Wiring colour convention UK2022 domestic situation

[Ventis]

UK 2022 based regs question.

Hello, I have a new extension and the builders electrician has required much of the house ( not asked for ) and replaced previously working wiring ( installed 2018) with new.

As a lot of the switches are hanging off the walls and nothing much is working yet I thought I would have a closer look. generally very tidy job but I am surprised to find no brown or blue L/N wiring. For example room 1: with 4 LED down lights switched live single pole switch has grey,black and brown + earth. My probe tells me that the brown is L the black is N and the grey is what? The wiring is b to switch, grey and black both in double terminal blocks so doing nothing at the switch. There seem to be multiple accessions where grey black brown have been used and other where conventional blue brown are in use. Some of the work in progress can be seen in the pics.( no they can’t the forum gives a security error when I try to attach them)

Is this normal and good practice and if so when did blue neutral disappear from domestic wiring codes ? And when do you get to choose which kind of cable to run, plus isn’t a three core and earth a bit of a waste of copper and cost in a lighting circuit anyway?

I would be very interested to read up on current regulations if there is a link,


Many thanks for any responses

 

[littlespark]

The brown/blue is the colours used in regular twin & earth (the earth being the bare conductor)
Brown/black/grey is the colours of 3-core and earth... and is perfectly usable.

Is there a new switch going in at that location? he maybe needs a second switchwire.... or is planning to carry the neutral through the switch to the next light....or is it becoming a 2 way circuit? There are many reasons.

Basically... dont worry.. Im sure the electrician knows what he's doing

Although... if switches are hanging off the walls.... nothing should be live that you can poke about with a probe.

 

[telectrix]

nothing should be live that you can poke about with a probe..

no fun there then?

 

[Ventis]

The brown/blue is the colours used in regular twin & earth (the earth being the bare conductor)
Brown/black/grey is the colours of 3-core and earth... and is perfectly usable.

Is there a new switch going in at that location? he maybe needs a second switchwire.... or is planning to carry the neutral through the switch to the next light....or is it becoming a 2 way circuit? There are many reasons.

Basically... dont worry.. Im sure the electrician knows what he's doing

Although... if switches are hanging off the walls.... nothing should be live that you can poke about with a probe.

Thanks for the reply, for the switch it controls 4 led down lighters all of the wiring to this is new, yes the switches are live but not to worry I may not be an electrician but I am an Engineer so I have done enough electrical theory to not grab housings while live, but good shout.

The reason for asking was in part curiosity and part that I don’t like not understanding what’s going on under my nose, and in my house.

I looked in the CU and everything there is regular blue brown. Is there a convention which says if picking up on an existing ring black is neutral or grey is neutral i take it only a complete twit would not keep the brown as a live or load

 

[loz2754]

The convention is that grey is to be used as neutral, but it must be over sleeved with blue.
You can use black as neutral, again over sleeved with blue. But the idea is to get away from thinking of black as a neutral conductor.
Another reason for taking a 3 core + e to the switches, that's becoming more common these days, is to provide a neutral at the switch to allow the use of smart switches.

 

[pc1966]

But the idea is to get away from thinking of black as a neutral conductor.

I don't really get the logic of that, though heard it a few times.

• In old systems black is the neutral.
• In over-sleeved systems both grey and black are line colours so you can't trust either, and even if sleeved you ought to check just in case.
• In most two-way switches (strapper-style) all are live anyway

Having consistency is helpful I guess but the potential usage of the 3 phase colours in other situations is so varied you can't really make a hard rule beyond sleeving it in a manner to say if line/neutral/CPC.

If anything making black/blue neutral makes more sense!

 

[brianmoooore]

If anything making black/blue neutral makes more sense!

It's a carry over from the old colours, when blue was logically used for the neutral in a red, yellow and blue 3 core.
Blue was L3 which, in the new colours, is grey

 

[davesparks]

I don't really get the logic of that, though heard it a few times.

• In old systems black is the neutral.
• In over-sleeved systems both grey and black are line colours so you can't trust either, and even if sleeved you ought to check just in case.
• In most two-way switches (strapper-style) all are live anyway

Having consistency is helpful I guess but the potential usage of the 3 phase colours in other situations is so varied you can't really make a hard rule beyond sleeving it in a manner to say if line/neutral/CPC.

If anything making black/blue neutral makes more sense!

In the old system when using a 3 core the convention was core 1 (red)-live, core 2 (yellow) switched live/earth, core 3 (blue) neutral.
Red became brown, yellow became black, blue became grey.

 

[telectrix]

In the old system when using a 3 core the convention was core 1 (red)-live, core 2 (yellow) switched live/earth, core 3 (blue) neutral.
Red became brown, yellow became black, blue became grey.

red/yellow/blue was used for donkeys. everone understood it as use same convention as you said. then along come IET and foists this brown/black/grey on us, to harmonise with who? nobody else uses it. waste of space. IET should be renamed "Incompetent Engineering ----pots".

 

[pc1966]

red/yellow/blue was used for donkeys. everone understood it as use same convention as you said. then along come IET and foists this brown/black/grey on us, to harmonise with who? nobody else uses it. waste of space. IET should be renamed "Incompetent Engineering ----pots".

The tale behind that is at the bottom of this article:

The history of colour identification of conductors

We consider identification of conductors by colour as the norm today, but it wasn’t always the case, as prior to 1916 conductors were not typically identified by colour.

bit.ly

 

[telectrix]

couple of years will see a change in the colours. another amendment.

pink to appease the transvestites.

grey to satisfy the gender neutrals

black to keep the wokes happy.

 

[Rockingit]

couple of years will see a change in the colours. another amendment.

pink to appease the transvestites.

grey to satisfy the gender neutrals

black to keep the wokes happy.

That's a bit harsh?

 

[Rockingit]

My interpretation of this from working with 1st gen apprentices after the change was simply that it encouraged the mantra of forcing people to assume nothing and double checking for their own safety. Up until that point I'd carried on using black as the N (oversleeved, obvs) but changed to using grey.