I have been turning on and off an installation, including some LED PAR lights, using a digital timer switch (Brennenstuhl Primera Timer DT). It's been running since half a year or so, but recently I noticed when all lights were off and the timer was in 'auto off' position, that the LED PARs were still emitting light, just very faint so you would only see it if the room was otherwise entirely dark. I am sure this is a new behaviour, and they were not having any current initially. Question: Is this an "aging" of the relays, is it something to worry about (safety etc.)? Like, should I change the switch, or this harmless or expected behaviour.

The photo shows the situation with relatively long exposure time (the blue LEDs are from a separately connected Wifi router, so are irrelevant to the situation).

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  • Does this answer your question? LEDs stay on (very dim) when switch is off
    – isherwood
    Feb 11, 2022 at 17:22
  • @isherwood thanks, it seems related. I'm still puzzled as to the question whether the timer has always had this leakage, as it seems improbably to me that I only noticed this effect after more than half a year. Would it imply that this behaviour is "normal" then, and nothing harmful? Or could it be that the switch is in a bad shape and I should replace it.
    – 0__
    Feb 11, 2022 at 17:25
  • It's not uncommon that adding another device on the circuit changes things. Any new LEDs elsewhere on the same breaker?
    – isherwood
    Feb 11, 2022 at 17:27
  • 3
    My guess is that it's been there all along and you've just now noticed.
    – FreeMan
    Feb 11, 2022 at 18:42
  • 1
    One thing I will check next time I'm the studio, is if this is perhaps an issue with the LEDs themselves, like they started showing the leaking current when they didn't do so initially. Because I deem it fairly impossible that I simply didn't notice it before: I have to turn off all lights before leaving the room, the light switch is away from the exit, so every time I leave the studio after dawn, it be an obvious thing to notice. The relays make a tiny click, so almost certainly they must be mechanical.
    – 0__
    Feb 11, 2022 at 21:07


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