Air-X Modification

System
System Posts: 2,511 admin
Hello

Two weeks ago my Air-X circuit board and stator fried up during three days of gale force winds. Well after much thought (should I fix it or just live without it), I decided to fix it again but this time make some modifications and remove the controller from the turbine and place it somewhere more accessible and reachable, i.e. at the bottom of the tower. I took the stator locally for rewinding and that's fixed, then modified the yaw shaft so that I will run the three wild phases down to the bottom of the tower. Add a three phase rectifier and the job is done.... or should be! Is it that simple? Could this simple setup work?

Basically, I'm not sure if to replace the controller or not. I'll try to fix it myself, however If I don't manage should I purchase a new one? Can the Air-X live without it?

The factory controller had an inbuilt overvoltage protection for the batteries. This is not an issue for me since 1) I have a large battery bank and after 6 years of use, the AIR-X never stalled due to fully charged batteries. 2) I can always plug in a diversion load.
The controller had also an over speed protection. This is something which I'm not sure about if I should have again. From the little information I found, the Air-X Industrial does not have an over speed protection... can someone correct me if I'm wrong? My idea is that when it's too windy, I'll shut down the turbine myself (well I have been doing this for the last 6 years...)

Any thoughts are more than welcome!

Regards
Brian

ps. I have attached two photos of the modifications done... The new brushes holder and the yaw assembly. A spacer have been placed on the bottom slip ring to isolate it from the turbine housing since this was previously used as the earth connection.

Comments

  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Air-X Modification

    hmmm. if you want to plan on continuing to use the turbine then why not improve upon it? maybe new controller, blades, and longer and larger tail? i'm not too sure of the parameters surrounding the turbine's controller requirements, but i wonder if the new classic controller would fit your requirements for it? it may be worth your looking into.
  • keyturbocars
    keyturbocars Solar Expert Posts: 375 ✭✭
    Re: Air-X Modification

    Brian,

    Sounds like you will be OK with eliminating the controller and just wiring your rectifier output directly to your battery bank. You said that in 6 years you've never had the turbine shut down because of fully charged batteries anyway, so you're probably OK just keeping an eye on your battery bank voltage. You also said that you've shut down the turbine manually anyway if the winds got too high. If you have a way to short out the 3 phases of the turbine, then you'll probably be OK shutting it down manually.

    If you had a much bigger turbine capable of outputting much higher power output, then this would be much more dangerous. In my opinion, it sounds like it'd be fine with your setup.

    The only thing I can think of is that your turbine might be noisier without the controller. My understanding was that the Air-X controller was designed to also slow the turbine at a certain RPM to prevent the blades from overspeeding and becoming very loud.

    Edward
  • Brianellul
    Brianellul Solar Expert Posts: 95 ✭✭
    Re: Air-X Modification
    Brian,

    Sounds like you will be OK with eliminating the controller and just wiring your rectifier output directly to your battery bank. You said that in 6 years you've never had the turbine shut down because of fully charged batteries anyway, so you're probably OK just keeping an eye on your battery bank voltage. You also said that you've shut down the turbine manually anyway if the winds got too high. If you have a way to short out the 3 phases of the turbine, then you'll probably be OK shutting it down manually.

    If you had a much bigger turbine capable of outputting much higher power output, then this would be much more dangerous. In my opinion, it sounds like it'd be fine with your setup.

    The only thing I can think of is that your turbine might be noisier without the controller. My understanding was that the Air-X controller was designed to also slow the turbine at a certain RPM to prevent the blades from overspeeding and becoming very loud.

    Edward

    Thanks for your reply!

    Yes, I'll be shutting down the turbine manually in case of very high winds. I was thinking of passing the three phase from the turbine through relays before being fed into the rectifiers. In high winds, the relays will disconnect the rectifiers and short the phases toghether.
    When shorting the windings, the turbine will still turn slowly... I'm assuming that this will not produce any power and therefore heat the windings. Am I correct?

    I will be trying to diagnose/repair the AIR-X circuit myself, in fact already located the three faulty mosfets! My only problem is that there is a surface mount component (I think it's a small capacitor - C10) connected between the ground (earth) and negative which blew up and don't know it's value... well I'll post my findings if I manage to fix the circuit.

    Regards
    Brian
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Air-X Modification
    Brianellul wrote: »
    When shorting the windings, the turbine will still turn slowly... I'm assuming that this will not produce any power and therefore heat the windings. Am I correct?
    In theory, that is correct.

    In practice, there have been a few reports here of some turbines failing from overheating the stator in very high winds (I don't remember the brands).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • MisterB
    MisterB Solar Expert Posts: 156 ✭✭
    Re: Air-X Modification

    You don't want to short the 3 phase lines together when the turbine is turning in high winds. This could create currents that could damage the stator. The turbine should be stopped or turning at a low rpm to brake it with a direct short on the 3 phase lines. To slow it down in high winds, you need to put some sort heavy--low but not zero resistance--load either accross the 3 phase lines or on the rectified dc line.

    I am working out a high wind braking circuit for my turbine and I am opting for a delta load of at least 300 watt resitors across the 3 phase lines. I have been taking voltage readings between the 3 phase lines to work out resitor values. I am going this way due to the controller I have. It would be simpler--and cheaper--to put a manual dump on the rectifed dc line--only one power resistor instead of 3 and a 1 pole switch instead of a 3 pole switch or relay.
  • Brianellul
    Brianellul Solar Expert Posts: 95 ✭✭
    Re: Air-X Modification

    Hmmm, good that I've asked then! I would have burnt the AIR-X stator a second time if I would have just shorted the phases. I think that the original AIR-X circuit shorts out the phases then!
    I have some large (power) wire-wound resitors which I could use and connect them directly at the output of the rectifier.

    Thanks


    - I've attached a couple of pics showing the modifications of the yaw assembly ready.
  • keyturbocars
    keyturbocars Solar Expert Posts: 375 ✭✭
    Re: Air-X Modification

    Brian, Your Air-X rebuild looks good. If you are able to do a 2 stage shut down, then that would be safer. First load down the turbine with a heavy load to try to slow it down, and then short out the 3 phases to try to slow/stop it further.

    From what I've read, if you short out the 3 phases of a turbine and it is still spinning fast afterwards, then it is best to flip the breaker and un-short the 3 phases as soon as possible. Apparently, if the 3 phases are shorted out and the turbine is still spinning fast, then that is where the windings can quickly burn out.

    I think there are many small wind turbine where the manufacturer uses the shorting of the 3 phases as the primray means of braking. Sounds like under certain high wind conditions, this is not good enough. Apparently, there is a "point of no return" where a turbine can be spinning so fast that shorting the 3 phases will not work to slow/stop it. In those cases, it is best to try to slow the turbine some first before trying to short out the 3 phases.

    I hope everything works out well with your new wind turbine system.

    Edward
  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    Re: Air-X Modification

    I have a friend who was trying to install his 6 blade Air-X in strong winds last week. I told him to short the wires to prevent the blades from turning but couldn't stop the blades. His wires started to warm up so he stopped. Of course my advise cane from the manual and before I read comments on this forum. 
  • keyturbocars
    keyturbocars Solar Expert Posts: 375 ✭✭
    Re: Air-X Modification
    tonygcan wrote: »
    I have a friend who was trying to install his 6 blade Air-X in strong winds last week. I told him to short the wires to prevent the blades from turning but couldn't stop the blades. His wires started to warm up so he stopped. Of course my advise cane from the manual and before I read comments on this forum. 

    Did he just take down his Air-X or did he let it free spin in the high winds?

    He was definitely brave trying to set up a wind turbine in strong winds. Whenever I raised or lower my wind turbine tower, I tried to wait for dead calm if possible.

    Edward
  • tonygcan
    tonygcan Solar Expert Posts: 91 ✭✭✭✭
    Re: Air-X Modification

    Apparently the nut of his hub came loose and fortunately no one was hurt when the blades fell into a bush below. Minor scratches on some blades. He applied locktite and tried to reinstall the blades during really windy conditions but aborted when he couldn't get the blades to stop spinning by shorting the wires.

    And yes you're right. It does say to wait for ideal conditions when raising up the pole.
  • Brianellul
    Brianellul Solar Expert Posts: 95 ✭✭
    Re: Air-X Modification
    tonygcan wrote: »
    I have a friend who was trying to install his 6 blade Air-X in strong winds last week. I told him to short the wires to prevent the blades from turning but couldn't stop the blades. His wires started to warm up so he stopped. Of course my advise cane from the manual and before I read comments on this forum. 

    I would suggest to advise your friend to pay extra attention to the 6 blade modification. I had modified my turbine my changing the 3 blades and replaced with longer ones (bought them from ebay). Well, due to the extra torque and greater swept area, when the internal controller shorts the stator, the turbine WILL not stop turning and that's why (most probably I fried my controller + stator).
  • mtjag
    mtjag Registered Users Posts: 32 ✭✭✭
    Re: Air-X Modification

    those of you with experience on the AirX, please let me know if you would buy this unit again. If not, please direct me to an alternative that might be better.
    Thanks
  • Brianellul
    Brianellul Solar Expert Posts: 95 ✭✭
    Re: Air-X Modification
    mtjag wrote: »
    those of you with experience on the AirX, please let me know if you would buy this unit again. If not, please direct me to an alternative that might be better.
    Thanks

    With that price tag NO WAY! It does produce power but not what has been advertised. Apart from that, in five years it fried twice the internal regulator and lately also the stator.
    I won't dump it yet, in fact I'm making modifications to extract a couple of more years service from the turbine.
  • MisterB
    MisterB Solar Expert Posts: 156 ✭✭
    Re: Air-X Modification

    Yesterday, there were 30-50mph winds and I had my turbine braked. The winds were strong enough to spin the prop even with the 3 phase lines shorted and I took a current reading of the AC current through the 3 phase lines. It was between 3 and 7 amps. I turned the turbine on in the afternoon and this morning when the winds had slowed to almost nothing and the turbine was spinning at below cut in speed, I shorted the 3 phase lines and measured the current. It surged to a little over 20 amps at a very low rpm so you can imagine the currents you will get shorting the windings at high rpms. Not a good way to brake a turbine spinning fast. Braking by putting power resistors across the 3 phase lines--or the DC line--is much safer.
  • keyturbocars
    keyturbocars Solar Expert Posts: 375 ✭✭
    Re: Air-X Modification

    Good info, MisterB. I agree that it's better to try to load down the turbine before trying to slow it. Nice to see some actual numbers as to the type of surges that are possible.

    Edward
  • Brianellul
    Brianellul Solar Expert Posts: 95 ✭✭
    Re: Air-X Modification

    Thanks to all for your posts!

    My modified Air-X is now without its internal regulator and I'm running the 3 phases down the tower to a control box were I've placed the 3 phase rectifier.
    I'm a bit confused regarding braking! I always thought that shorting the phases will achieve the best braking system since the turbine will be very hard to spin... and therefore unable to produce any power, however I'm not sure anymore from your measurements... and I don’t want to burn the stator of my Air-X!
    I have the following questions;
    1) Where is the best place to brake the turbine? Loading/shorting the phases or the DC output?
    2) Shorting the phases abruptly during high winds heavily stresses the turbine (I’ve tried it yesterday during a light breeze and the tower shaked once I shorted the phases) , therefore are you suggesting to first slow it down i.e. putting a couple of high power resistors across the phases and then shorting the phases down?

    Thanks
  • MisterB
    MisterB Solar Expert Posts: 156 ✭✭
    Re: Air-X Modification

    The best way to brake a turbine spinning in winds more than 12-15 mph is to use a low resistance load first and then short the 3 phase wires. I am working on a braking circuit right now and doing these measurements is to give me an idea of currents and resistance values needed. I am going to use 3 300 watt power resitors in a delta configuration across the 3 phase lines connected to a safety switch that is normally open. First I will apply this load and when the turbine slows down, I can safely short the lines. I also measured AC voltage between the phases--the voltage that is rectified is aproximately 1.414 times this voltage-- and, with the battery bank connected, this voltage reaches around 12.2 volts rms when the turbine is spinning pretty fast. I'm not measuring rpm at the moment but the charge current at this inter phase voltage is around 20 amps so I'm looking at maybe .5 to 1 ohm 300 watt resistors and a 30-60 amp switch. The biggest dump current I've seen in the 3 phase lines has been around 20 amps and I'm using that for reference. Right now, I can brake the turbine in the daytime when the batteries are charged by flipping the equalize switch on my solar controller which forces the wind controller into dump mode and holds it there and then I flip the switch that shorts the 3 phase lines.

    Basically, I'm using balast resitance to limit the initial braking load and once this slows the turbine down, the 3 phase windings can be safely shorted. I prefer loading the 3 phase lines in a delta load because this won't affect the DC side of the controller. If I had a simpler relay based controller, I would just mod it with a manual dump switch but this controller is microprocessor controlled with solid state switches and I haven't found any easy way to do this.
  • System2
    System2 Posts: 6,290 admin
    Re: Air-X Modification

    Sorry if it not the reight place, but.

    It seem that here is a lot of expertice so I want to ask:

    I want to know whey ?

    Bewfore I had an air-x and was happy for an year, then it start to spin up and shot down, messur a litle and then spin up and shot down.
    I sen it to repare and got it back a litle wheil lather, but but, it was just for short time. Then I got a compleat new AirBreez insted.

    It was both a + and a -. Lesser noice but also lesser w. Still it was an ok junit for me and my needs.

    But now 1,5 years lather I have the exact same problem. Spin up shot down, over and over.

    I wonder whaat is wrong ? where is the problem ? something I can do ?

    My tecnical spec.

    5m x 6mm alu wier.

    batteries:

    Banner Energy Bull batteri 230Ah/12V

    - Dimensioner: 517x273x 212/240 mm
    - Vægt: 48 kg
    - Kapacitet K5: 180Ah
    - Kapacitet K20: 230Ah
    - Kapacitet K100: 250Ah
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Air-X Modification

    One possibility...
    5m x 6mm alu wier.
    If you have aluminum wire--check all the connections. Aluminum will oxidize almost immediately on exposure to air (oxygen). Aluminum Oxide is a very good insulator.

    If you have a bad connection, you may see some browning/blackening from heat.

    You should take apart each connection and apply aluminum wire antioxidant paste to help keep the connection from corroding.

    Aluminum Wiring Problems for Homes

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
    Re: Air-X Modification

    Thanks for the answere, but

    I did that when I experied the problem with the air-x. I split all apart and put it together again, but the problem continued. Then I send it ti repare and got it back. Then it was ok for a short period, but start all over.
    Then I got that breez and put it on. Then I have just cut the air-x of. Now when I put the breez on it start and have run since.

    If I shortcut With the switch, it it stop as normal. If I for a short while remove the pols from batteri is start and go normal unto it has stoped first for messerin then it start that spin up and shot down.

    I think it is something in the turbin.
  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Air-X Modification

    I do not have a wind turbine--but another failure point can be the Slip Rings and their wiring.

    In general, wind turbines require a lot of repair work to keep going... One reason, on this forum, we tend to recommend people get solar panels instead (if they have good sun most of the day).

    Another possible failure point is the rectifier (usually a 3 phase diode bridge).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2
    System2 Posts: 6,290 admin
    Re: Air-X Modification

    All this weekend I was out sailing. My batteries was at the start 12,7 and at the end 12,1. The turbin all the time maked that start and stop. Maked no power.
    When I got home I start carage my batteries from the net. To day when I wend to the boad the generator worked propaly.
    Now I really became a BIG ?

    can you help telling me what gos on.

    karsten
  • fixer
    fixer Registered Users Posts: 12
    Re: Air-X Modification
    karsten wrote: »
    All this weekend I was out sailing. My batteries was at the start 12,7 and at the end 12,1. The turbin all the time maked that start and stop. Maked no power.
    When I got home I start carage my batteries from the net. To day when I wend to the boad the generator worked propaly.
    Now I really became a BIG ?

    can you help telling me what gos on.

    karsten
    Not sure what you are asking. Is this a new one or a old used one? The new ones have a CPU in them and that makes a lot of changes depending on the conditions, but one thing is that it needs 12V to operate so the battery must always be connected for the CPU to work.
  • System2
    System2 Posts: 6,290 admin
    Re: Air-X Modification

    Hi Brianellul,
    could you describe how you bypassed the internal regulator and how you wired to youre own external regulator. Wha is your experiance so far to this imrovment. I myself i´am thinking doing the same with my own Air-X.

    Regard
    Jan
  • Brianellul
    Brianellul Solar Expert Posts: 95 ✭✭
    Re: Air-X Modification
    Aussiejj wrote: »
    Hi Brianellul,
    could you describe how you bypassed the internal regulator and how you wired to youre own external regulator. Wha is your experiance so far to this imrovment. I myself i´am thinking doing the same with my own Air-X.

    Regard
    Jan

    I have blogged about it here

    Not much time to write my experiences but at least I've started!
  • MisterB
    MisterB Solar Expert Posts: 156 ✭✭
    Re: Air-X Modification

    I looked at the blog.

    Running 3 phase from the alternator to a rectifer and control box on the ground is the way to go. The more I come to understand how 3 phase works, the more I like it. Running raw 3 phase from the turbine to the gound gives you a lot of flexibility to adapt the rectified DC current and voltage to your system when you get it to the ground. Good work Brian.

    Dave.
  • Thomas
    Thomas Solar Expert Posts: 291
    Re: Air-X Modification

    Hi, I am suck a chicken about foolin' with my air-x, is that brush assembly in the thumbnail the actual one in the air-x? Can the regulator be removed and the rectifier and output intact? Any info you can give me would be appreciated.
    Based on positive support numbers I think the Air -x can handle very very strong winds if loaded, off the auto-brake. Free wheel I wouldnt try.
    Always troubleshoot with adequate sunlight.  Hi Ho Hi Ho
    2.3kW [10] Enecsys SMI-240-60 micro inverters

  • Thomas
    Thomas Solar Expert Posts: 291
    Re: Air-X Modification

    Hi I just read your blog, It seems as though it is custom built. I am having a lot of trouble finding out how to reconnect the stator wires, they're still labeled and do not work 'wire bundled' as described in the circuit replacement nonmeclature. South west wind states they cannot support re-wiring the stator an suggest a new one.
    I do not see a wire bundle in your picture. Do you have it wired in series or a wye? Do you know how sww had it wired ? Any help would be appreciated, it is purchased, stored for a few years and its up solidly now and not working...!!! I shuolda tested it before I mounted it.
    Always troubleshoot with adequate sunlight.  Hi Ho Hi Ho
    2.3kW [10] Enecsys SMI-240-60 micro inverters

  • Galileo
    Galileo Registered Users Posts: 1
    Re: Air-X Modification

    Hello Brian Ellul and Thomas,

    When you disconnected the Stator from the Circuit Board what were those connections like? On page 29 of my Air-X manual it appears that there are four (4) leads that come from the Stator and attach to the Circuit Board. Is this a screw connection? Were these screws hard to unfasten? Were they Locktite?

    I am trying to determine if a loose connection somewhere in my system, including any that might be possibly loose inside my Air-X is causing the situation that I am experiencing.

    Thank you in advance for any comments you may have.


    Galileo