LED lamp chandelier - wiring and potential loading issues

Discussion in 'The Projects Forum' started by hyoog, Nov 2, 2012.

  1. hyoog

    Thread Starter New Member

    Nov 2, 2012

    I have done some research on what I suspect is a simple problem for readers of these forums. In the interests of my own safety (!) and because I need to get this right for my client first time, I need to corroborate my solution.

    My brief is to design an interpretation of Rody Graumans' 85 lamps chandelier. This piece is in Moma in New York and the original used 85 incandescent lamps (http://www.moma.org/collection/artist.php?artist_id=7583).

    My interpretation uses 49 lamps - each being an LED lamp made to look like old fashioned incandescent lightbulbs (www.segula-led.de/).

    Power requirements are rated as 2.7W per lamp.

    The issues I am unsure of are:

    Q. Series or Parallel?
    A. I think parallel, although my memory from school days is for D/C circuits.. I have attached what I think should be the correct wiring for parallel? Please confirm this is correct..

    Q. Overall load requirement?
    A. At 2.7W per lamp, I calculate 132.3W for the assembly. This equates to pulling a current of just 0.55A on 240V supply. But I have been told that inrush current for LED lamps can be up to 50x for ~0.5ms. I have found info on circuit breaker types - it looks like a Type B should not trip for this load, but I want to be sure?

    Q. Finally, are there any other issues I am over-looking?
    A. I am a designer and have only patchy electrical knowledge from school. LED lamps are new to me and I am aware this arrangement is not typical. Are there any issues I am overlooking?

    I really appreciate your help.

  2. wayneh


    Sep 9, 2010
    You want parallel, since those bulbs are meant to connect directly to mains power.

    You are correct that the overall load is the sum of the individual loads. I'm not familiar with the inrush issue or circuit breaker details, so I'd prefer someone else chime in on that issue.

    Other issues? Well, there are always other issues but they can be hard to predict. One thing that comes to mind is heat. It doesn't seem that using LED bulbs should present a heat problem, but you should always have heat dissipation in your mind as you are designing and building.
  3. hyoog

    Thread Starter New Member

    Nov 2, 2012
    Thanks - Good tip I will look at heat generation.. I know that LEDs an dcontrol gear can get hot..