Why do my LED bulbs dim and/or retain power

[lardy1]

My wife replaced part of the bulbs in a set of light fixtures with led and kept some of the old bulbs in place. These are 3 bulb fixtures switched by s timer switch. When I remove a conventional bulb the led's remaining will dim. If I disconnect through the switch, the bulbs glow dimly.

I'm a sailor and a wood butcher. I can do basic residential wiring but this has me confused.

 

[mogandave]

N & L reversed maybe?

 

[Lassen Forge]

N & L reversed maybe?

Or maybe switched around in the fixture - - some of the "center taps" are hot, others are neutral, or vice versa... our old 1930's house (all knob and tube) had some *extremely* creative electrical wiring... since LED bulbs are generally monodirectional, if they're getting back voltage they can do some mighty strange things...

Wait until the LED bulbs near the end of their service life (which, I will warn you, is nowhere near the 12,000 hours promised) and they turn gray, and only light up after you've kshut off the switch. Spooky, that! (That, or our bathroom light fixture was haunted!)

 

[kaymccampbell]

Sounds like some of the sockets are inadvertently daisy chained, or you have two sources of power, or loose bad grounds, or you're grounding through a bulb, or dog knows what else. If I had a haunted fixture like that, I'd rewire it. Remember, the bumpy/ribbed side of the zip wire is neutral. And neutral goes to the outer shell of the light sockets

 

[David Paul]

Do a goggle search on “led bulb dim after turning off” or something similar. Several reasons the bulbs remain dim even when turned off. The main reason being poor quality led bulbs.

 

[CoogarXR]

My wife replaced part of the bulbs in a set of light fixtures with led and kept some of the old bulbs in place. These are 3 bulb fixtures switched by s timer switch. When I remove a conventional bulb the led's remaining will dim. If I disconnect through the switch, the bulbs glow dimly.

I'm a sailor and a wood butcher. I can do basic residential wiring but this has me confused.

Many "fancy" switches (timers, occupancy sensors, etc) that are connected inline (hot - switch - lamp - neutral) will pull a small current through the lamp. This was fine back in incandescent days, since it was nowhere near enough current to make a filament glow. LEDs use very little current, so they will glow faintly in these situations.

The solution (provided this is your problem) is to find a timer that has a neutral connection so it won't pull it's timer power through the lamp. You could test this theory by temporarily replacing the timer with a normal wall switch. If the lamps don't glow in the off position, bingo. If they do, then you have another wiring issue.

 

[lardy1]

I'm leaning towards timer. I haven't had time for it yet but I'll start by eliminating the timer which isn't necessary anyway.

Thanks everyone.

 

[Innovate1]

It's likely leakage current through the timer/dimmer. If you can keep one old style bulb in place that will keep the others from glowing when off. Or replace the control.

 

[theoldwizard1]

Inexpensive LED "shop light" don't like cold. When it is below freezing, some are slow to start. Others blink.

 

[kbuhagiar]

Inexpensive LED "shop light" don't like cold. When it is below freezing, some are slow to start. Others blink.

I guess I must be living right then, lol!

Going on seven years with Costco/Feit LED fixtures (total of 28) in both of my garages at my house in Sonora CA.

Zero problems yet.

Admittedly it only gets below freezing nine or ten times out of the year, but at those temps they performed flawlessly.

I will admit to finding a defective fixture during testing (before installation) which Costco readily replaced.
I also have two spare fixtures in storage.

 

[Lassen Forge]

the bumpy/ribbed side of the zip wire is neutral. And neutral goes to the outer shell of the light sockets

Damn, I never knew that - I thought it was to designate the hot side, not the neutral side... Fortunately (for me, anyway) the lamps I rewired were done correctly (except for that) - I'm glad modern plugs are polarized.

BTW - they're NOT polarized in Italy - they can go in either way (3 pins in a row), usually you find out when you feel the telltale "fuzz" on the back of your hand if you brush it against the metal parts of whatever and turn it around (a trick I learned as a kid, before there WERE such things as polarized plugs!!)...

 

[wyliesdiesels]

Sounds like some of the sockets are inadvertently daisy chained, or you have two sources of power, or loose bad grounds, or you're grounding through a bulb, or dog knows what else. If I had a haunted fixture like that, I'd rewire it. Remember, the bumpy/ribbed side of the zip wire is neutral. And neutral goes to the outer shell of the light sockets

umm the ground wire should have nothing to do with it. under normal operation a ground wire carries zero current. the ground wire is for carrying FAULT current.

 

[kaymccampbell]

umm the ground wire should have nothing to do with it. under normal operation a ground wire carries zero current. the ground wire is for carrying FAULT current.

I meant neutral. What can I say, old fingers type the bad things old brains garble.

 

[kaymccampbell]

umm the ground wire should have nothing to do with it. under normal operation a ground wire carries zero current. the ground wire is for carrying FAULT current.

I forgot to mention one wire light fixtures. In the day, with many knob n tube installations, ground and neutral were the same thing, and many light fixtures depended on friction fits and the metal carcass of the fixture to provide ground/neutral and there was only the hot wire to the sockets.
Turn on the lights, have it be dim/blinky, touch the fixture wrong, and get lit up for free. Especially swinging or chained fixtures. You learned to poke those with a stick. Though I did own a one wire torchiere, with a poor ground connection.

 

[wyliesdiesels]

I forgot to mention one wire light fixtures. In the day, with many knob n tube installations, ground and neutral were the same thing, and many light fixtures depended on friction fits and the metal carcass of the fixture to provide ground/neutral and there was only the hot wire to the sockets.
Turn on the lights, have it be dim/blinky, touch the fixture wrong, and get lit up for free. Especially swinging or chained fixtures. You learned to poke those with a stick. Though I did own a one wire torchiere, with a poor ground connection.

nope they werent the same thing. an EGC was and never is a grounded conductor.

 

[gtae07]

We had a lighted switch at the top of the stairs years ago. When I changed everything to LEDs they stayed dimly lit. Changed the switch to something else and it stopped.

 

[lardy1]

We had a lighted switch at the top of the stairs years ago. When I changed everything to LEDs they stayed dimly lit. Changed the switch to something else and it stopped.

I haven't had time for it yet but I believe that's the issue. Digital timer on the switch.

 

[Innovate1]

umm the ground wire should have nothing to do with it. under normal operation a ground wire carries zero current. the ground wire is for carrying FAULT current.

That's not exactly correct - it carries ALMOST zero current. Not sure if the leakage would be enough to cause an LED to glow and not saying that's the case here. There is some stray (unintended) capacitance in products (motors are one example where it might be higher than other products) and many products contain EMI filters that cause small currents in the ground wire. The limit is around 3-5 mA.

 

[Crazyjake8493]

Inexpensive LED "shop light" don't like cold. When it is below freezing, some are slow to start. Others blink.

Sounds like a bigger issue with the light. A properly functioning LED should have no trouble starting at below freezing temperatures. Replace it.

 

[My Old Tools]

I guess I must be living right then, lol!

Going on seven years with Costco/Feit LED fixtures (total of 28) in both of my garages at my house in Sonora CA.

Zero problems yet.

Admittedly it only gets below freezing nine or ten times out of the year, but at those temps they performed flawlessly.

I will admit to finding a defective fixture during testing (before installation) which Costco readily replaced.
I also have two spare fixtures in storage.

me too

 

[lardy1]

I have a dozen WalMart HyperTough LED lights in my shop. They were cheap. They pop and crack. But they work without a problem. I think I paid like $17.00 apiece for them.

 

[arrowhead]

It's possible the cheap bulbs are being lit by natural capacitance in the house wiring.

 

[lardy1]

I replaced the timer with a switch. It works fine now.

Thanks for all the help.