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Voltage Drop Compendium

Discussion in 'Landscape Lighting' started by INTEGRA Bespoke Lighting, Dec 11, 2007.

  1. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    Pete, do you really think 15v to a lamp wont burn them out just as quick. Fact is if you are using a 22v tap you probably are hundreds of feet away and need it. It would be no difference if you were closer and need a 15v. That argument is weak, stick with the fact that 16,17,18,19.........30v is so much more dangerous than 14, and 15. The fact that lamps burn out has nothing to do with the higher taps as much as it does with an increase when you lose a lamp. 13, 14, and 15 v are capable of overloading a lamp just as 22v can.

    Its all in how you test and wire your system. An unliscensed contractor or homeowner should not be wiring our systems. We build them for the professional that should know what happens when you touch 2 sides of the cable togeather and also what happens when you stick your tounge on a frozen metal pole.

    But hey if you dont need 15v then more power to you, I have said it before and I will say it again, we make a UL1838 TF, we just dont sell many of them.

    Joey D.
     
  2. pete scalia

    pete scalia LawnSite Senior Member
    Posts: 960

    Joey as much as I love you the higher voltage tap argument is not weak. When you have 11.8 volts at your homerun and you lose a 35 watt lamp you are in trouble on a long distant run with a higher than 15v tap. You are going to lose those other lamps very soon if you don't change that burnout immediately. Lamps were made to operate at 12v . They don't last very long at 12.5v and higher.
     
  3. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    Pete the chain reaction can and does happen when hooked up to taps 15v and below. Its all relative. If you are putting 12v on a run using a higher voltage tap you are going to increase the 12v no matter if its the 14 or 16v tap feeding it. This is just part of LV lighting. This is not a strong argument, do I have to break out the test equipment again?
     
  4. pete scalia

    pete scalia LawnSite Senior Member
    Posts: 960

    It doesn't take an electrical engineer.
    The voltage drop from lamp load is greater than the loss of voltage due to resistance in cable
    So if you are far out and get a burn out I'd rather be on a 15V tap than higher. The higher the tap in this instance the higher the voltage and the sooner the lamp will die.
     
  5. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    Quit avioding the fact that your 15 tap can create the same exact problem. That doesnt take an electrical engineer.

    I will test it, and then let you know the results.
     
  6. pete scalia

    pete scalia LawnSite Senior Member
    Posts: 960

    The higher the tap the higher the voltage.
     
  7. nate mullen

    nate mullen LawnSite Member
    Posts: 47


    Pete, hey Buddy I'm a big fan and I am happy to set the record strait on this topic today and I will be setting the record straight on the NEC, UL 1838, 506, 1571, 1593, 2108, and the non existent 5058, as well as Voltage Drop..

    I have sat back for my whole lighting career and watched how the industry has evolved and has ceased to evolve. There is no identity to this lighting industry. We as contractors sit here and have been taught by who? Yourself, a book that you cannot understand because you have no foundation, a manufacturer that has never installed a lighting job in their life...............I'm just about ready to get side tracked so back on point.

    Increased Voltage to Lamps Above 12

    FACT: you have 2 light bulbs @ about 100ft and you are using the 15v tap. This means you have a 3 volt drop shared between 2 fixtures, 1.5v per lamp. When one lamp burns out the other lamp will have 13.5v. At 13.5v the lamp life is dramatically reduced from 100% to 21% life which is 855 hours. If you had 15 volts at the lamp your life at the lamp is reduced to 5% of lamp life 215 hours. Above 15 volt.................what does it matter,.............fact is anything above 12 volts kills the lamp life.

    THERE IS NO DIFFERENCE BETWEEN 13.14.15.16.17.18.19.20.OR 22 IT IS EXPONENTIAL EVEN AT 12.5 VOLTS THE LAMP LIFE IS 59% OF RATED LIFE. This is where it all gets back to proper wiring design.( more on this later)

    So your right the higher the voltage the faster the lamp burns out. whether it burns out within 1 month or anything less it just does not matter.

    I just have to say this, it is the NEC that is mandated across the US (and almost every other country), it is the bible when it comes to electricity NOT UL! Article 411 states 30v or less not 15. There is no need to discuss this further although I know it is going to be (please find me one job that has been turned down in the US, 10's of thousands of inspectors cant be wrong). If any of you wish to discuss this further I am more than willing to pay for a conference call and discuss this with great dialog.


    To A Brighter future,
    Nate
     
  8. pete scalia

    pete scalia LawnSite Senior Member
    Posts: 960

    Finally a fan. You see you numbskulls Nate Mullen knows class when he sees it. I'm a huge fan of you too Mr. Mullen. Can I call you Nate?
     
  9. johnh

    johnh LawnSite Member
    Posts: 34

    We may have a different hierarchy here in Canada, the CSA who develops the standards and provides the testing (others like UL, ETL, CE are also acceptable, as long as they are to Canadian standards) also writes the CEC (equivalent to NEC). Then there are the local authorities that enforce the code. But the CSA standards and the CEC are closely tied together, one referring to the other.
    Do the NEC and UL not have a similar symbiotic relationship?
    JH
     
  10. nate mullen

    nate mullen LawnSite Member
    Posts: 47

    If the jobs are being inspected they need to be listed by a NRTL. at my last count there were 14 including ETL and UL. UL is a great company but all they do is wright standards. Then they come up with tests to meet those standards. 1838 was intended for lighting kits with every single conponate being tested and sold together, the wire, lamps, connectors,fixtures. With the expect ion of Malibu kits I know of nobldy that does this. I'm still waiting for some one to tell me why 120 volt lighting is OK .....if 1838 is the rule at 15 volts...by the way does't Kitchler, Nightscaping, Hadco, Vista and most other sell 120 volt lighting...........So back to UL standards there are many standards: under 15 volts, under 30 volts. over 30 volts to 120 volt's or higher. But make no mistake in the USA it is the NEC that stated what is legal or not legal. I really don't care .....I make all transformer's to comply with all listing for all standards for all uses.
    To a Brighter Future.
    Nate
     

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