LEDs on LE transformer/D2U not turning fully off.

Discussion in 'C-Bus Wired Hardware' started by ariddell, Apr 29, 2009.

  1. ariddell

    ariddell

    Joined:
    Apr 20, 2009
    Messages:
    58
    Likes Received:
    0
    Hi All,
    Having a bit of an issue with a new c-bus install we've just done here at home. We have a set of LED downlights attached to a transformer on a 4 channel dimmer (D2U).

    All is working great for the ON part of the equation, it's just the turning them back off bit that we are having a bit of an issue with..

    Dimming works fine, full brightness is as expected but when the channel is switched off it's staying on at a low dim level, but still very much on.

    Any ideas/advice on how to get it to switch the channel fully off? Probably doing something stupid but this is our first endeavour with c-bus.

    Thanks

    Al
     
    ariddell, Apr 29, 2009
    #1
  2. ariddell

    ashleigh Moderator

    Joined:
    Aug 4, 2004
    Messages:
    2,392
    Likes Received:
    24
    Location:
    Adelaide, South Australia
    In the programming of teh dimmer (in Toolkit) check:

    - Is the min level anything > 1. If so, you MAY experience difficulty in setting low levels (but OFF should be fine).

    - do you have any logic groups set in the dimmer? If you do, are you using MAX logic?

    Of these two things, the logic seems the more likely - its possible that the off level is being overridden by the level of the logic group.
     
    ashleigh, Apr 30, 2009
    #2
  3. ariddell

    OldSkool

    Joined:
    Apr 21, 2009
    Messages:
    22
    Likes Received:
    0
    I may be way off target But due to the fact that the dimmers have a voltage running thru them at all times (even when off) LED's do tend to stay on even when off just very dim. I'm assuming they are just staying on at a low level.
     
    OldSkool, Apr 30, 2009
    #3
  4. ariddell

    Newman

    Joined:
    Aug 3, 2004
    Messages:
    2,203
    Likes Received:
    0
    Location:
    Adelaide, South Australia
    When the dimmer channels are turned off there is still a very small amount of current trickling through the load. This is because of the EMC bypass capacitors fitted to the dimmer channels to meet regulatory requirements. Try fitting an X2 mains rated 1uF capacitor in parallel with the LED fixture. This will send that small amount of current past the LED fixture instead of through it.

    A related issue:
    http://www.cbusforums.com/forums/showthread.php?t=5092
     
    Last edited by a moderator: Apr 30, 2009
    Newman, Apr 30, 2009
    #4
  5. ariddell

    ariddell

    Joined:
    Apr 20, 2009
    Messages:
    58
    Likes Received:
    0
    Thanks guys, they go very dim so the small amount of current at the off state makes sense since we haven't modified the logic/min levels etc.

    I'll give the capacitor idea a try and hopefully that'll sort the issue.

    Many thanks.
     
    ariddell, May 1, 2009
    #5
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.