Add PIR sensor to porch light and switch?

[SJRSJR]

Hello, I would like to know how complicated it is to add a PIR sensor to a porch light. I have a nice lamp that I'd like to keep and don't want an all in one floodlight.)

I have a 2 gang switch in the hallway. One switch controls the hall light, the other controls the porch light. In this photo the hall switch is the one with sleeved blue in L1, the porch switch has sleeved yellow in L1. (The grey on the cable is paint).

The PIR has Live, Neutral and Load terminals. (It says it can be overridden by switching on/off twice in 2 seconds)

I've looked a various diagrams but it would help to have pointers e.g. where is neutral in the circuit?

Thanks

 

[EFLImpudence]

I have a 2 gang switch in the hallway. One switch controls the hall light, the other controls the porch light. In this photo the hall switch is the one with sleeved blue in L1, the porch switch has sleeved yellow in L1. (The grey on the cable is paint).

Ok.

The PIR has Live, Neutral and Load terminals. (It says it can be overridden by switching on/off twice in 2 seconds)

Actually "off/on" twice; there is a difference. Think about it.

I've looked a various diagrams but it would help to have pointers e.g. where is neutral in the circuit?

Well done for noticing that.

The neutral will be at either of the lights so it would take another wire from the hallway light to the switch.
There will obviously be one at the porch light as well but it will (probably) only have a switched live and no permanent live.

But -

wiring it from the porch light would be alright if you don't mind leaving the switch on all the time - where switching it off will disable the PIR as well.

 

[ericmark]

Is there any real need for a PIR? I have the lights turn on at dusk and off at set time, or on at set time, and off at dawn. I use a Tapo (TP-Link) smart switch which works with a battery, so no need for neutral.

 

[securespark]

Surely it's just a case of rerouting the existing switched feed to the light fitting into the PIR, then the output from the PIR goes to the light fitting.

 

[sparkwright]

Surely it's just a case of rerouting the existing switched feed to the light fitting into the PIR, then the output from the PIR goes to the light fitting.

Yes, or running a 3 core and earth cable from the porch light to the new PIR.
And keep the wall switch on (or by-pass).

 

[SJRSJR]

Thanks all for the replies.

Using 3 core/E from the PIR I connected the switched live (sleeved yellow) into the PIR Live and the Load from the PIR to the Live of the light. (I wrongly deduced that the red would be a permanent live and so could be used instead of the yellow but when I tried that it wouldn't fire the PIR.)

There's a second porch light around the side which comes on at the same time so I got another PIR and now both lights come on when either PIR is triggered, which is what I wanted. I have to leave the switch on but at least I can override it to get a permanent on by flicking the switch off/on twice (noted EFLImpudence).

The only thing I noticed is that when I first throw the switch on, the lights come on momentarily, go off and then come back on just as the PIR clicks. Is there an explanation for that?

Thanks again.

 

[EFLImpudence]

The only thing I noticed is that when I first throw the switch on, the lights come on momentarily, go off and then come back on just as the PIR clicks. Is there an explanation for that?

That's what they normally do.

After the first switch on they stay on for the set time.