Calling electricians: Weird can lighting behavior

Factual Questions
1

Today I finally got off my ass to replace a couple of lights in our living room. We have a setup of can (recessed) lights in a 2x3 grid:



1   2

3   4

5   6

These are all dimmable lights. There are two dimmer switches, one by the entrance, one by the end of the living room.

Light 2 went out a few weeks ago, and light 4 went out maybe two days ago. This is a new house we live in (moved in two years ago), so we didn’t set up the lighting or anything like that. Since all of the lighting was incandescent, I decided to just switch out all six lights with dimmable LEDs.

I replace all the lights, turn them on. They work fine; they dim fine (though not quite as low as the incandescents). So I turn them off. After about five seconds or so, light #4 starts flickering. Huh. That’s weird. Everything is off. Only that light is flickering. So I take it out. Now light #3, right across from it, starts flickering. Weird. It’s flickering at around minimum brightness, not maximum.

I decide to put an incandescent bulb into fixture #4. As soon as it makes contact, the flickering stops. So I exchange bulb #3 with bulb #5. When I remove the incandescent bulb, after a few seconds, the bulb in fixture #5 (the one that was in #3 and flickered before) is now flickering again.

So I thought maybe it’s the bulb. So I exchanged the bulb that is in fixture #5 with the original bulb that was in fixture #4, and now when I remove the incandescent light, bulb #1 is flickering !?

Also, if I put any other LED bulb in #4, one of the lights will flicker. I tried LEDs from different rooms and even slightly different types (wattage) and only the incandescent light keeps one of the other LEDs from flickering.

What is going on here? Is it miswired? Something to do with resistance?

2

It’s your dimmer.

3

Yes, your dimmer. LED bulbs need LED bulb dimmers. There are some bulbs that claim to work with standard dimmers, but even then they don’t work as well, can shorten the bulb life, and exhibit flickering or buzzing at some dimming settings.

4

That briefly crossed my mind and now, thinking about it again, makes the most sense. Phew. That seems to be a fortunate outcome.

5

Oh, no kidding. I had no idea there were LED-specific dimmers. This is good to know! The regular dimmers work fine in the rest of the house with LED bulbs, so it never occured to me to look for LED dimmers specifically.

ETA: Actually, now that I think of it, I may very well have replaced the dimmer in my daughter’s room with an LED dimmer. The other rooms, though, just have the standard dimmer. So I guess I did know, but just forgot, which is as good as not knowing, really.

6

By the way, dimmers still need to power themselves when off and some dimmers leak that power through the bulb itself. This isn’t a big deal with incandescent bulbs because their resistance when off is minimal at low power. But LED bulbs can be so efficient that they try to turn on with that low power draw and start flickering. When you put that one incandescent bulb in, it was probably acting as the path of least resistance and making everything work.

7

Yeah, I was wondering if it might be something like that. I picked up a couple LED dimmers and we’ll see if that works.

8

I think they also have to be 3-way compatible and wired a certain way if you have two dimmers on one circuit.

9

Hmm… OK, I’m not an expert at this. Looking it up briefly, it seems like what you really need if you want two dimmers controlling the same circuit is some specialized master/slave type dimmer configuration. Apologies if i’m confusing the issue.

10

The dimmer I bought came in a 3-way pair (that is they were both sold together as a single unit), so hopefully that should be fine. We shall see. They don’t appear to be a master/slave type thing, though, just two of the same dimmer, as far as I can tell. And, geez, when did light switched get so expensive? It was a bit over fiddy bucks for that.

11

OK, yeah, I’m a moron. Turns out I was looking at the two pack, but bought two individual dimmer switches. Only after hooking them up did I realize the idiocy of that as all the bulbs were flashing unless I had both dimmers set just right. So I’m a fricking idiot. Not sure why it didn’t occur to me to think “wait, how is this supposed to work if one is set dimmed all the way down, and the other all the way up?” The old dimmer was of the special type where dim level could be controlled from either switch, and was not of the slider style dimmer like I just bought. I should have just bought the exact same type as the old one, except LED compatible (that is what the two pack was). :smack: I suppose I could just put a regular toggle switch on one side and that should also solve the problem, but then I can only control dim level from one of the switches.

Moron moron moron.

12

Dont be so hard on yourself. it can be tricky. That’s why electricians get paid so much!

mc

13

What I usually try to do in more complicated situations like this one is just to buy the same type of switch as before, and connect all the wires to the same places. Easy peasy! (Well, assuming the wiring was done properly before.)

14

Maybe this will make you feel better.

I knew a guy who was remodeling his house on the cheap. Instead of hiring professionals, he hired the barflies who had a little carpentry or electrical experience to do the work. For his living room, he bought a ceiling fan with a dimmer for the lights and three speeds for the fan. Came home after the installation to find his “electrician” had connected the fan to the rheostat and the lights to the toggle switch. So his fan blades had three speeds that could be slowed up or down, but the lights were on or off. I can still see the look on his face.

See, you’re not such a moron, right?

15

:smiley:

16

OK, so somebody go over my work here. Like I said, I managed to get the lights working, but I need to install a 3-way switch in one of the receptacles in leave the dimmer in the other.

However, the wiring here is a little different than I’m used to.

In receptacle one, there are the following wires: red, black, green, yellow, and a capped-off white.

In receptacle two, it’s just red, black, and green, with a capped off (well, looped off, in this case, red wire and a looped off white wire.) (And in both cases, the green just connects to a wire soldered to the receptacle.)

Is this a usual setup? This looks very different than the other receptacles I’ve worked on in the past. I just connected the new dimmer the same way the old dimmer was connected. But does anything about this set-up seem odd? I do have a multimeter if needed.

17

Here is a helpful guide. Note that wire colours are meaningless in this situation and you need to establish where each one goes.

18

Yeah, I saw all those various diagrams. I think I’ve got it more-or-less figured out, but I just don’t understand what the capped off wires in the receptacle are. Maybe i should just not worry about it.

The thing is, in one of my receptacles, only two of the wires are wired in (I’m not counting green/ground as one of the wires.)

So receptacle one has three wires connected to it (not counting green) and receptacle two only has two wires connected to it (not counting green.) The connection works, but I just don’t understand it given all the three-way wiring diagrams I’ve seen which all have three wires coming out of them (not counting green.)

19

A light switch is not normally referred to as a receptacle. It is a different specific device.
Terminology aside, which wires were where on your old switch. It almost sounds like there was a dimmer unit in the can light circuit. And the switches controlled power to it. Thus a standard 3-way switch circuit won’t suffice. The yellow wire is non-standard. The capped off white may just be an unused neutral. And I am not following what the looped off phrase represents.

20

Sorry, by receptical, I meant the box, not the switch.

As for “looped,” I meant that the wires, instead of being capped off, were just snipped and folded around into a loop over themselves and electrical taped off. Effectively, two wires were capped off at the second box, but not with actual caps.

Anyhow, I got it working testing it out with the multimeter and figuring out the wires. I also double checked that neutral and hot weren’t flipped and we seem to be good.