Brown/Brown twin and earth.

[Lucien Nunes]

I agree that the harmonised colours aren't the best under adverse lighting but there was a bit of sense in their choice, because they are ones for which there are stable pigments that are compatible with all insulation materials, and they are not badly affected by colour-blindness.

On the subject of switch cables, the Americans do something a bit different. They run switches in normal cable with line & neutral colours (black/white), but they always use white (the neutral colour) with a black sleeve as the PL and black (the line colour) as the SL. It actually gives you a little bit more information when you have an unidentified cable, compared to our way with brown (the line colour) as PL. It also means that if you can only see SL and N in a luminaire, you are not reliant on sleeving to identify the polarity. They do a complicated thing with junction-box 2-way (aka 3-way) though, where one strapper changes colour midway so that you can identify which 'end' of the 2-way you are looking at (PL or SL) according to which colour is in which terminal.

Then you have the Australian method where they use a special switch cable with red and white cores, so you know it's a switch cable and which is PL and SL.

I have seen the cores of a twin brown identified with solid brown and brown-over-white 2-layer insulation. I'd be happier with some obvious marker on the outside, or the Aussie method with brown/black, or similar.

 

[7029 dave]

In part.

The installation I'm doing an EICR on at the moment has some areas with Red, White and Blue phase colours, also very sensible, easily distinguishable colours in my opinion.

Seen this colour in imperial pvc 3core, most used for 2way switching.

 

[Lucien Nunes]

L2 was white before it went yellow. I preferred white.

 

[pc1966]

I agree that the harmonised colours aren't the best under adverse lighting but there was a bit of sense in their choice, because they are ones for which there are stable pigments that are compatible with all insulation materials, and they are not badly affected by colour-blindness.

I am not convinced of those arguments.

• For a start, primary insulation should not be exposed anyway, so light-fade is not a high priority.
• Secondly the UK has had decades of experience with the R/Y/B colour and no issues of fade of insulation or degradation due to the chosen pigments.
• Finally I am far from convinced that a colour-blind person could reliably tell the difference between brown and grey. In some lighting even brown and black!

Most likely it was going with the majority of the EU colours in order to harmonise. At the time that made sense, so products and (importantly) people could safely work in differing member states. That last part has been thrown out of the window by recent events though.

 

[7029 dave]

I was listening to the radio the other day, talking about Brexit and saying that the old green card for driving in Europe might come back, maybe we will get our old phase colours back.

 

[Dustydazzler]

I was listening to the radio the other day, talking about Brexit and saying that the old green card for driving in Europe might come back, maybe we will get our old phase colours back.

i Would love to see the old red black & red yellow blue phase colours brought back post BrExit ....

 

[pc1966]

i Would love to see the old red black & red yellow blue phase colours brought back post BrExit ....

Well it might be a very thin silver lining to that cloud.

But more likely is bend-over-Borris would go with the USA colours, which are just as bad. Worse in fact, as they can't even spell colour right...

Mutter mutter, get off my lawn! Mutter.

 

[Lucien Nunes]

I'm not arguing in favour of harmonised colours personally, just pointing out that the original motivation for adopting them was neither arbitrary nor political. The present phase colours are an extension of the original brown and blue that were selected by the IEC 50 years ago on technical merit, and also to minimise clashes with existing colour schemes which at the time were quite varied and incompatible: Red was live in UK, neutral in Holland, earth in Germany.

People get on their high horse about the EU foisting colours on us, actually we were finishing a job that we left half-done in the 1970s before there was an EU, with our flexibles aligned with the IEC (for the benefit of appliance trade in the EEC) but installation cables not. Other remnants of older systems were tidied up at the same time, such as countries that used two black or two brown lines, 3-core flexible brown/black/blue where blue had to be used as a line that would otherwise have been a second brown, etc.

None of these variations and discrepancies ever gave me any trouble, I actually liked the variety, but one has to admit that it is not very logical to connect the blue wire of the flex inside a machine isolator to the black of the SWA and vice versa.

 

[Risteard]

But no cpc, I’ll bet!
I’ll bet there’s none of that where Risteard trades!

LOL. I don't recall a campaign for green, white and orange phase colours.

Interestingly, across the border when they abandoned red, yellow and blue decades ago and adopted brown and blue for phase and neutral, they used brown, red and yellow for the phases with a blue neutral. Obviously this later changed to brown, black and grey.

 

[pc1966]

I'm not arguing in favour of harmonised colours personally, just pointing out that the original motivation for adopting them was neither arbitrary nor political. The present phase colours are an extension of the original brown and blue that were selected by the IEC 50 years ago on technical merit, and also to minimise clashes with existing colour schemes which at the time were quite varied and incompatible: Red was live in UK, neutral in Holland, earth in Germany.

As I said, I am far from convinced there are any technical merits in the "new" phase colours.

Colours exist only for the benefit of humans, so in the ideal world they would be selected primarily on an ergonomic basis of:

• Danger warning for line conductors (especially to untrained public)
• Easy to distinguish under adverse light
• Minimise errors due to colour blindness (more commonly male, and most commonly red-green)
• Allow phase indicator lamps that are consistent with other common indicators.

Brown/black/grey fail on every one of those!

But the IEC's job is standardisation, and so the colours are more of a political compromise, not in the EU/gov sense of politics, but in the sense of having to get agreement with numerous national bodies and not overtly upset any of them. As a result, it is not a good choice but a least-worst agreement on something that can be standardised.

One of the arguments the IET put forward around the 2003 change to UK fixed wiring colours was the EU freedom to work aspect, but that kind of misses the other huge differences in national standards across the EU which make cable colour look trivial.

Was it worth a change to fixed wiring? Hard to say. While having a wider standard makes perfect sense, we still have many other colours used world-wide and we will have dual colours in the UK for many decades to come.

 

[Lucien Nunes]

I do largely agree with you, and you make some good, important points about the triviality of the colour code relative to other intractable differences between national standards, and the difference between political compliance and engineering compromise.

I remember in the consulation document the idea of a pink line being put forward, a similar flavour to red but not actually red, which was the most unsuitable colour to incorporate in a new standard owing to its diverse meanings. AFAIK it's the only colour that has served all five functions (GB: L1, US: L2, RU: L3, NL: N, DE: PE)

Anyway, switch cables. Brown & black anyone? Would we still have to sleeve the black core? Two kinds of brown? Colur tracers are more expensive but the rib shouldn't have much impact.

 

[James]

Light brown, dark brown? Seems obvious
Same materials, just a little more masterbatch in one core (colour)

Adheres to the standards and can be identified if required.

Or embossing one core with a symbol every inch and the other plane.

 

[davesparks]

But no cpc, I’ll bet!
I’ll bet there’s none of that where Risteard trades!

Yes, CPC is present and correct.
[automerge]1594801515[/automerge]

L2 was white before it went yellow. I preferred white.

And it was green before it went white.

 

[Let me think]

You think we’ve got problems.

What about the Hollywood stars that have to defuse bombs. Used to be simply, cut either the red or the other coloured wire.

Now they need to know when bomb was manufactured by which standard did they use, before they can figure out the correct wire to cut just before the count down timer reaches zero...?

Can you imagine them contacting us about a cable colour (‘color’ for our Hollywood friends) question? and still not have a clear answer before bomb goes off.

Probable best they just guess, correctly, like they normally do. ?

 

[telectrix]

"cut the brown wire"
"can't. they're all grey. where's mt fecking head torch?"
BANG.
"bugger, I cut the black"