Can I parallel PIR's?

Thread Starter

Ylli

Joined Nov 13, 2015
1,092
I've got a pair of motion sensor lights in the back, and I would like them both to come on if either one is triggered. They are "Defiant model DFI-5415-WH" units, and are rated for two 120 W floods each. They currently have LEDs installed that draw only 13W each.

What does the output structure of these PIR modules look like? Can I simply parallel the switched output of one unit with the switched output of the second unit? Whichever unit came on would be driving 4 lamps, at 13 W each, well within the ratings. But I'm a little concerned about backfeeding power into the PIR module that is 'off'.
 

Dodgydave

Joined Jun 22, 2012
11,395
Yes you can parallel them up if it uses a Relay output, then each sensor will put the lights on,. Each sensor will have a fused output, as long as you don't go over the current rating of the internal fuse, it should work fine.
 

Thread Starter

Ylli

Joined Nov 13, 2015
1,092
Yes you can parallel them up if it uses a Relay output,
I guess that is the question. Do these unit typically have relay outputs or do they use some basic SSR that would be damaged by putting voltage on the output of the unit not turned on.

Most of what I have found online seem to indicate paralleling is OK. I'll probably give it a try and see if I get any smoke.
 

TeeKay6

Joined Apr 20, 2019
573
Tricky to say with that low-high select output.

Probably just a diode.
@Ylli
I suggest that it would be good to check that the mains power (Line, Neutral) are connected identically on both light assemblies. If one unit has Line directly connected to the center pin of the bulb socket and the other unit has Neutral connected to that center pin, then paralleling the sockets would not be advisable...until the units had been reconnected identically.
 

Thread Starter

Ylli

Joined Nov 13, 2015
1,092
They were just recently installed, but I will be sure they are wired correctly. I just have to find the time to pull that extra wire between units.
 
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