Multiple motion sensors on one circuit
jonblakemore
| Posted in Construction Techniques on
I installed two motion sensing exterior flood lights at the eaves of my house. They are ~40′ apart and are not pointed in each other’s direction.
I’m getting some very strange behavior. They will turn on and off in unison erratically. When the switch is turned on they will turn on for about 30 seconds. Then they shut off together. After about 30 seconds off, they turn on again. This cycle will seemingly repeat indefinitely.
Did I do something wrong by installing two on the same circuit?
Replies
Did you forget to turn off the test switch at each unit?
Check the connections at the main switch or, change out that switch, even though the regular cycling does not really indicate a bad switch.
They may be seeing the light/heat from each other's bulbs and setting up an oscillator. I know when my Christmas lights were on the porch light MD they blinked on and off.
I have MDs on the same circuit here, one pair even interconnected but the detectors can't see the other guy's lights.
Sounds like the MD are affecting each other. Maybe paint the detectors so they can't see each other? Or reaim them.
By chance did the instructions say not to do this?
Instructions for the two I have (some type of Cooper from blowes) said specifically NOT to put them on the same circuit ... they didn't mention anything about location or negative effects, just said don't do it, period.
I did anyway, and so far no trouble (probably a year ago). They are around the corner from each other though.
I'm assuming your post was addressed to me.I did not read the instructions for these lights- I never even thought there would be a problem.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
Its strange to me also, but I got lucky I suppose. I do know that mine have the ability to stay on, without motion, if I simply turn them off and then back on after 5 seconds. If yours has that function, maybe the activity on the circuit is confusing that built-in logic. That's a very wild guess though, because in my mind that only makes sense if they are wired in series.
I'm not an electrician, and I didn't spend the night at an HIE, but I used to be smarter than a light fixture. Not anymore, eh?
I think I got them working right. A little white electrical tape applied to one sensor and some fiddling and it seems we're in business.
Thanks to all for the helps.
Jon Blakemore
RappahannockINC.com Fredericksburg, VA