No Amps from my 750?

Discussion in 'Windtura Generators' started by WindyFAQ, Nov 6, 2011.

  1. WindyFAQ

    WindyFAQ WindyNation FAQ Staff Member

    I have had windtura the 750 turbine up for roughly two months now and have only seen it put out 2-3 amps once for about three seconds during a big storm.
    I am not sure what I am doing wrong? I have recently went from 14 awg to 8 awg wire thinking that was the problem. The last couple of days the winds have been 12- 18 mph and the blades are spinning pretty good, still no amps! I took a reading from the three phase AC it reads between 10 - 18 volts ac off of two wires, not sure what it should read? Is that good? I am configured for a 24 volt battery bank. Could the rectifier be bad or perhaps the pma? I am out of Ideas, do you have any solutions or things to try?
  2. Minnesota

    Minnesota WindyNation Engineer

    1. Cable integrity - Disconnct the 3 wires from the 3-phase rectifier and measure the resistance (ohms) between each wire pair with the turbine stopped. They should match reasonable close and be no more than a few ohms per pair.
    2. Rectifier integrity - If the cable is good, then reconnect the wires to the 3-phase rectifier. Now disconnect the 2-wires from the 3-phase rectifier going to the charge controller. With the turbine spinning, a DC voltage should be able to be measured from the +/- terminals of the 3-phase rectifier. This voltage increases with windspeed; 12Vdc or so at 10mph and can get over 50Vdc in high winds. If the readings appear low, put your meter on AC volts and check the AC voltage between each pair of wires connected to the turbine side of the 3-phase rectifier while running. The AC voltage reading should be reasonable close between all 3 readings (A:B, B:C, A:C). If there is a major difference, the bridge is likely bad, or the slip-ring could be defective (if one is used).
    3. Load test - If (1) and (2) prove OK, connect a 12V battery to the bridge while measuring the DC current to it while the turbine is spinning in winds >10mph. Then try 24V. It will take a bit more wind for current to flow in the 24V case. The power produced should be reasonable close to the published power curve for 12V and 24V.

    If all 3 are OK, then the controller you have is the next thing to check. What controller are you using?
  3. windyguru

    windyguru WindyNation Expert

    Tom's suggestions are very good.

    Can you tell us the following:

    1. How high is your tower?

    2. Are there trees or any other structures about as high as your tower that are within 100 feet of the tower?

    3. How are you measuring wind speed? Where is your anenometer mounted with respect to your wind turbine (anenometer height and location with respect to wind turbine).

    I am asking all these questions because it may just be that your Windtura 750 is not "seeing" enough wind. Sure, there might be 20 mph gust but the wind turbine might only be seeing 12 mph gust. To see the kind of amps published in our power curve, you need to mount the Windtura 750 at least 20 feet above all structures within a 100 foot radius (This is addressed in the Owner's Manual). Of course, if the wind is coming straight out of the North and there is a large tree 30 feet directly East of your tower, the tree should have a very minimal effect on the power output of the Windtura 750. But, if the tree is 50 feet to the North of your tower and if the tree is about as high as your tower, it will have a significant negative impact on your power output.

    If you can, post a few pictures of your wind turbine and the surrounding area.
  4. Cable and Rectifier integrity seem to be ok. As for load testing, I am not getting any amps into the 24 volt configuration until very high winds, at which point I see 2-3 amps for a few seconds. My tower is 35 feet high and the only obsticales are trees on the west side about 400 feet away. If the wind is from the north south or east then it is wide open field. I do however have blades from hurricane wind, they are 48". Can blades be making that big of a difference?
  5. windyguru

    windyguru WindyNation Expert

    The answer is most likely that those Hurricane Blades are the culprit.

    1. They are longer than our WindGrabber Blades so they spin slower. Less rpm = less power. How long are those blades when mounted? 100 inch diameter?

    2. They are 3 times heavier than our blades because they are made from steel so they spin slower.

    3. Due to their design, they lack torque. The Windtura 750 is more powerful than the car alternators those blades were designed to spin. The Hurricane Blades most likely do not generate the torque required to match the power curve of the Windtura 750.

    You can try our WindGrabber blades and if they do not improve performance, you can send them back for a full refund .... we will even refund what we charge you for shipping. That is how confident I am that those blades are the problem.

    About six months ago we were trying out some new blade designs for a small wind turbine we developed. I thought I had come up with some nice designs. One of my nice designs made about 3 amps in 25 mph wind. This blade had pretty much the same overall design as our HyperSpin blades except for one problem: It lacked torque at the base of the blade.
    bluejay likes this.
  6. Minnesota

    Minnesota WindyNation Engineer

    Have you seen anyone get any reasonable power from a Hurricane/Prestowind product? I haven't. One guy on YouTube spent a ton of money, put up a nice tower, and never got above 7 volts using their PMA and their blades in good winds. Man was he pissed once he realized he was scammed. Those blades are simple bent flat metal and thus have terrible aerodynamic characteristics, restricting the RPM from getting very high. They don't spin fast enough in normal winds to get the voltage high enough on most PMAs to allow any current to flow to a battery. Go with the WindGrabbers and let us know how it works out.
  7. Thanks everyone for there responses. I will be buying the WindGrabbers and testing them soon. I will leave feedback once they are up and running. I should have bought everything from WindyNation from the start. Great service and very helpful website/forum.
  8. I just finished installing the new winddgrabber blades yesterday. They look great! Last night the winds were 10mph. and I finally saw some amps! What an exciting moment that was to finally see amps being created in only 10mph winds. I would barely get 2 amps in a 20-30mph wind before with the hurricane blades. For anyone out there who may be having trouble getting the amps or volts that there pmas are rated at, I would reccomend trying one of windynations blade sets! They improved my performance greatly!
  9. Minnesota

    Minnesota WindyNation Engineer

    Awesome. Post pics or videos when you can. "You now have your power."
  10. Just an update on the new blades. recently I saw 20 amps!:) and have been averaging 4amps. I can't wait to see what it will produce through the winter months when the winds get around 30mph!;) Has anyone tried moving their windgrabber blades in one hole on the hub to shorten the diameter a bit? Perhaps you could get a few extra rpms and start charging sooner on 24v systems or maybe a few more watts at a given wind speed.

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