Twin PIR on 1 lighting circuit with cut off switch

[rjwill10]

Hi,

Trying to plan for my single outside lighting circuit to be controlled by two PIR's.

I've tried to draw it out (image below). My plan is that if the PIR switch is on and light switch is off, the lights will run with PIR. If the PIR switch is off, and the light switch is on, then lights will work permanently.

I plan to use maintenance free junctions boxes to control this from one JB.

Thanks in advance.

 

[telectrix]

looks good from here. only thing you may get is if the PIR switch/isolator is turned off, when it's turned back on the lights may come on for whatever time the PIR/s are set for.

 

[davesparks]

Why the extra switch for the pirs?

 

[rjwill10]

looks good from here. only thing you may get is if the PIR switch/isolator is turned off, when it's turned back on the lights may come on for whatever time the PIR/s are set for.

Thank you. I'm not so bothered if the PIR switch turns the lights on for the set time period. I was more concerned that the dual PIR set up wouldn't work.

 

[rjwill10]

Why the extra switch for the pirs?

Well I wan't the ability for the lights to be left on permanently as well, so for the sake of a length of 3core + E I thought it was worth trying to implement.

 

[davesparks]

Well I wan't the ability for the lights to be left on permanently as well, so for the sake of a length of 3core + E I thought it was worth trying to implement.

I get that is why the override switch is there, but why the extra switch cutting the feed to the PIR? This just seems like a recipe for trouble when the PIR is put in to override mode by accident.
Or is it just there as an isolator for maintainence and not in general use?

 

[Andrew Hunter]

Hi,

Trying to plan for my single outside lighting circuit to be controlled by two PIR's.

I've tried to draw it out (image below). My plan is that if the PIR switch is on and light switch is off, the lights will run with PIR. If the PIR switch is off, and the light switch is on, then lights will work permanently.

I plan to use maintenance free junctions boxes to control this from one JB.

Thanks in advance.

View attachment 50351

Right had a good look and do confir with telectrix the light will come on for the period of the setting on the PIR when power is restored to them.
As Davesparks says not sure why the extr switch as they will have a Lux sensor so that they do not come on during the day also if the light is switched on at the switch the sensor switching on and off wont have any effect on the light other than staying on for the time of the settings when the light is switched off if the passive has just been activated.

 

[rjwill10]

I get that is why the override switch is there, but why the extra switch cutting the feed to the PIR? This just seems like a recipe for trouble when the PIR is put in to override mode by accident.
Or is it just there as an isolator for maintainence and not in general use?

I couldn't figure another way of doing it, appart from cutting the feed via the switch which is looped from the light switch. I originally set the L1 from the PIR's to the PIR switch rather than the live, but this would have required (in my mind) two SL out to the lights.

In theory the PIR switch will be constantly set to on, and then turned off to have manual control of the lights. both switches will be in the same box and are 1 way.

Is there another way of doing it?

 

[rjwill10]

Right had a good look and do confir with telectrix the light will come on for the period of the setting on the PIR when power is restored to them.
As Davesparks says not sure why the extr switch as they will have a Lux sensor so that they do not come on during the day also if the light is switched on at the switch the sensor switching on and off wont have any effect on the light other than staying on for the time of the settings when the light is switched off if the passive has just been activated.

Thanks Andrew. My thought process was based on being able to manually control the lights when the PIR sensors are turned off. I've tried to expand on the user case below:

User case 1 - Automatic lights via PIR: The lights would work automatically when the PIR switch is on and the light switch is off. The PIR's would control the lighting as set, with the light switch always being off.

User case 2 - Manual lights via Switch: The PIR switch would be switched to off, isolating the live to PIR sensors. I would then have manual on/off control of the lights via the light switch.

Is your point that the L1 from the sensors being connected to the SL from the lights switch will cause the PIR sensors to work?

 

[GBDamo]

Thank you. I'm not so bothered if the PIR switch turns the lights on for the set time period. I was more concerned that the dual PIR set up wouldn't work.

Also check the PIRs dont have a self calibrating function, some PIR lights do. Would be a pain as whenever you turn them back on they would self calibrate, some take 48 hours.

 

[rjwill10]

Also check the PIRs dont have a self calibrating function, some PIR lights do. Would be a pain as whenever you turn them back on they would self calibrate, some take 48 hours.

Good point, will keep that in mind.

 

[telectrix]

wire the PIR switch into the PIR sw/L instead. then the PIRs wil lbe powered but not activate the lights.

 

[davesparks]

Is there another way of doing it?

Yes, just don't fit the second switch which switches the feed to the PIR.

 

[rjwill10]

Just in case anyone wanted it, I've updated based one telectrix suggestion.

Thanks all

 

[telectrix]

good boy.3 extra Bonio

 

[Andrew Hunter]

Thanks Andrew. My thought process was based on being able to manually control the lights when the PIR sensors are turned off. I've tried to expand on the user case below:

User case 1 - Automatic lights via PIR: The lights would work automatically when the PIR switch is on and the light switch is off. The PIR's would control the lighting as set, with the light switch always being off.

User case 2 - Manual lights via Switch: The PIR switch would be switched to off, isolating the live to PIR sensors. I would then have manual on/off control of the lights via the light switch.

Is your point that the L1 from the sensors being connected to the SL from the lights switch will cause the PIR sensors to work?

Hi, No the switched live onto the switched live of the passive will not effect the passive in any way other than making that terminal live when the passive is not activated. My point is that if you switch the light switch on and then walk into the area that the passive is servicing then walk out of the area and switch the light switch off the lights will stay on until the time has elapsed on the passive due to the fact the passive was activated when walking into that area.

On the flip side if you wire it your way you have an extra switch and the lights will come on when you switch the supply back on to the passive again until the passive timer times out not sure it is worth the hassle of another switch with potential to cause some confusion should the circuit need some fault finding on later on unless you want to use the area without the nuisance of the passive switching on when not required.