What Is Causing This Problem?

Discussion in 'Electrical Forum discussion & Blog' started by molo, Aug 26, 2010.

  1. molo

    molo New Member

    Messages:
    840
    Location:
    cold new york
    Hello,

    I have a stairway with a 3-way setup. A switch at the bottom and one at top. I decided to install motion sensing switches. They worked for about 6 months. Now one of the lights flickers unless I turn one of the motion switches to the off position, defeating the purpose of the switch. The other switch does not cause the light to flicker when it is in the on or auto position. What could be causing this?

    Thanks,
    Molo
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,888
    Location:
    New England
    are you using a cfl?
  3. molo

    molo New Member

    Messages:
    840
    Location:
    cold new york
    No CFL, Incandescents.
  4. drick

    drick In the Trades

    Messages:
    392
    Are these motion sensing switches designed to replace a 3-way switch setup? If they are not the problem with this setup is whatever motion sensor did not trigger the light ends up being back fed with power. Electronic switches are not like regular switches and the internal components may not like being back fed . It can lead to immediate or sometimes eventual failure as you are describing.

    There are motion sensor switches available that are designed to work with CFLs. Internally these switches use relays instead of relying on electronics to do the switching. Generally these switches can be connected in a manner such as you have done with no problems because the relays don't care about back fed power.

    I have one trick you can try. If the fixture allows you to use a higher wattage bulb replace the flickering bulb with a higher wattage one.

    -rick
  5. molo

    molo New Member

    Messages:
    840
    Location:
    cold new york
    Hi,
    Thanks for the reply. The motion-sensing switches are designed for a 3-way setup. So I'm not sure what the problem is. I could replace the bulb, but am concerned about going above the heat rating for the fixture. The bulb doesn't flicker when it is turned on by one switch, but it flickers when it is turned on by the other one. Should I still try the higher wattage bulb. Could it be the wiring?

    Thanks,
    Molo
  6. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    21,888
    Location:
    New England
    Some of the motion sensing switches rely on a trickle current through the filament...a low-wattage bulb has too high of a resistance to enable the required current for the switch to operate. Often, they list a minimum wattage that can be supported.
  7. molo

    molo New Member

    Messages:
    840
    Location:
    cold new york
    I'll check to see if I can increase the bulb wattage.

    Thanks!
Similar Threads: Causing Problem
Forum Title Date
Electrical Forum discussion & Blog Ceiling fan problem Apr 6, 2014
Electrical Forum discussion & Blog BROAN Fan/Light Problem Feb 3, 2014
Electrical Forum discussion & Blog Recessed fixture problem Jun 28, 2013
Electrical Forum discussion & Blog Fan and Switch problem Oct 26, 2012
Electrical Forum discussion & Blog Electric problem? Jun 25, 2012

Share This Page