I purchased a motion sensor to operate the lights in my garage. The Motion sensor has four terminals labeled LNLN. When I remove the switch, I have a Black wire, white wire, bare wire, and a RED wire which is puzzling me.

The instructions are below. Motion sensor instructions LNLN The red wire is confusing me. Thanks for your Help 2]]2

  • Are you in the US or elsewhere? Can you take a photo of the switch that shows all the wires?
    – BowlOfRed
    Feb 19, 2021 at 23:22
  • I'm in the USA, and I'll get a pic asap. Feb 20, 2021 at 0:18
  • @MicahCarver -- what make and model is said motion sensor? Feb 20, 2021 at 0:29

1 Answer 1


Normally Black is the hot supply or L, the white is the neutral N both from the supply and to the load the red wire is the switched hot. This is how all the motion sensors work that I have installed. But you don’t show which wire is red but this is the most common. Most electricians use Red as a switched hot but it is not a requirement to do so.

  • Ok, so where do I tie in the switched hot Red wire? I am removing a switch to install the microwave motion sensor in the switch's place. Feb 21, 2021 at 0:20
  • The red switched goes to the load black if colors were followed.
    – Ed Beal
    Feb 21, 2021 at 2:51

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