- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
First let me apologize for the long post, but I don't know any way to shorten it much.
I have a customer that has a Maestro IR dimmer, (MIR-LFQMT-) that I installed about 6 months ago that stopped working. He asked me to look at it and told me something crazy sounding that it was doing. In case some are not familiar with this dimmer, I'll give a brief description of it.
It is a dimmer and fan control in one unit. It has a wall unit that replaces a wall switch. It also has a module that goes in the fan canopy. You don't need a neutral in the wall box. You just either wire it as a SP or 3-way, SP in my case. The module has four wires. One is black for power from the switched leg. The other wires are: red for the light, yellow for the fan, and white for neutral. It also has a remote to operate it. The wall unit has a top section (dimmer) and a bottom (fan) section. There are LED lights at each section to indicate the level you have it set at.
The problem is the dimmer stopped working. If you hit the button to dim/raise the light, the LEDs would just scroll up & down but no dimming took place. Now the crazy part I mentioned. He said he discovered that if he turned on another switch in the box the dimmer would work.:? I checked it and sure enough that was the case.
Here's what is in the 3-gang box where the wall unit is. The dimmer/fan control, a SP switch that isn't connected, (just a space filler), and a 3-way switch for the can lights in the room. Power comes into the box from a 14-2 NM cable. There is another 14-2 that I don't know where it goes, 14-3 to the fan/light, and 14-3 for the can lights. I'm only using two wires for the wall unit since the 3rd (red) wire was originally for controlling the fan/light separately, so it is capped off.
I checked the wiring and everything seemed ok. I reset the dimmer with a pullout service switch it has called a FASS. That didn't help, in fact the LEDs kept scrolling and finally just stopped. I called Lutron support and they had me do a factory reset. They said that if that didn't work they would send me a new unit. It didn't work and they sent a new unit.
When the new unit arrived, I checked all the wiring again then installed it. It did the same thing as the old one.:rant: So I turned on the 3-way for the can lights and it worked.
Just to add, once the lights are dimmed and fan running, if you turn off the 3-way it doesn't stop the fan or lights. So I decided to do a deeper check on everything. I first thought I would check voltage at the wall unit, it had 120V.
Just to rule out phantom voltage, I hooked a test light up that I have. It's just a light socket with pigtail leads. I connected one lead to the neutral in the box and one to the line side of wall unit. The test light lit and I had 120V, so I know the voltage was real.
Now in doing this, the 3-way for the can lights was not on. But I discovered that with the test light connected to the unit that it caused the dimmer to work correctly. So, it wasn't that the can lights had to be switched on, just a load paralleled with the unit made it work.
This sounded like maybe I had a bad neutral connection so I turned off the power to check everything. I took all the splices apart in the box, re-stripped them and put on new wire nuts. I also took the wires apart in the canopy. There is only the 14-3 at the ceiling, no splices. While I had this apart, I checked continuity with the neutrals and everything was fine. I put everything back and checked the unit again. Still wouldn't work without a load in parallel.
I completely disconnected the 3-way for the can lights and that didn't help. I hooked the test light back to the switch and the dimmer worked correctly. I even tied it both on the line side and load/switched side of the unit, either would allow the dimmer/fan control to work.
Ok, now I go back to the fan/light. I hooked my test light to the black wire that powers the module. It turned on my test light, so I know the power (120v) was getting to the ceiling. I also went to the wall unit while the test light was on and pulled out the service switch on the control and it turned off the test light, pushed it back in and turned the light back on. So I know the power is constant to the module. This was all done with no parallel load on, just power and neutral from the wall unit/box.
So I hooked the black wire back to the switched wire and disconnected the fan light from the red wire. I hooked my test light to the red wire and neutral. Then I tried the wall control again to see if it would dim the test light. It did not dim it either. So just to rule out the problem being in the ceiling light I connected the 3-way back up so I could get a parallel load. When I turned on the 3-way, it would then dim/raise my test light. So that ruled out any problem with the ceiling fan or light.
I got on the phone with Lutron and they didn't have an answer for me, other than a bad neutral which I ruled out already.
Anyone have any thoughts on why this thing worked for six months now it won't, even with a new unit?
I have a customer that has a Maestro IR dimmer, (MIR-LFQMT-) that I installed about 6 months ago that stopped working. He asked me to look at it and told me something crazy sounding that it was doing. In case some are not familiar with this dimmer, I'll give a brief description of it.
It is a dimmer and fan control in one unit. It has a wall unit that replaces a wall switch. It also has a module that goes in the fan canopy. You don't need a neutral in the wall box. You just either wire it as a SP or 3-way, SP in my case. The module has four wires. One is black for power from the switched leg. The other wires are: red for the light, yellow for the fan, and white for neutral. It also has a remote to operate it. The wall unit has a top section (dimmer) and a bottom (fan) section. There are LED lights at each section to indicate the level you have it set at.
The problem is the dimmer stopped working. If you hit the button to dim/raise the light, the LEDs would just scroll up & down but no dimming took place. Now the crazy part I mentioned. He said he discovered that if he turned on another switch in the box the dimmer would work.:? I checked it and sure enough that was the case.
Here's what is in the 3-gang box where the wall unit is. The dimmer/fan control, a SP switch that isn't connected, (just a space filler), and a 3-way switch for the can lights in the room. Power comes into the box from a 14-2 NM cable. There is another 14-2 that I don't know where it goes, 14-3 to the fan/light, and 14-3 for the can lights. I'm only using two wires for the wall unit since the 3rd (red) wire was originally for controlling the fan/light separately, so it is capped off.
I checked the wiring and everything seemed ok. I reset the dimmer with a pullout service switch it has called a FASS. That didn't help, in fact the LEDs kept scrolling and finally just stopped. I called Lutron support and they had me do a factory reset. They said that if that didn't work they would send me a new unit. It didn't work and they sent a new unit.
When the new unit arrived, I checked all the wiring again then installed it. It did the same thing as the old one.:rant: So I turned on the 3-way for the can lights and it worked.
Just to add, once the lights are dimmed and fan running, if you turn off the 3-way it doesn't stop the fan or lights. So I decided to do a deeper check on everything. I first thought I would check voltage at the wall unit, it had 120V.
Just to rule out phantom voltage, I hooked a test light up that I have. It's just a light socket with pigtail leads. I connected one lead to the neutral in the box and one to the line side of wall unit. The test light lit and I had 120V, so I know the voltage was real.
Now in doing this, the 3-way for the can lights was not on. But I discovered that with the test light connected to the unit that it caused the dimmer to work correctly. So, it wasn't that the can lights had to be switched on, just a load paralleled with the unit made it work.
This sounded like maybe I had a bad neutral connection so I turned off the power to check everything. I took all the splices apart in the box, re-stripped them and put on new wire nuts. I also took the wires apart in the canopy. There is only the 14-3 at the ceiling, no splices. While I had this apart, I checked continuity with the neutrals and everything was fine. I put everything back and checked the unit again. Still wouldn't work without a load in parallel.
I completely disconnected the 3-way for the can lights and that didn't help. I hooked the test light back to the switch and the dimmer worked correctly. I even tied it both on the line side and load/switched side of the unit, either would allow the dimmer/fan control to work.
Ok, now I go back to the fan/light. I hooked my test light to the black wire that powers the module. It turned on my test light, so I know the power (120v) was getting to the ceiling. I also went to the wall unit while the test light was on and pulled out the service switch on the control and it turned off the test light, pushed it back in and turned the light back on. So I know the power is constant to the module. This was all done with no parallel load on, just power and neutral from the wall unit/box.
So I hooked the black wire back to the switched wire and disconnected the fan light from the red wire. I hooked my test light to the red wire and neutral. Then I tried the wall control again to see if it would dim the test light. It did not dim it either. So just to rule out the problem being in the ceiling light I connected the 3-way back up so I could get a parallel load. When I turned on the 3-way, it would then dim/raise my test light. So that ruled out any problem with the ceiling fan or light.
I got on the phone with Lutron and they didn't have an answer for me, other than a bad neutral which I ruled out already.
Anyone have any thoughts on why this thing worked for six months now it won't, even with a new unit?