3 Core And Earth Colours

[sparkwright]

Bang. Bang.

I see what the reasoning is:

It is that 3p used to be R,Y,B for L1,L2,L3 respectively and when the cable was used for 1p the Blue was quite naturally used for Neutral. Then harmonised flex came along with a Blue neutral so all was well and obvious.

However, when harmonised 3core&E; Bn,Bk,Gy; arrived, and when used for 1p, you, and others, for some reason decided that '3p L3' must therefore be used for Neutral even though most properties would still have been cabled in Red and Black with Black as Neutral.

Of course, any instruction to this effect; that Grey should/shall be used for Neutral; is irrelevant and impossible because Grey is not a colour that signifies Neutral so must be over-sleeved or marked for identification; exactly the same as a Black wire - the base colour being immaterial.

The trouble was/is, too many people wouldn't accept that the harmonised colours were in no way whatsoever linked to the old colours.

Too many people decided to use black as the neutral because 'black always used to be neutral'.

These people didn't bother to work out the best colour to use, or do research, or study the structure of the old cable compared to the new cable.

And there was, was guidance on the new colours back in 2004.

 

[EFLImpudence]

The trouble was/is, too many people wouldn't accept that the harmonised colours were in no way whatsoever linked to the old colours.

Surely that is what SUNRAY is doing.

Too many people decided to use black as the neutral because 'black always used to be neutral'.

Seems logical to me.

Why should they not have?

These people didn't bother to work out the best colour to use,

What is the best colour as any colour may be used and identified?

or do research, or study the structure of the old cable compared to the new cable.

I thought you said it didn't matter - "in no way whatsoever linked to the old colours".

And there was, was guidance on the new colours back in 2004.

Ah that's alright, then - more guidance - from NICEIC or someone else with no authority?

 

[JohnW2]

I interpreted this: .... a different way.

I realised that, and such is obviously your prerogative.

Kind regards, John

 

[SUNRAY]

The trouble was/is, too many people wouldn't accept that the harmonised colours were in no way whatsoever linked to the old colours.

But they are totally and inextricably linked

Surely that is what SUNRAY is doing.

In a 3ph installation everyone would expect any mixture of new and old colours of a 3ph circuit to look like this:

But in that same installation EFL is advocating mixing the colours within a single phase circuit like this:

All I see there is confusion and hazard, I've been there a few times.

 

[JohnW2]

Of course, any instruction to this effect; that Grey should/shall be used for Neutral; is irrelevant and impossible because Grey is not a colour that signifies Neutral so must be over-sleeved or marked for identification; exactly the same as a Black wire - the base colour being immaterial.

Very much so. That seems to be the crucial point which nearly everyone seems to be missing, which really makes this whole discussion rather silly and unnecessary.

In those countries which work to BS7671 (hence identify conductors per BS7671), the situation for single-phase wiring is very clear - if conductors are identified by colour (which is not compulsory) then any neutral conductor must be identified with blue, and any L conductor (including S/L) must be identified with brown. It doesn't matter a jot what colour the insulation of the conductor (as manufactured) is, if L & N are correctly identified by appropriate colour oversleeving at terminations.

Specifically, it "doesn't matter a jot" whether the blue sleeving is put on a conductor which was manufactured with grey or a black insulation. Maybe the arguments would go away if cables were only available as pink+pink or pink+pink+pink, and the user had to add the appropriate sleeking to achieve compliance with BS7671 ?

As I've been discussing, countries which do not work to BS7671 as regards conductor identification (but, instead, forbid 'over-sleeving') have got a bit of a problem. Since cables with all combinations of possibly-required core colours are readily (if at all, except 'bespoke') available, the consequence is that they have to use more cables than is necessary, with all the downsides I have discussed.

Kind Regards, John

 

[EFLImpudence]

You are forgetting something:

But in that same installation EFL is advocating mixing the colours within a single phase circuit like this:
View attachment 312699 All I see there is confusion and hazard, I've been there a few times.

But you are forgetting something:

So, it doesn't matter

 

[JohnW2]

You haven't seen our cat catching flies!

Indeed I haven't, but I've lived with a good few cats and have seen them catching flies (and other flying things - even once a small bird in our kitchen ).

My point, perhaps not made clearly enough (per my qualification "...even jumping ones") was that, even when gthey jump[ed high (as they can do) it would be very improbable that they would do so in just the right place to break a narrow IR beam. In fact, if I remember correctly, when I had such things (very many moons ago), they were generally across doorways - so even tall human beings would probably struggle to trigger them without first opening the door!

Kind Regards, John

 

[sparkwright]

You are forgetting something:



But you are forgetting something:

View attachment 312701
So, it doesn't matter

Once again, harmonised wiring, with reference to old colours.

While I would happily oversleeve old coloured cable with new coloured sleeves, I wouldn't oversleeve new coloured cable with old coloured sleeves.

And I certainly wouldn't oversleeve a new coloured cable with a mixture of new coloured and old coloured sleeves. That is certainly a backward step as far as harmonisation goes. If you can't buy old colour cable, why should you use old colour sleeving??

I don't see why anyone would deliberately join old yellow to new grey, and old blue to new black, regardless of sleeving.

You only have to compare the structure of 3 core+E cable, to realise the colours should go:
Red - brown
Yellow - black
Bare earth - bare earth
Blue - grey.

 

[EFLImpudence]

Once again, harmonised wiring, with reference to old colours.

But that was the point - adding a harmonised 3core&E on an old installation.

While I would happily oversleeve old coloured cable with new coloured sleeves, I wouldn't oversleeve new coloured cable with old coloured sleeves.
And I certainly wouldn't oversleeve a new coloured cable with a mixture of new coloured and old coloured sleeves. That is certainly a backward step as far as harmonisation goes. If you can't buy old colour cable, why should you use old colour sleeving??

Ok, but the result is the same; the original colour of the Neutral is irrelevant.

I don't see why anyone would deliberately join old yellow to new grey, and old blue to new black, regardless of sleeving.

Maybe not, but you have no good reason for thinking that.

You only have to compare the structure of 3 core+E cable, to realise the colours should go:
Red - brown
Yellow - black
Bare earth - bare earth
Blue - grey.

Of course, the more numerous instances would be joining harmonised Bn,Bk,Gy to old R & Bk.

 

[JohnW2]

While I would happily oversleeve old coloured cable with new coloured sleeves, I wouldn't oversleeve new coloured cable with old coloured sleeves. .... And I certainly wouldn't oversleeve a new coloured cable with a mixture of new coloured and old coloured sleeves.

If one is only concerned with single-phase wiring, I think you may have mis-identified the one potential cause for possible concern, which only exists for conductors which are not over-sleeved..

With over-sleeving, there is never any ambiguity or uncertainty, even if one has a messy mixed situation of new colours over-sleeved with old coloured sleeves AND vice versa. All conductors (opther than CPC) in single phase wiring have to be identified as either L or N. Regardless of 'old' or 'new' colours, there are only four possible 'over-sleeving colours' for live conductors - red, black, brown and blue.

Oversleeving with either red or brown will always identify the conductor as an L, regardless of the colour ('old' or 'new') of the underlying insulation​

Oversleeving with either black or blue will always be identifying the conductor as an N, regardless of the colour ('old' or new') of the underlying insulation​

​

However, with conductors which are NOT over-sleeved, whilst there will rarely be any ambiguity, there is perhaps one situation in which one might feel that there was some uncertainty (if one couldn't trust the person who did the wiring):

Unsleeved yellow or grey conductors have no meaning (in single-phase wiring) in either old or new colours. This is simply 'wrong' (should be sleeved') and so one has to use some method other than colour to identify what the conductor is being used for.​

​

It seems almost beyond belief that anyone would (in single phase wiring) use either unsleeved red or unsleeved brown to identify anything other than L, so hopefully not really an issue.​

​

Any issue therefore relates to unsleeved black and blue, which is where this discussion started. IF one can trust that whoever did it would always have over-sleeved a conductor when that was required, then an unsleeved black (presumably in an old colours cable) or an unsleeved blue (presumably in a 'new colours' cable) would have to be neutral. However, if one couldn't trust that sleeving had always been applied when required, then all bets would be off.​

Having said that, if one can't trust that sleeving was always applied when required, most bets are off, anyway - i.e. an unsleeved blue (new colours) or an unsleeved black (old colours) might be being used as a S/L, without the required sleeving, even in a T+E cable.​

Kind Regards, John

 

[SUNRAY]

I had an EICR situation a little while back where several old colour SWA's had been installed without oversleeving the blue, however the CU was clearly marked as containing wiring to 2 colour schemes (and indeed contained significant harmonised later works).
The difficulty I had was trying to establish whether to sleeve to old standard or harmonised. For a start I didn't have any black sleeving with me and the neutral bar contained 50:50 blue and black anyway and the idea of adding a brown sleeve to a correctly coloured Line conductor just felt and looked daft.


Further back I worked on some commercial building 3ph lighting wired in singles in trunking/conduit, initially old colours with black neutrals and later alterations had been done in harmonised with blue neutrals. The colours flipped back and forth along the circuits. I'm sure I posted it on here but cant find it. The stupid thing was in places there was situations like all blacks or all blues for example.

 

[EFLImpudence]

Do you mean someone had used Black for Neutral???

 

[SUNRAY]

Do you mean someone had used Black for Neutral???

Oh yes, some of the wiring was red/black T&E.

 

[bernardgreen]

How about a DIY total rewire using only purple singles of varying sizes. Every wire end was labelled.

 

[JohnW2]

The difficulty I had was trying to establish whether to sleeve to old standard or harmonised.

As I wrote last night, it doesn't really matter.

IF (in single-phase wiring) a conductor is over-sleeved, then either blue or black identify the conductor as being neutral, since there are no other situations in which either of those colours of over-sleeving could mean anything else.

As I also wrote, if there is perhaps scope for uncertainty (in some people's minds) in mixed-colours situations, it's really with blue or black conductors which are NOT over-sleeved. However, if everything has been done correctly (per BS 7671) (i.e. if one is confident that that's how it has been done), then either of those can also only denote 'neutral'.

Kind Regards, John