Overriding a lighting sensor

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laketime

Senior Member
Notes on new plans I am looking at for a commercial TI project say:

1. Switch to override occupancy sensor.

How do you wire that up so the switch overrides the occupancy sensor?
 

iwire

Moderator
Staff member
Location
Massachusetts
Notes on new plans I am looking at for a commercial TI project say:

1. Switch to override occupancy sensor.

How do you wire that up so the switch overrides the occupancy sensor?
If you mean override it on ......... you do not if you have to comply with energy codes. But that would be a parallel connection

If you mean override it off ........... the only way I have ever seen it done. This would be a series connection.
 

gar

Senior Member
101109-1746 EST

laketime:

I would want an accurate definition of what actual function is wanted and why?

What is a TI project?

Suppose this is a room with no outside light, assuming it is not a photo darkroom, or a theater.

Then logically it seems one would want a motion sensor to turn the lights on anytime motion was detected in the room. If the motion sensor can always detect major motion, someone walking, then this device would usually use a simple form of off delay timer. The delay would be set long enough that the lights would not turn off automatically between major motion events.

But suppose this is a room where a person walks in, lights turn on, and the person sits in a chair and reads with little motion. Now you do not want the lights to automatically turn off after some delay. Here you may want the detector to set a latched relay, and then have an off button for when the person leaves.

The above give you an idea of some questions to ask.

Dinner time so end of examples.

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Barndog

Senior Member
Location
Spring Creek Pa
You could do do both with one three way switch. run power into the commom post and use one side to the hot of your sensor and the other directly to your light. so if you diable your sensor the lights will stay on. if you want to shut them off manually you will have to add another single pole switch to do this. or you may just want to use to single pole switches to do the same thing as they say one series for the controller and one parallel to run the lights.
 
A ti project means tenant improvement, usually a shelled space that is built out after the main project is complete and they have acquired more funds. I also don't want to hijack but what I want to know is why would you want to turn the sensor off? I understand you are being instructed to do so but what is the advantage to turning off the sensor head? If I'm not mistaken the sensors are what they call intelligent and can learn patterns and adjust themselves and whatever else I don't know. But if you install the power pack so that the switch turns the sensor on and off it would reset evertime you flip the switch.
As for wiring it, it depends on the manufacturer but the ones we're doing now have blue contact wires so to wire it per spec you would hook the switch leg from the light switch to one blue and the black, then hook the remaining blue to the fixture whip. The other way is to hook line power into the room to the blue and black and the remaining blue to the line down to the switch, leaving the switch leg from the switch going to the fixtures as usual. I hope this helps and if anyone has a reason to do it a certain way I'd like to hear your reasons why.:)
 

stevebea

Senior Member
Location
Southeastern PA
A ti project means tenant improvement, usually a shelled space that is built out after the main project is complete and they have acquired more funds. I also don't want to hijack but what I want to know is why would you want to turn the sensor off? I understand you are being instructed to do so but what is the advantage to turning off the sensor head? If I'm not mistaken the sensors are what they call intelligent and can learn patterns and adjust themselves and whatever else I don't know. But if you install the power pack so that the switch turns the sensor on and off it would reset evertime you flip the switch.
As for wiring it, it depends on the manufacturer but the ones we're doing now have blue contact wires so to wire it per spec you would hook the switch leg from the light switch to one blue and the black, then hook the remaining blue to the fixture whip. The other way is to hook line power into the room to the blue and black and the remaining blue to the line down to the switch, leaving the switch leg from the switch going to the fixtures as usual. I hope this helps and if anyone has a reason to do it a certain way I'd like to hear your reasons why.:)
Well, I could understand having a switch in series with the occ. sensor as long as its on the load side of the occ. sensor. As you stated to put a switch on the line side of the occ. sensor it would reset itself and cycle on and off. I dont remember the manufacturer but installed some ceiling mount occ. sensors in the past that if the room was occupied for less than 30 seconds it timed out after 3 minutes. If you were in the room longer than that it would time out at 20 minutes thus it could tell the difference between a walk-thru and the room actually being occupied.
 

gar

Senior Member
101222-1953 EST

Until there is a clear definition of the logic of the current sensor, and the desired logic defined by "override", then there is no possible answer.

.
 
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