My sexy DB's.. (Even if I do say so myself..)

[Spark123]

I imagine it is to do with half the outer sheath being a live (neutral) conductor.
It would be daft to allow it for switch drops but I'm sure they could have written that out too.

 

[Lectrician]

Cant say I would ever consider it for a switch drop.....4mm being the smallest size available.

Used to use it all the time (and still do actually) for domestic submains.

 

[Spark123]

Me neither - I can't say I have ever used split con tbh. I was just trying to think of a situation where half the outside sheath could be line conductors

 

[RF Lighting]

What about a failed neutral connection at the supply end. Although the outer cores are not a line conductor, it will still be at a potential of 230V to earth.

 

[LoveRocket]

What about a failed neutral connection at the supply end. Although the outer cores are not a line conductor, it will still be at a potential of 230V to earth.

Which would be exactly the same on SWA if a TNC-S supply.