Twin brown and earth - can one core be marked blue for neutral?

[sparkwright]

The electrons care little, or not at all, what the colour of the plastic insulation is -the colour is simply for identification by the installer, and those who might follow.

Not at all, I would say.

 

[JohnW2]

Not really any different to using brown and blue cable for a switch drop when you have to put brown sleeving over the blue. ... Not really any different to multicore flex or swa where the cores ate all the same colour, but do have numbers printed on them. ... It's inconvenient, definitely will give the next man something to think about, but I seem to recall pyro would have black sleeves on each conductor, and that had to belled out, and then the live wire was (nearly always) identified with a piece of red sleeve or similar.

Exactly. As I wrote, I certainly wouldn't personally describe it as 'very undesirable' - and, as I also wrote, presumably less desirable than (non-compliantly) leaving L and N both identified only by brown insulation.

If it doesn't break any rules, and it's not easy to replace, then it's going to stay that way - I would imagine.

I feel sure that's the case but, as above, I would certainly advise oversleeving the appropriate brown-insulated conductor.- not the least so as to achieve compliance with BS7671.

Kind Regards, John

 

[craig1234]

Thanks all for your input. The cables in question are 1.5mm so what I have done is purchase some blue sleeve which I have added to one of the brown cores in such a manner (i.e. the sleeve is the same length as the core) that unless you look closely (or notice that one core is thicker than the other!) then it looks as though the "correct" cable has been used.

For the outside socket, this is now fed from a switched spur which forms part of the ring.

 

[Sureitsoff?]

Fwiw I use small brown cable ties on blue cables to identify SW live

 

[craig1234]

I was wondering what was acceptable for cable marking - thought about brown tape with a cable tie!

 

[ebee]

Personally I always prefer sleeving to tape, tape can fall off after a while. OK then sleeving can fall off too but it is held in place if the end of the conductor is correctly terminated. Also if long enough and has sufficient bend in it that also helps it stop falling off too. Of course as John says then heat shrink helps quite a lot too. I also prefer to leave the sleeve very nearly as long as the insulation on the conductor that might help to retain it a bit than just a short "flag" length piece but leaving just a small witness of insulation colour at each end helps aid in identification.
I would actually rather see a True Brown for L and a Blue mostly sleeved throughout its length as say a SW L than see two Browns or a light brown and a dark brown. Therefore vice versa if you identifying a brown as a N conductor.
I might be peculiar though (I am sure that some on here would agree that I am!).
It is important to make it clear, make it robust, even though anybody working on it should verify any polarity before touching it anyway.
Things often get mixed up and muddled so always assume they have been util you have checked adequately for safety.
Never ASSUME anything . "ASSUME" can make a "ASS" of "U" and "ME".
And ditto to all of that with the old, lovable, Reds and Blacks too.
And we have only mentioned single phase colours.
Three phase old colours were Red/Yellow/Blue for phase colours (but older still could be Red/White/Blue) and Black was N.
"New colours" (No I do not like them) are Brown/ Black/Grey for phase and Blue for N.
Some flexes, for a while, could have been Brown/Black/Black again! for the three phases colours and Blue for N.
So test and verify 100% of the time. Being 99% certain is never good enough for anybody.
Elek Trickery is a big bad force that is always trying to bite you.

 

[JohnW2]

And we have only mentioned single phase colours. .... Three phase .... "New colours" (No I do not like them)

Nor do I. I can't understand why someone came up with idea (for both single-phase or 3-phase) of brown being used to identified line/phase/'live' conductors - since that colour is (I would suggest 'obviously') associated with ('the') earth in most people's minds!

Kind Regards, John

 

[DetlefSchmitz]

of brown being used to identified line/phase/'live' conductors - since that colour is (I would suggest 'obviously') associated with ('the') earth in most people's minds!

At the time there was an expression 'George Brown is a live wire'

 

[JohnW2]

At the time there was an expression 'George Brown is a live wire'

 

[sparkwright]

Fwiw I use small brown cable ties on blue cables to identify SW live

Trouble is, it looks like a cable toe rather than an indicator.

For me, tape looks like a bad repair job, rather than an indicator.

Sleeving all the way for me.

 

[ebee]

I think Red was a good colour for a Line (Phase) conductor. It is often associated with danger, maybe one reason because blood is red and if someone is too red then it might be a warning sign that they are bleeding so possible health issue.
It is also one of the six primary colours so stands out a bit too.
If we need a second Line/phase colour the Yellow seems Ok to me, bright vibrant and the older white conductors might naturally yellow a bit too.
Again it is one of the six.
Blue, a nice bright colour too and again one of the six. So I like Blue for the 3rd Line/phase.
Black to me suggests a good choice for N so I am happy with that one.
and, although I was brought up on Green for Earth, I think that Green/Yellow was a sensible change as it also stands out a bit better to some of the less sighted people.
So I was happy with Earth to be the only two colour combination.

Brown/Black/Grey - well I think they are more wishy washy colours that do not really stand out as much.
Blue for N, well no comment.
Actually the chances of miss connection betwixt old and new colour coding - I was told that some reckoned it would only kill about 12 electricians so not deemed that unsafe in comparison with other dangers!


So yes I am pretty much a fan of our "Old Colours" but not really of our "New Colours" I`m afraid.

 

[JohnW2]

I think Red was a good colour for a Line (Phase) conductor. It is often associated with danger, maybe one reason because blood is red ...

Exactly I would say that it is almost universally regarded as a 'danger' - so was the obvious choice to identify line/phase.

If we need a second Line/phase colour the Yellow seems Ok to me,

Yep, agreed. Again, at least these days, often with danger/warning connotations ('high vis' items, road warning signs, even the background of electrical 'warning labels/signs' Etc.)

Blue, a nice bright colour too and again one of the six. So I like Blue for the 3rd Line/phase.

Maybe - although it feels a bit like a 'harmless' colour to me I think I'd probably personally favour something like purple or violet.

Black to me suggests a good choice for N so I am happy with that one.

Agreed - and, again, I would say the 'obvious' choice for N.

and, although I was brought up on Green for Earth, I think that Green/Yellow was a sensible change as it also stands out a bit better to some of the less sighted people.

I was happy with green and also am with G/Y. As I recently wrote I think brown evokes thoughts of 'earth' in most peoples's minds, and green is probably not that far behind (grass etc.) - so, were I 'starting from scratch, I'd probably choose one of those two.

Green/Yellow was a sensible change as it also stands out a bit better to some of the less sighted people. .... So I was happy with Earth to be the only two colour combination.

True, but if one were creating something which "stood out a bit better to some of the less sighted people" would it not have bene better to use that for line/phase? In fact, what about red for line/phase, with the second two phases having different stripes (maybe differnt in 'type'as weell as colour)?

So yes I am pretty much a fan of our "Old Colours" but not really of our "New Colours" I`m afraid.

You are not alone

Kind Regards, John

 

[ebee]

Maybe - although it feels a bit like a 'harmless' colour to me I think I'd probably personally favour something like purple or violet.

Good comment there lad.

True, but if one were creating something which "stood out a bit better to some of the less sighted people" would it not have bene better to use that for line/phase? In fact, what about red for line/phase, with the second two phases having different stripes (maybe differnt in 'type'as weell as colour)?

Again that has some merit too.
If we did stripe/dots/bands bands or something that might induce us to not think of E as the only two colour identifier though.

Again I think that some way of making E stand out to all and again making all three possible Lines stand out and including each Line standing out from each of the other Lines too.

 

[RandomGrinch]

Interesting article from the IET, about conductor colour identification here...

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.

electrical.theiet.org

 

[SUNRAY]

Interesting article from the IET, about conductor colour identification here...

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.

electrical.theiet.org

T'as oft been quoted on here and hopefully will continue to be so to clarify older instalations.
I have quoted from this before:

Particularly highlighted blue, showing the use of white in flex for phase 2 right up to 1970 and in blue showing all browns afterwards, specifically forbidding the use of coloured markers.

Also allowing yellow or blue for single phase up to the final DB which many interpreted as all of the wiring to and from a DB, even to the point of it being spec'ed on jobs.

I love the fact that 100 years ago we switched the colours of L3 & N, then 75 years later the same thing happened in a 3 way flip and it caused all sorts of dangerous issues. Not only that, I was manufacturing equipment right up to 2005 using R, Y, B & black neutral.