LED lighting don't fully turn off without single pole switch?!

Thread Starter

pmd34

Joined Feb 22, 2014
520
I have a couple of LED ceiling lights - some mains powered LED strips, and (in a different location) a floodlight - one of these:
https://www.ledvance.com/profession...aires/floodlights/floodlight-asymmetric-c8949

They are switched with separate single pole (mechanical) light switches, however even when they are switched off, there is still a faint glimmer coming from the LEDs themselves. The LEDs strips also actually give off a slight hum.
It seems the only way to completely switch them off is to use a double pole switch - switching both the live and neutral. This kills them dead, no hum, and no glow, but it seems a bit over the top, and means a cant have a double switch in one location.

The main circuit in both cases has an earth leakage circuit breaker, and electronic fuse circuit breakers.

Just to answer some comments I saw on a similar post on the net, these LEDs seem to genuinely have a tiny amount of power, even when one of the mains connections is physically disconnected, its not fluorescence or a discharging capacitor...

So whats going on?!
 
Last edited:

Externet

Joined Nov 29, 2005
1,706
Nothing magical, very common weird behavior when the AC lines in the house circuits/conduits/wiring behave capacitive. The few picofarads between live conductors and the LED feed pass a tiny, tiny current enough to be visible as faint light in darkness. Have it in a couple of places in my house; a two way circuit aisle lamp and a night light do it.
 

MisterBill2

Joined Jan 23, 2018
9,792
If the mains power is 120 volts you can try connecting a resistance across the LED lights. I think that 6200 ohms was used at ome time. For a 220 volt system I would start wit perhaps 15,000 ohms.
Of course this does waste a bit of power when the lights are on, so you also need to consider how important it is to switch them off completely. In addition, you should verify that your switch does not have some sort of shunt impedance or illumination device that adds leakage current. Do the lights go dark when you physically disconnect the switch?
 
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