Brown, Blue, Black and G/Y flex?

[JohnW2]

Looking at colour blindness spectrums and the like, a vivid green and a vivid yellow earth wire 'may?' appear striped to a colour blind person IMO.

Indeed - not just 'may' but 'usually would'. Even if the person had a complete inability to distinguish between green and yellow, they would see it as striped provided that the two colours were of different 'intensities'.

Kind Regards, John

 

[sparkwright]

I suppose the green and yellow was chosen because it was similar to the plain green, and they didn't want it to be drastically different.

I imagine changing to a vastly different colour or colours is one step too far; especially as ten years or so before, green was relatively new - only in that many earth wires were left bare.

 

[JohnW2]

I notice the picture shows blue but the description says grey.

Which picture and which description?

It does seem that way (presuming 4 core flex existed prior to the 70s which I can neither confirm or refute). I distinctly remember "grey" being a new thing during the fixed-wiring harmonization.

Fair enough. Like you, I can't really remember whether 4-core main-rated flex was around prior to the 70s (4-core ELV certainly was). Although the need for it was presumably quite limited, I imagine that there would have been some need (particularly in 'control' applications) - so it probably did exist.

As I remember it 2 and 3 core flex in the 90s were the same as today. 4 core flex was brown/blue/black/g+y ....

Fair enough. In that case, that's probably what I found.

The apparent 'jump' we see in today's colours between 3-core and 4-core does seem rather odd. Particularly with the smaller CSA cables, I doubt that 4-core is significantly used for 3-phase+E (with no neutral), yet it is the 3-phase colours (plus G/Y) that it now appears to have. Far far more often when one uses small-CSA 4-core, 3 of the cores have the same function as with 3-core (L, N & E, for which the colours would be brown, blue and G/Y) wiuth the fourth doing something different - usually some other 'L'. It therefore would have seemed to be far more logical to keep the brown blue and G/Y, as per 3-core, and add an extra colour (maybe black)

Kind Regards, John

 

[JohnW2]

I suppose the green and yellow was chosen because it was similar to the plain green, and they didn't want it to be drastically different. ... I imagine changing to a vastly different colour or colours is one step too far ...

Yes, perhaps.

If they had changed to green/blue (rather than green/yellow) (perhaps even more similar to the previous 'plain green'), that would have ensured that it was perceived as obviously striped by a person with any degree of severity of the most common type of colour vision but, ironically, it might have been less obviously striped to some people with normal colour vision!!

Kind Regards, John

 

[sparkwright]

I suppose the modern 4 core flex consisting of brown, black, grey and green/yellow ties in very nicely with the modern flat 3 core+e colours.

Logical in many ways.

 

[sparkwright]

Yes, perhaps.

If they had changed to green/blue (rather than green/yellow) (perhaps even more similar to the previous 'plain green'), that would have ensured that it was perceived as obviously striped by a person with any degree of severity of the most common type of colour vision but, ironically, it might have been less obviously striped to some people with normal colour vision!!

Kind Regards, John

Yes but green and blue together would be confusing as blue was the European neutral.

It would be like a combined earth and neutral!

 

[JohnW2]

I suppose the modern 4 core flex consisting of brown, black, grey and green/yellow ties in very nicely with the modern flat 3 core+e colours. Logical in many ways.

Well, certainly consistent, but I don't think very 'logical' in either case....

... just as I said about flex, I would imagine flat 3C+E (which, to the best of my knowledge, is only available in 1.0 and 1.5mm²) is virtually never used for L1+L2+L3+E (with no neutral) - although that is what the colours relate to. Conversely, just as I said of flex, what it virtually always is used for is L, N & E (brown, blue and G/Y in T+E) plus one extra core, usually a S/L or some other L. Hence, as I said of flex, it would seem far more 'logical' for the colours to be brown, blue, G/Y and 'something else' (quite possibly black!).

Kind Regards, John

 

[plugwash]

You have to remember that harmonisation is a game of compromises, the new harmonised colors didn't just have to satisfy us brits, they also had to satisfy standards bodies across Europe. Take red for example, the brits used it for live, the germans used it for earth, so clearly it couldn't form any part of a harmonized scheme without risky deadly confusion.

 

[JohnW2]

Yes but green and blue together would be confusing as blue was the European neutral. It would be like a combined earth and neutral!

True, but I was merely illustrating the concept. Anything at the blue end of the visible spectrum would do. Violet would be even better than blue (colour-blindness-wise) - can you see any problem with green+violet?

Kind Regards,, John

 

[aptsys]

Our experiences clearly differ. I've used a fair bit of 4-core fles, and have a fair bit 'on my shelves' but, as must be apparent from the fact that I started this thread, I've never seen those colours used before.

This will blow your mind then
https://www.electricalworld.com/en/gb/Zexum-4mm-4-Core-42A-Brown-Black-Grey-Blue-6944X-Steel-Wire-Armoured-SWA-Outdoor-Mains-Power-Cable---25-Meter/s-897-2400.aspx?

The 3-Core SWA from the distributors around here is available in G/Y, Blue and Brown or in 3-phase colours.

I've just gone through my collection of flex, and they all have Blue, Brown and G/Y. 4-core adds black and 5 core adds grey. I've not seen 3 phase colours in 4 core flex until this thread.

 

[AndyPRK]

John.

Green had been used in flex, long before the 70s sleeving introduction so it wasn’t really new.

 

[sparkwright]

I think he knows that.

 

[AndyPRK]

I think he had forgotten going by his comment earilier about green being a new colour and then shortly changing to g/y

 

[JohnW2]

This will blow your mind then ....

Not really - that cable is 'intended' for L1/L2/L3+N, with sheath as CPC, so the colours are completely togical/'correct'.

The 3-Core SWA from the distributors around here is available in G/Y, Blue and Brown or in 3-phase colours.

That's interesting. I was about to observe (which I still think is largely true) that the real problem seems to be that we generally use cables with core colours which don't take usage into account - hence, for example, the 3-phase colours in 3C+E and all the small-CSA 'modern' 4-core flexes I'm seen. Hence I find it very reasonable (probably desirable) that 3-core SWA should also be available in Brown,Blue,G/Y and would find it equally reasonable (probably desirable) if 3C+E were available with colours which didn't imply that it was intended for L1/L2/L3+E (which I doubt it is ever, or hardly ever, used for).

I've just gone through my collection of flex, and they all have Blue, Brown and G/Y. 4-core adds black and 5 core adds grey. I've not seen 3 phase colours in 4 core flex until this thread.

I'm still intrigued by the differences in our experiences -= as I illustrate, all five of the suppliers I most commonly use (all of which are 'mainstream' ones) appear to offer only 3-phse colours in their 4-core flex.

Kind Regards, John

 

[JohnW2]

John. Green had been used in flex, long before the 70s sleeving introduction so it wasn’t really new.

I know. I was 'brought up' on green earth conductors

I think he knows that.

As above, I do.

I think he had forgotten going by his comment earlier about green being a new colour and then shortly changing to g/y

What comment are you referring to? Either I wrote it badly or you misunderstood - since, as above, I am very aware of the prior use of green as the colour for 'earth'/CPC. Actually, there are still some places in my house which have green sleeving, if not also green-insulated conductors!

Kind Regards, John