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

[Toneyz]

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.

I suppose using L1, L2, L3 there would be no confusion.

 

[Lucien Nunes]

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?

There is a problem now that two colour systems exist, which is that a single-phase distribution circuit on the black phase (harmonised colours) would have a black line and a blue neutral, while one on the blue phase (old colours) would have a blue line and a black neutral. This is the only situation with completely ambiguous polarity, as in any 3-phase circuit the colours of the other phases imply the functions of blue and black. Requiring the line to be brown on a single-phase distribution circuit prevents possible confusion.

Historically, I did prefer phase identification colours and wired many distribution circuits that way. I would tag the line on a 2-core MI submain with the phase colour too.

 

[Toneyz]

Of course on commercial jobs, we now identify using Brother printed labels, engraved labels etc. Which helps.

 

[Bobster]

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.

From what I remember the panels I designed for Tate and Lyle all phase colours were black, but every wire was numbered. It was also a control suit so not exactly the same as distribution.