Good Article Written by a Member

Discussion in 'Landscape Lighting' started by Dreams To Designs, Sep 4, 2007.

  1. Dreams To Designs

    Dreams To Designs LawnSite Bronze Member
    Posts: 1,406

  2. Pro-Scapes

    Pro-Scapes LawnSite Platinum Member
    Posts: 4,181

    informative as usual from Steve.

    30 volts huh. Crap this is a can of worms waiting to happen. One more BIG reason why we need standards of training. This may force the little guy out and require more low voltage techs to become licensed electricians increasing the costs to our clients.

    I dont see a reason to raise it to 30v. 18v maybe... 30v no.
     
  3. NightScenes

    NightScenes LawnSite Silver Member
    Posts: 2,207

    There is a standard for installation out there right now. Contact the AOLP!! This is one more reason for certification.
     
  4. David Gretzmier

    David Gretzmier LawnSite Gold Member
    Posts: 3,645

    what a great read for beginners. I hope UL does update to 22 volts, perhaps even 30. as wire gets more expensive, I am seeing more and more folks use less 8 and 10 guage. 12 seems to be the standard, just make the voltage work.
     
  5. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    Here was somthing our Transformer engineer wrote after reading the article. Our engineer is also the same guy who invented the GFI.

    "The article is basically correct. But the efficiency of a toroidal transformer is only as good as the design. An EI core can be designed to be just as efficient as a toroidal core. The toroidal core itself is more expensive than EI’s and more difficult to insulate between primary and secondary, especially when it comes to meeting stringent specifications such as pool and spa requirements. (layer of .005 inch thick copper foil between windings). Toroidal cores are more expensive to buy, wind, and insulate. But they do have lower profile.

    As far as electric shock goes there is an International standard for SELV (safety extra low voltage) which is less than 60 volts DC. or 42.4 volts AC. This voltage is considered safe for people to touch. So the 15 VAC limit is ridiculously low."

    John R.

    He (John Reeves) also stated that if you are using cheaper materials building a Toroidal then all arguments of it being more efficient are out the window. The fact that we use the highest quality components in our EI core's make them just as efficent, run just as cool, and as quiet as any other unit out there.

    Unique uses an EI core and have been from day one. We have a 1% failure rate on our units. Very efficient and long lasting EI cores!
     
  6. Dreams To Designs

    Dreams To Designs LawnSite Bronze Member
    Posts: 1,406

    Joey,

    Thank you for that added information. It gives all of us some more information to make educated decisions.

    Kirk
     
  7. NightScenes

    NightScenes LawnSite Silver Member
    Posts: 2,207

    It's always good to get both sides of an issue. Thanks Kirk and Joey for this information.
     
  8. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    Sure, I thought it was a well written article as well. It spawned us to inquire how we were doing things. This type of stuff is great for everyone involved int he industry.
     
  9. ar-t

    ar-t LawnSite Member
    Posts: 49

    First off, I need to 'splain that lighting is my second profession. My previous one was as an R&D engineer. (You are toast at 45 in engineering.....couple that with R&D labs are the first cost-cutting measures big companies take when slashing expenses.)

    Anyway, I have designed plenty of transformers. Both EI stacked lamination, as well as toroid. Many of the cons expressed in the article about EI can be traced to not enough copper on the primary. You can do the same thing with toroids, as well.

    Yes, a bit more efficient, as there is no air gap. Not sure that is a concern here.

    Toroids can radiate quite a bit, if the windings are not evenly spaced, across the entire core. Again, not a big problem here. Buzzing.......yes, that is. I have rejected more than one toroid, as the steel band that makes up the core can come loose internally. So, while very rare, toroids can buzz.

    UL is a subject I best stay away from. I have friends who worked there, and their opinion.....based in fact.......is more cynical than mine. Yes, their focus should be safety, but they are believed to be very arbitrary in what they consider safe. 'Nuf said.

    But 30V??????????

    This sounds like a red herring. C'mon, if anyone is daft enough to put 30v on any bulb that we use, how long do you think it will last? Even 22V seems out of the range for 99% of the applications.

    It would take over 200' of 12 ga wire to drop 10V on a 180W load. (15A, which is all you can put on 12 ga.) So, when is the last time anyone has needed to run 375' of cable?

    Just because UL will let someone make a 30V tap transformer is no reason to expect one the hit the market any time soon. Or ever.

    But, if it does, it will most likely not be a low-cost item. The contractors who won't understand how to use it properly probably won't rush out the buy one. Not sure we should panic. Not quite yet.
     
  10. steveparrott

    steveparrott Sponsor
    Posts: 1,189

    Good discussion going here. You're absolutely right about good toroids and bad toroids. There's recently been some low-cost toroids coming out of asia. Our engineer ripped one apart and found the problems that Joey described.
     

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