I recently had 4 hard-wired LED light fixtures installed within my cabinets as part of an office renovation. The electrician installed 1 on/off switch that controls all these light fixtures even though the LED lights themselves are dimmable (each has a maximum LED wattage of 14 W). I was hoping to switch out the on/off switch for a Red Series Dimmable switch, but I am a little confused about how to wire it given what is (or isn’t) in the existing wall switch. There is only one bundle of wires coming into the switch (line, load, neutral, copper). Currently, the neutral is in a wire nut and the line, load, copper are attached to the on/off switch. Should I be wiring the red series dimmable as a non-neutral and keep the neutral in a wire nut?
Could you post a picture? That way we can confirm the setup. You may have a switch loop.
This is a schematic of exactly what the wires look like coming into the switch (one bundle with load, line, neutral, ground).
The lights we had installed were: dweLED LED Wall Mounted Picture Light & Reviews | Perigold
Here is the owner manual for the lights: https://secure.img1-ag.wfcdn.com/dm/document/4f65cff4-1352-4d23-bb0e-9ce7f5c34492/owner%20manual
Help would be appreciated.
Something to note, the LED manual says they use ELV or TRIAC dimming, but the red series uses MOSFET (MLV). Based on my admittedly limited understanding here, I think you will likely run into issues with buzzing from the lights if you use the dimmer with these.
I did try to wire the switch to the dimmable red series switch and noted buzzing from the switch, not lights. To be honest, I don’t care about the dimmable feature, but the on/off red series switch isn’t in stock. I do have some on/off black series switches already installed in my house that I could swap out. With the current switch loop wiring, would you anticipate any issues with replacing an on/off black series switch?
If you don’t have any need to dim them, then yes I believe you’d be able to use an on/off black series switch without any issues. As far as the wiring though, I can’t speak to that personally and would defer to @harjms recommendation there.
To get a good picture, turn the breaker off and pull the existing switch out of the box to get a good look at both the wiring and what’s coming in to the box.
As long as the electrican connected the WHT wire to the neutral bundle at the light fixture, then this should be an easy install. This would not be considered a switch loop. You will want to verify the WHT wire is in fact connected to the neutral bundle at the light fixture where the box and fixture end up at. The concerns of the dimmer noise could be contributed what @chack referred to with the MOSFET.
If you use the Black Series On/Off switch, wire it this way: *Normally BLK is LINE and RED is LOAD in a typical fashion; however electricians can do their own thing and reverse the two. You can confirm when you look at the light fixture while checking neutral. If the BLK wire coming from the switch is connected to the BLK wire on the light fixture, then you’ll need to swap the RED and BLK below. If the RED wire is connected to the BLK wire on the fixture wire it as below.
BLK to LINE
RED to LOAD
WHT to NEUTRAL
GRN/BRASS to Ground
Yep, you will see this more and more now with the requirement for a neutral at the switch in a lot of cases.
It used to be common to have a switch loop where the hot and neutral started at the light. From there you would route a 2-wire to the switch box, sending just the hot (usually over the white) and returning the switched hot (usually over the black). That resulted in no neutral at the switch.
The drawing you posted is the correct way to run what I term a “modern” switch loop. Instead of using a 2-wire to the switch, you use a 3-wire. The black is the hot, the white is the neutral and the red is the switched hot. As @harjms pointed out, there is no requirement regarding color, but electricians do tend to follow conventions. If you’re using a dumb switch, the white will be capped.
You’ll find that more than likely if you measure between the black and the white using a meter, you’ll have a constant 120VAC.
Thank you all for your insight. This is very helpful. My electrician did state that the WHITE neutral wire is connected to the neutral bundle at the light fixture. I’m going to try using one of my pre-existing black on/off switches and hope that it works!