Original description of problemI believe this is what Harper - Reinstate Monica is suggesting I do. Is that correct? Is that correct?]2]2[enter image description here]2I have wired a 120v water valve with a motion sensor and it works fine (see top photo). I want to add a switch (see bottom photo) that will bypass the PIR(motion sensor)for cases where I do not want the motion sensor to operate. Sometimes I want the valve to just run off a timer. Does the wiring look correct? I already fried one motion sensor with a different wiring attempt.

  • Hello, and welcome to Home Improvement. 120VAC wiring isn't really a "try various combinations until one works" scene; you might start a fire or get killed. – Daniel Griscom May 8 at 0:02
  • Yeah. I know. Thats why Im asking for advice. Thanks. – deez_nutz May 8 at 0:13

So your proposed wiring scheme looks great when it's in PIR mode.

However, throw the switch to "other thing" mode, and what do you see?

  • The PIR's supply wire is disconnected.
  • The PIR's lamp-side wire is being back-fed with hot. Is that good for it? Does its instructions say that's alright?

The other problem with PIRs is you really want to power them 24x7. They also have light sensors, and they need 24 hours to see the maximum and minimum absolute lux in the location, so they can distinguish night from day in adverse conditions.

So I would flip it around. I would make sure that PIR supply (brown) always sees hot, and PIR neutral (blue) always sees neutral. I would run PIR switched-hot to one side of the switch, and always-hot to the other side of the switch. The pump goes to the common.

Now the PIR is always up, but it either has a load, or does not.

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  • The idea with the switch is that I can completely turn off the PIR while the valve is being operated by a timer. What this device is is a 120 valve that connects to a garden hose that can be used to scare cats out of my garden by using a motion sensor and a lawn sprinkler. Other times I may use the valve without the PIR when I use it for a plant misting system. Thats why I want the PIR to be off. Fig 3 is what I believe you are suggesting. Is that correct? – deez_nutz May 8 at 18:33
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    @deez_nutz Yes, you have it! Although I'm weirded out by the blue/brown leads on the thing. That's either Euro/230V or Chinese/junk. If it doesn't have a UL, ETL or CSA listing, don't put it on mains! Lutron & Cooper make perfectly fine PIRs that are listed. – Harper - Reinstate Monica May 8 at 18:54
  • It says it will take 85-265 volts! lol Yes it is Chinese. $8 on amazon. – deez_nutz May 8 at 20:57
  • @deez_nutz -- is there any reason you're wedded to ordering your PIR from Amazon, or the Cheese pipeline generally even? – ThreePhaseEel May 9 at 1:53
  • I'll order a PIR from whoever is cheep and delivers in a few days. Do you have a recommendation? Who said I was wedded to Amazon? What is a cheese pipeline? – deez_nutz May 10 at 23:19

You only need a SPST switch. Just connect it across brown and red keeping all connections how they are.

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