Help wiring a neutral for timer switch

[Andycumbo]

Hi, I have ran a light ring off a fused spur with two lights on, each with their own switch (outside and lobby light) I want to put the outside light on a timer but the light only has one wire coming into it (twin and earth). I have wired up the lights as shown on fig 2 in the link below using junction boxes with a feed in, feed out, switch and lamp… I can still access the Junction box to add an additional wire for the outside timer switch I’m just not sure where it needs to run off…

The timer switch needs a wire from mains and a wire to appliance so I’m guessing the wire I currently have is the wire to appliance and now I need one from the mains to run the switch intself? Any advice on which wire to break to run a wire to the switch for the supply?

Cheers

Old multi-point radial lighting diagram using junction boxes

Fig 1 shows what is referred to as a radial circuit (sometimes called a 'loop-in' or 'multi-point radial lighting circuit'). which uses junction boxes instead of ceiling roses. You may find this wiring arrangement in older properties.

www.lightwiring.co.uk

 

[littlespark]

If the timer is going where the switch is, you will need an extra core run from the junction box. (3 core and earth) to bring a neutral.
The switch only has a live, and a switched live back up to the box, which is the connected to the light.

There are push button mechanical timers which run for about 15 minutes if I recall. Direct replacement for a normal switch- only uses the 2 cores.
You push in the button in to close the switch, and it slowly returns to the out position where it opens.

There are also some Smart switches that don’t need a neutral to work, and set the time with a smartphone.

 

[Andycumbo]

If the timer is going where the switch is, you will need an extra core run from the junction box. (3 core and earth) to bring a neutral.
The switch only has a live, and a switched live back up to the box, which is the connected to the light.

There are push button mechanical timers which run for about 15 minutes if I recall. Direct replacement for a normal switch- only uses the 2 cores.
You push in the button in to close the switch, and it slowly returns to the out position where it opens.

There are also some Smart switches that don’t need a neutral to work, and set the time with a smartphone.

Okay so I bought the “Greenbrook 24 Hour Mechanical Socket Box Timer 16A Resistive 2A Inductive” from tool station… the instructions have the two neutrals together and then the 2 lives in different sections… if I just run a 3 core so I get the additional neutral I will still be without the additional live? Is that not needed?

 

[littlespark]

with that timer, yes, you need a live, neutral and switched live to make it work.
If it’s only a twin and earth running from junction box to switch, you’ll need to replace with a 3 core and earth

 

[Andycumbo]

with that timer, yes, you need a live, neutral and switched live to make it work.
If it’s only a twin and earth running from junction box to switch, you’ll need to replace with a 3 core and earth

Perfect thanks for your help! Very tempted to just get a smart one that only needs the two wires I currently have to save the faff