Mystery Glowing Lights

Discussion in 'Electrics UK' started by suffolkoff, 5 Jun 2019.

  1. suffolkoff

    suffolkoff

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    Hi, is there anyone who could provide a diagnosis? I have 3 LED lightbulbs in the bathroom light fitting.
    Last night all 3 were glowing... the only thing that has changed is that on that same evening I fitted a new light fitting on the landing on the same floor of the house. (LED bulbs in new fitting are not glowing). Could this be related or just a coincidence? If anyone knows I would be very grateful for an explanation- especially if it is signalling danger. Thanks!
     
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  3. bernardgreen

    bernardgreen

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    The capacitively coupled power from Live to Switched Live in the cable to the switch is enough to "glow" an LED lamp when the switch is OFF.

    A capacitor in series with a resistor across the supply to the LED will in almost all cases solve the problem. The capacitor absorbs the capacitively coupled power without the voltage being high enough to affect the LED.

    0.1 microfarad 400 volt capacitor polyester and 100 ohm 1 watt resistor have proved sucessful.

    400 volt as it has to cope with the approx 320 volt peaks of 230 v AC It cannot be an electrolytic or polarised capacitor.

    Contact suppressors such as the ones below provide the necessary circuit in a single convenient package. The use across LED lamps is not their intended purpose but they do provide the function required.

    http://uk.rs-online.com/web/p/rc-network-capacitors/0209241/

    There are other suppliers.



    Read more: https://www.diynot.com/diy/threads/led-problems.490849/#ixzz5pzhSaBwS
     
  4. suffolkoff

    suffolkoff

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    Thank you- I have had these bulbs in for months and this is the first time they have glowed since fitting the new light fitting? Is it dangerous? I don't really mind the fact that they are glowing now... I just needed to know if it's indicating a problem with the new light which is only about 3 metres away outside the bathroom LEDs.
     
  5. WhydidIstart

    WhydidIstart

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    The slight glow from LED lights caused by the capacitive coupling effect described very well by bernardgreen is not dangerous.

    If the glowing started at the exact time you fitted a new light fitting I would suggest the two are related.

    As well as the capacitive filter suggested above, some LED lamps are more susceptible to this effect than others, i.e some may glow and others may not. You could try swapping bulbs around if you don't want the glow.
     
  6. bernardgreen

    bernardgreen

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    In theory changing a different light fitting should not have any affect on other lamps unles you have changed the wiring at the new lamps. Maybe the Earth wire are no longer poperly connect, ( an earth wire can absorb some of the capacitive coupled power )
     
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  8. suffolkoff

    suffolkoff

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    I removed the new light fitting and re-attached it. Now the glowing has stopped...
     
  9. John D v2.0

    John D v2.0

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    It's a bit worrying that your house wiring may not be 100% , it's worth considering getting a full test to make sure everything is in order.
     
  10. Taylortwocities

    Taylortwocities

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    Sounds like it’s your wiring expertise at fault here.
     
  11. WhydidIstart

    WhydidIstart

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    Did any of the wires seem lose when you were removing the light fitting? As mentioned above maybe the Earth wasn't properly connected?
     
  12. suffolkoff

    suffolkoff

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    The new light fitting was one I put up to replace a previous fitting that was fitted by an electrician. He didn't seem to to comment on wiring issues.
    I would say that it was my fault because the Earth appeared to be a little loose. I replaced the old block I used with a wago. That seems to have helped.
     
  13. DIYnot Local

    DIYnot Local

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    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


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