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Extending cable of BigW lights operating on DC Controller

Discussion in 'Lights - Store Bought and Home Made' started by BundyRoy, Jul 20, 2014.

  1. BundyRoy

    BundyRoy Senior Elf

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    I need to extend the wires on some of my bigW lights. I am running them through one of Alan's 2811DC 30 controllers on around 29V. They are a string of 200 Leds and I will run them as two banks. ie put one of the wires that used to come from the controller in the v+ and the other two in outputs 1 and 2.

    I need to extend them by say 10m. What sort of current do these strings draw so I can work out the voltage drop with different size cables. What sort of voltage drop do you think is acceptable. The strings say 10VA (10W) on the power transformer. The cables (wire) used measure around 0.6mm in diameter from memory (measured it a few days ago and getting old). Some sections of these lights are wired in series aren't they? How does that effect my calculations.

    Thanks for your help.
     
  2. David_AVD

    David_AVD Bite my shiny metal ass!

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    I've used 4 core security cable (14/0.20) for extending Big W strings. More than man enough.
     
  3. gnarmstr

    gnarmstr Full Time Elf

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    You will not need that size cable as a 100 led string (you will have 100 per channel) is below 200mA and there will be very little voltage drop.

    I run 200 led (per channel) strings on my mini trees and use cat 5 (8 wire) to give me 6 channels plus the other two wires as +v over a distance of 17m and they look very bright. My Cat 5 is only 23 AWG.
     
  4. aussiexmas

    aussiexmas Sinnamon Lights

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    Hi BundyRoy
    Some years back, there were a series of posts on Big W string current draws. eg http://auschristmaslighting.com/forums/index.php?topic=362.msg2600#msg2600


    The current depends on the applied voltage, but at 29 to 30 V, none of the colours draw more than about 200ma for the entire string. You can design happily at 10ma/bulb and the 200 bulb strings have 2 channels each with 10 parallel segments of 10 bulbs each. ie 2 * 10 @ 10mA/segment = 200mA.


    For most of my extensions, I have used 'light speaker wire' (14 * .14mm), but now also use security cable (7 * .2mm). With this cable for extensions of 20+ metres, the cable will handle about 1 Amp with minimal voltage drop. You can run several Big W strings at the end of a 20 m extension without seeing a voltage drop effect on brightness.
     
  5. OP
    OP
    BundyRoy

    BundyRoy Senior Elf

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    Thanks. Glad I asked. I have some 4 core 14/0.2 left over. Thought I might need something bigger and was working out what to order. No need now. Love it when a plan comes together.
     

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