Overloading query / Issue dimmer turned off

LightwaveRF Community: Welcome Forums Installation and Troubleshooting Overloading query / Issue dimmer turned off

This topic contains 6 replies, has 5 voices, and was last updated by  stringman 3 months ago.

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     PurpleNurple says:


    Hey Guys,

    I have two questions. Firstly, I have a LW400 dimmer powering 11 7-watt downlight LED bulbs. This situation worked fine for about a day but then all of a sudden the lights went off. The dimmer still had the blue LED lit. I then tried turning it off, so the amber LED showed, but none of the 11 7-watt downlight LED bulbs turned on / off. I tried reseting the switch and unlinking it but nothing happened. I turned the power off to my house and on again. The dimmer went of all together and is completely dead. Does this sound like an overloading issue? I have various other LW400′s around the house powering different sets of the same brand LED bulbs, though admittedly significantly less in terms of wattage, and they work fine.

    Secondly, what is the minimum LED loading for the LW400 dimmer and how can you calculate this? I have been told…

    - LW400 load is 60W LED or 250W Hallogen

    - LED loading can be calculated by just multipling the amount, so 11 7-watt would be 77

    - LED loading can be converted into Hallogen equivelant by multiplying by 5 so 11 x 7 x 5 = 385w (I read this somewhere but the equation looks and sounds wrong)

    - An electrician told me that dimmers don’t have seperate loading specifications for different types of bulbs. They said that if a dimmer has a maximum load of 250w you just make sure the LED load stays below 250. 250w dimmer % 7-watt LED bulbs = 35 LED bulbs. This also sounds wrong.


     eme160 says:


    I have exactly the same issue with an LW400 aswell. Its been replaced once and now the replacement has the same issue.
    Is there a bad batch?

    I have 10 x 5w Megaman dimmable led lamps on this circuit, so not overloaded according to all the info I can find.

    Any help greatly appreciated ( The wife wants to go back to std rotary manual dimmers! :-( )

     Jules says:


    LightwaveRF only state the incandescent load, 20W min 250W max, and not LED load.

    As I understand it, the initial inrush current of the drivers in dimmable LED lamps means that it’s not just a case of adding up the wattage of each lamp as printed on the packaging.

    On https://www.simplyled.co.uk/easy-guide-to-dimming/ they give an example for a 400W max dimmer and say
    “…the rule of thumb for the amount of bulbs is to divide the 400W by 10, which then gives you 40 watts or rather, the maximum worth of LED bulbs for the dimmer…”
    “…8 bulbs (8 x 5W = 40W x 10 = 400W)…”

    My Mazda CX-3 Blog: jtonline.info
      Home automation: 1 x LW930 Lightwave Link / 4 x LW400WH Dimmer / 1 x LW205 Wire-Free Switch / 6 x LW381 Basic On/Off Socket / 1 x LW830 In-line Relay 3000W / 1 x Echo / 2 x Echo Dot / 1 x Harmony Companion.
       PurpleNurple says:


      I read that same article but it conflicts with guildelines Lightwaverf offer. They state that the maximum LED load for the LW400 is 60W with a maximum incandescent load of 250W. 10% of 250 is 25, so Lightwaverf’s recommendation for LED bulbs is slightly under 25% of the recommended incandescent load.

      I have come to the conclusion that the technology is too new and there are no standards in place yet for LED bulbs and LED dimmers. I am slightly regreting buying into this product as the only way to successfully use the product is with trial and error – which costs money.

       PurpleNurple says:



      A couple of weeks ago I was pointed in the direction of a compatibility chart partly filled out by Lightwaverf. There is a Megaman 5w LED GU10 listed and it looks like it isn’t compatible with the LW400. I have just bought the Aurora Elite EN-dgu005/40. It flickers for 1 and 2 bulbs but looks fine from 3 – 10 with no buzzing. I am wanting to use 11 of these and it looks like it might work in my situation as 5w x 11 bulb = 55 and Lightwave’s minimum LED land for the LW400 is 60w.

      Again, continuities form my previous post, I am going to have to keep buying bulbs in batches of 11 until I find the brand that works. It cost me £50 for the Aurora bulbs.

       Zoodle says:


      I suffered the same problem, see my posts in another thread http://lightwaverfcommunity.org.uk/forums/topic/advice-for-new-installation/
      To summarize, I had a working installation of 8 Megaman 6W dim-to-warm leds but added a further six leds which resulted in dimmer failure after a few tens of minutes. I tried a second dimmer which failed the same way.
      I decided to investigate the non-functional hardware. I discovered that each dimmer power module uses two power mosfets which are protected by a wired-in thermal fuse. In both cases of my failed dimmers, this fuse has blown. The fuse is a SETfuse K4, rated at 2 amps and 130 deg C. I could not find a local source for these so I have ordered some Profuse TZ-P130/2 replacements, costing about £1 each. The repair does require some electronic soldering skills but nothing beyond those of a tv/computer repair man. I will let you know if replacing these fuses restores operation.
      Fingers crossed!

       stringman says:


      Hi Zoodie
      did your fix work? I have blown one of my dimmers and rather than replace the whole lot it would be great to just replace a fuse.

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