Looking to install LED lighting that has separate constant current LED drivers. Rather than using a separate driver for each light I want to run the drivers centrally and then run a number of lights in series from each driver.

For example, these drivers are rated at 50w http://www.mr-resistor.co.uk/item.aspx?i=8670 so should be able to run a single driver for each circuit.

I can’t work out from the regs what cable is allowable? At that kind of power standard 1.5mm twin will be more than adequate but is there a requirement to use differently marked/coloured cable for LV applications or is standard blue/brown OK?

Rather than using a separate driver for each light I want to run the drivers centrally and then run a number of lights in series from each driver.

You can’t do that regardless of the cable you use.

You mean ‘parallel’ I hope, or have these lights got multi connectors on each unit to daisy chain them?

Yes, in theory, it sounds fine, if I do them (I dont generally do low voltage lighting any more, complete waste of time and money IMO) I’d put one driver for 4 or 5 light fittings.
The multi-capable drivers are only around £3 more than a single unit, so makes sense to use the multis.
Any decent cable will do. You dont need insulated and sheathed for extra low voltage (<50V), but the run must be separate from mains cables. 1.5mm T+E may be too large for some of the LED fittings, 1mm T+E may be suitable, but I’d be happier using 2 core flex, so long as it is protected well enough from damage, and has a large enough cross sectional area – >0.75mm , possibly >0.5mm
However, I’d still be looking at using mains voltage for any new lighting.

You can’t do that regardless of the cable you use.

Flaperon – why do you think that?

You mean ‘parallel’ I hope, or have these lights got multi connectors on each unit to daisy chain them?

Definitely mean Series and not parallel – very clear from – Astro instructions
and PhotonStar instructions

When you say the ‘run must be separate’ I can’t see that there would be many cases where 240v would be running alongside. If it’s going in the same direction am I right to assume running between different studs / joists (circa 400mm) would be sufficient?

Why do you think LV lightings a waste of time? 240v LEDs in a ‘traditional’ lamp body are just packing individual drivers into each lamp in a restricted space. Given the life of high quality LEDs it feels like it’s worth spending the money once and doing it properly

Depends on the driver. For constant current they run in series. Constant voltage in parallel. Haven’t read the links to see what you have. Regs say little to nothing about extra low voltage so use whatever cable will handle the current (which is likely to be low)

Mains vs LV LEDS – why pay for a transformer/driver?
12V – takes longer to connect up, costs more, an extra part (the driver) to go wrong,a small delay between turning on at the switch and the light coming on, costs very slightly less to run.

230V – fits into existing fittings with no driver/transformer compatability problems. Most are a straight swap. Simple to run – no driver needed, just connect your cables. Wider choice of lamps/wattages/colours. Costs very slightly more to run.

SELV cables – REG.414.4 – basically, 2 core unsheathed cable cannot run alongside 230V cables/equipment. So either separate their runs if using 2 core unsheathed, or, use insulated and sheathed (T+E style) cable,

For a low voltage setup like you describe I would use 1.5mm sq pvc twin flex. 1.5mm sq flat twin is also OK just harder to work with due to it being stiffer.

I’d also sleeve the cores to be red/black too differentiate is from an ac system

I’d also sleeve the cores to be red/black too differentiate is from an ac system

That’s the real question I was asking. Sensible but not a regs requirement from what i’ve read above.