BELL 7W Dimmable LED using Universal Dimmer

Discussion in 'General Discussion' started by MrEcosse, Aug 18, 2010.

  1. MrEcosse

    MrEcosse

    Joined:
    Aug 5, 2004
    Messages:
    22
    Likes Received:
    0
    We are looking at job which has specified these LED GU10 lamps in most of the fittings. The manufacturers website has details at http://www.belllighting.co.uk/Products/698-7w-dimmable-intensity-led-gu10-warm-white-cool-white.aspx

    We have experimented with four of these connected to a C-Bus universal dimmer but we are experiencing some problems. If we connect the four to the dimmer it first tries leading edge dimming (Green LED) then trailing edge (Orange LED) during which time the lights just flicker. Then it switches the lamps off showing a flashing green to orange LED which suggests a short circuit. Am I correct in thinking it is showing this because the load is not high enough.

    I can't find any documentation on what the minimum load requirement is for the Universal Dimmer - can anyone assist?

    We have some circuits that have only two lamps on and since it doesn't work with four - it doesn't work with two. What can we use to bring the load up to the correct level for the dimmer. I hate to use the 'L' work on these forums but is there anything equivalent to Lutron's synthetic minimum load that we can use with these fittings?

    The problem is I know these fittings will work on an 'L' system and I don't want to lose out because C-Bus can't dim these fittings.

    Here in the UK we are seeing LEDs specified by designers everywhere these days and I desperately need to find a way of getting reliable dimming of these 'dimmable' lamps using Clipsal.

    Here's hoping

    Simon
     
    MrEcosse, Aug 18, 2010
    #1
    1. Advertisements

  2. MrEcosse

    Newman

    Joined:
    Aug 3, 2004
    Messages:
    2,203
    Likes Received:
    0
    Location:
    Adelaide, South Australia
    There is no information about dimming compatibility of those lamps other than the word "dimmable" on the website, so how dimmable they really are is anyone's guess.

    The minimum load for the Universal dimmer is about 25W per channel so 4 x 7W puts you above that point. Having said that, every LED lamp I've seen runs at less than the nominal power.

    Lots of manufacturers are targeting leading edge dimmers when designing dimmable LEDs, since leading edge dimmers are more common and cheaper to make. Have you tried these fittings on a regular C-Bus leading edge dimmer? If the Universal Dimmer tried leading-edge mode then there's a good chance that they will work on a standard dimmer.

    If the issue is one of load type you may be able to make them work by fitting a 31CAP or 5100NLA to the channel.
     
    Last edited by a moderator: Aug 19, 2010
    Newman, Aug 18, 2010
    #2
    1. Advertisements

  3. MrEcosse

    MrEcosse

    Joined:
    Aug 5, 2004
    Messages:
    22
    Likes Received:
    0
    Thanks

    I'll give those a try and report back
     
    MrEcosse, Aug 19, 2010
    #3
  4. MrEcosse

    MrEcosse

    Joined:
    Aug 5, 2004
    Messages:
    22
    Likes Received:
    0
    Hi Newman

    Have spoken to our C-Bus distributor here, who have spoken to the powers that be at Schenider in the UK and needless to say they don't keep those parts over here. They'd be looking at a 'slow boat from China' kind of timescale to get one in to test.

    Any chance of knowing what kind of thing I might find inside these two parts - if they are caps or resistors we should be able to get something similar.

    Many thanks

    Simon
     
    MrEcosse, Aug 20, 2010
    #4
  5. MrEcosse

    Newman

    Joined:
    Aug 3, 2004
    Messages:
    2,203
    Likes Received:
    0
    Location:
    Adelaide, South Australia
    How about a 32EIND, which provides additional inductance to the load, which will encourage the Universal Dimmer to select Leading Edge mode?

    Keen to hear the test results of these lamps on a standard C-Bus Leading Edge dimmer too.
     
    Newman, Aug 23, 2010
    #5
  6. MrEcosse

    Newman

    Joined:
    Aug 3, 2004
    Messages:
    2,203
    Likes Received:
    0
    Location:
    Adelaide, South Australia
    The 31CAP is just a suitably rated capacitor that has been tested and packaged for installing across the load. You can install any X2 rated capacitor across the load. I'd suggest you start with 220nF or so. Bear in mind that the maximum capacitance for a channel on a C-Bus Leading Edge dimmer is 300nF.

    The Universal Dimmer does not have the capacitance limit, since it will run a capacitive load in trailing edge mode.

    The 5100NLA is designed to allow dimmers to work with dimmable Neon lighting and is a bit of a different beast.
     
    Last edited by a moderator: Aug 23, 2010
    Newman, Aug 23, 2010
    #6
  7. MrEcosse

    MrEcosse

    Joined:
    Aug 5, 2004
    Messages:
    22
    Likes Received:
    0
    Hi there

    Newman you're right sometimes we should try the simple things first.

    So I can happily report that these lamps just great on a standard (non universal) dimmer without any adaptors, resistors or capacitors. :D

    I have tested on both the 1A and 2A versions and both are stable down to two lamps on the circuit. Dimming curve is comparable to a standard halogen - perhaps a little more step like than the smooth analog response you would normally get. But that's only noticeable on l..o..n..g fades.

    The lamps dim down to about 7% or so. But then they hold and stay on at that level even if you set a level of 1 (i.e. 0.4%) on the dimmer. Haven't noticed any flicker or other problems.

    I'd say they were pretty damn fine. I'll probably now swap out a few channels of my system at home to live with them for a while.
     
    MrEcosse, Sep 1, 2010
    #7
  8. MrEcosse

    theboyg

    Joined:
    Apr 3, 2005
    Messages:
    181
    Likes Received:
    0
    MrEcosse

    You have these working on a standard 8-way 1A dimmer ? Do we have any UK prices and dealers to get these bulbs from ?

    Thanks
     
    theboyg, Sep 17, 2010
    #8
  9. MrEcosse

    NickD Moderator

    Joined:
    Nov 1, 2004
    Messages:
    1,417
    Likes Received:
    46
    Location:
    Adelaide
    Good to hear.

    You may need to watch the maximum number per circuit. With these electronic type loads the limiting factor is the input capacitance, and depending on the topology of the circuit this can be much higher on CFLs and LEDs compared to normal electronic transformers.

    If you set the minimum level on your dimmers to 8 or 10% then they will re-scale the output so that they come on at this level... this way to the user everything looks normal and there is no strange behaviour at low settings.

    Nick
     
    NickD, Sep 20, 2010
    #9
    1. Advertisements

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.