# Combine Motion Sensor and Timer for One Light



## fritzycat1 (Aug 5, 2007)

I would like to have a single porch light controlled by both a timer, and a motion detector. The timer would illuminate the light nightly from 7PM to 11PM, while the motion detector would turn on the light any time outside that time window (when it is dark). 

I currently have a wall-switch timer installed for the light (this one) and would like to add the motion detector (such as this one) to the circuit.

Can anyone explain how this would need to be wired? Or better yet, do you have a diagram? I've installed motion sensors and timers in the past, just never both on the same circuit in this fashion and I don't want to mess this up.

Thanks All,

Fritz.


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## theatretch85 (May 17, 2008)

Just wire the timer and motion sensor in parallel. the motion sensor will still try to turn the light on when its already on with the timer, but this is no big deal so long as its on the same circuit. I have two motion sensors on the stairway lights wired like this, standard single pole motion sensors wired in parallel so that either one will turn the lights on. Both would have to be electrically off in order for the light to be off.


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## RippySkippy (Feb 9, 2007)

You might consider an occupancy sensor. They generally have an infrared motion sensor with a setting to control the level of darkness before the switch will work. FWIW -- I used a cheaper version, and ended up replacing it with a commercial version. The cheap one didn't work consistently and I got fed up with trying to adjust it any more. Spend the $ and get the good one.


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## theatretch85 (May 17, 2008)

RippySkippy said:


> You might consider an occupancy sensor. They generally have an infrared motion sensor with a setting to control the level of darkness before the switch will work. FWIW -- I used a cheaper version, and ended up replacing it with a commercial version. The cheap one didn't work consistently and I got fed up with trying to adjust it any more. Spend the $ and get the good one.


If you'd look at the links and read the Op's post, you'd see that he is putting the motion sensor and light outside. So an occupancy sensor would not do any good outside.


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## RippySkippy (Feb 9, 2007)

D'OH! Missed it by thisssss much....


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## Ultrarunner2017 (Oct 1, 2008)

Sounds pretty simple, using the advice the others have already given, but as I can see, the motion sensor is integrated into the light. This may make it more difficult to parallel the timer to it.
Perhaps you should consider a wall switch mounted motion sensor, and a standard light.
Then, you simply install a double-gang wall box, the timer in one side, the motion sensor in the other, and wire them in parallel.
The timer you have chosen looks like a good one, since it can be used with fluorescent (ballast) lamps, which indicates to me that it has a relay switch rather than a semiconductor (Triac) one.
You might want to consider such a switch for the motion sensor, to allow you to use a more energy efficient fluorescent or sodium lamp.


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## J. V. (Jun 1, 2007)

KE2KB said:


> Sounds pretty simple, using the advice the others have already given, but as I can see, the motion sensor is integrated into the light. This may make it more difficult to parallel the timer to it.
> Perhaps you should consider a wall switch mounted motion sensor, and a standard light.
> Then, you simply install a double-gang wall box, the timer in one side, the motion sensor in the other, and wire them in parallel.
> The timer you have chosen looks like a good one, since it can be used with fluorescent (ballast) lamps, which indicates to me that it has a relay switch rather than a semiconductor (Triac) one.
> You might want to consider such a switch for the motion sensor, to allow you to use a more energy efficient fluorescent or sodium lamp.


The motion sensor built into the light enables you to install the timer in parallel without any issue. As said above it must be on the same circuit otherwise you could create a short circuit. All that is needed is the timer. The motion sensor already exists.


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## Ultrarunner2017 (Oct 1, 2008)

OK. I just wasn't sure if the wires from the motion sensor and light were easily accessible. If the fixture has just 2 + ground, then it wouldn't be possible to parallel.


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## theatretch85 (May 17, 2008)

Every outdoor light with motion sensor I have seen has all the wires and connections accessible on the back of the fixture. True they are already crimped and ready to wire with a white, black and bare wire, but its easy enough to re-wire it to accommodate the timer setup in parallel.

All you would need to do is supply constant hot to the black motion sensor wire and the timer, wire the output of the motion sensor (usually red) to the lights black and the output of the timer; then wire all the neutrals together. You will of course need 14/3 w/grd or 12/3 w/grd to run between the light and the timer box location. Use the black for the motion sensor constant hot wire and the red to power the light from the timer. 

If you really wanted you could put in a marker light (some call it a "pilot light") in the house next to the timer to indicate when the light is on (whether its on because of the timer or because of motion).


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## fritzycat1 (Aug 5, 2007)

Thanks for the replies everyone!


theatretch85, once you replied with "Just wire the timer and motion sensor in parallel." it immediately made sense. What I ended up doing was wiring an Insteon SwitchLinc Relay in the same box and in parallel with the timer (I replaced a 'dummy' switch I already had in the box that was no longer in use for anything). I then installed an X-10 motion detector outside to trigger the SwitchLinc. This way, I didn't have to run any new wires to a motion sensor outside and I can re-position the motion sensor for the best location. If the X-10/Insteon combination proves unreliable, I'll go through the effort of wiring an external motion sensor for now it is working well.

Thanks again to all that replied! 

Anyone have suggestions for a CFL lamp that lights and ramps-up to full brightness quickly? Right now I have two (cheap) FEIT R-40 Reflector CFLs over the front porch controlled by this circuit. They take about a minute before they are at full-bright (I'm in southern california, so cold-weather start isn't an issue).


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