LED upgrade: flickering bulbs

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  #1  
Old 10-13-15, 12:13 PM
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LED upgrade: flickering bulbs

We are slowly upgrading to LEDs in our house. Yesterday we replaced three lights above our kitchen island. We put in BR30 Floods, 5000K daylight, Leds. These lights are operated by a three way switch. When we switch it off with say #1 switch they go off as normal, i.e. they get dim and then shut off. When we switch off with #2 switch, they dim, flicker/pulse slowly but never fully shut off. I assume we have a faulty 3 way switch that is letting some current through, enough to partially energize the bulbs. I am fairly familiar with AC but am not quite sure where to start diagnosing this problem. Thanks for your help.
 
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Old 10-13-15, 12:19 PM
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I wonder if the switch is switching the neutral instead of the hot conductor.
 
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Old 10-13-15, 02:26 PM
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OK Where to start? These 3 ways are Pass and Seymour switches. The kitchen switch common is blk(upper right), lower left is red and lower right is blk.

The hall switch common is white(upper right), lower left is blk and lower right is red.

Switched one way readings are:Kitchen Rd-Com/Blk 104v, Rd-Blk 104v, Com/Blk-Blk .003v Hall Blk-Com/Rd 104v, Blk-Rd 104v, Com/wht-Blk .006v

Switched the other way: Kitchen Rd-Com/Blk .003v, Blk-Red 97v, Com/Blk-Blk 97v Hall Blk-Com/Wht .006v, Blk-Rd 97v, Com/Wht-Blk 97v

Hope this is understandable!
 
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Old 10-13-15, 03:12 PM
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Either your meter has a problem or your wiring or house voltage has a problem. Test the meter at a known working location to see if you get something near 120 volts.

Question, when you replaced the bulbs, I assume you did not change any wiring? Correct?

Bud
Note, the common on the 3-way switch is not a neutral. The white wire tucked in the back is the neutral or the bare copper goes to the same place.
 

Last edited by Bud9051; 10-13-15 at 03:15 PM. Reason: addition
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Old 10-13-15, 03:14 PM
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Measuring voltages at the switch really doesn't tell us much and you seem to be using a digital meter which can show false readings. A three way switch has two travelers and one common. Location of these on the switch will vary with manufacturer and there is no standard wire color code.

Sound like a slight voltage leak at one switch. Replace the switch with a good quality switch. When replacing mark the common wire and besure it goes to the odd color screw on the new switch wherever it is located on the switch (travelers are interchangeable).
 
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Old 10-13-15, 10:11 PM
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You need to measure the voltage at one of the light sockets.

Remove only one bulb and make your tests.
Remove a second bulb and put in any incandescent bulb and measure again.

See if two LED bulbs flicker with the incandescent bulb.
 
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Old 10-14-15, 06:15 AM
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Are the switches the illuminated type? If not, you have enough capacitive current from traveler to the hot to cause enough current to light the led's. THe very easiest fix is to replace one LED with an incandescent.
 
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Old 10-14-15, 06:56 AM
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I also find it much easier to work with an old fashioned analog meter that has a needle that swings back and forth. They are much less susceptible to reporting phantom voltages/current.
 
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Old 10-14-15, 08:02 AM
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@telcom guy "If not, you have enough capacitive current from traveler to the hot to cause enough current to light the leds." Although I have wondered about this I have not found it being discussed nor any possible solution. If indeed the proximity of the conductors twisted together in a 3-wire cable are contributing to this, would it help to run 2 two conductors and find a working combination. Two conductor wire is also not twisted and has the ground located in between.

The pros will tell me if this would be allowed by code.

Bud
 
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Old 10-14-15, 08:27 AM
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@telcom guy "If not, you have enough capacitive current from traveler to the hot to cause enough current to light the leds." Although I have wondered about this I have not found it being discussed nor any possible solution. If indeed the proximity of the conductors twisted together in a 3-wire cable are contributing to this, would it help to run 2 two conductors and find a working combination. Two conductor wire is also not twisted and has the ground located in between.

The pros will tell me if this would be allowed by code.
Actually, lots of ways to fix the issue, but not so many EASY ways. I would put the replacement of home wiring in the not easy category. But, yes, tight physical coupling exacerbates this coupling effect. It is also against code to NOT run related current carrying conductors in the same wireway.

Electronically, you could load the fixture with a fixed capacitor. This would shunt the leakage current away from the LED's. A lot easier to put in a line rated capacitor at one of the devices, but this is still beyond "easy" for most homeowners. Many of the variable speed ceiling fan manufacturers use capacitors near the pull switch for speed control.
 
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Old 10-14-15, 12:15 PM
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Going to try and answer as much as I can. Voltage tests at about 122 at the outlets. Did not change anything else except change bulbs. Removed one bulb and voltage is 122.2 v. removing another and replacing with incandescent, voltage is 122.4v. Can't see glowing/flickering in daylight so that will have to wait until dark. What rating of a capacitor inline are we talking about and how to install? Thanks
 
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Old 10-14-15, 02:42 PM
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Ceiling Fan Capacitor CBB61 4uf 450VAC 2 Wire 50/60Hz - Walmart.com

UL rated, 450V rated, can't beat the price, shipped. Can install in any ONE of the fixtures.

Installed in parallel with the lamp, not series.

ps; May not work with some dimmers.
 
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Old 10-14-15, 03:18 PM
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lahoyer: Let us know if this works as the flicker problem seems to be common.

telcom guy: There are wireless controls that place a relay at the light. Now, I don't know what might be available at a reasonable price, but a relay activated by the 3-way power would remove the long traveler when powered off. Having the two travelers tightly wrapped around with the power feed is probably the worst possible configuration.

Bud
 
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Old 10-14-15, 03:37 PM
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Ok. I didn't answer the illuminated switch question. They are not. I'd rather not replace one LED with and incandescent so, is it the consensus that the capacitor is the best idea?
 
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Old 10-14-15, 04:53 PM
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It's certainly worth a try.
 
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Old 10-14-15, 06:45 PM
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Well it's dark. I duplicated the glowing LED but not the flickering. With the circuit off, I removed one LED, replaced it with an incandescent and when turned back on- no glow. Replacing the bulb with the LED restores the glowing situation. Going to order a capacitor. Will report later. Thanks
 
  #17  
Old 10-29-15, 05:57 PM
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Well, I received the capacitor today, finally!! Installed it as suggested and it must be working :-) Haven't been able to duplicate the issues that I first wrote about. Thanks for all you suggestions!
 
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Old 10-29-15, 06:54 PM
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Thanks for letting us know what worked.
 
  #19  
Old 10-29-15, 09:24 PM
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Just curious, where did you attach the capacitor, across the lights?

Bud
 
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