LED bulbs remain glowing when 4 way switch is off
I recently replaced a CFL bulb with a LED bulb in 1 of 2 lights fixtures that are conneceted to a 4 way switch (can be operated from 3 different switches). When I turned off the lights I noticed that the LED bulbs in both fixtures emitted a faint glow. Does anyone have a clue what is happening? Do I have a bad switch that is leaking enough power to cause this?
Thanks, Don
Replies
Most likely there is capacitive coupling in the wiring, causing voltage to "jump" from a live wire to the "dead" one that feeds to the bulbs. This is not uncommon in complex wiring (such as you have with a 4-way), and it's usually not a problem (save for a slight shock hazard).
If you remove the lamps and meter the voltage on the sockets when "off" you will see about 50v present. The simplest solution is to put back ONE of the CFLs, to "pull" the voltage down.
Thank you for the prompt reply. I understand the capacitve coupling theory. My questions are: Is it likley this has been happening since day 1 and is this power transfer likley happening in one of the switches? What about the LED bulbs causes this to manifest itself? When I change back to an incandencent or CFL is this still happening? I never saw the glow until both fixtures were using LED bulbs.
Thanks, Don
It's happening in the wires, not the switches -- it's inherent in the wire layout. And you don't see it with incandescent and CFL bulbs because they need more current before they will glow.
Well ain't that sumptin.........
in our camper I thought I was nuts or should that be, what I saw confirmed that fact.
A very slight glow from the two 12 v. led's that are operated off the coach battery with a switch as well as the vehicle battery upon door opening. With switch off and no door open a phantom glow so faint you think you're seeing things.
another reason I keep hanging on this last of the Tauntons once great forums.
It wouldn't be exactly the same mechanism in a vehicle, operating off of 12v DC. The effect that Don sees requires AC voltage.
So,
I'm nuts?
Well, that's a given.
awww.....
Give the old guy a break, likely he can't help it.. sheesh..
Interesting! Learned something new today.
I bet there is something else going on there. Are any of these switches "illuminated"? (Light up when the lamps are off)
Any thoughts on LED bulbs that continue to flicker when the switch is turned off?
There is no danger in smoldering light. The lamp will not burst in the middle of the night. The main disadvantage of the fact that LED bulbs glow when the switch is off is the rapid depletion of the illuminator. The fact is that the circuit is designed for a certain number of starts and burning times. Therefore, the light bulb becomes unusable after several months of continuous illumination in a non-standard mode. There is no danger of this problem for wiring and smart led light(https://www.amazon.com/smart-light-bulbs-wifi-bluetooth/dp/B09K38ZXYG), but the service life of LED lights will be markedly reduced if they are constantly flashing or glow dimly. Call an electrician, and he will help you with this.