Colours Of Conductors.

[7029 dave]

Just looked at a thread, got me thinking of old imperial cables etc. The mention of the old red white and blue 3 core pvc no cpc got me thinking about a situation. I remember because have only seen it once in 37 years on domestic installations.

Block of flats in East finchley North London,Local authority full conduit system, on the lighting circuit all live conductors were white . Anybody else ever seen this in their time.?

 

[Leesparkykent]

I only really ever see it on YY cable with numeric marking but even then 9/10 times its black.

 

[westward10]

It was acceptable to wire single phase circuits to the phase colour, eg red, yellow or blue on larger installations but only time I have seen it on domestic was when an Octoflex modular wiring system was used where all the returns from the lighting switches were yellow.

 

[davesparks]

It was acceptable to wire single phase circuits to the phase colour, eg red, yellow or blue on larger installations but only time I have seen it on domestic was when an Octoflex modular wiring system was used where all the returns from the lighting switches were yellow.

Any idea which regulations that was?

 

[westward10]

Can't check at moment but look in 15th Ed under conductor identification sure there is some reference it can be used on larger installations, see it alot on 80s installations tested a school this week where single phase circuits were wired red, yellow and blue.

 

[davesparks]

Can't check at moment but look in 15th Ed under conductor identification sure there is some reference it can be used on larger installations, see it alot on 80s installations tested a school this week where single phase circuits were wired red, yellow and blue.

Ok, unfortunately that's one of the ones I don't have yet.
I've only got 1st, 6th, 9th, excerpts of the 12th, 13th, 14th, 16th and 17th so far.
One day I will have a complete set!

 

[Octopus]

Ok, unfortunately that's one of the ones I don't have yet.
I've only got 1st, 6th, 9th, excerpts of the 12th, 13th, 14th, 16th and 17th so far.
One day I will have a complete set!

Out of interest, how many pages in the 1st edition?

 

[HandySparks]

Can't check at moment but look in 15th Ed under conductor identification sure there is some reference it can be used on larger installations, see it alot on 80s installations tested a school this week where single phase circuits were wired red, yellow and blue.

15th edn, Table 52A, Colour identification of cores of non-flexible cables ... for fixed wiring

Phase of a.c. single-phase circuit: red (or yellow or blue*)

*As alternatives to the use of red, if desired, in large installations, on the supply side of the final distribution board.

 

[westward10]

I have just had chance to look at the 15th Ed and Table 52A and it seems it was acceptable on the supply side of the dist bd and maybe not outgoing ways (see preceding post). Unless other versions are different seems a lot of specifiers misread that.

 

[Sintra]

I actually remember wiring circuits in the mid to late 80's using the phase colour along with a black neutral. Don't know if it complied to the regs though but it was specified.

 

[stevethesparks]

Cant see the problem with it myself regardless of regs, seems to make good sense to me and keeps anyone working on such wiring informed. Well, until the new colours messed things up.

 

[Octopus]

Why did we ditch red for Brown?

 

[snowhead]

Why did we ditch red for Brown?

WE ditched Red and Black in flex for Brown / Blue around 1970 as part of European harmonisation, around the same time we were also going Metric in measurements.

Brown phase colour was more common than Red in Europe so we lost.

 

[davesparks]

Out of interest, how many pages in the 1st edition?

It's a double page spread, it is posted in PDF form on the forum somewhere, which is where I got the pdf from.

 

[starni999]

Hi all,
In 1987 I came out of my time and started running a section of a school rewire. We wired all SPN circuits from TPN DB's in phase colour & black. Half way through the consultant visited site, and we had to rip out all the yellow / blue wiring and rewire in red & black only.
It was far easier to trace circuits in trunking the old way IMHO.
Also, one of our buildings, built in 1936, still clearly has R W B marked up in the busbar chambers as phase colours.
Cheers
CW

 

[Risteard]

It was acceptable to wire single phase circuits to the phase colour, eg red, yellow or blue on larger installations but only time I have seen it on domestic was when an Octoflex modular wiring system was used where all the returns from the lighting switches were yellow.

Actually it was never permitted for final circuits - only for distribution circuits (submains).

 

[ipf]

Doing an industrial EICR and found a socket in a conduit system with the live ring conductors blue and yellow...with a red spurred. Can't see the problem though, I knew what they were without having to think about it and it tested fine.

 

[Risteard]

Doing an industrial EICR and found a socket in a conduit system with the live ring conductors blue and yellow...with a red spurred. Can't see the problem though, I knew what they were without having to think about it and it tested fine.

I can see a problem. What is a circuit wired with blue and black live conductors? Is it L3 and neutral or L2 and neutral with either swapping between phase and neutral?

It is however permitted by ETCI Wiring Rules in the south of Ireland.

 

[ipf]

I can see a problem. What is a circuit wired with blue and black live conductors? Is it L3 and neutral or L2 and neutral with either swapping between phase and neutral?

The neutrals are 3 blacks. The lives R,Y,B.
It's an old installation, all wired in old colours and not a chance of any alteration, and if someone can't get their head round the situation they are either thick as pig s*** or from across the sea...in Europe somewhere..
Use a Reg for a situation.....after weighing it up.

 

[Lucien Nunes]

But Risteard has a point there, that a blue/black circuit has become ambiguous since harmonisation. In a 3-phase circuit, you can tell which version of colours applies, so you can identify which of blue or black is neutral. But in a single-phase circuit with blue and black only, the absence of the other phases makes it impossible to know with certainty.

I like the setup in France, where line conductors can be any permissible colour other than blue or G/Y, which makes lighting wiring much more obvious. For example, brown for supply, red for S/L, a pair of oranges or purples are popular for strappers. You can 2nd-fix a 2g 2-way switch on a conduit system and know the functions of all the conductors more or less straight off.