2 and 3/4 yrs and still going

Discussion in 'Landscape Lighting' started by pete scalia, Oct 29, 2007.

  1. pete scalia

    pete scalia LawnSite Senior Member
    Posts: 960

    nearly three yrs ago I wired in an electronic dimmer switch to one of the transformers that feeds 12 lamps on a portion of my yard. The kind that has variable ramp rates. I adjusted it to the slowest setting. Soft on and soft off. This spring the lamps will be 3 yrs old and not one has been replaced yet. They are all operating between 11.5 and 12V. 12 lamps is hardly a test. Has anyone tested this on a larger scale and have you found this to be an effective way to extend lamp life?
     
  2. Pro-Scapes

    Pro-Scapes LawnSite Platinum Member
    Posts: 4,180

    hrmmm kinda a soft start rigging ? I often thought manufactures should build this into transformers. I find lamps most often blow at start up and recently had 3 mr bulbs pop on initial installation

    Interesting approach. I wonder if we can do this with UPB and upstart software ? I will also see about doing it on that touch screen project we have going on.
     
  3. ChampionLS

    ChampionLS LawnSite Bronze Member
    Posts: 1,066

    Now that's a nice way to overheat your transformer and cause a possible fire. You should never try to 'dim' the primary side of a transformer. Read the label on your power unit. As per UL labeling, it must say:

    Mount power pack vertically at least one foot above ground. Do not lay on the ground.
    Plug power pack directly into an outdoor GFCI outlet with a weatherproof
    cover marked “wet location.” Do not use extension cords.
    Mount power pack at least 10 feet from pool or spa.
    When connecting wire at terminals, do not allow insulation to get under the clamping plate, and firmly tighten the terminal screws.
    Do not use cable smaller than listed in the table below.
    Do not coil extra cable around the power pack. Either cut off extra cable and discard, or leave at the end away from the power pack.
    Do not repair or tamper with cord or plug.
    Do not submerge power pack.
    Do not connect two or more power packs in parallel.
    Do not use with a dimmer.
    If house circuit breaker trips when power pack is turned on, unplug power pack from AC outlet, correct fault, restore power, then reset circuit breaker.
    Power pack and fixtures must be installed in compliance with national and all local electrical codes and ordinances.
     
  4. NightScenes

    NightScenes LawnSite Silver Member
    Posts: 2,209

    So enlighten us Anthony on the proper way to dim a transformer.
     
  5. Eden Lights

    Eden Lights LawnSite Senior Member
    Posts: 805

    I am interested in your comments, please explain the science behind them. I am truly interested in your experience or knowledge since I was unaware that as a general rule you couldn't't dim a transformer on the primary side. Yes your relayed transformers are not dimmable and not all dimmers are Magnetic transformer rated.
     
  6. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Posts: 4,102

    Anthony, that is pretty funny. I guess all those engineered, approved, magnetic low voltage dimmers out there we designed for doing something other then dimming magnetic low voltage transformers?

    I have said it before and I will say it again... before you post here.... do some more research!
     
  7. ChampionLS

    ChampionLS LawnSite Bronze Member
    Posts: 1,066

    James,

    No... That's not what I said. Installing an off the shelf Dimmer, such as that used for your dining room chandelier is not suitable, and can be a possible fire hazard when used on the wrong type of transformer. Unless the end user or installer has a clear understanding of transformer knowledge, it is advised and required by UL to clearly mark and label those products that can possess a hazard. It is also a requirement that all instruction sheets and shipping containers be clearly marked as well. The Canadian UL marking may be slightly different.

    Type of Dimmers: The dimmer selected to control an electronic transformer should be specifically designed to control that type of transformer whereas a dimmer selected to control a magnetic transformer should be specifically designed to control that type of transformer. Now that there are newer and older systems in use, it is important to identify the differences between them.

    Older style electronic transformers are generally lighter in weight, smaller in size, cooler to operate, and quieter than a magnetic transformer. However, electronic transformers cannot provide more than 300 watts of power whereas some magnetic transformers can provide as much as 1200 watts of power. On Pete's post, he indicated approximately 12 lighting fixtures, so there can be a issue here if it's an electronic one.

    Newer systems use a Toroidal Magnetic Transformer. If a magnetic transformer is used to power a low voltage lighting system, a toroidal magnetic transformer should be considered. This type of magnetic transformer is more efficient, lighter in weight, smaller in size, cooler to operate, and quieter than a conventional EI magnetic transformer.

    Peter also mentioned the voltage was less than 12 volts. A voltmeter reading can be false because an electronic transformer provides its power at very high frequencies (usually greater than 20,000 Hertz) a standard voltmeter cannot be used to accurately measure the output voltage. Instead, a “true RMS" voltmeter must be used to measure the secondary voltage of an electronic transformer.

    We are in the progress right now with Underwriters Laboratory in Melville, NY with approval for two new units, so this has been an ongoing issue. We feel it is just easier to manufacture lamp modules using 14 volt incandescent lamps to extend the lamp life VS teach the correct use and wiring for dimmers.

    May I help you with something else? :usflag:

    -Anthony
     
  8. INTEGRA Bespoke Lighting

    INTEGRA Bespoke Lighting LawnSite Platinum Member
    Posts: 4,102

    I am pretty sure you simply said "You should never try to 'dim' the primary side of a transformer." Which is inaccurate.

    The jury on Toroidal transformers is still out.
     
  9. Chris J

    Chris J LawnSite Silver Member
    Posts: 2,837

    Seems like someone is trying to back-peddle on this one really quick.
     
  10. pete scalia

    pete scalia LawnSite Senior Member
    Posts: 960

    The voltage reading is highly accurate and the dimmer is inductive load for magnetic transformers. Don't throw me under the bus to make yourself look good when you clearly have no clue what you are talking about.
     

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