Sleeving 3C+E

[JohnW2]

Having said that (and not the least because I don't have any dealings with any all-harmonised-colours installations), I would personally always utilise (small bits of) brown oversleeving, 'just to be sure'.

Not red & black?

Certainly not black (for a live conductor)! And, no, not red, either, for me (assuming that it's a black or grey conductor we're oversleeving, as per OP). I don't know if it's what everyone does, but, in mixed-colours installations, I always oversleeve as appropriate to the 'base colours' of the cable concerned. Hence, if I had two cables coming to a two-gang switch, one red/black and the other brown/blue, I would oversleeve the black with red and the blue with brown. Is that not what others do?

The problem with the two-colours 'warning notice' is, IMO, that those who might possibly benefit from the warning will almost certainly not have a clue as to what is meant by "...wiring colours to two versions of BS7671". If we are to have such warning lables, they should (again, IMO) at least be worded so as to be understandable by those who most need to be 'warned'!

Might it not be be difficult to come up with wording which would impart the message in a way which would be understood by somebody whose grasp of electrics was so flaky that they thought that L & N could be the only conductors going to a switch?

The wording could certainly be such as to make it much more likely that a 'lay' person understood. For a single-phase installation, explicit mention of red/black vs. brown/blue would have instant meaning to such a person, whereas 'colours to two versions of BS7671' almost certainly wouldn't. It could even include information on the correspondence bewteen red/back and brown/blue.

Kind Regards, John

 

[Spark123]

Hence, if I had two cables coming to a two-gang switch, one red/black and the other brown/blue, I would oversleeve the black with red and the blue with brown. Is that not what others do?

I'd sleeve the red, black and blue conductors with brown sleeving, not that it matters too much what you propose.

 

[JohnW2]

Hence, if I had two cables coming to a two-gang switch, one red/black and the other brown/blue, I would oversleeve the black with red and the blue with brown. Is that not what others do?

I'd sleeve the red, black and blue conductors with brown sleeving, not that it matters too much what you propose.

That's another approach, but I generally don't sleeve an old-colours cable to bring it up to 'new colours' specification. If, say, two cables going to a socket (or the 'in' and 'out' cables of a loop-in ceiling rose) had different identifying colours, would you oversleeve the red and black (to brown and blue)?

Kind Regards, John

 

[Spark123]

Nope, I wouldn't bother too much about that.
If there was already red sleeve on the black in the switch you mentioned before I'd be inclined to leave it be, but if there wasn't I'd just sleeve the black and red with brown. I usually have brown sleeve handy and I'm lazy

 

[JohnW2]

Nope, I wouldn't bother too much about that.

Nor would I, but I don't think it's just a matter of 'bothering' (which suggests that it really ought to be done) - I don't think it's ever been suggested that old-colours cables in a mixed-colours installation need to be oversleeved to new colours.

If there was already red sleeve on the black in the switch you mentioned before I'd be inclined to leave it be...

Me too, but ...

... but if there wasn't I'd just sleeve the black and red with brown. I usually have brown sleeve handy and I'm lazy

OK, that's a practical enough a reason! It simply would seem more logical to me to sleeve it red if one could, but it doesn't really matter - hopefully either brown or red should be interpreted as indicating live/line.

Kind Regards, John

 

[Spark123]

It isn't a requirement of BS7671:2008 to oversleeve a new - old colour interface where they are being used as live (red-brown) and neutral (black-blue). A notice must be fitted at the circuit origin warning of two colour versions of BS7671 tho.

 

[JohnW2]

It isn't a requirement of BS7671:2008 to oversleeve a new - old colour interface where they are being used as live (red-brown) and neutral (black-blue).

Not that I've heard of. If there were such a requirement, it would presumably be in Appendix 7 (which, in any event, is only 'informative') and there is no such requirement there. On the contrary, 2.1 of Appendix 7 seems to be saying that such oversleeving at the interface is not required.

A notice must be fitted at the circuit origin warning of two colour versions of BS7671 tho.

Indeed, and I commented on that notice a few posts back. It (the required wording) strikes me as a prize example of an utterly useless 'warning notice', since it will, on the whole, only be understandable to those who don't need to read it!!

Kind Regards, John

 

[ban-all-sheds]

Certainly not black (for a live conductor)! And, no, not red, either, for me (assuming that it's a black or grey conductor we're oversleeving, as per OP).

Sorry - I wrote that very badly. I knew what I meant.

I'll try again.

Having said that (and not the least because I don't have any dealings with any all-harmonised-colours installations), I would personally always utilise (small bits of) brown oversleeving, 'just to be sure'.

Not red on any brown, black, grey or blue conductors used for line, and black on any brown, grey or blue used for neutral?

 

[JohnW2]

Certainly not black (for a live conductor)! And, no, not red, either, for me (assuming that it's a black or grey conductor we're oversleeving, as per OP).

Sorry - I wrote that very badly. I knew what I meant.

No problem - I know thatsiutaion well

I'll try again.

Having said that (and not the least because I don't have any dealings with any all-harmonised-colours installations), I would personally always utilise (small bits of) brown oversleeving, 'just to be sure'.

Not red on any brown, black, grey or blue conductors used for line, and black on any brown, grey or blue used for neutral?

That's right. As I've said, I would (in a single-phase installation) only ever oversleeve a harmonised colour conductor with brown or blue. Is that unreasonable?

Kind Regards, John

 

[ban-all-sheds]

There's a case to be made in SP installations which are predominantly non-harmonised for oversleeving harmonised conductors with red/black as appropriate to their function.

 

[SimonH2]

Might it not be be difficult to come up with wording which would impart the message in a way which would be understood by somebody whose grasp of electrics was so flaky that they thought that L & N could be the only conductors going to a switch?

I think it would be impossible to come up with wording which actually imparted any useful information to such people. The only wording I can think of would be along the lines of "If you need to read this warning notice, then you shouldn't be doing anything on this installation !"

That's another approach, but I generally don't sleeve an old-colours cable to bring it up to 'new colours' specification. If, say, two cables going to a socket (or the 'in' and 'out' cables of a loop-in ceiling rose) had different identifying colours, would you oversleeve the red and black (to brown and blue)?

Interesting point.
Something that came to mind earlier ... If sockets (say in a workshop/industrial environment) were being wired in conduit & singles, would you use all red regardless of phase, or would you use (have used) red, yellow, blue depending which phase the circuit was connected to ? Then what if you extend a circuit with new harmonised colours.
That brings up the possibility of having a socket with black wires in both the L and N terminals or blue wires in both L and N terminals After a while and the grey has gone a bit dark, you could have a socket with 'black' and blue in L, and black and blue in N.

 

[JohnW2]

There's a case to be made in SP installations which are predominantly non-harmonised for oversleeving harmonised conductors with red/black as appropriate to their function.

...or the converse. Yes, I agree that, if one of the colour coding systems is dominant in an installation, there's a bit of the case for oversleeving the 'minority' colours. Of course, anyone who would have any problem without such oversleeving shouldn't be working on the intstallation in the first place - so it's really a question of how far installation practices should go in 'making allowances' for incompetent people who might work on the installation in the future.

Kind Regards, John

 

[ban-all-sheds]

Well that's what the regs do...

 

[JohnW2]

I think it would be impossible to come up with wording which actually imparted any useful information to such people.

• "CAUTION. Some cables in this installation use red insulation to indicate live** conductors and black to indicate neutral ones, whereas other cables use brown to indicate live and blue to indicate neutral. Great care should be taken before undertaking extension, alteration or repair that all conductors are correctly identified"

**They probably wouldn't understand 'line'.
Only the red bit has been changed in comparison with the BS7671 wording. Anyone who could not understand the above version certainly ought not to be working on an electrical installation!

Kind Regards, John

 

[SimonH2]

Some cables in this installation use red insulation to indicate live** conductors and black to indicate neutral ones, whereas other cables use brown to indicate live and blue to indicate neutral. Great care should be taken before undertaking extension, alteration or repair that all conductors are correctly identified"
**They probably wouldn't understand 'line'.

Don't think that would be any more helpful - it still leaves people (at least the people its aimed at) thinking that "if it's black (or blue) then it's neutral".