I installed 2 smart switches. They are wired back to the panel with an existing 3 conductor 14 (two hots one shared neutral, as per my previous question. The switches buzz slightly, apparently a common thing. But when both light switches are on the breakers in the panel buzz. A slight hardly noticeable, but I hear it. Is this an issue!

  • 1
    Would turn off breakers then post pictures of breakers and how you wired your switches, in your question.
    – crip659
    Jun 23 '21 at 19:11
  • 3
    Are these UL listed smart switches?
    – Ed Beal
    Jun 23 '21 at 19:21
  • 1
    Yeah, that ain't right. Buzzing at the switch might be attributed to the switch, but buzzing at the breaker means both buzzes are due to a wiring fault. What make is your panel? What make are the breakers? Jun 23 '21 at 20:27
  • What make and model are the breakers/panel, and the smart switches for that matter? Jun 23 '21 at 23:25
  • The panel is. Square D QO panel with square d 15 amp breakers. The switches are 2 cooper halo switches I got from a neighbour who bought lights that came with the switches. I’m currently away working for a week. So I don’t have pics. So it only buzzes at the panel when both switches are on. I think I’ll ditch the smart switches and see what happens. Jun 23 '21 at 23:53

I can't know for sure if this is the issue because I'm not there, but I personally have experienced buzzing from a panel caused by corrosion on the bus bars that feed the breakers to the point that they destroy themselves at the back side. I used a plastic and rubberized handled, small brass wire brush to scrub them clean and replaced the damaged breakers and haven't had a problem since.

I don't recommend you remove the breakers and certainly don't touch the bus bars at the back with ANYTHING unless you know what you're doing! Electricity kills. A licensed electrician would probably replace the panel in my mentioned case in particular, but I'm not made of money, so I did it the cheap-arse way.

The buzzing inside the "smart switch" on the other hand is likely coming from the internal relay's coil. The coil is much like a speaker coil, and plays the note that's being sent into it: 60Hz sinewave. This coil is what magnetically pulls the switch contacts together to allow current to flow to your device. There's also a power supply inside to drive the microcontroller unit inside that might be the cause.

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