INCANDESCANT LOADS AND DIMMER failure!!

Discussion in 'General Discussion' started by bocelectr1cal, Jul 29, 2009.

  1. bocelectr1cal

    bocelectr1cal

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    Can any one advise regarding protecting 1 amp dimmers from potential short outs when 240v incandescant globes blow.

    Is there a high risk of dimmer damage from this occurrance, sorry i ask this question as i have a job we are on and it has mostly chandeliers and candelabras through out. As you would be aware these types of lamps have a some what shorter life span than others and lamps blowing will be quite common.
    I am aware these are now an obselete item however my client has a stock pile of globes so will be right for the next few years

    checking the forum of past it seems even fuses/mcbs on the output side are of not much use(?)
    i guess also my question is that if the risk of dimmer damage is quite high why are they rated for incandescent loads at all if globe failure can cause dimmer failure?

    Finally are the new universal 2.5 amp dimmers which have a thermal protection rated better for this.

    Any help or experience in this arena would be greatly recieved

    regards

    boc
     
    bocelectr1cal, Jul 29, 2009
    #1
  2. bocelectr1cal

    kelly

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    Hi we had a similar issue years ago. The problem we had and I dont know if your installation is the same is our incandescent lights were mounted upside down with the base of the lamp pointing down. What then happened was when a globe sometimes blew the filament would fall to the bottom of the lamp accross what was left of the filament. This would then be a higher resistance of the original lamp and could blow the channel. Our problem was solved quite easily as the building manager was trying to make the building more energy efficient and these were some of the lights he de commissioned.
    Have fun
     
    kelly, Jul 30, 2009
    #2
  3. bocelectr1cal

    NickD Moderator

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    MCBs and fuses are designed to protect the fixed wiring of the installation against fire, not to protect equipment...
    The risk is not that high, but it does still exist. Installations where the lamps are inverted do increase the risk though.

    The universal DIN dimmers have both thermal and overcurrent protection built in... I have several in my place and they routinely shut themselves down and automatically restart when a lamp filament fails like this.

    The other alternative is one of the new modular Professional Series dimmers.. the leading edge cards in these have much beefier output stages and are designed to survive such events long enough for either the fault to clear itself or for the MCB to trip.

    Nick
     
    NickD, Jul 30, 2009
    #3
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