a hadco transformer test.

Discussion in 'Landscape Lighting' started by David Gretzmier, Sep 6, 2010.

  1. starry night

    starry night LawnSite Gold Member
    Messages: 3,320

    My post is a little off the subject i.e. it's not about Hadco units. I think I asked in a thread some time ago why, with LEDs being more widely used, why we needed the standard multi-tap transformers going up to 16, 17, 18 volts or above. Why not a multi-tap with maybe an 11 volt tap and maybe 2 or 3 separate 12 volt taps. so we wouldn't have to cram several wires into one tap.

    So, now doing some smaller jobs and using LEDs, does any of the quality manufacturers make a 100 watt or 150 watt full-featured tranformer?
    For instance, I have a small job at a condo entrance. Only need 6 or 7 fixtures which will be LED but I also want the transformer to be fully-protected for shorts and to have a receptacle for a plug-in astronomic timer. Who makes such a thing? Anyone.........anyone.....?
  2. David Gretzmier

    David Gretzmier LawnSite Gold Member
    Messages: 3,646

    I would say a 300w like the hadco would be good for many LED jobs. you still have voltage drop when 200 feet away from a trans with a 20 watt load. also folks doing more LED are using 18 and 16g, thinner wire to take advantage of the lower price and lower load and just using higher taps. 18g spt2 is rated for 10 amps, or 120 watts, but probably only for 75-100 feet or so. if you keep your runs under 50 watts, which in LED would usually be 6-8 fixtures, you can probably use 18g wire and the 15v tap and easily be within LED spec.

    not really sure if you realize much cost savings going from a hadco 300 watt to a 100 watt. most of what you are paying for is the timer and or photocell, stainless case, taps, cords, circuit breaker, plug in timer area, etc. I can't imagine a 100 watt being much cheaper.
  3. starry night

    starry night LawnSite Gold Member
    Messages: 3,320

    Thanks David, I was kind of thinking the same thing about the foundation of a transformer: the core, the case, the timer, etc.. That would be the main cost of the transformer. I guess that I can explain that aspect to a client who thinks I am using more transformer then what they need.
  4. NightScenes

    NightScenes LawnSite Silver Member
    Male, from Kingsland, Texas
    Messages: 2,214

    I know Kichler now has 100 and 200 watt pro series units but the 300s usually cost less so why not go big for any future additions?
  5. Thoren

    Thoren LawnSite Member
    Messages: 3

    I am still using pantech, no problems.

    I use the gallon of paint story with customers.

    300w is a gallon of paint, I can sell you a quart but the price only drops 5%.

    My problem with under 300w transformers is that it is untested (for me anyway). I have 1000s of 300watt cores out there, they all keep humming along.

    Also when it comes to size, I think they are small enough as I am the one that has to fit my hands inside to make adjustments and measurements.

    Also after re-reading this post, I realized a flaw in the testing of transformers. They all cut the power (in our case) by 10% so if you have 110v at the outlet your 12v tap will only read 11v. Conversely if you have 130v at the outlet you will have 13v at the 12v tap. So to be fair if you were comparing transformers it would only be fair to make sure the incoming current was the same.

    I learned this the hard way at a customer's house that only had 105v at his outlet. By law the power company is supposed to supply within 10% of 120v.
  6. David Gretzmier

    David Gretzmier LawnSite Gold Member
    Messages: 3,646

    I find that not all trans, even among the same manu's and same trans itself are perfectly 10% linear trans on all taps. at 120v the 12v tap may very well read anywhere from 12.2 to 13 unloaded, 11.2-12.6 loaded, and at 108 volts it may not necessarily drop 10% on loaded or unloaded. voltage imput and amps used is not a perfect science as trans have different efficiencies at different loads, and at different imput voltages. and all manu's seem to set them a bit differently, and there seems to be an acceptable range within a given manu. if you grab 10, 300 watt trans from the same manu at the same imput voltage, you will still find various loaded and and unloaded tenths of a volt difference.

    I would not lose sleep over it. accept it and try to volt your lamps properly regardless of imput voltage.
  7. djt22

    djt22 LawnSite Member
    from Ohio
    Messages: 113

  8. starry night

    starry night LawnSite Gold Member
    Messages: 3,320

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