Voltage Drop Compendium

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

  1. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    James you should know how we Unique guys roll. We start work at 6 am and going until 10-11pm is not uncommon. Dont get me wrong this isnt an academy award winning film, this is a real basic thing that I did by myself with a video camera. But it works.

    Joey D.
     
  2. PatriotLandscape

    PatriotLandscape LawnSite Bronze Member
    from MA
    Posts: 1,209

    for my systems I have used the cast ligthing system calculator. I have only installed one system but have used it for proposals.
     
  3. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    We have the Unique wiring wizard which does the same thign but also allows you to print detailed reports for all your transformers and hubs. It is a really cool program that is going through revisions to make it even better. It soon will be it;s own web page so we can constantly update it. You can request one for me to mail out or you can download it from http://www.uniquelighting.com/product_pages/Wiring_Wizard.htm

    Joey D.
     
  4. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    Ok boys so after reviewing my video I can tell you the results are very very interesting. I think you ugys will be surprise to see the method that actually comes out closest. After reviewing I decided that I could use it for so much more than just for us here on Lawnsite. So I reshot it this afternoon with my Creative Director and we are going to use some graphics to better explain. I origionally shot it with my hand held camera and used a white board for the graphics. It worked but me being a darn perfectionist had to go on and re film it. I will post within a few days as my guy just has to edit and put in some porno music in the background........bow-chika-bow-wow
     
  5. klkanders

    klkanders LawnSite Senior Member
    from Midwest
    Posts: 848

    Oh My! Is it titled " Joey does Voltage Drop"
    I hope this has a G rating.
    Sorry for this but you made me do it Joey!
     
  6. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    LOL......Dont worry you will not see any bare flesh. I want you guys to be able to learn like I did here and not throw up!! When I did it myself it was good enough but my creative director saw it and about freaked out. "Why did you do this without me!?" I can make this much better......waaa waaa waaa..." So I let the guy re do it so he could sleep at night. He's my good buddy so I guess I will just have to put my homemade video away.
     
  7. steveparrott

    steveparrott Sponsor
    Posts: 1,173

    John,

    Your assessment of the IEC TS 60479-1 is correct on the assertion that 30V is the maximum safe voltage for ventricular fibrulation (assuming a bodly resistance of 1000 ohms). Note that this corresponds to large surface area contact between two sweaty hands. In practice, the scenario would need to be something like grasping an energized wrench firmly in each hand. How that would ever happen during an installation is a mystery to me.

    Much more likely (as a worst case scenario) would be holding (with sweaty hands) onto an energized screwdriver shank and a live bare wire. The bodily resistance of such a contact would be about 9 times the above - resulting in a current exposure of about 2 mA (at 22 volts) that would deliver a shock but nowhere near the let-go threshold.

    Let's not forget that there has never been a serious injury reported from contact with any circuit under 30 volts. In fact, in a 12-year study from OSHA, there were zero deaths reported from contact with any volltage under 110 volts.

    The 1838 voltage limitation of 15 volts has no authentic scientific basis.
     
  8. steveparrott

    steveparrott Sponsor
    Posts: 1,173

    A further note - the reason I'm taking the time to dispute any claims that lv lighting is dangerous is because I'm working hard to change state laws that restrict lv lighting to licensed electricians. We're introducing legislation that will exempt lv lighting in NJ and will move onto to other states. Half of our 50 states require some form of licensing and there is movement in other states to adopt new licensing.

    Let's all of us, the landscape lighting professionals, deliver clear and indisputable assertions that lv lighting is 100% safe from harmful electric shock. Electricians across the country would love to make people believe otherwise.
     
  9. JoeyD

    JoeyD LawnSite Silver Member
    Posts: 2,933

    Very well put Steve. We are all in this togeather and all this talk of anything non UL 1838 being dangerous and a hazard is just proposterous and simply is not true.
     
  10. pete scalia

    pete scalia LawnSite Senior Member
    Posts: 960

    I will tell you that I've gotten some very real shocks from 12 volt lighting. Try touching a conductor to an open cut on your hand. Try holding two conductors loosely between your thumb and forefinger and you will singe your skin. Also with twelve volts it's not so much the shock risk but the risk of fire due to overheated conditions during shorting and overloads. It's the high amperage that'll get ya there. Better safe than sorry.
     

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