Wiring a new 2 gang switch from a single two way switch.

Flam98 · Aug 1, 2024

I want to wiring in some new lights in an old shed I have. There’s an existing light switch for the toilet that powers a light, a fan and fan isolator, and it works fine. The shed can be dark in winter and I want to put a couple of lights in it with a switched light for the outside, and a light for inside. I believe I’ll need to wire in a 2 gang switch so I can switch the two new lights on and off separately.

I was hoping to take the supply I need for the 2 gang switch from the existing shed toilet switch. I am kind of stumped to know what to run to what and would be grateful for the help needed to know what to run where. The existing WC switch, is what I think you’d call a single gang 2 way switch. Here’s a photo of the back of it.

[ElectriciansForums.net] Wiring a new 2 gang switch from a single two way switch.

There’s a permanent power in at the top of the switch and there are L1 and L2 connections. As it is currently wired.
Switch OFF: L1 No Power - L2 Powered
Switch ON: L1 Powered - L2 No Power

It’s all working fine, but I want to take a supply from this switch to the 2 gang switch and then provide separate supplies from that 2 gang switch to the two new light fittings. Here’s a photo of the back of the 2 gang switch. Please ignore the wires. I was just trying to work things out in my head and figured it was best to ask the forum first.

The existing light switch and fan are the only things powered from a 5amp fuse on the power board for the shed.

Could somebody please help me and explain what wires go where? I figured I’d have to run the permanent live to the new two gang and then loop that supply to the second switch on the 2 gang (like I did in the image, but I am not sure so I need your help.

A big thanks

Flam

loz2754 · Aug 1, 2024

Looks like you have the right idea with regard to the permanent live. You have not mentioned how you propose to connect neutral and earth to the new lights though....

Flam98 · Aug 1, 2024

loz2754 said:
Looks like you have the right idea with regard to the permanent live. You have not mentioned how you propose to connect neutral and earth to the new lights though....

Hi Loz, Thanks for your reply. I edited the post to include information about the power going to L1 and L2 in the on and off positions, in case that was needed. Everything is working 100% with the existing shed toilet light, fan and fan isolator. All works as I want/expect it to work, and I'm OK with that. I thought running a 'feed' form the existing light switch to a new (2 gang) switch, and then wiring the two new light fittings from the two switches on the new 2 gang switch was possible, but maybe it's not. You've spoken about earths, but I have to work with what I have, and I don't think earths are part of that, it's a 100 year old shed. Will anybody advise?

loz2754 · Aug 1, 2024

I spoke of earth and neutral. For the new lights to work, they will need both a live from the switch, and a neutral to complete the circuit.
The switch you currently have has the permanent live and the switched lives, but it does not have a neutral (unless there is a neutral in a connector block in the back box, not shown in your photo).
The earth is for safety in the event of a fault, and should be present at every point in the circuit.

Flam98 · Aug 1, 2024

loz2754 said:
I spoke of earth and neutral. For the new lights to work, they will need both a live from the switch, and a neutral to complete the circuit.
The switch you currently have has the permanent live and the switched lives, but it does not have a neutral (unless there is a neutral in a connector block in the back box, not shown in your photo).
The earth is for safety in the event of a fault, and should be present at every point in the circuit.

Hi Loz, Thanks again, but I don't have a solid answer for you. You said the existing single gang switch has permanent live, and switched lives, I nderstand the permanent live, and I am presuming the switch changes the permanent live feed inisde the switch between the switched lives, but the pupose of that in my setup I don't know.

I thought I would be connecting L1 to one side of the light fitting and L2 to the other, and it was at that pint I thought I should ask the forum. Forgetting about earth for the moment, you're saying there has to be a neutral in the mix somehwere. It's at this level (i know it's basic) that I get lost.

I'm presuming here'd have to be a neutral at the light fitting? for the whole thing to work, but I don't know if that's how it works. If I checked the live at the bulb would this mean the other side is the neutral? because if there are only two wires at the ght fitting, one should be a swicthed live, and the other would be neutral?

If this is correct then can I run feed from the neutral (if what I've said above is the case) at the existing light fitting to the new light fittings?

From what you've said it seems I could run a neutral from the existing light bulb to the new bulbs. Would this work for different switches?

Flam98 · Aug 1, 2024

Flam98 said:
Hi Loz, Thanks again, but I don't have a solid answer for you. You said the existing single gang switch has permanent live, and switched lives, I nderstand the permanent live, and I am presuming the switch changes the permanent live feed inisde the switch between the switched lives, but the pupose of that in my setup I don't know.

I thought I would be connecting L1 to one side of the light fitting and L2 to the other, and it was at that pint I thought I should ask the forum. Forgetting about earth for the moment, you're saying there has to be a neutral in the mix somehwere. It's at this level (i know it's basic) that I get lost.

I'm presuming here'd have to be a neutral at the light fitting? for the whole thing to work, but I don't know if that's how it works. If I checked the live at the bulb would this mean the other side is the neutral? because if there are only two wires at the ght fitting, one should be a swicthed live, and the other would be neutral?

If this is correct then can I run feed from the neutral (if what I've said above is the case) at the existing light fitting to the new light fittings?

From what you've said it seems I could run a neutral from the existing light bulb to the new bulbs. Would this work for different switches?

I know I am replying to my own post, but I resolved it after my last mesage here. I tried it like I explained above and it worked for me. I wouldn't call it a solution because I realise that it's not a solution that a electrician would approve, but it gets me by. Thanks Loz for your help, it was help, it got me brain thinking in the right direction.