How to add second sensor to security lights!?

Thread Starter

socast

Joined Feb 21, 2018
11
Hi Everyone,

As the title states really, I have a standalone PIR sensor connected to two LED Flood lights. I'd like to add a second PIR sensor but I'm unsure how to integrate it to the existing setup.

I was thinking that a diode between each of the PIR sensors outputs would do the job. But I'm unsure what size/type to use, or if this is even the best way to achieve my goal.

Any help/advice would be great :)

IMG_1795.jpg
 

Reloadron

Joined Jan 15, 2015
5,338
I assume the PIR Out is 240 VAC? If that is the case a single diode as drawn will only half wave rectify the output. If both sensors have the same source just parallel them. Either one should turn the floods on.

Ron
 

Tonyr1084

Joined Sep 24, 2015
4,369
Here's one that is rated to operate on 90 VAC to 250 VAC. It has a 2 star rating but nevertheless, I've linked it to show that you can get stand a lone devices that can power your lights. Since I don't know what sort of lights you have other than they're LED and there's a drawing of some sort - I can't say if it will interface with your PIR. I DO know that if I had two of these, two of the three wires would connect to power and the third would connect the light. Being in the US, common voltage is 120 VAC. Black wire is for hot, white is for neutral, and the third can be blue or orange or yellow - I'm not sure, but it is for the lamps. The white wire is the common wire between the sensor and the lights. The other wire provides power to the lights when motion is sensed.

Will this work on your system? I ABSOLUTELY DON'T KNOW! I don't know what you have. If you post a link to what you have then someone with considerably more skill and experience will be able to direct you in the best way possible.
 

wayneh

Joined Sep 9, 2010
16,384
All my security lights include a relay for switching power to the load. So I could just parallel them as noted, to get all the lights on when either sensor triggers. Two caveats: The relay in each PIR must be rated to handle the total load AND the power must be in the same phase. In a U.S. system, it would be possible for the two PIRs to be on different circuits that are out of phase.
 

Reloadron

Joined Jan 15, 2015
5,338
Would putting them in parallel not cause a short if/when both PIR sensors activate ?
No.

If I run two simple SPST switches from Hot to a lamp if either switch is On the lamp is on. I did mention the same power source and post #6 also mentions that. All you have is two switches in parallel where if either is On the lamp is On.

Ron
 

MisterBill2

Joined Jan 23, 2018
5,749
Hi Everyone,

As the title states really, I have a standalone PIR sensor connected to two LED Flood lights. I'd like to add a second PIR sensor but I'm unsure how to integrate it to the existing setup.

I was thinking that a diode between each of the PIR sensors outputs would do the job. But I'm unsure what size/type to use, or if this is even the best way to achieve my goal.

Any help/advice would be great :)

View attachment 198754
We need to know a lot more before anybody can provide a useful answer. First, are the two devices the same or very similar types and models? Next, are they fed from the same power circuit? Are they DC powered or mains powered? Is it likely that they would on some occasion both be triggered at the same time?

If you have two identical units fed from the same mains circuit and thy have the standard 3 wires coming from the sensor head, then it should work well to tie black to black, white to white, and red to red, which will illuminate both sets of LED lights. The one concern I offer is about the corrent handling capacity of the switching device, since the load current will be doubled. That maybe a problem, or possibly not.
 
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