Brown, Blue, Black and G/Y flex?

[ericmark]

Flex was harmonised before fixed installation and I think grey only came in with fixed installations, we had red, yellow, blue and Europe had brown, black, black there was no grey. So the forth wire in a flex had no standard colour. Would have likely have been 14 or 15 edition, not got one that old.

 

[AndyPRK]

Was it true that harmonised colours were to help colour blind.

They can’t tell difference between green and yellow. So I guess it’s true.

 

[JohnW2]

The colour code for flex was harmonised decades before non-flexible cables.

Exactly - and Andy suggested that aptsys was talking about "old colours" for flex - which I therefore took to mean prior to the harmonisation of flex colours in the 70s.

What else could 'old flex colours' mean?

Kind Regards, John

 

[JohnW2]

Was it true that harmonised colours were to help colour blind.

One hopes that was taken into consideration in deciding upon the colours.

They can’t tell difference between green and yellow. So I guess it’s true.

There are many different types of colour blindness. The most common is red-green (inability to distinguish the two) and yellow-blue the second most common.

Colour blindness apart, it has always been my view that whoever thought of brown as the colour for Line/Live was a bit crazy, since it flies against intuition. Brown is a benign, 'non-alarming' colour and is the colour of the earth. One would have thought that they should have chosen an 'alarming' colour (such as bright red, yellow, orange etc.), just as for 'warning labels' etc. - but maybe consideration of colour blindness had something to do with thjis decision.

Kind Regards, John

 

[JohnW2]

I think I might be starting to understand some of what is being said ...

... is it being said that the colours of conductors in flexible cable (at least, 4-core ones) in the UK has changed twice - once when colours of flexible cables were harmonised in the 70s, and then again when fixed wiring cable colours were harmonised in the early 2000s (2004 in UK, 2002 in mainland Europe, I think)?

If so, what were the colours in the UK between the 70s and 2004?

Kind Regards, John

 

[sparkwright]

See this today, how would you connect this for 3 phase and N
Red, Brown, White, Blue and Earth

Screenshot_2019-08-30-18-54-56

• 333rocky333
• 30 Aug 2019

Today - I would do this;
Brown - L1
Red - L2
White - L3
Blue - N
Green and Yellow - Earth

I think there was once some 5 core flex which had a red and a yellow, probably pre-1970, I don't really know.

 

[sparkwright]

Was it true that harmonised colours were to help colour blind.

They can’t tell difference between green and yellow. So I guess it’s true.

As I understood it, a green AND yellow striped wire was designed to show up clearly to colour blind people for safety. It should be easily identifiable to blind people.

 

[JohnW2]

As I understood it, a green AND yellow striped wire was designed to show up clearly to colour blind people for safety.

The most common form of colour-blindness, although called "red-green colour blindness' actually results in (varying degrees of) inability to distinguish red, yellow and green from one another. I would therefore presume that those with a marked degree of this problem would see the green and yellow of G/Y cable as the same colour, and therefore would not be able to see that it was 'striped'.

It should be easily identifiable to blind people.

Do you do miracles

Kind Regards, John

 

[AndyPRK]

If so, what were the colours in the UK between the 70s and 2004?

Kind Regards, John

The colours in the first post of this thread! For single phase.

Yes I think we got there now.

 

[plugwash]

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

- once when colours of flexible cables were harmonised in the 70s, and then again when fixed wiring cable colours were harmonised in the early 2000s (2004 in UK, 2002 in mainland Europe, I think)?

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.

If so, what were the colours in the UK between the 70s and 2004?

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 and 5 core flex was brown/blue/black/black/g+y. IIRC higher core counts were (like today) done with numbered black or white cores.

 

[AndyPRK]

The flex cable I used to use on 3 phase 400hz was

Red
Yellow
Blue
Green neutral ?
White earth
Black n/c

 

[ericmark]

It has been a long time since I have used 7 core, but the white was a larger size to other cores, although mainly used with auto mobile wiring it was rated for mains use, and so can see why white as with auto use was earth, black and brown were side lights, red stop light, yellow left hand and green right hand indicator, and blue changed many times, vac warning, inside lights, reversing light, and rear guard fog light have all used pin 2 blue.

 

[plugwash]

The most common form of colour-blindness, although called "red-green colour blindness' actually results in (varying degrees of) inability to distinguish red, yellow and green from one another. I would therefore presume that those with a marked degree of this problem would see the green and yellow of G/Y cable as the same colour, and therefore would not be able to see that it was 'striped'.

I would presume that even if they couldn't identify them as different colors, they would almost certainly see them as different shades when placed next to each other and would therefore be able to tell that the insulator was striped.

 

[sparkwright]

I would presume that even if they couldn't identify them as different colors, they would almost certainly see them as different shades when placed next to each other and would therefore be able to tell that the insulator was striped.

Exactly.

Vivid green and yellow 'may?' at least appear striped to a colour blind person, even if the stripes do look a bit similar.

Wiring is not designed to be fully clear to colour blind persons (colour blind persons could not become electricians - though there are some wonderful colour correcting products nowadays) but the theory was, I believe, to make the earth wire distinguishable by adding stripes. I gather plain green as an earth is a major no no now, though no real requirement to replace it.

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.

Sorry to make such assumptions.

 

[JohnW2]

I would presume that even if they couldn't identify them as different colors, they would almost certainly see them as different shades when placed next to each other and would therefore be able to tell that the insulator was striped.

Hopefully that would usually be the case, but I'm not aware of any requirement for the yellow and green to be of different intensities.

However, I was merely commenting on the suggestion that G/Y was chosen because of colour blindness, pointing out that those with the most common form of colour blindness have difficulty in distinguishing (in some cases can't distinguish at all) between yellow and green. Were they concerned about colour blindness, it would probably have been better if blue (or a 'blue heavy' colour) were substituted for the G or Y, since colour-blind people whould then be able to see the stripes even if bot were of the same intensity.

If they really wanted to be certain that anyone, even someone with total colour blindness (which does exist), would see it as striped, I suppose they could have made it black and white!

Kind Regards, John