LW 420 Dimmer switch getting hot and lights flashing

LightwaveRF Communi… > Forum > Installation and… > LW 420 Dimmer switc…

LightwaveRF Community: Welcome Forums Installation and Troubleshooting LW 420 Dimmer switch getting hot and lights flashing

This topic contains 3 replies, has 3 voices, and was last updated by  Jules 5 days, 18 hours ago.

Viewing 4 posts - 1 through 4 (of 4 total)
  • Author
    Posts
  • #24869
     pmelec says:

    pmelec
    Participant

    This is the 2nd switch I have installed as the first one stopped working because it got too hot.
    Now I’ve had to remove the replacement as its doing the same and making lights flash?

    The switch is controlling 12 x10watt Loxa LED dimmable downlights so it should be well within the switches limits.

    The back box is 35MM.

    Any ideas??

    #24872
     Jules says:

    Jules
    Participant

    Quote from LightwaveRF LED Lamp Compatibility Guide: “We have guidelines of 60W~70W as a maximum rating per gang for one and two gang dimmers, but there have been instances where surpassing this has worked, and instances when falling below this hasn’t worked. One company with an 8.5W lamp recommended putting no more than 5 onto a 250W dimmer. When 6 were put onto our dimmer (51W), the dimmer did not operate correctly.

    It is the heat that gets generated by each LED lamp, so it is the heat that goes back to the wires and the dimmer will not be able to handle more than x10 LEDs, it might do but the plate on the touch will be warm and the switch will eventually fail. So the the dimmer should not go over its maximum demand.”

    My Mazda CX-3 Blog: jtonline.info
      Home automation: 1 x LW930 Lightwave Link / 4 x LW400WH Dimmer / 1 x LW205 Wire-Free Switch / 4 x LW381 Basic On/Off Socket / 1 x LW830 In-line Relay 3000W / 1 x Echo / 2 x Echo Dot / 1 x Harmony Companion.
      #24873
       btidey says:

      btidey
      Participant

      The reason why the dimmer switches need to be derated when using LED bulbs is due to the nature of the load they present to the circuit not due to any heat transmitted from the bulbs themselves.

      A traditional incandescent bulb represents a resistive load which provides a smooth load to the dimmer circuit and the maximum rating is based on this.

      LED bulbs have a complex load but can have a high capacitive component. This means that when they are switched on during the mains cycle there is a high pulse current even though the average current is low. The high pulse current combined with the high voltage as the dimmer switches on produces a disproportionate amount of power dissipation in the dimmer itself. This is what leads to the derating of the maximum LED power load down to the 60-70 watt level.

      This is also why the maximum load for LEDs can be quite dependent on the type of LED as they will have different load characteristics even for the same power rating.

      12 10 watt LEDs is almost certainly well in excess of the dimmer’s capability.

      #24874
       Jules says:

      Jules
      Participant

      I thought the bit they wrote about the heat going back to the wires was a bit weird.

      My Mazda CX-3 Blog: jtonline.info
        Home automation: 1 x LW930 Lightwave Link / 4 x LW400WH Dimmer / 1 x LW205 Wire-Free Switch / 4 x LW381 Basic On/Off Socket / 1 x LW830 In-line Relay 3000W / 1 x Echo / 2 x Echo Dot / 1 x Harmony Companion.
      Viewing 4 posts - 1 through 4 (of 4 total)

      You must be logged in to reply to this topic.