Sleeving Brn-Blk-Gry cores for SP. Is there a convention?

[Mark42]

If using 3-core SWA Brown/Black/Grey for a single-phase circuit, what colours do you use?

I leave the brown as live, then sleeve the black with blue for N and the grey with grn/yel for E.

It's arbitrary, but was wondering if there's an informal convention, and if maybe I've been 'doing it wrong' for twenty years?

 

[Andy78]

The convention was/is black as green/yellow and grey as blue, to try and disassociate the black from being neutral.
But as long as they are labelled accordingly they are compliant.

You can get brown/blue/green yellow 3 core SWA.

 

[Mark42]

The convention was/is black as green/yellow and grey as blue, to try and disassociate the black from being neutral. But as long as they are labelled accordingly they are compliant.

Thanks: I must have missed that years ago!

You can get brown/blue/green yellow 3 core SWA.

Yes I know that, but for some reason it costs more

 

[PEG]

As above,but emphasis on "labelled accordingly". In the past i have blanked all three conductors,with white heat-shrink,and fitted cable markers,to further disassociate any colour mix-ups.
In the choice of none marked,two marked,or all marked,i would go for the all.

Regardless of colours,markers or numbers,one would always check to confirm,either the bizarre,or the obvious.

 

[Mark42]

...In the choice of none marked,two marked,or all marked,i would go for the all. ...

I agree.
But I didn't want to admit that I do also sleeve the brown with brown shrink-fit, for consistency and to remove any doubt, in case I'm considered weird.

 

[PEG]

I agree.
But I didn't want to admit that I do also sleeve the brown with brown shrink-fit, for consistency and to remove any doubt, in case I'm considered weird.

Nope,not weird,just thorough.

Do not ever be embarrassed about being diligent,and going the extra mile,to ensure those who follow,do not have to think too hard

 

[Deleted member 26818]

The NICEIC introduced this convention shortly after the Harmonised colours were adopted.
The stated purpose is as Andy78 says, to disassociate the Black from Neutral.
No one has been able to explain why we need to disassociate the Black from Neutral.

I’ve worked on sites where the use the Grey, and on other sites where they use the Black.
I now ask when I start on a site which colour they use for Earth, usually get the response of G/Y.

 

[Deleted member 26818]

During the transition period for the harmonised colours, we had the option of using either the old or the new colours.
With new installations, we had to choose a colours scheme and stick to it through out.
Wholesalers were supplying whatever colours they had available, so it was a ---- up as to which colour scheme would involve the most sleeving.

Because we had to choose a colour scheme, it was taken that the whole of the exposed insulation of a conductor had to be sleeved, not just a small amount to identify.

On one installation, the client wanted us to wire in the old colours and then sleeve each conductor with the new.
So with 4 or 5 core cables, we would be sleeving red with brown, yellow with black, blue with grey and black with blue.

Fortunately we managed to convince the client that this would be too expensive and unnecessary.

The only time I would consider sleeving a brown conductor with brown, would be to identify a switch line, or a permanent feed.

 

[Zdb]

I have always used:

Brown = Live.
Grey = Neutral.
Black = Earth.

I wish that this (and also permanent and switched live) would be included in the regs or OSG so that there is no room for confusion.

 

[Taylortwocities]

I have always used:

Brown = Live.
Grey = Neutral.
Black = Earth.

I wish that this (and also permanent and switched live) would be included in the regs or OSG so that there is no room for confusion.

The colour ceonversion guide certainly is included in the 17th edition OSGs. Appendix K starts by stating that for single phase additions & alterations the cores must be sleeved to avoid any confusion.
The other tables in that appendix, that refer more for 3-phase, show clearly what the IET intends the colour equivalents to be. I've always followed that.

 

[Deleted member 26818]

The colour ceonversion guide certainly is included in the 17th edition OSGs. Appendix K starts by stating that for single phase additions & alterations the cores must be sleeved to avoid any confusion.
The other tables in that appendix, that refer more for 3-phase, show clearly what the IET intends the colour equivalents to be. I've always followed that.

We’re talking about using 3phase colours for single phase.

 

[telectrix]

also begs question as with, for example, em. lights, do we use black for perm L and brown for switched, or vice versa? (in either case, the black being sleeved the colour of shyte).

 

[Mark42]

... ensure those who follow, do not have to think too hard ...

Indeed so. For, as we all know, some electricians* struggle with that activity

*Generally not those on here, so no offence please. The reason I learned electrics decades ago and took the exams, is because I became fed up with the atrocious standard of some 'professional' installations I'd seen. I therefore wanted to do all the work myself on my own gaff (with no time/cost pressures), which is a lifetime’s restoration project on a sprawling house built between 1480 and 1510. Some of the existing electrics looked original

 

[Mark42]

also begs question as with, for example, em. lights, do we use black for perm L and brown for switched, or vice versa? (in either case, the black being sleeved the colour of shyte).

I have a personal convention (no doubt others will say it's wrong ) of using a small length of yellow shrink-fit to identify switch lines, and violet for other oddities (over a base sleeve of brn).

Yel and vio are legit colours for phase inside equipment. (As is plain green, but I can’t bring myself to ever use that.)

I’m retired now so not having much contact with other tradesmen I may be getting out of date as to what is ‘normal’.

 

[Deleted member 26818]

also begs question as with, for example, em. lights, do we use black for perm L and brown for switched, or vice versa? (in either case, the black being sleeved the colour of shyte).

I tend to use Black for perm live, simply because that’s how click wire their flexes.

 

[Mark42]

And here's another thing: when wiring a single phase circuit from a TP DB might one sometimes ignore convention, and 'export' the phase on the 'correct' line colour? (L1 brn / L2 blk / L3 gry).

It's sometimes useful to immediately know which phase is present at the far end, without testing or referring to (lost!) documentation.

 

[Deleted member 26818]

And here's another thing: when wiring a single phase circuit from a TP DB might one sometimes ignore convention, and 'export' the phase on the 'correct' line colour? (L1 brn / L2 blk / L3 gry).

It's sometimes useful to immediately know which phase is present at the far end, without testing or referring to (lost!) documentation.

That’s been prohibited by the Regs for some time now.
I believe it was allowed for distribution circuits up until either the 16th or 17th.

 

[Mark42]

That’s been prohibited by the Regs for some time now.
I believe it was allowed for distribution circuits up until either the 16th or 17th.

Oops! I admit I didn't know that! I'm 17th Ed'n and a bit out-of-date.

I'm puzzled why it should be absolutely prohibited though: brn, blk, and gry are clearly legit phase colours, so as long as the remaining two are clearly sleeved blu & grn/yel at both ends, where's the danger?

 

[Deleted member 26818]

Oops! I admit I didn't know that! I'm 17th Ed'n and a bit out-of-date.

I'm puzzled why it should be absolutely prohibited though: brn, blk, and gry are clearly legit phase colours, so as long as the remaining two are clearly sleeved blu & grn/yel at both ends, where's the danger?

I don’t know?
When I worked at Tate and Lyle, we used to use the phase colours for all circuits.
I dread to think what the trunking will look like now Black is a phase colour.

 

[GBDamo]

Tin hat on but, I tend to maintain the convention already being used in the installation.

It pains me but I think having two conventions in play is potentially more dangerous that having one that is technically incorrect.

However more often than not there are multiple conventions in play in which case I use the whatever is in use in that part of the installation.

I don't tend to do many new installs, mostly additions and alterations.