Which electrical cable

[soprano]

Hello all

A couple of years back we had an extension/refurb and full rewire. In order to future proof ourselves, we had the electrician run a cable from the back of a switch in the kitchen (but not connected to anything) to a junction box outside (also not connected to anything) to allow us to install lighting in the garden. That time has now come.

The cable installed behind both the switch and at the other end in the junction box has grey, white, brown and earth.

I will call an electrician to undertake the actual installation, but woud like to run the cable whilst I am doing the decking/patio area.

Is it something like this that I need to run?

https://www.toolstation.com/pitacs-swa-single-phas...

Many thanks

Edited by soprano on Thursday 16th July 16:13

[grumbas]

Sounds like they've run a 3 core + earth to give some flexibility.

What you run now is very much dependent on what you want to install, where, how you plan to switch it, etc.

If you put a diagram up you might get some useful suggestions, but many electricians have their preferred way of doing things so the right answer is probably get them in now to nail the design.

[biggiles]

Agreed, every electrician will have their own interpretations/preferences. e.g. some would want 2.5mm, even though it's for lighting only. The actual colours on your original cable don't make such a difference, so long as the electrician can see both ends and sleeve them. It's a curious cable though to have those colours? White isn't very common.

[soprano]

Thanks both - I was naively hoping there was one answer! Might be a good idea to call the electrican sooner than later, as suggested.

You are quite right about the colour of the wiring, having double checked it is brown, black and light grey.

Currently there is a single switch which operates three outside lights on the house, which will stay 'as is'

Behind that switch and running to the junction box outside, is the three core and earth, mentioned above. That is not connected to anything. My recollection is that the intention was to add a second switch, and connect it to a further outside lighting circuit which will probably be something like

(a) 4/5 small lights in the decking, to light the step;
(b) 2/3 small uplights for a raised planter' and
(c) possibly some lights along what will be a newly installed path. the path will be about 25/30 metres long in total, but unsure if we will want lights along the whole length
(d) The above to all run off what will be the new, second switch (though I don't know if it is possible given the wiring which has been put in place, to have the outside lighting on three, rather than two switches, as intended).

Hopefully that provides a bit of an idea as to the intention.

[Mr Pointy]

The switching doesn't have to be done next to the existing switch - you could just use the cable to carry power to a position outside where you can add switches as required. If you have a four core cable you can only switch two circuits anyway.

The lighting doesn't have to 240v & frequently low voltage DC lighting is used/preferred, powered by a PSU in a waterproof box. You can also add wireless or Alexa-controlled switching so you don't even have physical switches. Start by working out what you really want (how many circuits, can you find DC lights etc) & go from there.