LED blubs staying on.

Discussion in 'Electricians' Talk' started by boarder, Mar 16, 2012.

  1. boarder

    boarder New Member

    Hi,

    I have replaced the 8, 40w Candle bulbs in a light fitting with equivalent 1w LED bulbs. However when I now switch them off they remain on, not fully on but sort of glowing as if they had been dimmed.
    There is no dimmer involved and the 40w bulbs worked fine before.

    I have tried the one of the bulbs in a lamp and it works fine, going completely off almost immediately after switching it off.

    Any ideas on why this should happen and how to resolve it

    Thanks
     
  2. J.P.

    J.P. New Member

    DP switching will cure it Mr B.
     
  3. wally

    wally Screwfix Select

    I thought it was normal, my xmas tree led lights do the same.   How long are you talking about, i guess less than a minute.   Think about it JP, why should double pole switching alter it.
     
  4. snezza31

    snezza31 New Member

    I had exactly the same problem with some GU10 fittings. I changed standard lamps for Led replacements about 6 months ago. They glowed permanently, even after the light switch had been off for hours.  I never found the reason why.
     
  5. Lokkars Daisy

    Lokkars Daisy New Member

    The led lights require so little current to operate that if there is any induced current or leakage within the circuit then they will try to operate.
    Replace one of the lamps with the original halogen lamp, it will drain away any induced currents and the leds should go completely out
     
  6. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    Test with a new switch, I would try first.


    Mr. HandyAndy - Really
     
  7. Dale76uk

    Dale76uk Guest

    Daisy's right! I've had the same issue years ago.  Whack a halogen in one and they all fade away!
     
  8. GeorgeT

    GeorgeT New Member

    If the gap between the contacts on the switch is small then it will act like a capacitor and since AC current can flow through a capacitor then the switch doesn't turn completely off. With a normal bulb the light is not bright enough to see although some fluorescents will glow slightly in a dark room. With an LED light it only needs a small current to be fully on and hence the problem. Using a switch with a larger gap or using a DP switch as JP suggested should solve the problem.  
     
  9. wally

    wally Screwfix Select

    I thought switches had a minimum 3mm gap when open
     
  10. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    I once had reason to suspect the electrical 'grease' inside some switches, having become inductive through small particles of copper worn from the contacts over the years contaminating the grease.


    Mr. HandyAndy - Really
     
  11. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    ?????Where'd 'e go ?
     
  12. Mr. Handyandy

    Mr. Handyandy Screwfix Select

  13. removed 7

    removed 7 New Member

    George T:  That isn't the best post you've made here, dear.  It shows a complete ignorance of the nature of Capacitance and a lack of knowledge of switches in general......




    I strongly suspect that this might be a 2-way lighting circuit.  LED's and certain CFL's are prone to induced charges in the strapping wires between the switches.


    Lucia
     
  14. J.P.

    J.P. New Member

    Dunno Wal - should have mentioned loop in box tbqh as DP switching on loop in rose would be ridiculous. Just put up with the glow and stuff Mr B - flipping heck its only an auxiliary  aurora.
     
  15. boarder

    boarder New Member

    Hi,

    The light in question is at the top of the stairs and in a 3 way lighting circuit. Replacing one of the bulbs with a halogen does switch all the bulbs off which is a solution but not very pleasing to the eye as the bulbs are all visible and the odd one sticks out.

    Will changing the switches have any effect then ? If it would what make is most likely to help ?

    Thanks
     
  16. Lokkars Daisy

    Lokkars Daisy New Member

    Changing the switches won't make any difference unless they are contaminated and tracking is taking place , very much doubt it. It's only a faint glow isn't it,, just put up with it, look upon it as a sort of night light.  You could probably fit a bleed resistor inside the switch,,,but that's just complicating stuff
     
  17. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    ....but a possibility (and cheapest fix if it is, not much lost if it isn't)!


    Mr. HandyAndy - Really
     

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