I’d like to preface by saying my issue is almost certainly due to lack of experience and likely a stupid mistake I’ve made on my end. Looking back I should have hired an electrician, but I have installed 5 of these blue series switches in my apartment and have had no issues with 4 of them over the past 2 years.
So I replaced two Lutron dimmer switches with blue series dimmer switches in the same 3 gang box (only two switches, one is empty). When I initially installed them, they worked fine for the first year, then suddenly one of the switches died (no power). When I opened it up I carefully tested with a voltage tester that that it was still getting power, and it was.
I had extra switches that I hadn’t installed in other rooms yet so I installed one of those the same way, thinking that something went wrong with the switch and not something with my wiring and when testing the new one it worked for about 2 mins before also getting fried. This has become a very expensive mistake as you can see.
I’ve put back in the old Lutron switch and everything works fine again.
I took pictures of the second wiring attempt. They aren’t the best, but I was hoping someone might be able to identify the mistake I made.
My uneducated guess is that in this picture the green wires are the ground and they are connecting the two switches and not going anywhere else, where as with the Lutron the ground is connected to the metal around the switch that gets screwed into the box.
The dead switch didn’t have a neutral wire, or at least I didn’t see one connected to the Lutron when I first replaced it. The other dimmer that works did have a neutral wire, so I tried to wire that one the same as the Lutron and it has worked. I also have a Aeotec Bypass for Dimmer Switches connected to it so it wouldldn’t stay on since all these lights are LEDs (not smart LEDS). I did not have a bypass connected to the problematic switch.
When your wiring is THNN/THWN individual conductors in conduit, it’s pretty tough to troubleshoot via pictures. I can only make a couple of observations without providing an absolute answer.
Regarding the grounds, if your configuration is conduit and metal boxes, then the box is the ground. The switches get grounded when the switch contacts the box. Some boxes have a fitting for a green ground screw to allow for attaching a bare ground conductor, although that is not always the case. In any event, a good practice is to scrape the paint away from the back of the switch frame to ensure good contact with the box.
Your switch is presently wired as a non-neutral. I can’t tell if your switch leg is a non-neutral or not, since you have individual conductors. There appears to be a neutral in the box (for the other switch), but that doesn’t necessarily mean that is the appropriate neutral for the switch leg in question.
The neutral wired to the other switch is bundled with a black white conductors. The black conductor seems strange to me. While colors don’t absolutely matter, there are common conventions for colors used in wiring schemes. I don’t believe a licensed electrician would have used a black for a neutral conductor.
You have a bypass wired to the other switch. These are typically wired at the light, not the switch. But if it’s working, then that’s ok.
So if your dead switch is a neutral configuration, it’s missing a neutral conductor, which MAY have contributed to it’s demise. If it’s a non-neutral, then there wouldn’t be a neutral conductor. But as I mentioned previously, it’s tough to diagnose via pictures when you don’t have Romex.
I’d get an electrician to take a look at your wiring configuration, as individual conductors always involve a bit of hands-on testing.
Hey @Bry, thank so much for the thorough response.
Understood about the grounds. For the non-neutral switch (dead switch), the light is physically between the switch and the breaker box. I can’t confirm, but I assume the neutral wire would go back the box instead of back to the switch. But, as established I have too little experience so I could be wrong.
But I think the best course of action is to hire an electrician to investigate as you suggested. Thanks again for you help.
