Important changes to the colours in electric cables


8 April 2003


The Joint IEE/British Standards Institution (BSI) Technical Committee
(JPEL/64), representing both the engineering profession and industry, has
issued a draft for public comment proposing changes to the cable core colours
for fixed electrical installations.

The proposals, if accepted, mean that from April 2004, single-phase cables will
follow the same colours as are used today in flexible cords; brown (phase) and
blue (neutral). This will be a change from the existing colours of red (phase)
and black (neutral). For three-phase supplies, the three phases will have the
colours brown, black and grey. Blue will be used for the neutral conductor. The
green/yellow striped colour will continue to be used for the earth conductor in
both single and multi-phase applications. The existing colours will be phased
out over a two-year period ending April 2006.

In order to coordinate the necessary changes, the IEE, Europe’s largest
professional engineering body, and the British Electrotechnical Committee (BEC)
have formed a joint National Safety Umbrella Group (L/12).

The membership of the L12 committee includes the IEE, the Heath and Safety
Executive (HSE), designers, manufacturers and others with interests in the
safety of electrical workers and consumers. The Technical Committee, JPEL/64,
has already started preparing an amendment to the ‘IEE Wiring Regulations’
to accommodate these changes. Work has also begun on altering all the product
standards that make reference to identification by colours.

The L12 committee will work on a large-scale exercise to produce guidance to
installers of the changes of the core colours and on a large-scale public
awareness campaign.

The draft for public comment, number 03/302646 – cost £20, is available from
the BSI by ringing 020 8996 9000.

That's just following normal CENELEC guidelines. The Irish system's already changed over to that colour scheme (quite a while ago for Neutral (blue) and L1 (Brown) )

Makes a lot of sense as most consumers are only aware of the flexible cord colours from wiring plugs etc.. if they're suddenly confronted with black and red cables they get confused.


[This message has been edited by djk (edited 05-05-2003).]

C-H,
Regarding the colours for 3 phase cables,
I think that the proposed colours are too similar and could be confused in areas with poor lighting(and I've worked in a few places like this).
I prefer the Red-White-Blue system.
Besides, how many more times are they going to muck around with the wire colours, pretty soon, we'll ALL be confused!.

I don't like to say I told you so, but see my post in this thread from October 2002: https://www.electrical-contractor.net/ubb/Forum9/HTML/000079.html

I am not particularly thrilled at the prospect of changing our fixed wiring code, which has been standard for decades, albeit with minor changes.

If you look at any residential installation in the UK you will see red phase & black neutral conductors, whether it is 70 years old or 7 months old.

However, I don't see a problem adopting brown (L) & blue (N) in single phase situations, everyone is familiar with this code for flexes.

The problem / danger I see will be in 3 phase installations where black (N at present) will become a phase (L2) & blue (L3 at present) the neutral.
This would probably be OK for brand new installations wired from scratch, but for additions to existing installations this could present a serious safety hazard. I am thinking particularly of industrial / commercial premises wired in trunking & conduit with single insulated conductors.At the distribution board you could have blue cores as phase in older circuits & neutral in newer circuits, and black neutral (old) & phase (new) conductors.
To my mind this is not a satisfactory situation. I would like to see a black phase banned from the new 3ph coding system & substituted by another colour.

Thank you CENELEC/EU for helping make our electrical installations safer!
I look forward to adopting Schuko sockets in due course also!!

Sorry about the rant guys, but this is a subject that gives me cause for concern.

[This message has been edited by David UK (edited 05-06-2003).]

Thanks for posting that C-H. I hadn't yet heard about the schedule for the change, although I know it's been talked about for some time.

I have to agree with David's concerns over the possible confusion. When the U.K. adopted the Continental colors for flexible cords in 1970, we were left with blue in fixed cables still being a phase and blue in a new flex being neutral. (Older flex could still have blue as a phase!) Confusing enough?

In a conduit installation, if somebody opens up a box and sees brown/black/gray/blue instead of red/yellow/blue/black, they'll recognize it as the new system (we hope).

But what about where all phases are not present? The IEE Regs. have for decades specified that red be the phase on single-phase ciorcuits, with an exception that yellow (formerly white) or blue may also be used before the final distribution panel to help identify phases.

Open up a box on an older single-phase feeder in such a system and you may be confronted with just blue and black. Problem: Is this an old system with a blue phase and black neutral, or new wiring with a black phase and blue neutral?

Sure, anyone messing around in 3-phase commercial systems is more likely to know what he's doing than the average householder, so if there's any doubt he should check.

For residential wiring, I suppose that having the colors the same as for appliance cords makes sense in a way, but I can see the DIYers getting into all sorts of muddles when confronted with the two systems side by side.

The point about black and brown is valid as well. We already have 4-core flex used on control circuits etc. in which the fourth wire is black. It is sometimes quite difficult to distinguish it from the brown when working in a dark corner. If we could make sure that the brown used in a black/brown/gray phase arrangement is a light brown, then it would be helpful.

I agree, though, that our present red/yellow/blue, the older red/white/blue, or the American black/red/blue makes for colors which are more easily distinguished.

Is there really any need to change?



[This message has been edited by pauluk (edited 05-06-2003).]

You don't need to have the same colours in conduit as with cables: In a cable there will always be a light brown wire to warn you. To avoid problems with wiring in conduit, you could substitute black for red.
Thus, there should never be a situation where you have only blue and black in a new installation.

Had the UK adopted the entire colour code when it changed to green/yellow instead of green, it would have been easy to distinguish new and old by the different earth wires.

The Irish regs require that the 1st phase in 3 phase is always to be brown... and that single phase will always be blue (N) brown (Live) This means that you'd never find a single black cable as a live conductor.

We also have lots of Red & Black cable installed as well as our old unique irish 3-phase colour system.

If you come across brown, black grey it will be together and very obviously 3-phase.

This sounds like a disaster waiting to happen, especially with swapping Phase/Neutral colours around.

I received the latest IEE newsletter a few days ago, and the adoption of the new colors was one of the articles.

Where cables conforming to the new color code are to be joined to existing (old color) cables, they are proposing the following re-identification of conductors (with tape, sleeves, etc.):

Existing red, yellow (or white), and blue phases be tagged brown. Existing black neutrals be tagged blue. New black and gray phases be re-identified brown.

In other words, where new and old cables meet, identification will be applied such that all phases will be brown and all neutrals will be blue.

I suppose this is logical in its own way, but I still see room for mistakes here.

Paul,
What is going to happen where an Electrician who can't be bothered to sleeve the wires joins two different cables?.
I know it's a silly question, but it does happen quite frequently over here.

Well, it will mean the colors joined as follows:

Old cable <--> New cable

Red <--> Brown
Yellow <--> Black
Blue <--> Gray
Black <--> Blue

The thread about sizing SWA cable and whether to use a separate conductor as a parallel earth has also got me to thinking about the colors.

At present, a 2-core (plus earth) cable has red & black, 3-core has red, yellow, blue, and 4-core has red, yellow, blue, black.

When using a 3-core for a single-phase line, I think most electricians follow what I do and tape the blue wire black to use as the neutral, and use green/yellow tape on the yellow to use as earth.

I assume when the new colors come in that 3-core cable will be brown, black, gray. My bet would be that for single-phase use most will associate black with neutral anyway and tape that conductor blue, leaving the gray to be re-identified with green/yellow for earth.

Thankfully in Ireland Black has been banned in 3-phase installations for quite a while. I wonder if the ETCI has been planning this change for quite a while?

The only place you'll find black as "N" is in older domestic single phase installations.

Hopefully this will mean no major problem.

I don't know why they didn't simply introduce new cables with stripes to identify them as new system?

E.g. the new 3 phase cables could all carry a red stripe on all phase and neutral cables.

I guess striped conductors might have been a good way to identify the new cable. I'm not sure about red though -- Could there have been room for confusion in the Germanic countries in which red might still be associated with earth?

I still think that CENELEC could have decided on a better combination of phase colors than brown/black/gray.

Yeah, orange had been better than grey. But I think you should be barking up a tree closer to home:

Andy Wade wrote in uk.d-i-y

"The adoption of grey represents a battle won for the UK by the IEE[*] in CENELEC. The rest of Europe uses various combinations of brown and black for phases. The IEE wanted to keep three distinct colours and proposed grey as the 3rd phase colour. It's now clear that they've got their way.

[*] The joint IEE/BSI national committee (JPEL/64) to be pedantic."

Hmm, so gray is there at the behest of the British contingent -- I hadn't realized that.

The orange that you suggest might have been a good idea, and certainly a better choice than gray. There must surely be gray still in use as a neutral in older installations in Germany, so they'll be stuck with the awkward dual-use of the color (just as with blue in Britain).

If they were trying to propose three distinctive colors, I wonder why nobody proposed that we don't use both black and brown? Or was this proposed and rejected?

If we accept that brown is going to be one phase and orange another, then perhaps yellow would have been the logical choice for the remaining phase. It's already in use as such in the U.K., and we'd then have the same BOY coding as used for 277/480V in the US, albeit with a blue neutral.

I'm just thinking out loud here -- Too late to get them to change it now, I guess.