I have a light fixture in our laundry room that has been using two regular 60 Watt lights bulbs for years. The bulbs burned out and I replaced both of them with 60 Watt Sylvania Ultra LED 60W replacement. It actually uses 9W according to the package. They are also dimmable.
With the regular bulbs, if there was motion it would turn the lights on. After it timed out from no motion, the lights turned off. The standard motion sensor lights you come to expect.
With the LED bulbs, the lights stay on all the time dimmed very low. When motion is detected, the lights brighten up. If I use the manual off switch for the lights, there is no light. But when it is in “auto” the lights are dimmed all the time even though there is no motion.
I don’t understand this. With the regular light bulbs it never did this.
Why is it doing this with LED lights, but wasn’t with the regular 60 Watts light bulbs?
Do motion sensor light switches normally supply power to the light bulbs even with they don’t detect motion? In other words, is this simply how they work and I’m only seeing the dim lights because the LEDs are more sensitive to lower voltage than the regular light bulbs?
disclaimer: not an electrician, just someone who’s used a lot of LEDs
Dimmable LED bulbs don’t work the same way as dimmable incandescents. Usually they want to be paired (ideally) with a LED dimmer designated compatible with that specific kind of bulb and by the same manufacturer, or at the very least, at least a dimmer designed for LEDs. (Read more: http://luxreview.com/article/2016/02/10-things-you-must-know-before-you-dim-led-lamps)
You can:
Try to find a LED compatible with your existing dimmer (difficult)
Replace your motion sensing dimmer switch with one compatible with your LED (probably expensive and will be obsolete in a few years)
Replace the dimmer with a regular switch and use a motion-sensitive LED bulb (probably the cheapest and most modular solution)
This is not a dimmer switch. It is a motion sensor light switch. It has three positions for the switch. ON, OFF or Auto. Auto senses motion and turns the light on, and after a time-out of no motion it turned the light off.
same thing, replace the motion sensor with a modern one compatible with LEDs, or replace it with a regular switch and use a LED with built-in motion sensing
I don’t know much about the characteristics of the power circuits in an LED light bulb, but I can’t think of a reason the LEDs would get power from the motion-sensor switch when the incandescents didn’t. My guess is that the motion-sensor switch is still letting some current through even when it’s ‘off’, with either type of bulb. But that small current isn’t enough power to noticeably light up the incandescents, but is enough to dimly light the LEDs (which need a lot less power for the same amount of light).
So I don’t think you’re any better off with the incandescents, unless for some reason you really want it absolutely dark when you’re not in there. You’re still using less power with the LEDs. You could replace the motion-sensor switch with a new one that presumably doesn’t leak at all, but unless the dim light is an issue, no hurry.
Your motion sensor switch likely uses a triac (or two SCRs) as a switch. When the triac is “off,” it isn’t really off… it is high resistance. For an incandescent bulb, this isn’t a problem due to the low impedance of the bulb, especially when the voltage at the bulb is low. An LED bulb has significantly more impedance at low voltage. When the triac is “off,” the resistance of the triac - though high - is low enough to keep the LED somewhat powered.
One solution is to replace the motion sensor switch with a sensor switch that uses a mechanical relay as the switching element, not a triac. The other solution is to go back to incandescent. (Because it’s a laundry room, and thus the light is not on very often, you’re probably not saving much money by installing LEDs.) And yet another solution, of course, is to simply ignore the fact the LEDs are dim when “off.”
Or just accept the situation as it is: You now effectively have a light in the laundry room that turns on when you’re in there, plus a nightlight so you don’t stub your toe when you first step in. The power consumption of your bulb in “dim” mode would be completely negligible.
Remember, the motion sensing “switch” is a solid state switching device. They can bleed small amounts of current.
I have found that replacing incandescent lights with LEDs can produce just about any effect you can imagine. I use several X10 modules to control outside lights. I recently tried replacing the 3 regular lights on one circuit with LEDs. With one LED, things are OK, normal operation. With 2 LEDs, all 3 lights slowly ramp up and down in brightness, no control. With all 3 replaced, lights are off until you turn them on once, then they stay on all the time with no control. The effects of the last two configurations might be reversed, it was a month ago.
I replaced one bulb out of 4 in a bedroom with an LED. It dimmed in a very jerky fashion, going to discrete levels rather then a continuous ramp. At about half brightness it just went off. I replaced that dimmer with an LED compatible version and things were OK.
I think this further proves the point that in general LEDs are not ready for prime time. They aren’t simply plug n’ play replacements for regular lightbulbs. I feel the marketing of these has glossed over the requirements for the light fixtures and switches they would be used with. I used some LED 100 Watt replacements that had such a terrible buzzing sound, I returned them and bought another company’s LEDs and while they didn’t have the buzzing sound they flickered.
My guess is that when your LED switch is fully OFF, there is an air gap relay that provides a true “off” in the sense that it completely cuts power to the bulb. When it is in the sensing position there is a solid state circuit doing the switching. This circuit is not fully compatible with the LED bulb, most likely it’s a minimum load issue, the circuit just isn’t going to work properly with a load of less than 25 Watts.
BTW, I’m a professional dimming specialist.
And although this isn’t a dimming issue, if you use a lot of LED bulbs you might be interested in this tool we use to match dimmers to LED’s.
Well, yes and no. Yes, in the sense that when a new item comes to market that relies on other things, they both have to roll out at the same time. If I invented a light bulb that ran on store bought fuel cells and could light a room for a tenth the cost of LEDs, but no stores stocked the fuel cells, that would be the same thing. We saw this with CNG cars. It was/is very hard to find gas stations that have CNG and, personally, I’ve never, ever seen a charging station for an electric car (but I have been seeing more and more Teslas around). In this case, it’s simply a matter of light bulbs progressing, but you’re using with, lets call it ‘obsolete’ hardware. No one promised they were backward compatible. I’m sure they could add something to the chip to sense that a dimmer is set below a certain level and cut power to the bulb, but then everyone is paying because a small handful of people need it. It’s easier, for the greater good, for those people to upgrade their dimmers.
Yes. However, if the dimmer is cutting the voltage, you may need a sensitive meter. If you touch the wires and your autosensing DMM reads .19V, is that nothing or is it leaking past the dimmer. OTOH, I’ve been bitten by wires I thought were off and it was just that the dimmer was all the way down. Yet another reason I always test all the wires (neutral, ground, everything).
If you’re serious, I’ve got a question. I’m in the middle of swapping over all my florescent tubes to LED tubes*. It’s going to be about 75-100 of them or so. One thing I noticed as that when compressor (think reach in cooler, RTU for large deli case) kicks on, they’ll blink for just a split second.
My WAG is that the voltage is falling below a threshold and it’s shutting off whereas the fluorescent tubes and ballasts would just ever so slightly dim and it wouldn’t be (as) noticeable.
I buy these from my ‘light guy’ and asked him. He hadn’t heard of it, but he was going to ask his Eiko rep and see what they say. I figure if ‘it’s not a thing’, at the very least if other people mention it as well, I’ll be another data point.
*FYI a troffer with 4 48inch T8 bulbs runs at .79amps. The same one with the ballast removed and 4 LED tubes is .42amps. I was hoping for better, but that’s still huge. A bulb on 24 hours a day at 10¢/kWh (to make the math easy) is saving about 75¢/month. Which confirms that they’ll pay for themselves in less than a year. Plus the bonus of not having to replace ballasts and not adding heat to refrigerated cases.
Oh, and just for kicks, I ran 120 into the pins on a regular floruscent bulb. It did not explode and take out half a city block like everyone seems to think. It light up and burned out very quickly. I wouldn’t recommend, but I stopped making bright flashy warning labels for each fixture as a I swap them.
Correct; if you remove both bulbs and measure the voltage at one of the sockets, the meter will show a non-zero voltage. The voltage value reported by the meter will depend on the off resistance of the triac and input resistance of your voltmeter. (Both resistances form a voltage divider.) It’s important to note, however, that the voltage will likely be less than this value when an LED bulb is installed, because the resistance of the bulb is probably less than the input resistance of your voltmeter.
I am serious, although I don’t really work on any commercial/ industrial applications. I specialize in high end residences with an occasional foray into restaurants and country clubs.
But it does sound like an in-rush issue to me, even though you are using much less power than you did before. Those tubes have some sort of driver (transformer) built into them, the LEDs themselves aren’t running at 120v. My educated guess is the drop in voltage is causing a corresponding spike in amperage, and in that moment you are overloading the driver.
Also, it would be hard to evaluate until you have changed out an entire switch leg worth of tubes. Because if you still have fluorescents in the mix they could be causing some sort of interference that affects the whole circuit. It’s probably unlikely, given your description- and that type of interference is more likely in dimming applications which are much trickier.
And it is very common to get “bitten”, as it were, when you are working with dimmers and electronic switches. Because you can turn the circuit off and it will test at 0v, but those devices require resistance to work. But as soon as you remove the load, you’ll get 120v. That why you have to cut the power instead of turning off the light at the dimmer or switch.
Another possibility is that the motion detector is bleeding electricity through the light bulbs in order to operate. Unlike a dumb light switch any sort of electronic switch itself needs electricity to operate. You of course have a hot wire available, but often there’s no neutral at a light switch location, so you bleed electricity through the bulbs to complete the circuit. This is small enough to not light an incandescent lamp, but all bets are off with LEDs. The way to tell if this is the case is if the motion sensor has no white neutral wire, just a black for line and probably a red for load
The problem of retrofitting electronic controls into switch loops was enough of an issue new electrical code requires a neutral at all switch locations to end it going forward. For a while it was permissible to use the equipment ground as a neutral for electronic switches, but this is no longer the case.
Yes, there is a reason to hurry. (Besides the annoying flicker.) Those LED lights will soon die. They are being used improperly, and are constantly attempting to turn on, but unable to fully do so. Thus flickering, overheating the electronics, and putting premature wear on the light. They will soon burn out.
I had a similar situation with a lighted on-off switch. It contained a small neon bulb in the switch handle, and allowed enough current to flow through the circuit to light the neon in the switch, but not to produce any light from the incandescent bulb in the ceiling. But a CFL or LED bulb was sensitive to light up dimly or to flicker from that small amount of current. And that caused those bulbs to wear out prematurely.
I was never able to find any CFL’s that would work, but eventually I found LED’s that work OK in this situation – the switch is still lighted, but the LED bulb isn’t until you turn the switch on. It was just trial & error to find one, though. Maybe dimmable LEDs are more likely.
Unless you’re switching the neutral, I don’t see how what you describe here would cause current flow in the fixture due to an illuminated switch or pilot light. In this circumstance, I’m not sure the internal lamp would even illuminate. Properly wired illuminated switches will still glow even with the switch(ed) loop (fixture) wires physically disconnected. The tiny internal illumination circuit isn’t in series with the fixture, it’s in parallel.
Am I missing something?