Electrical – Installing one way light switch

electricalelectrical-panelmultiway-switchswitchwiring

I accidentally bought a one-way switch for a receptacle that is wired for a three-way switch. I found that the only way it works so far is:

  1. Connect the two black wires from the wall to the black wire coming from the one way switch and use a wire nut to connect those three wires together.

  2. Connect the one red wire from the wall to the red wire to the switch

  3. Connect the ground and neutral from the switch to the ground coming from the wall

Since I've never had to do it this way before I was wondering is this safe? I initially thought that I could just leave the neutral from the switch capped and taped off but the switch didn't work when I did that. I am in North America if that makes any difference. Thank you all for the help in advance.

Attached is a link of the picture of the way I currently wired it
https://photos.app.goo.gl/e4EcvFN19QJfQYQN6

Best Answer

You have two problems here: one, hacking a two way switch where you ought to have a three way switch, and two, using a ground as a current carrying conductor. You should put back the original three way switch immediately to be safe, and come up with a plan B.

Resolving the first problem is simple: buy a smart switch made to replace a three way switch.

Resolving the ground wire issue is a little more difficult. Your smart switch requires a neutral, but the box it's going in doesn't have a neutral. (At least not that I can see in the photo.) This is common when switches were wired with a switch loop, which is what it looks like you have here.

You have used a ground wire in place of a neutral. Using a ground wire in place of the neutral works, but it isn't safe. The ground wire should only conduct current in the event of a ground fault. So you shouldn't have bootlegged the neutral, it's a code violation and a safety issue.

To rectify this, you could bring a neutral to the box by rewiring, that may be a small job, may be a big job, but it will work with just about any smart switch.

You could also choose a different smart switch. There are smart switches that work without a neutral. Most of these actually bootleg the neutral internally. This seems like a terrible idea, but UL will only list a switch that bootlegs the neutral if it is tested and only passes a very small amount of current on the neutral - small enough that it isn't a safety issue. So if a UL listed switch does it, it doesn't count as bootlegging.

Just make sure the switch is UL listed, and stick to a reputable brand - there are tons of products on the market from sketchy brands that are putting the UL logo on products that are not really UL listed.