enter image description hereI am trying to install a new z-wave light switch. But I have encountered something I can't figure out. I have two light switches in the same box. They both have a hot and neutral wire connected to them. But there is also a wire that goes between the two (I think hot) terminals. They are the old kind of switch so they don't have screws, so the extra wire is just jammed into one of the terminals. Do I need this extra wire? What is it for?

All the wires that come out of the switches and out of the picture, go into the wall, beyond that I don't know what they do.

  • 2
    Neutral should never be switched. It may be repurposed as a separate hot. Do you have a photo? Have you looked at the devices which are downstream from the switch, e.g. light fixtures?
    – user4302
    Mar 10 '16 at 2:50
  • 3
    I'd guess that one of the "hot" wires feeds power to one switch, the jumper takes power to the other switch, then the other "hot" wire carries power on to another device. However, without being there, or seeing it, it's difficult to say for sure.
    – Tester101
    Mar 10 '16 at 4:16
  • 1
    @Snowman Considering that both hot and 'neutral' are connected to the switch, it's likely that this isn't a neutral. Probably the white wire is being repurposed as hot, but has not been reidentified.
    – TFK
    Mar 10 '16 at 11:37
  • I only see black wires with texture or paint on them. I agree with tester that the hot is a jumper to feed the second switch. + tester
    – Ed Beal
    Mar 10 '16 at 14:12
  • @TFK question states there is a neutral going to the switch, and I specifically stated it may be repurposed. Based on the photo, it appears "neutral" was conflated with "black wire with white paint on it."
    – user4302
    Mar 10 '16 at 17:41

The black wire coming in from the top and attaching to the right terminal of the left switch is likely the "incoming" hot wire from the panel or upstream somewhere.

The black wire on the left side of the left switch is the switch leg for one receptacle, and the black wire on the right side of the right switch is the switch leg for another receptacle.

The second wire connecting the two is simply there to bring electricity from the left switch's hot to the right switch. It is possible to daisy chain switches this way, or one could use a wire nut and two tails to connect to the switches (this is how I would do it, easier to rewire later if e.g. a switch fails or if you want to swap one for an upgrade like you are now).

Note: your question says there are neutrals going to the switches, but these appear to be black (hot) wires with white paint on them.

The Z-wave switch appears to require a neutral based on images of the product, so you will need to tap into a neutral.

  • Be careful that you are using a real neutral and not a hot with white paint on it (this is one reason to put painter's tape over receptacle boxes when painting).

  • The neutral must be on the same circuit as the hot being switched. If only one circuit feeds this box there is no problem.

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