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Discuss Strange problem with PIR/motion sensor switch in the Lighting Forum area at ElectriciansForums.net


New EF Member
Hi, I have an odd problem with a motion sensor switch in a bathroom.
The sensor detects motion and switches the light on, but then doesn't switch the light off.
However, when I switch the fuse off and then on again at the fusebox, it resets the motion sensor, which works fine, but only once - after which, it goes back to turning the light on but not off.
I've tried replacing the motion sensor (it's a Timeguard PIR, with five terminals, including a switched live).
Any ideas please? I can't work out why this would happen?

Barnaby Stedman

Regular EF Member
have you looked in the light and checked that there is only a switched live running into it?
also are you sure you are buying the right type of motion sensor?
have you tried waiting for the light to turn off say 10 minutes after you leave the room?


Forum Mentor
Can you show us how you have wired it up?


Forum Mentor
I know that timeguard pirs can be on for maximum 30 minutes after the last presence detection
OP probably won't get back to us if he finds out he's stuck it on max time..

static zap

Regular EF Member
( or shield the sensor/bulb if sensor is seeing flicker)
...Max timer most likely as AN & Spoon already mentioned...


New EF Member
Thanks for all your responses!
The timer is set to the minimum, 30 seconds. The light stays on permanently (or at least, more than an hour). I've included a photo of the wiring set up, maybe that will help! IMG_20190419_173011.jpg

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