Occupancy detector light switch and nearby router; can router affect switch?

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,460
Recently I moved the router into the laundry room and placed it about three feet away from the motion detector light switch. The switch would come on by itself and sometimes it would stay on for hours even though it's set for 15 minutes. Can the presence of the router (Netgear Nighthawk 2.5G / 5G) cause the switch to think it's detecting motion? I believe the switch is an IR type. (Leviton DI-000-PR180-22C) It's about 13 years old and has never given any indication of a problem until after moving the router. The switched load is not meant for LED lighting but by putting a standard incandescent bulb in parallel with the LED lights stops the flicker and the failure to fully extinguish. Without the incandescent bulb the LED's would never fully go out but be about 60% lit and flicker until turned fully on. So the inc-bulb is required for normal switching. And the inc is good.

I know random events can sometimes occur at a similar time making it look like one affected the other. My first guess would be that the router shouldn't cause any issues with the motion sensor switch. I could be wrong.
 

crutschow

Joined Mar 14, 2008
28,206
Yes the switch likely detects IR to turn on the light, but the its electronics may be susceptible to the strong RF field of the router (WiFi?).
Can you test by leaving the router off for awhile?
 

prairiemystic

Joined Jun 5, 2018
198
I have seen PIR outdoor lights malfunction due to RF interference from WiFi or smart energy meters. They false trigger. Also due to a spider walking around inside the lens, this is a common problem with home alarms false motion detector trips.
You can try an aluminium foil or metal screen cover and see what that does.
It seems to be the PIR sensor is not designed to reject RF, take it apart and add a capacitor lol
 

Ian0

Joined Aug 7, 2020
3,768
Motion detectors detect a change in IR radiation, as someone walks from one zone to the next on the fresnel lens.
A point source of IR that varies in intensity would create the same effect.
If the router runs warmer (say about 37°C) when there is more WiFi activity and then cools down, it could possibly generate the same changing IR radiation. . . .perhaps?
Try the tinfoil as @prairiemystic suggested and see what happens.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,460
Well, I replaced it with another Occupancy Sensor (OS) and it's working properly. No false triggering so far. As for the lights on the router - they're LED, blue LED. I wouldn't believe they're causing false triggering. Bugs inside the lens? That I'd believe. But having removed the cover there's nothing inside the chamber to suggest any unwanted visitors moving furniture around inside the lens. The RF thing ? ? ? That's what I'm suspicious of; so if that's the cause then having the router that close COULD be causing the unwanted triggering. But like I said, new switch and no more problems for now.
 

MrSalts

Joined Apr 2, 2020
733
Well, I replaced it with another Occupancy Sensor (OS) and it's working properly. No false triggering so far. As for the lights on the router - they're LED, blue LED. I wouldn't believe they're causing false triggering. Bugs inside the lens? That I'd believe. But having removed the cover there's nothing inside the chamber to suggest any unwanted visitors moving furniture around inside the lens. The RF thing ? ? ? That's what I'm suspicious of; so if that's the cause then having the router that close COULD be causing the unwanted triggering. But like I said, new switch and no more problems for now.
In other words, even with all of the advice, the interest, the easy-to-set-up experiments - we'll never know the cause of the false triggers with the original occupancy sensor.
 

Thread Starter

Tonyr1084

Joined Sep 24, 2015
6,460
I can always bench test it - away from routers and microwave ovens and coffee makers. If you really need to know I'll go ahead and set it up. Easy as wiring a plug to the Hot In, connect the neutrals together and also connect the grounds together and then bodge a light onto the output. Will set it into test mode so I won't have to wait 5 minutes between activations.

Do I really need to? Please, if you have a need to know - I'll be happy to set up a test. Heck! It may even make a good motion detector to let me know when someone is sneaking up the stairs. Maybe there IS a use for it - IF it's working correctly away from the router. BTW: The new switch has not had any false triggers so far.

Gotta go. Peach Crumble fresh out of the oven and it's calling my name.
 

MrSalts

Joined Apr 2, 2020
733
I can always bench test it - away from routers and microwave ovens and coffee makers. If you really need to know I'll go ahead and set it up. Easy as wiring a plug to the Hot In, connect the neutrals together and also connect the grounds together and then bodge a light onto the output. Will set it into test mode so I won't have to wait 5 minutes between activations.

Do I really need to? Please, if you have a need to know - I'll be happy to set up a test. Heck! It may even make a good motion detector to let me know when someone is sneaking up the stairs. Maybe there IS a use for it - IF it's working correctly away from the router. BTW: The new switch has not had any false triggers so far.

Gotta go. Peach Crumble fresh out of the oven and it's calling my name.
Did it really yell, Tonyr1084? Or are you more familiar with your Peach Cobbler than members of AAC and it just calls you Tony? Or are you more formal with the Peach Cobnler and it calls you Mr R?

EDIT - if you don't want to do testing, don't do testing. We're all too old to do things we don't want to do. Enjoy the cobbler.
 
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