I have a few lighting circuits in my house where the lights have been upgraded to LEDs but the the wall switches only have a 2 wire set up (black, white, and ground) I am getting vague reports you can just wire in a microdimmer at the fixture itself rather than in the wall gang.
is this true, and if so can someone point me to a guide on how to do it?
There has to be a neutral on the circuit somewhere. There is often one at the light fixture. This is why many people do use one of the micros at the fixture rather than at the wall switch. So that’s quite a common solution, you’ll find much discussion of it in the forums.
If there’s no neutral at the fixture, again there has to be one on the circuit somewhere. So it may be possible to find one of the junction box or someplace else and use that.
As to exactly how to use it, the wiring varies somewhat by model, so you have to start with specifying the model.
When the microdimmer is installed in the box it is usually connected to constant power and the dumb switch is connected to the microdimmer as an auxiliary switch. This way the fixture/microdimmer can be turned on/off with the wall switch as well as remotely.
Usually the wall switches turn the fixture on and off. If you install the microdimmer in the fixture you need to leave the wall switch in the ON position to be able to control the microdimmer remotely. So, yes, it works but with limitations - if you turn off the wall switch you can turn on the microdimmer remotely.
No neutral at the fixture is very odd unless it’s a very old house using knob and tube wiring.
There are four basic options for the switchbox that doesn’t have a neutral.
Bring in an electrician and have them “fish up” a neutral from somewhere else on the circuit. This won’t work if you have knob and tube wiring, but otherwise it will.
use one of the Z wave switches that doesn’t require a neutral. However, this will probably only work with incandescent bulbs, GE used to make some of these switches, but they are hard to find now. Cooper still makes one.
See the following thread for some of the issues:
And specific model links:
Use a smart bulb and cover the existing switch with a battery-operated " smart switch cover". This is a “no wiring” solution.
use a Lutron Caseta switch and get indirect integration through IFTTT. The switch will work fine as a wall switch. Scheduling lights at specific times will work fine. Issuing an “all off” Comand should work fine. However, IFTTT does introduce additional lag which would be noticeable for things like having a motion sensor turn on the light.
So you do have options, just depends on which direction you want to go.
Ok opened up my fixture and I’ve got a green (ground), white (neutral), and a black (hot). It’s two can lights (probably in series, i havent opened the second) a single switch. If they’re in series I just need to wire the dimmer in before it goes into the first of the two cans in series right?