Any reason I can't use a dimmer on MR16 lamps?

Discussion in 'Landscape Lighting' started by OKSooner, Jan 13, 2012.

  1. OKSooner

    OKSooner LawnSite Member
    Messages: 235


    My client wants lights down from a balcony onto a water feature on the other side of the pool. I'm going to use a couple of 75w features (I forget the model number - they're Vista, composite, 75w max MR16) with cool blue lenses to light it up blue.

    I was at the store picking up some zip ties and stuff and got to looking at the electrical stuff and the thought occurred to me - why not put a dimmer on each of the 75w fixtures so they can be attenuated to suit the uh, mood of the situation by the pool... know what I mean?

    Help me out. Should I go buy a couple of dimmer switches, one for each fixture? (Each fixture is going to run on its own 12v circuit off the transformer.) Or is there a downside that would be a show stopper?

  2. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Messages: 4,102

    Since you are talking about dimming the secondary side (low voltage) of the transformer you will not be able to use a standard 120V dimmer. You can however use a low voltage dimmer from Zane that will handle the relatively high amperage that will be on that secondary circuit. A call to Gerry at Terradek will get you sorted out.

    You could also choose to dim the entire zone by installing a magnetic low voltage dimmer on the primary side of the transformer, but this would dim all of the lights on that transformer.

    Be wary of continuous operation of 12V Halogen MR16 lamps below 10V or so. For one it will significantly alter the colour temperature of the light and if you dim down really low, to around 50% or more, you will reduce the life of the lamps.

    Finally, I would suggest you set up a mock up of this application and try out a number of different lamps in different intensities and beam spreads. In all my years of doing this I have never used a 75W MR16 for any application. Beware the HEAT! You may find that using more fixtures with lower wattage lamps provides a much more desirable effect.

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