Home>Discussions>ELECTRICAL & LIGHTING>Perplexing motion detector behavior
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philipt
Perplexing motion detector behavior

I have a motion detector that behaves very odly.

In wet conditions, ie: rain and wet ground/landscape, it works as expected, ie: switches on with motion sensor, stays for the time set, switches off and stays off until motion is detected.

In dry conditions, it switches on, stays for the time set, switches off and then on again within a couple of seconds, and repeats forever.

I swapped with another one around the house, which is working perfectly, same behavior when fitted to this position.
I swapped a new one, same behavior.

I tried to change the position of the sensor, sensitivity etc but no luck.

This was working fine until the house was painted with semi-gloss paint. Coincident? but why if it is the cause? and why only in the dry?

A. Spruce
Re: Perplexing motion detector behavior

I would back trace this circuit back to the panel and make sure any splices or connections are in good working condition. Something that recently occurred to me is that the light would come on and stay on. That was traced to the motion light needing a switch in the circuit. I don't understand what the relevance was, but it did the trick and as an added benefit should the light have problems again, flipping the switch is supposed to reset it. Secondary benefit is sometimes I don't want the light to come on, so it's nice to be able to turn it off when necessary.

bsum1
Re: Perplexing motion detector behavior

Check what A.Spruce posted.
To add, something else can be the cause between wet weather and dry weather.
Something that is in the line of sight of the sensor is different when wet than dry. Maybe even something that moves when dry and doesn't when wet or something reflecting back to the sensor. Just a guess.

philipt
Re: Perplexing motion detector behavior
A. Spruce wrote:

I would back trace this circuit back to the panel and make sure any splices or connections are in good working condition. Something that recently occurred to me is that the light would come on and stay on. That was traced to the motion light needing a switch in the circuit.

This is what I have, a switch in the circuit.

I will check the circuit.
Thanks

philipt
Re: Perplexing motion detector behavior
bsum1 wrote:

Check what A.Spruce posted.
To add, something else can be the cause between wet weather and dry weather.
Something that is in the line of sight of the sensor is different when wet than dry. Maybe even something that moves when dry and doesn't when wet or something reflecting back to the sensor. Just a guess.

I am guessing reflection, hence the mention of recent semi-gloss paint, but this would even be worse wet than dry, no?
I was watching the trees and shrubs moving in the wind and rain recently and contrasted that to the calm, dry condition the following day, yet this is when the light behaved odly.

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