I have two wall switches side-by-side. There appears to be only one neutral wire.
I'm trying to install WEMO wifi enabled wall switches. My WEMO switches require a neutral wire. Can I wire both WEMO switches to the same neutral wire? enter image description here

  • Are you assuming it's a neutral wire based on the color, or have you actually put a voltmeter to it to confirm? A picture of the inside of the switch box would also help – mmathis Aug 24 '17 at 19:25
  • I assumed the white wire that was simply capped off was a neutral. So I connected one WEMO switch using that (and two black wires and a ground), and the switch works fine. It's the second WEMO switch for which I cannot find another white wire capped off. The inside of the switch box looks like a rat's nest. – John Dennis Aug 24 '17 at 19:52
  • Picture of switch box below. The working WEMO switch is hanging down out of the picture on the right side. I cannot paste the picture in this chat box. – John Dennis Aug 24 '17 at 19:56
  • Click edit on your question to add the image – mmathis Aug 24 '17 at 19:59
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    You have what appears to be at least 5 white neutrals bundled together at the back of the box. – brhans Aug 24 '17 at 21:02

If both switches are powered by the same breaker you can wire both to the same neutral. From the wad of wiring I would expect the hot,neutral and ground to be in the box but it should be verified and that there is only 1 hot going to the box. If there are 2 separate circuits or power from more than 1 breaker the switch needs to be wired to the same neutral that the power comes in on.

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This question is at least partly dependent on where you are. I can offer sort of general advice that is most likely correct in the US. Each state and even cities are different in the parts of the electrical code that they adopt, and the latest version of the National Electrical Code is most likely where you should get the answer, but....

That rat's nest of wires: looks like too many. If you measure the area of the cross sections of the wires in the box, exclusive of the ground wires (generally) in circular mils, then you will see the size box that they can occupy. The reasoning is, I think, that too many wires are too hard to work with properly, devices won't fit properly into a crowded box, and heat may not dissipate or be generated at too high of a rate by too much electricity in too small of a box.

That said, unless there is a need to have the devices on completely different circuits, then they can likely share a neutral, but make sure to 'bond' the neutrals together. (if they are on two different circuits, DO NOT bond the neutrals together) To bond the neutrals, you can use a wire-nut to connect the end of the single neutral to two 'pigtails' or short wires that Y-off the one wire and become two new ends, one for each device. Common practice in wiring a box but it could conceivably interfere with control circuits. The manufacturer would be the best reference in this case.

When you're wiring, don't depend on luck, find out for sure!

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