Security light motion sensors in parallel

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electron49
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Security light motion sensors in parallel

Post by electron49 » Wed Mar 21, 2018 1:46 pm

I want to use two motion sensors for security lights to control one light. The motion sensor I am wanting to use is a Defiant Model DF-5716 sold by Home Depot. This is a sensor that turns the lights on dim at dusk and goes to full bright when motion is detected. My question is, will connecting the red lead from the detectors together cause any problems? If one detector is off or on at the dim level and the other detector turns on full bright, will there be any feedback through the other detector? I have attached a diagram of how the detectors would be connected.
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sghioto
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Re: Security light motion sensors in parallel

Post by sghioto » Wed Mar 21, 2018 2:50 pm

Yeah there will be feedback through each other. The motion from one detector will override the dim function on the other. Will it cause any damage? Not sure without seeing a schematic. Can you use a two bulb fixture and run the red wires separate? Or run a 3 wire cable from the light to the junction where the motion detectors connect.
SG

dyarker
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Re: Security light motion sensors in parallel

Post by dyarker » Thu Mar 22, 2018 4:53 am

Do NOT connect the red wires (at least not yourself). They are switched AC hot leads. If AC to the detectors happens to come from different phases you'll at least pop a breaker. Even if you "get lucky" with the phases, one detector being on "bright" could damage the other as sghito said.

It is possible to make it work (maybe), but -

This is AC mains wiring. It needs to up to code. Get an electrician!

Cheers,
Dale Y

electron49
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Re: Security light motion sensors in parallel

Post by electron49 » Thu Mar 22, 2018 6:33 am

sghioto - "The motion from one detector will override the dim function on the other." - that is exactly what I want it to do. The scenario is that the light would be on dim until either sensor detected movement, then it would go to full brightness. I assume the output of the motion sensor is a triac - so that should block the "feedback" from the other sensor? I basically want to increase the range of the "window" the motion sensor sees.

electron49
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Re: Security light motion sensors in parallel

Post by electron49 » Thu Mar 22, 2018 6:38 am

dyarker - "If AC to the detectors happens to come from different phases you'll at least pop a breaker." - Help me understand this - it is fed from the same phase - there are only two wires feeding both sensor - a neutral and a hot leg (120 v). I agree with your statement if the sensor were fed from different circuits.

Thanks!

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Re: Security light motion sensors in parallel

Post by dyarker » Thu Mar 22, 2018 8:30 am

Didn't say fed from single circuit in post 1.
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electron49
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Re: Security light motion sensors in parallel

Post by electron49 » Thu Mar 22, 2018 9:00 am

Sorry - I thought attached diagram made that clear.

Thanks!

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Re: Security light motion sensors in parallel

Post by dyarker » Thu Mar 22, 2018 10:04 am

sorry too! no downloads here (at my end), so haven't seen the diagram.
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sghioto
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Re: Security light motion sensors in parallel

Post by sghioto » Thu Mar 22, 2018 3:49 pm

You will have two dimmer circuits in parallel so as I said it may work OK or not. You would have to turn the DualBrite switch to OFF on one of the units.
SG

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dacflyer
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Re: Security light motion sensors in parallel

Post by dacflyer » Fri Mar 23, 2018 9:15 am

if the 2 sensors do not share the same leg of power, it will do more than just pop a breaker, it'll blow both sensors out, because you will have a clash of 240v
i never tried triac based sensors for your set up, but have done the relay type sensors, and they worked just fine,, i have even done a override switch, so you can have it on automatic or manual use.
if you do not know how to find out if your power shares the same leg.. you can find the breaker that feeds the sensor, and see if it also controls the other unit as well. if it does, then all is well.

they sort of do this circuit in some parking garages,, sensors all about, will turn the garage light on / off to save power, so a car entering or pedestrian using doors, etc, will trigger or reset the timers, til no movement is detected, then it's lights out.

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CeaSaR
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Re: Security light motion sensors in parallel

Post by CeaSaR » Sat Mar 24, 2018 4:42 am

(There is a PDF attachment at the bottom of the first post)

Basically, his schematic is one cord from the mains, both sensors attached to the same wire (same hot, same neutral), and then the outputs of the sensors tied together which feeds the light, which in turn connects back to the mains to complete the circuit.

Hope that helps to clarify the question.

CeaSaR
Hey, what do I know?

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dacflyer
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Re: Security light motion sensors in parallel

Post by dacflyer » Mon Mar 26, 2018 8:35 am

i think it should work then....

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