanical protection and NOT insulation. The use of an uninsulated live conductor is generally prohibited (except through placing out of reach, with barriers and enclosures etc. but placing out of reach is absolutely not ever permitted in a domestic installation!

 

It will still pass a 1000v IR Test. So it's not that uninsulated. Just saying... not advocating using the CPC as a live conductor.

 

As a dreaded DIYer (who rewired his first house 40 years) ago it would never even occur to me to use "the earth wire" for anything other than that it was designed for.
In a new house I bought 30 years ago there was a short in a porch light when first operated. The electrician said he would connect it up another way. I often wondered how he did it.

 

SWA doesn't have insuated armour (the cpc) so I'm not sure that your comparison is justified.