Wiring colours.

[SUNRAY]

I've started a thread on this as it is so far OT from where it was in RCBO doesn't align...

As I understand BS7671, if conductors are identified by numbers/letters, then it doesn't matter what colour they are, so long as green and G/Y are not used for live conductors (and even G/Y in multi-core cables might be acceptable, if identified by numbers/letters).

Kind Regards, John

Indeed this is my understanding of the situation, however using 'wrong' or 'old' coloured singles without markings seems to be a big no-no

From my notes this is how we left the factory lighting, orange circles represent a light fitting. This was one 3ph board powered by a 3ph contactor.

I wasn't happy with the silly combinations of colours but it wasn't my call.

EDIT: line 7 colour corrected

 

[JohnW2]

Indeed this is my understanding of the situation, however using 'wrong' or 'old' coloured singles without markings seems to be a big no-no

As for 'old' colours, is that not still acceptable, even for singles (given a 'two colours' sticker on the CU/DB)?

'Wrong' is a different matter. Unless one can argue that what one has is a 'control/signal' circuit (not very convincing if it is supplying, say, just lights!), I think one is (as far as BS 7671 is concerned) stuck with just red, black, brown and blue for 'live' conductors, isn't one?

Kind Regards, John

 

[mattylad]

Bejeezus!

 

[SUNRAY]

As for 'old' colours, is that not still acceptable, even for singles (given a 'two colours' sticker on the CU/DB)?

'Wrong' is a different matter. Unless one can argue that what one has is a 'control/signal' circuit (not very convincing if it is supplying, say, just lights!), I think one is (as far as BS 7671 is concerned) stuck with just red, black, brown and blue for 'live' conductors, isn't one?

Kind Regards, John

Yes old colours are perfectly acceptable for existing wiring and there is no reason to change it [assuming it's safe and sound] but when a system gets into the state of that shown above with some of the horrendous colour combinations and the potential hazards, I for one question the decision to prevent the use of existing wiring colours for alterations. I also question the sense of people allowing it to get to that state.
Sadly the history of the colour for phase 2 [edit] is green, white, yellow and currently black so theoretically all 4 of those could be included.

 

[SUNRAY]

Bejeezus!

Exactly but perfectly conforming to regs.

 

[mfarrow]

You shouldn't mix different colours like that in my opinion, the person who told you to do so hasn't got a clue about safety and consistency.

 

[Jackrae]

You shouldn't mix different colours like that in my opinion, the person who told you to do so hasn't got a clue about safety and consistency.

You missed out 'common sense' which tends to be somewhat lacking in today's regimented elfin culture. The Princess Royal went to town on the subject just before Christmas.

 

[SUNRAY]

You shouldn't mix different colours like that in my opinion, the person who told you to do so hasn't got a clue about safety and consistency.

I totally agree with you, I was only assisting a group of electricians working for a very respected local company. I had no say in the colours and around half of the harmonised colours shown were there before we started, my particular pet hate is the black and blue confusion especially in circuit 3 where there are some black lives on phase 3 [should be grey].

 

[SUNRAY]

You missed out 'common sense' which tends to be somewhat lacking in today's regimented elfin culture. The Princess Royal went to town on the subject just before Christmas.

Fooooorr F***s sake yeaaah... soapbox time...

The really silly thing is the paperwork these day gives really specific instructions to the point where common sense is ruled out, especially in H&S

 

[John D v2.0]

Last i checked you can use pretty much any colours as anything, even green and yellow in a flex as a live conductor although you'd need a CPC in the same wiring system. If you don't use the harmonised colours on new work you would have to identify it at the terminations at least with an over sleeving or similar.

 

[JohnW2]

Last i checked you can use pretty much any colours as anything, even green and yellow in a flex as a live conductor although you'd need a CPC in the same wiring system. If you don't use the harmonised colours on new work you would have to identify it at the terminations at least with an over sleeving or similar.

Yes, provided one uses oversleeving (or identification by numbers/letters), on can use any colour for anything - other than green (or G/Y singles). However, unless one can argue that it's a 'Control circuit', everything in a single-phase installation would presumably have to be oversleeved with brown or blue.

Kind Regards, John

 

[SUNRAY]

Yes, provided one uses oversleeving (or identification by numbers/letters), on can use any colour for anything - other than green (or G/Y singles). However, unless one can argue that it's a 'Control circuit', everything in a single-phase installation would presumably have to be oversleeved with brown or blue.

Kind Regards, John

Ah?
At what ppoint does a circuit become 3 phase?
This particular system consits of a 3ph 32A fused circuit to a contactor feeding a 3ph DB with 3 10A single pole mcb's per phase feeding the 9 lighting circuits with no additional switches. Are the lighting circuits classed as single phase or 3ph and should they all be in red or brown?
It's all a bit moot as the colours will not be changed unles they need to be due to faults or alterations.

 

[JohnW2]

Ah? At what ppoint does a circuit become 3 phase? ... This particular system consits of a 3ph 32A fused circuit to a contactor feeding a 3ph DB with 3 10A single pole mcb's per phase feeding the 9 lighting circuits with no additional switches. Are the lighting circuits classed as single phase or 3ph and should they all be in red or brown? It's all a bit moot ...

As you say, it's a bit moot. However, I would personally say that the spirit of the situation is that a '3-phase circuit' is one supply 3-phase loads. If the lights are being supplied from 2-wire (plus CPC) circuits, I would say that they were single phase. It's like my house, with a 3-phase supply, essentially distributed as one phase per floor. I would not dream of describing anything (whether distribution or final circuit) downstream of the (3-phase) meter as being a '3-phase circuit'.

I suppose a grey area might arise if you had 2-, 3- or 4-pole switches controlling two or more sets of lights on different phases - but it doesn't sound as if you have that situation, anyway.

In any event, even if you could come up with a convincing argument that it was '3-phase', that would only add black and grey (in terms of harmonised colours) to the over-sleeving colours you could use.

Kind Regards, John

 

[SUNRAY]

As you say, it's a bit moot. However, I would personally say that the spirit of the situation is that a '3-phase circuit' is one supply 3-phase loads. If the lights are being supplied from 2-wire (plus CPC) circuits, I would say that they were single phase. It's like my house, with a 3-phase supply, essentially distributed as one phase per floor. I would not dream of describing anything (whether distribution or final circuit) downstream of the (3-phase) meter as being a '3-phase circuit'.

I suppose a grey area might arise if you had 2-, 3- or 4-pole switches controlling two or more sets of lights on different phases - but it doesn't sound as if you have that situation, anyway.

In any event, even if you could come up with a convincing argument that it was '3-phase', that would only add black and grey (in terms of harmonised colours) to the over-sleeving colours you could use.

Kind Regards, John

This was originally installed when it was commonplace to retain phase colours throughout 3ph installations [whether required in the regs or not], there are no indivudual switches, just the one to control the main contactor. If there was a 3 pole switch controlling ccts 1,2 & 3 [say] then I would not hesitate it a 3ph cct.

 

[JohnW2]

This was originally installed when it was commonplace to retain phase colours throughout 3ph installations [whether required in the regs or not]...

Yes, but that again begs the question as to what is a "3-hase installation", doesn't it? Returning to the example of my house, although what goes into and comes out of my meter is undeniably '3-phase', everything downstream of the meter is, in commonsense terms, single-phase - so I don't think it would occur to me to think of it, or describe it, as a '3-phase installation'.

Also, unless one was going to oversleeve all the Ls throughout two of the 'phases', the practice you mention would, if one was wiring in T&E (like my house), really require blue/black and blue/grey T+E to be available, which I imagine it isn't!

... If there was a 3 pole switch controlling ccts 1,2 & 3 [say] then I would not hesitate it a 3ph cct.

Well, I did concede that as being a potential 'grey area', but I think I would 'hesitate' more than you before deciding which way to go.

Kind Regards, John