3 core and earth cable colours

[mick]

Those are the new phase colours too. It makes it damn hard trying to replace red, yellow & blue phase indicator lamps with new-coloured ones! ;-)

[Ed Sirett]

When it comes to mains voltage heating controls all the bets are off. It is a good move to put brown sleeving or tape on any wire that could be at line voltage in your scheme. Never use the green/yellow for anything except an Earth. When working out what others have assume every could be live even a green/yellow one.

There is no specific colour code but brown indicate line voltage in a single phase installation.

[ARWadworth]

Your heart says do it. But please do not do it. Grey is now the neutral on 3 core and earth.

Adam

[fred]

In article , ARWadworth writes

Thank f'ck for an informed opinion without the grief, thx too to JR. Btw, hi, back from holiday.

[Dave Plowman (News)]

The snag is three phase colours have only one which relates to single phase. Before and now. With the old red blue and yellow, most used red for the line and blue for the neutral. With the new colours it seems using brown for the line and black for the neutral is not recommended - as I've just read here. And once you go to things like three port valves you soon run out of colours for cables that may be live under some conditions.

The other confusion is, of course, most use ordinary TW&E for switch drops so you have a neutral 'colour' being live. Of course you should sleeve it to show what you've done - so the same applies to any other arrangement.

[Dave Plowman (News)]

Was yellow the colour for neutral with the old colours?

[Bob Mannix]

Exactly and (FFS) who on earth said we shouldn't follow the correct convention for CPC - that was no part of the OP's question?

[Bob Mannix]

It tells you nothing about the situation where you are wiring up thermostats, which was the OP's question. Granted, if he were wiring up a two way switch he could follow the "convention" (of which there are probably several variants) by going across the page. This isn't a two way switch though. In the OP's case, it really doesn't make a lot of difference (except that it would be particularly foolish not to use brown for live). There are no conventions one can find in such circumstances and he was right to ask here just in case.

The only useful information (that is not on the leaflet, and which he (and I) have acquired here) is that the use of black for neutral in such cases is not recommended in certain quarters. I feel this is an arguable point but useful nonetheless.

[Andrew Gabriel]

Blue was most often the neutral IME (actually, I don't think I ever saw anything different when triple+E carried a neutral).

[John]

Competent - has a defined meaning - it is not intended as a means of questioning someone's intelligence. It means that someone is suitably qualified to 'sign off' that the work has been done to the correct standard.

See:

have previously wired houses and even a stage (conduit and MICC) - however, I am no longer "competent" - so I steer clear. I would hate to leave my off-spring with the problems with my house when I pop my clogs. (however I still have a bit of red and black in case I need to do a minor job!)

In the context questioning if a person is "competent" is no different to asking if someone has a driving licence.

No - I don't like it either - but this is where we are and Insurance companies and others will turn their back if they find work has not been done to the proper standard - and approved properly. Changing times!

[Andy Wade]

Table 51 of BS 7671 allows 10 colours for line ('live') in control circuits:

brown, black, red, orange, yellow, violet, grey, white, pink, and turquoise.

These are in the table, so don't need sleeving. There's no explicit definition of what constitutes a control circuit though.

[John Rumm]

I expect that last bit comes from the observation that many plumbers or boiler installers when faced with the need for three control wires and equipped only with T&E, have used the earth for something other than its normal purpose!

[John Rumm]

Your initial statement read (to me at least) as if you were using the traditional meaning of the word "competent". Especially as you made no reference to Part P, and did not capitalise or quote the word. Especially as you inferred there were other "issues" to address.

installing or upgrading main or supplementary bonding is notifiable (something explicitly stated as non notifiable in part P itself), It suggests (again incorrectly) wring in a shed, garage or outbuilding is notifiable (installing a feed to a detaced building would be - but not work in it necessarily). It lists nebulous terms such as "Lighting circuit" and "Ring/Radial power" etc. which again are meaningless and likely to confuse.

work by the sounds of it)

You would be better going to the "horses mouth" in these cases:

's are notorious for their lack of understanding of part P and their proclivities to not follow the approved documents themselves or "gold plating" the requirements.

Even under part P there is no requirement that notifiable work be done by someone who is a member of a competent persons scheme - there is the option to have it signed off by building control.

I think you are being over cautious in this instance.

Not the same at all. Someone without a license is not legally allowed to drive on the road. There is no legal requirement that you are competent (in either sense of the word) to carry out electrical installation work.

I have not seen even the faintest hint that insurers are attempting to avoid their responsibilities by using part P as an excuse.

Secondly, because one it not a member of a competent persons scheme, does not mean that work will be carried out in a substandard way.

[Bob Mannix]

True enough. I was presented (in a previous house) by the arrangement put in by the previous occupant who clearly didn't know about 3core+E cables and wondered how you could possibly wire up a two way switch. In the end he did it using 2core+E. No, not using the earth, he fed the upstairs switch from the upstairs lightling circuit and the downstairs switch from the downstairs lighting circuit, the landing light using either (or both) depending on the switches. All well until I started work on an upstairs light fitting (having pulled the upstairs fuse). XSWMBO turned on the light from downstairs and the landing bulb glowed dimly as the current went through my fingers. Grrr

[George (dicegeorge)]

have you a source for black, grey and brown indicator lamps?

[Andrew Gabriel]

classed as incorrect. Go and read Part P -- it's clear enough itself, clearer than those web pages.

A claim I've never seen substantiated. My insurance explicitly states it covers things that go wrong as part of DIY work.

[Dave Plowman (News)]

Indeed. So not using black under the same circumstances seems a tad idiosyncratic. But hey - professors in their ivory towers...

[Dave Plowman (News)]

An insurance company couldn't back out of a claim where the work was competently done just because some bit of paper or other doesn't exist. Nor could they back out of a claim where the work *was* incompetent unless they could prove intent to defraud.

[Dave Plowman (News)]

Doesn't leave many spare...;-)

[Andy Dingley]

Lucas