Brown, Blue, Black and G/Y flex?

[sparkwright]

There's no 'real answer', since this isn't defined in any Standard or regulations. Those (probably the majority) who advocate using grey do so (I think) solely because they do not want to perpetuate memories of the days when black indicated neutral - which seems, to me, to be a fairly lame reason!

As I've said, the problem is that the Standards/regs about identification colours do not (to some extent necessarily) take into account the purpose for which a cable is going go be used. In an ideal world, if a particular type/size of cable was very commonly going to be used for an application which required a neutral, it would be available in a version in which one of its cores was blue.

Kind Regards, John

Blue was always on a 3 core+e cable. Not set in stone, but everyone used that. Old blue = new grey. Look at the structure of a cable. Look at NIC guidance. Look at the info distributed to wholesalers between 2004 and 2006.

No logical guidance to use black as neutral, only some misguided belief that 'black was always neutral'.

How would it be done in the rest of Europe? Some European PIRs and the like give us a good idea.

Anyhow, we discuss this too much, there are pages of it tucked away over the years on this forum.

 

[sparkwright]

As I've just written, I think it is precisely because "it seemed extremely logical at the time" (since we were used to the association between black and neutral) that some/many people decided that grey would be better/'safer', since using black would perpetuate memories of that previous association, hence might conceivably make some people forget that black now indicated something potentially more dangerous than neutral!

Kind Regards, John

Absolute misguided nonsense to assume black should be neutral - for a start it goes totally against the whole concept of harmonisation and is nothing more than an ill-judged attempt to cling to the past when all these new requirements were being launched.

Anyhow, we can't discuss this further, we will have more and more pages of drivel which deviate from the original post.

 

[SUNRAY]

Yes, of course, but certainly in the case of flat 1.0/1.5mm 3C+E what the 'average sparks' use it for must represent the vast majority of usage of such cable - which makes the colours it currently comes in at least 'illogical'.

What would, in your opinion, be more logical. What I see is 3 recognisable unambiguous 'Lives' which makes a lot of sense to me when its used as strappers, additionally I don't see a need for brown sleeves in this situation, but I do use them to conform.

I use 2 core cable far more for DC [possibly floating], loudspeaker, other audio, controls and signalling than I ever do for mains.

So do many people, but I would think that's mainly in relation to the smaller CSAs, including many too small to be used for 'electrical' purposes.

Oh no. most control is 1mm² or bigger except some of the screened cables. I do have 10mm² figure 8 in grey,blue but any other sizes are difficult in those colours. Speaker cables (low impedance) I'll typically use 2.5mm²to 16mm²

You may well have but, at least if it's for DC 'power', Table 7E of Appendix 7 of BS7671 seems to bve saying that you probably should now be using brown and grey for a floating DC circuit, brown and blue for a negative-earthed DC circuit and blue and grey for a negative-earthed DC circuit

let's start there and make it available ... with brown,grey and grey,blue.

so why is it far more difficult to source?

There are certainly 'different requirements' but, as I've said, if a particular cable is very commonly used for one type of application/'requirement', then it would seem to make sense for the colours to reflect that application.

kind Regards, John

So again I'll ask what are the logical colours?

 

[SUNRAY]

Blue was always on a 3 core+e cable. Not set in stone, but everyone used that. Old blue = new grey. Look at the structure of a cable. Look at NIC guidance. Look at the info distributed to wholesalers between 2004 and 2006.

No logical guidance to use black as neutral, only some misguided belief that 'black was always neutral'.

How would it be done in the rest of Europe? Some European PIRs and the like give us a good idea.

Anyhow, we discuss this too much, there are pages of it tucked away over the years on this forum.

Just to clarify I totally agree with neutral = grey, albeit initially I went with black.

 

[sparkwright]

Just to clarify I totally agree with neutral = grey, albeit initially I went with black.

Yes, a lot of people did in 2004.

However, these days it seems a lot less people use black, having worked on other people's work I've noticed grey is more usual.

 

[JohnW2]

Absolute misguided nonsense to assume black should be neutral - for a start it goes totally against the whole concept of harmonisation and is nothing more than an ill-judged attempt to cling to the past when all these new requirements were being launched.

Agreed. As I said, many of those who advocate using grey as neutral do so in an attempt to prevent people 'clinging onto the past'

Anyhow, we can't discuss this further, we will have more and more pages of drivel which deviate from the original post.

Well, it's my thread, so I suppose that gives me some right to decide what counts as drivel which deviates from the OP

My OP was answered as soon as it was pointed out to me that the colours in the cable I had found were the norm for pre-2004 4-core flex. Everything subsequent to that probably qualifies as drivel.

Kind Regards, John

 

[sparkwright]

Ah well, good, in that case we can go on and on till the cows come home...!

 

[SUNRAY]

My OP was answered as soon as it was pointed out to me that the colours in the cable I had found were the norm for pre-2004 4-core flex.

Kind Regards, John

And it is still a very common combination, in my experience.

 

[SUNRAY]

Ah well, good, in that case we can go on and on till the cows come home...!

MMmmmmmmmmoooooooooo

 

[SUNRAY]

Thinking about this some more, heating valves are usually brown, blue, orange, grey or white & green/yellow

 

[sparkwright]

They certainly are.

 

[JohnW2]

What would, in your opinion, be more logical. What I see is 3 recognisable unambiguous 'Lives' which makes a lot of sense to me when its used as strappers, additionally I don't see a need for brown sleeves in this situation, but I do use them to conform.

Yes, when used as strappers (particularly with the 'modern' method of 2-way switching) the current colours make as much sense as anything else would. The other fairly common use is when both a L and a S/L are required - in that case blue, brown and 'something else' (e.g. black) would be more logical. In other words, there is a case for having two different variants (although I can predict the objections gto that!).

... so why is it far more difficult to source?

You're asking the wrong person!

So again I'll ask what are the logical colours?

If you're talking 3C+E then, as above (and although I understand the 'objections') I would say there is a case for two variants. If you're talking 4-core flex then, since I would think that is most commonly used when a L and S/L are required, then the pre-2004 colours (like the stuff I found yesterday) would seem the most logical.

Kind Regards, John

 

[sparkwright]

It does seem more logical for a 4 core flex to have a blue rather than a grey. Bearing in mind flex isn't generally used for completely concealed wiring such as house lighting or 3 phase wiring, then I think a neutral is usually going ti be required.

 

[JohnW2]

And it is still a very common combination, in my experience.

Your experience is obviosuly similar to aptsys's, so I wonder where you shop. As I said and illustrated, the five (all 'mainstream') suppliers I moist commonly use appear to only be offering 4-core flex with "3-phase"+G/Y colours.

Kind Regards, John

 

[JohnW2]

It does seem more logical for a 4 core flex to have a blue rather than a grey. Bearing in mind flex isn't generally used for completely concealed wiring such as house lighting or 3 phase wiring, then I think a neutral is usually going ti be required.

Exactly - that's what I've been saying all along. Flex wouldn't normally be used for 'fixed' 2-way light switching and small-CSA flex is unlikely to be used for 3-phase and, even if it were, it probably would probably be unusual not to have a neutral.

Kind Regards, John