Ideas for PIR / time clock switching

[mole2006]

Hi,


I'm after some ideas for the best way to do this -


A client wants his office lighting to be on PIR's (I think it's to lower his carbon footprint) but he has also added he wants them on time clocks say from 8am until 7pm then to go to PIR incase anyone works late.
The office is wired in T&E with 1 switch controling one area via the Hager Klik wiring modules above the ceilings. I'll need about 3 PIR's in each area to get coverage.
There's about 7 areas over 3 floors.


Hope I've explaned it well enough thanks.

 

[Plonker 3]

What sort of lighting are we talking about?

 

[Guest77]

Hi,


I'm after some ideas for the best way to do this -


A client wants his office lighting to be on PIR's (I think it's to lower his carbon footprint) but he has also added he wants them on time clocks say from 8am until 7pm then to go to PIR incase anyone works late.
The office is wired in T&E with 1 switch controling one area via the Hager Klik wiring modules above the ceilings. I'll need about 3 PIR's in each area to get coverage.
There's about 7 areas over 3 floors.


Hope I've explaned it well enough thanks.

Easy, you start with your idea first

 

[tazz]

wire all pir contacts, and timer switch contacts in parallel in each area....jobs a gooden

 

[mole2006]

All the lights are fluorescent modules.
I was thinking if the PIR's were triggered it would bring the lights on via the contactors for the time period.
This way they would not initially switch on if no one is in the area.

 

[Guest77]

As Tazz pointed out you only need to feed the pirs and parellel the supply back from them with the main switchfeed from the time clock, basically the time clock will switch and energise the circuit and work all day, then at 7pm the supply will be cut off and the lights will go out, however if anyone is still in the building and a pir activated the switchfeed from the pir will send the supply down to the same switchfeed as the time switch switchfeed feeding the lights and bring them back on for a set time the pir is set at. You could wire the pirs straight to the time clock and connect on the switch side so even if the supply isn't on from the timeclock the pir will energise the circuit at that point

 

[Guest77]

You will need to consider a contactor per floor really with the timeclock controlling the coil, the switch back from the pir can then double up with the outgoing supply to the lighting circuit from the dead side of the contactor, I should stick a wiring diagram up really, but it is late and I cannot be arsed at this exact moment. if more than one circuit per contactor then you could switch the coil, lots of variables to consider, but is easily doable.

 

[mole2006]

Cheers guys - just checking best options.

 

[Plonker 3]

If the customer is looking at carbon footprint wouldn't it be wiser to change the tubes for T5s or even LED tubes?

 

[Guest77]

There are lots of ways to save energy, absence detectors and lux dimming as well as t5s or LEDs, so many variables it would take all night to go through them.