Is it allowed ...

Nov 23, 2013 46 Replies

... to use 3 core (ie, brown/blue/earth) flex where the earth is used as a live conductor? (With appropriate red markings)?



The twilight sensor on my outside lighting has failed, and I don't really want to reuse the 20 y/o wiring to it, nor do I want to buy a couple of meters of 3 core (no earth required; the sensor isn't earthed). Last time I just used 2 pieces of 2 core flex in parallel & marked one of them up as the switched live, but that's a nasty kludge, too.


What if the OP used brown markings and not red ones:-)?

I suspected not. Oh, well, better look forward to getting reamed for a couple of meters of appropriate cable. Probably costs more than the bloody sensor, which was 6 quid on eBay.

I'd think not really, but I doubt if ,in practice if it matters, just disconnect it before you

1 die 2 Move 3 go into hospital!

Brian

It's disconnecting it before someone else dies that's the issue!

The chapter and verse is

"514-04-02 The bi-colour combination green-and-yellow shall be used exclusively for identification of a protective conductor and this combination shall not be used for any other purpose. Single-core cables that are coloured green-and-yellow throughout their length shall only be used as a protective conductor and shall not be over-marked at their terminations, except as permitted by Regulation 514-04-03"

514-04-03 relates to combined earth/neutral conductors which can be green/yellow marked with blue sleeving, or blue marked with green/yellow sleeving.

This

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is £3.50 a metre on ebay.

Triple+E cable is a lot cheaper.

Or strip some flex to get the cores you need and heatshrink them all togeth er to make your own cable?

Owain

5m for just under 6 quid delivered on ebay so not quite :-)

Darren

I've got a drum of 3+E sitting in the garage, that's of no use as it's old colours. I'm sure a couple of meters could find their way into a jiffy bag ...

BTW, when the original one failed & I came to replace it with the present one, it had been wired with T+E, with the earth used as a live conductor. It had been wrapped in red tape ...

Well, a little more:

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but you will have some spare for the next time.

Looking at that reg I'd say it wasn't a problem. He's thinking of using 3 core with the terminations marked, not single core, nor an unmarked green/yellow core.

I realise you can "twist" it that way ... if you're saying the second sentence isn't the operative one in Huge's case because he isn't using single core cable, then the first sentence must be, and it says green/yellow must not be used for any other purpose.

The second sentence outlaws marking at the terminations for single core cables, the first sentence does not outlaw marking at the terminations.

On Saturday 23 November 2013 17:00 Huge wrote in uk.d-i-y:

No, never.

If anyone cares, I'm pretty sure that I can locate a specific regulation, because I *think* I recall coming across it a long time ago.

Anyway, Irrespective, to use a core that is designated along is length with green/yellow markings is highly unwise when some other bugger[1] comes along, makes a valid assumption then kills themselves.

[1] This type of scenario usually involves "some other bugger" because you know what you did. But not your sparky (if heaven forbid, you got too old to fix something, or you were away and SWMBO had to call one in in an emergency) or the guy you sold your house to...

It's a safer kludge... The correct way of course is a bit of 4 core, earthed at one end and the redundant earth terminated blind at the far.

>

On Saturday 23 November 2013 17:23 Andy Burns wrote in uk.d-i-y:

Ah - knew I'd seen that before...

On Saturday 23 November 2013 17:42 Huge wrote in uk.d-i-y:

Even worse - conductor without basic insulation (the sheath's job is to protect not to insulate).

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- a useful supplier for short lengths - do YY control flex by the metre at sensible prices. N-core YY cable gives you one grn/ylw core for the CPC plus N-1 numbered black cores which you can sleeve brown or blue etc. as required.

In message , Tim Watts writes

I asked a similar question in here a little while ago when I found my electro-mechanical thermostat actually needed a neutral to work correctly. Like you I remember the answer was definitely no.

For short lengths of twin/triple and earth in that situation, I tend to just pull out the whole conductor. Being uninsulated, it comes out pretty easily.

Cheers,

Colin.

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