Two core wiring with the same sleeve colour

[Risteard]

I like being able to identify strappers without having to read painted or plaster coated sheaths, but it's not something I generally use. Conversely every spark I know uses the stuff, but that's probably a good thing as none of them ever carry any sleeving that isn't green/yellow.

Brown & blue for switch drops is unheard of here (and incidentally expressly prohibited across the border).

 

[nicebutdim]

Brown & blue for switch drops is unheard of here (and incidentally expressly prohibited across the border).

I wouldn't say it's unheard of, but certainly uncommon. There's no regulatory reason for not using blue/brown T&E on switch drops, provided conductors are correctly identified.

I didn't realise that ROI mandates the use of twin brown for switch drops - in light of that it's surprising the OP had never seen it before.

 

[ipf]

For the OP.
It is the norm for two (or all) blacks with one type of cable, and hence the 'belling out'/continuity as well as IR testing....pyro.

 

[Marvo]

Apart from ripcord and maybe a speciality flat elevator type ribbon cable I've also never seen a cable with two identical blue wires. I highly doubt such a cable would be available unless it was a special order. I've seen cables that contain more than 1 black wires with numbers on them but the numbers only appear every 10 or 15cm along their length so you might not see them if you only strip a short section.