LED Lamps flicker when OFF

Status
Not open for further replies.
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Similar situation to another thread but in this case, LED lamps are installed in can lights in a mobile home. Lamps are OFF, bedroom or bath exhaust fan turns on and LED lamps flicker for a second then remain off. Neutral connections are good. Any ideas ??
 
Neutral connections are good, but are they mixed in the circuits?
All bets are off on a mobile home!

I have had a bath fan cause an LED to flicker, but not just another switch. There is just enough neutral bleed-off from somewhere causing the LED to energize. It doesn't take much to do this. Try putting an incandescent bulb in at one of the LED locations and see what that does.
 
Little Bill said:
I have had a bath fan cause an LED to flicker, but not just another switch. There is just enough neutral bleed-off from somewhere causing the LED to energize. It doesn't take much to do this. Try putting an incandescent bulb in at one of the LED locations and see what that does.
Click to expand...

I agree with trying an incandescent bulb.
When the light switch is open, if there's capacitance between the switched hot conductor going to the light and the switched hot going to the bath fan, then that could bleed enough current to cause LED bulbs to flicker. An incandescent bulb will have a relatively low impedance and will shunt this leakage current to the neutral.
 
My Guess, and I've read plenty of these is that the power to this circuit / lights does not
originate at the switch. There is enough EMF field to build up in the LED to have a visual release as the power goes by,
beside the fact that the positive side of any diode is still sitting on the hot + wire - it gets excited and it releases.

Not to mention poor design of circuitry and minimal material to get products out to the street.

At night I have a kitchen sink light that has a slight glow and haven't even investigated my own theory!

There are ten different types of Diodes (if one cares to read up - https://byjus.com/physics/diodes)


LED
noun
  1. a light-emitting diode (a semiconductor diode which glows when a voltage is applied).
    "light sources can be fluorescent tubes, optical fibers, or LEDs"


 
augie47 said:
Similar situation to another thread but in this case, LED lamps are installed in can lights in a mobile home. Lamps are OFF, bedroom or bath exhaust fan turns on and LED lamps flicker for a second then remain off. Neutral connections are good. Any ideas ??
Click to expand...
I have had this happen before on a stairway LED when I had lit 3 way switch handles at top and bottom of steps. This was on a new house being built. I had the option of changing the fixture to an incandescent fixture which I did. Didn’t want complaints from home buyer about light flickering occasionally. Did not have a problem after I changed to incandescent fixture!
 
We have LED lights in our house. I haven't had a problem. Going back a few years (1992 ish) we got a project in a cement works. The chief engineer wanted use to LED pilot lights. We accepted - they significantly more were more the regular incandescent but in the context of the size the project of the project I agreed - not worth haggling over it. I retired at 68. At that point the LEDs no failures.
 
It takes so little energy to make an LED light up, that induction from adjacent parallel wires is sometimes enough to do it on some LED driver designs. When that happens, it's difficult to solve.
 
Jraef said:
It takes so little energy to make an LED light up, that induction from adjacent parallel wires is sometimes enough to do it on some LED driver designs. When that happens, it's difficult to solve.
Click to expand...
Maybe we do it differently.
 
Status
Not open for further replies.
Top