I want to install two LeGrande RRW600UBCCCV4 motion sensor switches. One on each end of the kitchen area so that the light comes on no matter which entry is used.

From the ceiling I have a black wire and white/taped black and another white that is connected to it.

I went through and disconnected every terminal at both switches and the fixture and ran continuity tests to see what went where.

Then I went back and connected the wires and energized the circuit.

This is where we are at this point, awaiting some instruction.

What I do NOT know is what the use of the blue/white wire is on the new sensors.

Nothing in the wiring diagrams on the sheet supplied seem to address this situation.

First image is all wires disconnected and continuity tested: enter image description here

Second is wiring connections made and hot circuit voltage tested: enter image description here

  • 3
    Your diagram cannot possibly be correct. The light would be always on (and the switches would do nothing) if things were actually wired as you have drawn.
    – nobody
    Feb 2 at 17:30

1 Answer 1


If you'd like to see the functional diagram of what's going on, here's what you've got.

You can see where there's a whopper of a problem getting neutral at the switches.

enter image description here

Fortunately, you have switches which UL has approved to use ground as their power return. (owing to very particular design features therein).

To make this less mind-numbing, I advise buying a 5-pack of colored electrical tape and spiraling tape down the wires to re-color them by their function. Trust me, 3-way boxes are a maze, and you'll thank me later, boy howdy! When re-marking wires, always re-mark both ends of the wire exactly the same, and do it at the same time.

To adapt to these particular Legrand switches, I would

  • On the "first switch to lamp" cable, re-mark WHITE to BLACK - this is a Code requirement and is mandatory.
  • On the "first switch to lamp" cable, re-mark BLACK to RED - this is "Switched-Hot". Why not shortcut and mark white to red? Code forbids it. Reasonably: markers do fall off sometimes
  • On the "between switches" cable, re-mark RED to YELLOW. This will be a data/signal cable, call it a "traveler" if you want, but there's only 1 of them due to smart switch magic.
  • On the "between switches" cable, you will no longer use white for anything. Cap it off and coil it into the back of the box.

On the far box, the RED wire from the switch won't be used for anything. Cap it off.

On both boxes, the BLUE-WHITE and GREEN wires from the switch go to GROUND, per the instructions. NEC 110.3(B) requires that you follow the instructions, so it goes without saying that you read them :)

Other than that, everything should match up by its (assigned) color.

  • Whoops, I should've actually read the entire instruction manual to see that these switches can use ground instead of neutral, so the setup is in fact possible.
    – nobody
    Feb 3 at 15:07

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