Adding second light switch to garage circuit

Hi.

First up, I am not a qualified electrician so this is a DIY project However, I am physicist by training with a specialism in electromagnetism, so I know the principals of circuits.

I want to add a second switch to my garage lighting, so that we don't have to fight our way to one corner of the garage to turn the lights on or off.
I have seen the standard 1-gang 2-way lighting diagrams and understand the principal of how that works.

What I am currently struggling with is slightly strange way the lights seem to have been installed. There is a live in to a 2-gang light switch, the first serving the interior lights and the second serving the internal lights. I have sketched out the wiring below. The mains in comes from the house (this is a detached garage), from the sockets ring. There is a switched fuse box which takes in the live wire, which isolates the lighting circuit only. The always live cable goes to the sockets in the garage. The switched cable goes to the 2 gang switch, with 1 switch controlling the internal lights (2 lights) and another controlling the exterior flood lamp with PIR.

It's also worth noting that the PIR External light would appear to wired up strangely as well, because usually these are wired up so there is a permanent live that feeds the PIR regardless of the switch position, and the switch acts as a always-on override. That means the light sensitive PIR will always activate the light in the dark. In this case, it appears that the light switch isolates the external light completely when it is in the off position.



The question here is, how can I replace the 1-way interior switch with a 2-way switching arrangement?

I don't mind separating out the internal and external switches so there is separate box for each light circuit, something like below. What I am trying to do is replicate the supply being shared between the lights (which is done with the bridge live bridging wire in the current setup), but to do it in a junction box so that I can have two single gang switches.

What I am unsure about is how the 2-way wiring would work with the non-standard arrangement of the circuit to the internal lights.

Would this arrangement below work [in the two way switching arrangement, I have omitted the earth's for clarity, but in the first switch the intention would be to collect them altogether with the supply earth]?

Any advice would be very well received.

I think your proposal will work. Others may have observations. You could use a 2 gang 2way switch in the existing box to avoid another box for the external lamp.

The Quinetic range gives a solution that would not require any more wiring, but is a little more costly:
You could replace the current 2 gang light switch with one of these:
Quinetic 2 Gang Wireless Switch & Built In Receiver - White | Quinetic (QURS2W) - https://www.tlc-direct.co.uk/Products/QURS2W.html (I think it would be a 'drop in' replacement)
and put one of these elsewhere in the garage to give the 2 way operation of the internal light.

You just pair the remote switch with the powered one for the internal light, and away you go!

Avo Mk8 said:

I think your proposal will work. Others may have observations. You could use a 2 gang 2way switch in the existing box to avoid another box for the external lamp.

The Quinetic range gives a solution that would not require any more wiring, but is a little more costly:
You could replace the current 2 gang light switch with one of these:
Quinetic 2 Gang Wireless Switch & Built In Receiver - White | Quinetic (QURS2W) - https://www.tlc-direct.co.uk/Products/QURS2W.html (I think it would be a 'drop in' replacement)
and put one of these elsewhere in the garage to give the 2 way operation of the internal light.

Quinetic 1 Gang Wireless Switch - White - IP67 | Quinetic (QUWS1W)

You just pair the remote switch with the powered one for the internal light, and away you go!

Click to expand...

Thank you so much for the advice and information, very much appreciated.


With regards to the external PIR light, my consideration right now is that it appears the switch is wired corrected because it means the black wire (on the original diagram) is always on, and thus should go to the PIR, which would then have a switched live going to the light, as well as the switched live coming from the other terminal of the switch [brown in the diagram]. Therefore, this should be working as an override switch rather than an isolating switch, so the light itself must be wired up differently.

Sorry, I hadn't paid sufficient attention to your post!

Firstly, in the last diagram where you label the PIR switch "Ext" do you mean you wish to put the switch physically outside, or is that just your way of identifying the switch, and it stays inside?

Secondly, do you have any more info on the PIR lamp, or the cable colours and labelling at the fitting?
From its behaviour, it sounds as if the brown and black wires are transposed at the switch (ie the brown should be permanent live and the black switched live), assuming it currently doesn't ever come on unless the switch is on.
Have you tried swapping brown and black at the PIR switch in your current configuration - with the power off obviously!

Previous thread:

Avo Mk8 said:

Sorry, I hadn't paid sufficient attention to your post!

Firstly, in the last diagram where you label the PIR switch "Ext" do you mean you wish to put the switch physically outside, or is that just your way of identifying the switch, and it stays inside?

Secondly, do you have any more info on the PIR lamp, or the cable colours and labelling at the fitting?
From its behaviour, it sounds as if the brown and black wires are transposed at the switch (ie the brown should be permanent live and the black switched live), assuming it currently doesn't ever come on unless the switch is on.
Have you tried swapping brown and black at the PIR switch in your current configuration - with the power off obviously!

Click to expand...

Please don't be sorry at all, you are offering your help, which is very much appreciated.

Sorry if that wasn't clear, the physical location of the switch is internal to the garage, I was merely labelling that as the external PIR light, to identify it from the internal ones.

You are bang on the money, the light works correctly when switched "on", as in, it will illuminate for a period of time and then turn off itself. From that point, the PIR takes over and activates the light. When switching the light switch to the "off" position, this effectively renders the light completely isolated. The PIR is not working when the light is turned off. So I think your suspicions are correct, and I need to get my head into the rafters and have a look at the wiring on the light end. I was thinking the same as you, that the wires were crossed, and that both had become switched live, when in fact one should be permanent live for the PIR sensor, and the switched live is for manual override of the light, regardless of the PIR condition.

And thank you for keeping me safe!

Edward Morris said:

Please don't be sorry at all, you are offering your help, which is very much appreciated.

Sorry if that wasn't clear, the physical location of the switch is internal to the garage, I was merely labelling that as the external PIR light, to identify it from the internal ones.

You are bang on the money, the light works correctly when switched "on", as in, it will illuminate for a period of time and then turn off itself. From that point, the PIR takes over and activates the light. When switching the light switch to the "off" position, this effectively renders the light completely isolated. The PIR is not working when the light is turned off. So I think your suspicions are correct, and I need to get my head into the rafters and have a look at the wiring on the light end. I was thinking the same as you, that the wires were crossed, and that both had become switched live, when in fact one should be permanent live for the PIR sensor, and the switched live is for manual override of the light, regardless of the PIR condition.

And thank you for keeping me safe!

Click to expand...

@Avo Mk8 if I am reading this correctly then, using a 2-gang switch, you can control both the PIR and the manual override of the light separately?

That is, the first switch controls the power to the PIR, and the second will manually override the PIR and turn the light constantly on, assuming that the PIR is powered. So the first switch effectively becomes a total isolation switch for the light then?

I think in my case, this isn't needed, as the circuit currently has fused isolation switch on the supply side, which does the job of isolating the light circuits in the garage.

Avo Mk8 said:

You could use a 2 gang 2way switch in the existing box to avoid another box for the external lamp.

Click to expand...

@Avo Mk8 following your comment, I revisited the drawing, and I think this is how I could maintain the first switch being a 2-gang as you say, but making the internal lights 2-way.

The first switch is the 2-way internal light setup.

The second switch is the PIR, and if wired correctly at the other end, should provide PIR mode or manual override of the external light, as the black wire provides the permanent live, and the brown wire is the switched "manual on" live.

Edward Morris said:

View attachment 89141
@Avo Mk8 if I am reading this correctly then, using a 2-gang switch, you can control both the PIR and the manual override of the light separately?

That is, the first switch controls the power to the PIR, and the second will manually override the PIR and turn the light constantly on, assuming that the PIR is powered. So the first switch effectively becomes a total isolation switch for the light then?

I think in my case, this isn't needed, as the circuit currently has fused isolation switch on the supply side, which does the job of isolating the light circuits in the garage.

Click to expand...

Yes, you are reading that correctly. I thought it might be of interest - as you say, you don't need both switches in your situation.
I hope you get the PIR lamp working as intended. I don't think you can do any harm trying it with the wires swapped as discussed.

You appear to know where the earth and neutrals go so leave them out of your next drawing, it will make them slightly clearer. From the original post I think you just need to ignore the external light switch and install a second two way switch for the internal garage lighting where ever you want it.

Edward Morris said:

@Avo Mk8 following your comment, I revisited the drawing, and I think this is how I could maintain the first switch being a 2-gang as you say, but making the internal lights 2-way.

The first switch is the 2-way internal light setup.

The second switch is the PIR, and if wired correctly at the other end, should provide PIR mode or manual override of the external light, as the black wire provides the permanent live, and the brown wire is the switched "manual on" live.

View attachment 89143

Click to expand...

That should work fine.
There's quite a lot of wires to deal with - if the patress is not a deep one, you might be better off with your original idea of twin boxes.
If you are familiar with Wago connectors you might find they help.

Avo Mk8 said:

That should work fine.
There's quite a lot of wires to deal with - if the patress is not a deep one, you might be better off with your original idea of twin boxes.
If you are familiar with Wago connectors you might find they help.

Click to expand...

Thanks again for all your comments, I really can't thank you enough.

I am familiar with Wago, I have a box 3 wire 32 amp connectors already, but point taken about the amount of wires, it did also cross my mind that it might be a challenge to fit it all in.

I can't be the only person who gets hungry when talking about Wago, it's so close to Wagu beef!

Just wanted to follow up with a big thanks to @Avo Mk8.
Did the job last weekend, and it all went really well.
I bought an extra deep back box and managed to fit it all in the existing 2 way 2 gang switch, so it looks nice and neat, and everything worked first time.
Thanks again.