Wiring PIRs

[nicebutdim]

One of those ideas that sits at the back of my mind came back to me tonight and I've managed to run up against a brick wall with it. It's been a long term idea to provide external lighting as my parents move around outside and I'm not sure if this can be done as simply as I'd like. My thoughts have been to have two (possibly three) lights with separate PIRs running from a single switch and I'm not seeing a way of doing this.

I understand how to switch multiple lights from a single PIR and how to switch one or more lights (at the same time) from multiple PIRs. What I don't know, and can't conceive of, is how to have two or three PIRs on a single switch line, but with each PIR operating its own individual light. Am I right in thinking this can't be done or am I missing something really obvious?

 

[timhoward]

I'm not sure I'm quite grasping the question...as I'm not yet seeing the problem.
I'm reading it that you want a light switch controlling a switched live feed, running to PIR1 which activates Light1, and on to PIR2 which activates Light2, and on to PIR3 which activates Light3.
So when the switch is on, it all happens, when the switch is off, it all stays dark.
Is that correct?

 

[nicebutdim]

That's about the height of it. One switch and 2 or 3 PIRs, each controlling a single light.

Have I been overthinking this?

 

[Spoon]

Ok, so the PIR's are only active when the switch is active. Correct?
What's wrong with wiring mains to the 2 (or 3) PIR's through the switch. Then from each output of the PIR to their individual light?

 

[nicebutdim]

Ok, so the PIR's are only active when the switch is active. Correct?
What's wrong with wiring mains to the 2 (or 3) PIR's through the switch. Then from each output of the PIR to their individual light?

If I'm getting your point this is fairly simple - 3 cores to switch for N,E & L , then take 3 cores through PIRs for N,E & use SL to PL terminal of PIRs. From there take N,E & use L from SL terminal of PIRs to respective lamps?

 

[nicebutdim]

 

[Spoon]

View attachment 90229

Yep, that's what I was thinking of.

 

[nicebutdim]

Yep, that's what I was thinking of.

My brain was intent on bringing mains to PIRs and trailing 4 cores between them, where triggering any PIR would activate all lights.

Thanks for simplyfying this for me ?

 

[telectrix]

i would use GJD gear. alarm cables to each PIR which are all connected to a central control. the controller then activates all lights when any of the PIRs sense movement. even has audible buzzer in daytime when the lights only come on below a set lux level.

 

[GBDamo]

My brain was intent on bringing mains to PIRs and trailing 4 cores between them, where triggering any PIR would activate all lights.

Thanks for simplyfying this for me ?

Though I was missing some fundamental as I've done similar a quite a few times only with PIR floods on a timer, not identical but the same in principle.

 

[brianmoooore]

I might not be fully understanding what you're trying to achieve, but note that PIRs, in my experience are intended to have a permanent live. If powered through a switch, they will all switch on when the switch is closed, and light all the lamps for their pre programmed times, before starting to work as they should.

 

[nicebutdim]

It's all theoretical and one of those things that my runs through my mind from time to time, while never getting around to doing anything.

There were originally two lights from a single switch and I believe this was all in pyro from a terminal box. The porch was rebuilt about 35 years ago and at that time one light was replaced with a plastic pir lantern and that section rewired in T&E. Currently the pir activates both lights and all is fine, except the internal wiring still needs to be replaced and switch moved as it's now behind a newish inner door. The switch will have two ways - intermediate for hall light, as it currently switches from other end of hall and from landing, and the other way for front outside lights.

It may be that the existing set up with two lights remains or I might add a third, but it will all run from a single switch to keep it simple for my parents. The current set up works okay, but means no light if they walk round from the rear and they aren't getting any younger, so convenience for them is key

The main issue is activation from either direction, so I might simplify this by just using a pir lantern at the front and corner light at rear, with separate pir due to lack of choice for corner lights, then allow either pir to activate both.

Sorry about the long explanation, but I should have laid out what the aim was from the outset. No idea when time constraints will let me look at this, but I just couldn't figure out how to activate individually from several pirs and it really hurt my head last night.

 

[nicebutdim]

I might not be fully understanding what you're trying to achieve, but note that PIRs, in my experience are intended to have a permanent live. If powered through a switch, they will all switch on when the switch is closed, and light all the lamps for their pre programmed times, before starting to work as they should.

That's how they're currently set up - switched on some time around dusk and off at bedtime. I'd thought about using a photocell, so switch could stay on, but this might spark arguments about wasted electricity when lights are triggered during the night ?

 

[telectrix]

That's how they're currently set up - switched on some time around dusk and off at bedtime. I'd thought about using a photocell, so switch could stay on, but this might spark arguments about wasted electricity when lights are triggered during the night ?

surely lights triggered in the night is what they are there for????

 

[nicebutdim]

My mother (whom I seem to have taken after) believes lights should only be switched on when you need to see where you're going. I don't think she's interested in helping potential buglars to not break their neck ?

 

[telectrix]

yeah, but once they are lit up, you can see what you're shooting at.

 

[w0z]

If the PIRs are powered up but not triggered and the lights are off the PIRs will consume some power whether or not it's dark so if your mother (or you) are worried about the 24/365 overhead of powering the PIRs (which actually isn't quite as trivial as you might assume), feed them from a smart plug which you can program to power them up at dusk and off at dawn. Then you can reduce the worry to only the smart plug using power 24/365...
If you get the timing right and they are powered up perhaps 30 mins before dusk you might not notice the lights coming on briefly before dusk then settling down to their real job...
If you use Alexa better still you may be able to depower and power by just shouting ...
(I assume there will be no manual override)