3 Core And Earth Colours

[SUNRAY]

It's always possible.

Ahh in that case perhaps you could let me know where I can purchase cable containing 6 brown, 6 blue and 7 green/yellow.

 

[SUNRAY]

It probably was, but as well as 'convenience' and reduced use of materials,it also had the great benefit of minimising EMC issues.

Which requires extremely careful planning to reduce interference issues and, as I understand it, the reason conversion method was introduced.

To have AC current flowing in one direction in a conductor without the same current flowing in the opposite direction in a conductor within the same cable is, in my opinion, bad practice.

 

[Risteard]

Ahh in that case perhaps you could let me know where I can purchase cable containing 6 brown, 6 blue and 7 green/yellow.

Firstly, these don't necessarily need to be in one cable. Secondly, the Rule doesn't apply to 6 core or greater cables, which can be identified numerically or by colour, with numbered neutral and protective conductor cores having blue and green/yellow markings respectively at their terminations (e.g. heat shrink sleeving).

 

[SUNRAY]

Firstly, these don't necessarily need to be in one cable. Secondly, the Rule doesn't apply to 6 core or greater cables, which can be identified numerically or by colour, with numbered neutral and protective conductor cores having blue and green/yellow markings respectively at their terminations (e.g. heat shrink sleeving).

so not

always possible.

then?

And yes they have to be in one cable and there is no space for sleeves or markers.

 

[robinbanks]

3 core has grey brown black, so sleeve the grey with blue sleeving, tape ?

Pardon our interruption...

www.ebay.co.uk

Heat shrink sizes typically refer to the inner diameter before the heatshrink is shrunk. I expect your 3C+E cable is 1.5mm (the cross sectional area of a single core) which means the colored sheath has a diameter of about 3mm. Aim to get heat shrink with a "before shrinking" inner diameter of between 3.5 and 6mm if it shrinks 2:1. Do not strip the original colored sheath off, fit the shrink over the sheath. A typical hair dryer will heat sufficiently to shrink

 

[ebee]

At the risk of repeating myself here is my take on it.

It was, for a number of years Red/Yellow/Blue representing the three phases (or Lines if you like) and Black was N.
Actually before that it was Red/White/Blue too.
A common trick, especially after the event of European harmonisation of flexes, was to use Red as L, Yellow as SL and Blue as N . Red being commonly L and Blue being commonly a N colour of flexes. The Yellow should have been sleeved Red really (but often was not) and of course the Blue should have been sleeved Black but very rarely was in reality.

So, although we were told for years that fixed wiring colours "Will never change, only flexes have changed for Europe", we did all change to the horrible Brown/ Black/Grey.

One thinking was that if RYB became Br Bk Gy then R now Br, Y now Bk, Blu now Grey.
That also dissociated Black from N.

So, we end up with Brown = L, Black (now sleeved Brown) = Sw L and Grey (now sleeved Blue) = N.

Well that`s what I think how it became/should have become what it is today.

Others may well disagree.

Oh, and another thing, it has been said by some a few years after the change, some fellow Europeans agreed that our old RYB was a very good combination that the rest of Europe could have changed to but it wasn`t because it would put the UK at an advantage over other nations.

I do not like those "New Fangled, Killer Colours" that we have today.

PS - we used to have E as Green which I liked but I thought Green then becoming Green Yellow striped was probably a good idea.

 

[EFLImpudence]

And if a cable is being extended the most obvious option would be this:

That is no more obvious than yellow to grey and blue to black - especially if the Twin&E in the property is still red and black.

 

[EFLImpudence]

One thinking was that if RYB became Br Bk Gy then R now Br, Y now Bk, Blu now Grey.

Well, yes - one thinking.

Presumably another was the alternative.

That also dissociated Black from N.

Why did we want to do that?

 

[ebee]

Well, yes - one thinking.

Presumably another was the alternative.


Why did we want to do that?

The Scenario known as "Red to Brown and Blew to Bits " Perhaps???

 

[SUNRAY]

View attachment 312629
That is no more obvious than yellow to grey and blue to black - especially if the Twin&E in the property is still red and black.

It is the most obvious to anyone who works on 3ph systems.
It is the most obvious as that's the way the 3C&E cables are laid out.

But as I mentioned before, initially it wasn't obvious to me in the first instance.


Now if the harmonised colours had settled on Brown, Grey, Black then I believe the whole of the UK electrical industry would have had the very easy choice of:

Red and Brown can be very similar colour ✔Yellow and Grey can be light colours ✔ Blue and Black can be similar colours and we have been using both as neutral for 40 years✔✔

 

[ebee]

I think some of the continent had Brown for L1, Black for L2 and another Black for L3. OOOhhhh join two blacks? Oh dear.

Some 5 core flexes a while back had the "new" single phase colours plus two blacks.

Our Older Line colours were 3 of the six primary colours so I liked that

 

[SUNRAY]

I think some of the continent had Brown for L1, Black for L2 and another Black for L3. OOOhhhh join two blacks? Oh dear.

Some 5 core flexes a while back had the "new" single phase colours plus two blacks.

Our Older Line colours were 3 of the six primary colours so I liked that

Oh yes we are one of the few countries of Europe to use the colour scheme we call harmonised. Brown, Black, Black seems to be very normal for 3ph.

Multicore flexes have always been a law unto themselves, I used to do a lot of disco lighting work and tended to have a decent stock of 5 & 7 core cable. It was common for the colours to change between purchases from the same wholesaler.
I really hated it when there were 3 browns.

 

[ebee]

What bout signal cable? (Alarm cable) 4 core, 6, core, 8 core, 12 core and 20 core? wow, some colour choices?

I did once buy a roll of 12 core but never 20 core!

 

[EFLImpudence]

It is the most obvious to anyone who works on 3ph systems.

Surely it doesn't matter with 3p.

It is the most obvious as that's the way the 3C&E cables are laid out.

Genuine questions:

Is there a reason for this lay-out?

In a single phase system, would it not be 'better' electrically if the neutral were where the black is instead of at the edge?

But as I mentioned before, initially it wasn't obvious to me in the first instance.

Perhaps you could share your enlightening moment.

Now if the harmonised colours had settled on Brown, Grey, Black

Did they not do that? Edit - just realised you mean instead of Brown, Black, Grey.

then I believe the whole of the UK electrical industry would have had the very easy choice of:View attachment 312630 Red and Brown can be very similar colour ✔Yellow and Grey can be light colours ✔ Blue and Black can be similar colours and we have been using both as neutral for 40 years✔✔

I do not understand.

On the one hand, they did not do that. How could they?
On the other hand, they did not do the alternative either; hence the requirement (in sp) for brown or blue sleeving on black and grey wires.

 

[bernardgreen]

I did once buy a roll of 12 core but never 20 core!

Data from Elandcables