PIR lightswitch for hallway

[SiFrGo]

We have 3 wall switches which control the hallway lights. The wiring is as the picture below I downloaded (which implies this is a fairly standard wiring arrangement). I'd like to replace one of the wall switches (either Switch 1 or Switch 2 in the diagram) with a PIR switch but I can't find a suitable wall-mounted PIR switch as the ones I've seen either require a Neutral and/or are simple on/off switches, whereas I think what's needed is a 3-(live)wire 2-way PIR switch, if such a thing exists. Can anyone advise on this and whether (and from where) such a PIR switch is available?

 

[SiFrGo]

We have 3 wall switches which control the hallway lights. The wiring is as the picture below I downloaded (which implies this is a fairly standard wiring arrangement). I'd like to replace one of the wall switches (either Switch 1 or Switch 2 in the diagram) with a PIR switch but I can't find a suitable wall-mounted PIR switch as the ones I've seen either require a Neutral and/or are simple on/off switches, whereas I think what's needed is a 3-(live)wire 2-way PIR switch, if such a thing exists. Can anyone advise on this and whether (and from where) such a PIR switch is available?View attachment 99797

After posting this up it occurred to me that if I put a simple on/off 2-wire PIR wall lightswitch across L1 and L2 on Switch 1, and (assuming enough space in back box) permanently connect L1 to com on Switch 1, when 'activated' the PIR would make the connection between L1 and L2 and enable current flow to the lights. When activated the PIR would override Switch 2 and the Intermediate switch but that would be fine. I can't see a problem with this as there's no possibility of a short circuit given all connections are Live. Thoughts welcomed.

 

[James]

Are you certain that your wiring is as the diagram above shows?
it is not impossible but it is an unusual configuration

 

[SiFrGo]

Are you certain that your wiring is as the diagram above shows?
it is not impossible but it is an unusual configuration

Thanks for your reply James. I've not tested the configuration wire to wire but there's definitely a permanent Live as per L1 on Switch 1, and L2 and com on Switch 1 go Live as expected when the switches are operated. The Intermediate switch has 4 wired connection points (albeit embossed as L1, L2 L3 and L4, not 2 x L1 and L2 as per the diagram), and Switch 2 has 3 wired connection points as Switch 1 but no permanent Live. Given those 3 switches I don't know what other wiring configuration could control the switching of the Hall lights, but that's why I'm glad to receive advice.

 

[littlespark]

Nothing wrong with the diagram, I don’t think.

It’s one of the standard ways to connect… having line in L1, switchwire in L2 and a 3 core on C, L1, and L2….. 3 core to another 2-way, or intermediate crosses over L1, L2 with C linked through..

Yes, a PIR on first switch would work, basically overriding all the switches there, but a PIR will require a neutral at the switch to operate.

 

[SiFrGo]

Nothing wrong with the diagram, I don’t think.

It’s one of the standard ways to connect… having line in L1, switchwire in L2 and a 3 core on C, L1, and L2….. 3 core to another 2-way, or intermediate crosses over L1, L2 with C linked through..

Yes, a PIR on first switch would work, basically overriding all the switches there, but a PIR will require a neutral at the switch to operate.

Thanks for your reply littlespark, that's extremely helpful and good to know its one of the standard ways to connect a multi-switch (e.g. Hallway) arrangement. The PIR I'm planning to use has two wiring connections (live in, switched live out, no neutral needed): https://www.amazon.co.uk/dp/B00AVZLXK0/ref=cm_sw_r_api_i_W0JRGHF0FNWMM99MZXJW_0 so will hopefully work ok.

 

[littlespark]

yes... wiring lightswitches can be bothersome if you're not used to them.

We get lots of questions on here, such as "how do i do this?" We ask for a photo and its just a dozen or so red wires, all disconnected from the switch. We haven't got a clue what goes where, and a lot of the time, the stock answer of "get a pro in" doesnt go down well.

"We cant tell from here... you need someone to test it all out now you've taken it to bits!"


But... yours is fairly straightforward.

By your diagram, are all the wires in reality red? apart from black on neutral? theres no yellows or blues..... (or brown, black, grey, blue, in new money)

Rereading... i see its not your diagram, and just one downloaded from internet. Then is this definitely how yours is wired?

 

[SiFrGo]

yes... wiring lightswitches can be bothersome if you're not used to them.

We get lots of questions on here, such as "how do i do this?" We ask for a photo and its just a dozen or so red wires, all disconnected from the switch. We haven't got a clue what goes where, and a lot of the time, the stock answer of "get a pro in" doesnt go down well.

"We cant tell from here... you need someone to test it all out now you've taken it to bits!"


But... yours is fairly straightforward.

By your diagram, are all the wires in reality red? apart from black on neutral? theres no yellows or blues..... (or brown, black, grey, blue, in new money)

Rereading... i see its not your diagram, and just one downloaded from internet. Then is this definitely how yours is wired?

Hi littlespark, yes I'm not going to be disconnecting any wires unless I know exactly where to put them back. Re the diagram, I presume all the wires are coloured red to indicate they are all Live (or potentially Live). The Neutral is coloured black which perhaps lends some logic to that assumption. I'm not 100% sure the diagram is representative of how the switches are wired but next time I'm at the flat I'll check all switch contacts to ensure they go Live as expected (as per the diagram) when the other switches are toggled. Thanks again for your advice.