Windtura 500 Wire Size

Discussion in 'General Questions' started by TomT, Sep 14, 2010.

  1. TomT

    TomT WindyNation Engineer

    I was running a 12v 500w system on 50ft of 12 gauge wire.

    Noticed on speed up that the turbine would only go so fast and like stall. Current would jump up to 5 amps and quickly go back down. The turbine was erratic and the blades stopped while searching for new air direction. Also alot of noise like a bad bearing. :shock:

    I cut the wire back to 35ft now I get 5 amps, No noise till later and it spins faster and at lower wind speed. The noise is not noticeable till higher wind speeds. Also real smooth while searching for new wind and the blades don't stop while doing this. :cool:

    The internet standard.

    [attachment=0:3lt996yx]WireSize.png[/attachment:3lt996yx]




    After doing some searching I found that the current in a 3 phase is roughly .82 of full current. Which at 12volts 500w would be about 20amps. Reason I ask is if you are using a furling system. Using undersized wire and it stalls the blades while cogging .

    1. The tail will not furl till much higher wind.
    2. The vibration at those speeds can not be good for the system. Or in my case woke me up in the middle of the night.

    [attachment=1:3lt996yx]12vWireChart.jpg[/attachment:3lt996yx]12vWireChart.jpg



    So I will be using the 5 percent chart. Using the 30 amp line. Also Windy Nation Please do another video of the Windtura 500 at 12 volts with the 3 blade windgrabbers.

    So we know how many amps are put out before it furls. That way we can size the wire right so the turbines don't vibrate apart.

    TomT
     

    Attached Files:

  2. Minnesota

    Minnesota WindyNation Engineer

    The truck test video into a 24v battery hit 500w at 29mph and 17.3A. A 12V setup one should expect to see over 30A rectified in the same wind. Maybe safe to design for 50% marging, 45A. 6 gauge runs about $1/ft per conductor in 100' spools.
     
  3. murray2paddles

    murray2paddles WindyNation Engineer

    Tom, you had asked me what wire I was running for my 500.
    As you know I am using # 12 wire and well over 100 ft. I get very good amps, my turbine runs smooth, quiet, catches wind fast and blades do not stall if it has to look for new / true wind when the weather is erratic.

    I am happy to hear your turbine is working better now that you have shortened your wire but how can one turbine of the same watts run & preform so different than each other ?

    For the SWEA inverter system we had to use a larger wire to handle the braking heat of the turbine but the heaviest we had to use was # 8 wire and this is for a 750 watt turbine & I run this one with more wire length than the 500.

    A few years ago I had a stall problem but it was due to using too large of blades on a turbine and also having the shaft of the tail too short.

    I also had a turbine that was noisy and slow to perform till I found out one of the blades were damaged.

    hope you find the solution.
     
  4. TomT

    TomT WindyNation Engineer

    Murray,

    Is the 500w turbine the only one on the 12 ga line? Do you use a slip ring assembly? 12 or 24 volts?
    Mine is stranded wire. Even at 35 ft it is still slowing down but not near as fast as when it was 50 ft. I will be getting high wind tomorrow and will report back more on that.

    TomT
     
  5. murray2paddles

    murray2paddles WindyNation Engineer

    Tom

    Yes the 500 is the only one on that 12 ga line.
    No slip ring.
    12 V. feeding a 1030 amp hr bank
    My first 50 ft is stranded 12 ga. construction extension cord.
    The remaining 50 ft plus is 12 ga. solid.

    How does it turn over when you let it run wild ?
    Is it still slow and noisy.

    Please keep us updated.

    murray
     
  6. TomT

    TomT WindyNation Engineer

    Mines a 530 amp hr battery bank.
    I just checked the extension cord ohms on the line and is 0 ohms. And between the lines is full scale.So no broken or shorted wires.
    No shorted or open diodes in the rectifier.

    Today 12 mph winds and no noise at all. Supposed to be higher tomorrow.

    Any one else using slip rings???? How is your setup doing????
     
  7. TomT

    TomT WindyNation Engineer

    Also forgot to ask is the Windtura 500 a Delta or Wye winding in the generator ???

    [attachment=0:e11na8s7]delta_wye.jpg[/attachment:e11na8s7]
     

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  8. murray2paddles

    murray2paddles WindyNation Engineer

    Tom
    the winding is Wye

    I also gave you some wrong info on my wiring. I have solid wire for the whole 100 ft plus.

    Sorry forgot I changed it over and then used the same color solid wire as the extension cord was. :oops:

    murray
     
  9. mark99

    mark99 WindyNation Engineer

    Tom, I have a system very much like yours.I used a # 12 wire out door extenion cord to feed a 300 amp hour battery bank. It is 40 feet long and I am not using slip rings. I feed a 12 volt system .I have a DC amp meter and offen get 10 to 15 amps in 15 to 20 mph winds. I also do not get any bearing noise but my tower goes into the ground.When I test for resistance I get around 2.5 ohms between the 3 ph legs but it goes up and down before it stops. I always thought it was because of the magnets, I could be wrong. I looked at your pictures and see that you are using a ferling system. I played with that Idea for a while but found mounting my windmill in the center of my bearing assembly to be the most effective.I do not know if that is causing your amp stall but it caused mine. My tower is 30 feet high.I am just sharing my infomation in hopes it will help.Please keep us informed on your progess, thanks Mark
     
  10. bluejay

    bluejay WindyNation Engineer

    Does anyone have a link to learn how to check resistance?
     
  11. TomT

    TomT WindyNation Engineer

    You need an ohm meter.
    Why I was wondering about delta or wye is that if it is a delta it will read high ohms between the wires and the case. If it is low it is a wye.

    Mine is high but I have to measure thru the bearings.

    I was hoping Windy Guru would tell me cause they have them not up on a tower.
     
  12. murray2paddles

    murray2paddles WindyNation Engineer

    Windy is the one who told me it is Wye windings.
     
  13. TomT

    TomT WindyNation Engineer

    If it is a wye it would have to use the ground as a neutral.
    I get no reading from the wires to ground do you? If you do then I have a broken neutral line in the windings.
     
  14. mark99

    mark99 WindyNation Engineer

    Tom, I have checked winding to ground and did not have a reading even at a high ohm setting.I did this with the alternator on the ground.I was puttihg pins in screw cupplings so they could not back out and drilled through the wires causeing a short between two of the legs.The only reason I found it was the blades turned hard when I turned thewindmill.
     
  15. windyguru

    windyguru WindyNation Expert

    Tom,

    We specified wye windings to the manufacturer. They are usually very good about building things to spec.

    If you think the problem is your PMA send it back to us and we will send you a new one.

    Sorry I have not been posting too much on the forum. We are incredibly busy trying to finish up the complete mount and our solar tracker .... not enough time in the day.
     
  16. TomT

    TomT WindyNation Engineer

    Windy

    Would you please check one of the pmas and see if there is continuity from the wires to the case and report back on it.

    TomT
     
  17. TomT

    TomT WindyNation Engineer

    Found more on internet. That wire chart is for single conductor 12v single phase.
    For 3 phase with 3 wires you do this.

    [attachment=0:bln7o1v8]Wiring.png[/attachment:bln7o1v8]

    Also use a voltage drop calculator. :geek:

    http://www.nooutage.com/vdrop.htm

    This makes alot more sense to me for our kind of wind generator.
     

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  18. windyguru

    windyguru WindyNation Expert

    Tom,

    There is no continuity from the wires to the case (checked three PMA's)

    The resistance between phases is about 1.0 ohm.
     
  19. TomT

    TomT WindyNation Engineer

    Windy,

    Thanks then the wye winding for higher current at lower speeds is like this.

    [attachment=0:aucrykdk]wye.jpeg[/attachment:aucrykdk]


    I had it wrong. :oops:

    The neutral tap would be for getting half the voltage and not needed for this pma.
     

    Attached Files:

  20. bluejay

    bluejay WindyNation Engineer

    Something is not right,It takes gale force winds at a 2:1 ration to only put out 125 watts..I can unplug it and watch it spin up till it whizzes and then plug it in and it grinds down to a set spin....This seems way to much loss
     

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