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Lutron Maestro Motion Sensor Switch | No Neutral Required, 150W LED, Single Pole | MS-OPS2-WH, White

It similar to this question here: lutron sensor switch - wiring help

I have installed 13 of these lutron motion sensors all across my house so I am not a NOOB in terms of wiring.

when I installed the latest motion sensor in my bathroom, I connected each of the black wrie from lutron to each of the black wire in the switch and both green and bare wire from lutron to ground/bare wire in switch. When I turned on the power, the light turns on but when I click lutron switch on/off manually it just remains on. This is what I did per lutron manual.

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I kept scratching my head thinking why its not manually turning off? I thought perhaps the switch maybe defective so I went back to home depot and got another one and that too behaves the same way, light always remains on no matter if I manually touch it to turn on/off. As if it has no effect.

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I then connected the green wire to neutral white wire and bare wire from lutron to bare wire in the switch ... still nothing and same beahvior. light always on.

Why in the world is my switch always on? Is there something wrong with ground?

Here's troubleshooting doc from lutron. The first question is what my problem is: https://assets.lutron.com/a/documents/3682373.pdf

  • 1
    @manassehkatz-Moving2Codidact I corrected the text. Its each black wire to each of the black wire in switch. Unfortunately I dont have a picture as I have put the original dumb switches back.
    – Sam B
    Jan 8 at 1:21
  • did you try switching the blacks just for fun
    – Ruskes
    Jan 8 at 1:33
  • @Ruskes yup, I did that too. No effect.. The only thing I can think of is that somehow the ground is not really grounded.
    – Sam B
    Jan 8 at 1:33
  • 1 - Pictures of your actual wiring would help; 2 - If you check with a multimeter between each pair of wires and between each wire and the box (if the box is metal) what voltages do you get? Jan 8 at 2:46

1 Answer 1

  1. Is the bathroom lamp a low-power LED? If so, the Lutron switch might not be able to turn it off completely. If you can easily replace the lamp, test using an incandescent, which draws far more current.

  2. Is the passive infrared (PIR) motion detector near a heat register or other source of motion (moving air currents, vibrating wall from bath fan, blowing curtains, etc.)? That could activate it.

  3. A bad ground could, indeed, cause the switch to malfunction, if it derives power through that ground. Definitely check on that for safety reasons. With power off at circuit breakers, connect an ohmmeter between the putative ground connection in the switch box and a known good ground (e.g., faucet or ground prong of another outlet). It should read zero (or the same as when the meter leads are touching, perhaps a fraction of an ohm).

  4. If you remove one connection between black wire and switch (capping both bare leads) and turn on power, is the light off? Perhaps there's another switch controlling that light (e.g., 3-way).

  • 2
    Even with cold water entrance pipe grounded properly, you might not get a good ground at the faucet - any section of plastic pipe between entrance/ground connection and the faucet will cause it to not be grounded. Ground prong of a receptacle is the way to go, and unless extremely old, the bathroom should have grounded receptacles. Jan 8 at 2:56
  • @manassehkatz-Moving2Codidact, Good point. An ungrounded bathtub is a bit scary, though -- it could add new meaning to the word "hot-tub". Jan 8 at 3:05
  • 2
    That's why we have GFCI required. The GFCI actually provides a huge amount of protection especially if the bathtub is not grounded. In theory, a bathtub not grounded (let's say all incoming and outgoing pipe is plastic, water not running at the time) would actually be relatively safe - touch a hot wire while sitting in the tub full of water and if the electricity can't actually go anywhere then you are OK. (But I don't recommend trying it.) But if it is grounded - even just a little bit - then some of that power goes through you. Which a properly functioning GFCI will stop very quickly. Jan 8 at 3:08
  • @manassehkatz-Moving2Codidact GFCI have nothing do with this
    – Ruskes
    Jan 8 at 3:40
  • 1
    @Ruskes GFCI has nothing to do with the original question. It is in response to DrMoishePippik's comment in response to my comment regarding how to test the ground wire of the switch - which is an issue that is relevant. Jan 8 at 3:44

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