Outside fence lights

[MisterBoy]

For that job with such minimal load, and considering a thinner cable might look less conspicuous, I'd go for two-core and use the armour for the cpc/earth. It's perfectly adequate, so long as good solid connections are made with the brass glands, and obviously the banjos are earthed correctly using brass nuts and bolts connecting an earth wire to the supply.

A slightly thinner cable would make for neater bends.

Alternatively, if you did use three-core, you could do what I've done on a similar job recently. Use the third core for a permanent live, and put a PIR at each end of the run (or a manual one-way switch if that's a consideration).

If the fittings are suitable, you could bring the glands into each side, rather than a separate adaptable box. It is always a nice idea to aim for bottom entry, but with the shrouds, and some sealant over the meeting of the gland and fitting, it should be okay. I usually put a small drain hole in the bottom.

Thanks for that. Regarding the light fittings, the plan is that they are on one side of the fence and everything else hidden on the backside. I don't know there's an easy way to get cables directly to them neatly without a separate box... Are you suggesting pushing the cable through a hole in the fence so the light fitting is the box effectively or have I misunderstood you?

I might get a 3 core to keep my options open.
Did you mean the two lives would effectively be a ring/loop... The lights would be fed off the return live so it can be switched easily?

 

[MisterBoy]

To clarify, if I've got black brown and grey 3-core on a 10m run, is the idea to connect brown to my live at the near end and join the brown+grey wires at the far end (through a switch most likely) so I've in effect got a 20m live wire running along the cable and back?
Lights connect to the grey and black wires, grey wire presumably this just gets terminated safely.

 

[EFLImpudence]

No, what was meant was,

a permanent live wire to the PIR at the far end and a switched live from PIRs to the lights.

 

[MisterBoy]

No, what was meant was,

a permanent live wire to the PIR at the far end and a switched live from PIRs to the lights.

Sorry to be dumb, I am happy wiring things together but designing it less so I don't think I need to go this route but any chance of a sketch as I would like to understand?

Anyway an update: I decided to dump the conduit and go for 3-core 1.5mm SWA. Got some gland fittings and figured out how those are installed - nothing too onerous. Only to discover the plastic boxes I want to use are not rated for SWA so need to source different ones! Then reading up around earthing SWA glands, fell down a rabbit-hole of banjos and piranhas and double lock-nuts (https://www.diynot.com/diy/threads/acceptable-method-to-bond-earths-in-a-plastic-junction-box.368524).

Screwfix don't have piranha things in and looking around it seems for my small job, going with Miska boxes might just save me a load of headaches on the basis I'm not experienced, and would rather trade a few quid for an easier job? As in, get the 308 boxes and the earth bars from TLC and then I'd just need some crimps to attach my earths and job's a good 'un?