User Tag List

Results 1 to 5 of 5

Thread: Led floodlights and motion sensor compatibility

  1. #1
    Join Date
    Mar 2017
    Location
    Florida
    Posts
    96
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Led floodlights and motion sensor compatibility

    So I go on a service call to get some outside floodlights working. There are two hard wired dual head fixtures mounted on the wall of the residence. They have the motion/light sensor installed on each. Customer tells me one fixture wont come on and the other strobes. One fixture has halogens which are bad the other have LED floods installed. The LEDs strobe when the power is applied. I go through the circuit and buy replacement parts for what was out - the motion sensors and the two halogens.

    After installing the new sensors and LEDs the one fixture with new LEDs works fine but the fixture with the existing LEDs (new sensor) is strobing again. I put new LEDs in their place which were SAME MAKE AND MODEL and voila it works all of a sudden!? Any explanations?

  2. #2
    Join Date
    Mar 2017
    Location
    Florida
    Posts
    96
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Didnt add this important piece: those existing LEDs worked fine when I put 120v to the shell

  3. #3
    Join Date
    Apr 2008
    Location
    Ann Arbor, Michigan
    Posts
    7,228
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    180226-2429 EST

    Use a motion sensor with an electromechanical relay that controls the light. When the motion sensor changes state you can hear the relay click.

    .

  4. #4
    Join Date
    Mar 2017
    Location
    Florida
    Posts
    96
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by gar View Post
    180226-2429 EST

    Use a motion sensor with an electromechanical relay that controls the light. When the motion sensor changes state you can hear the relay click.

    .
    My question is why does one pair of leds work in the fixture while the other flicker? Same make and model and they all work with 120v outside the fixture.....???

  5. #5
    Join Date
    Dec 2012
    Location
    Placerville, CA, USA
    Posts
    19,855
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by 2Broke2Sleep View Post
    My question is why does one pair of leds work in the fixture while the other flicker? Same make and model and they all work with 120v outside the fixture.....???
    Even for the same make and model there can be differences over time or production batch or at random because of:

    1. Deliberate changes in driver circuit design or manufacturing process that do not rise to the point of changing the model designation.
    2. Changes in component values based on availability.
    3. Variations in component specifications within their nominal tolerance range.

    A motion sensor may be three wire type that has a neutral or EGC connection for power return (least likely to behave very differently with changes in exact load characteristics or the two wire type that depends on a circuit through the load to provide operating current to its electronics. These are very dependent on the current versus voltage curve of the load. Most robust with an incandescent lamp load, shakier with an electronic load, either LED or CFL.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •