What could cause flashing LED lights when other LED lights in a different room are turned on?

Question

I have the same problem and I'm pretty certain it's NOT related to bad switches - let me explain.

We have LUTRON switches through the house. All was fine. We then had a minor 2nd floor renovation creating my wife's walk-in closet. LED's were installed in the closet. In the kitchen on the 1st floor which never had any issues, we always had LED's. We started noticing the lights in the kitchen would go on/off with 1/2 second intervals - couldn't figure it out. The renovation occurred during the summer so we didn't connect the lighting issue with the renovation because, being in a northern climate, it was bright and the lights weren't needed. We then realized in the winter that whenever the lights in the walk-in came on, that's when the on/off occurred. I would add that its NOT a flicker - definite on/off; I would also note that the walk-in switch is a sensor switch.

We were just living with it. Then we created a media closet - I screwed in LED bulb - then all of a sudden the LED pot lights in the adjoining hall started to do the same thing! Off/on. I switched the media closet light back to incandescent and the problem ceased. I would add that the media closet switch is also LUTRON sensor.

Q: Any thoughts? We have a few sensor switches as well as regular touch switches and LED for all pot lights though some fixtures are regular halogen/incandescent.

Answer 1

Some LEDs with switching power supplies demand power in pulses, which can get coupled back onto the power line as small surges. If you have bulbs which are making that demand at different frequencies, and the current available is a bit marginal, this can sometimes make one or more take longer to charge than they should and cause flashing.

I have a chandelier which takes 16 bulbs, which is something of a worst case since they are all trying to draw power through the same ten-foot lamp cord and am using a dimmer to control its brightness. When ask the bulbs were identical, there was no problem. When one failed and I replaced it with a bulb that drew a tiny bit more power, some dimmer levels would cause that new bulb to flash badly. Replacing it with a bulb that drew slightly less power than the others solved the problem. I have some guesses about exactly why, but they are more detailed than I think we want to into here.

So I'd try making sure all the bulbs are identical and see if that helps.

Some folks have reported that replacing one of the bulbs with an incandescent or fluorescent may also solve the problem, since these draw power differently. Again, I have some guesses about why, but they are mostly guesses. Might be worth trying an experiment, though.

We're playing with a product that's still in the early stages of its evolution. There are likely to be a few hiccups before the manufacturers learn how to make them "as cheap as possible, but not cheaper." I am trusting/hoping that those companies are aware of this effect and will solve it eventually. Unfortunately, given the long life of LED bulbs, that may not help us early purchasers very soon.

Answer 2

Many electricians are used to installing three-way lighting systems with incandescent lights, which are forgiving. With an LED system any dimmer has to be on the load side (the lamp) and the second switch has to be on the power source side. If you think of the lighting system in simple electrical flow terms you would not consider that important, but LED dimmers work by varying pulse width, and long wire runs and other components can affect that.

Additionally, a three wire LED dimmer (typically red, black, and red/white) that relies on the neutral path through the load (the LED) may be more sensitive to wiring issues or the design of the LEDs. A four wire dimmer with an additional white wire so the neutral path for the dimmer doesn't pass through the load might be less susceptible to issues.

Answer 3

I stumbled on the solution so easy, I was stunned!!!!! If you have LED flicker, just try mixing bulb manufacturers. Even if you have a fixture with 6 bulbs in it; just replace any one of the 6 bulbs with a LED from a DIFFERENT manufacturer. It worked for me in 5 different fixtures where I was having a flickering problem.

Answer 4

Mine flicker when they are on depending on the dimmer setting of the LEDs and the dimmer settings of the incandescent lights on the same circuit. Part of the problem is noisy dimmers and part is the LEDs susceptibility to small voltage changes, outside the noisy dimmers. I just change one dimmer setting slightly and it stops; until the next time.

Answer 5

Your lights should not switch on and off or flicker. If they are not lighting consistantly then they are not working right.

A couple things I would check: They are miswired. You need to check (or have checked) the wiring for mistakes.

The power supplies for the lights are somehow interacting with each other to cause a drop in voltage at on a regular interval. You could try putting them on separate circuits if they are on the same circuit.

If all that comes to naught then I would experiment with changing the switches to a different brand or type and then change the lamps to CFL or incandescent.

It is never fun having a unique problem so I wish you luck.

Answer 6

I moved the on/off led bulb to another fixture and it is doing the same thing. Must be the bulb. This is something new I have never seen. At first I thought it was loose in the socket, but it wasn't/.