anyone with H80 problems?

Ralph DayRalph Day Solar Expert Posts: 985 ✭✭✭✭
Has anyone out there got problems with the bearings on their Southwest Windpower H80 units? Mine is 3 years old and at low productions...100-200 watts (windspeed unknown) it will transition through a shudder from low speed to moderate speed. There's no problems at low low speed or higher speeds, just the interim where a good deal of it's time is spent.

What have been other's experience with the bearings and bushings on the H80 units...how much play, how fast to they deteriorate, anything you can tell me would be helpful. Is it much a job to replace the bearing? etc.

thanks

ralph

Comments

  • BB.BB. Super Moderators, Administrators Posts: 32,741 admin
    Re: anyone with H80 problems?

    If it is a bearing caused shutter--your best bet is to pull it down now before it does further damage to itself (vibration/sudden seizures throwing blades or fracturing a shaft somewhere, bearing chatter beating out the casting, bearing inner or outer races spinning on shaft, fretting wear on shaft/housing, metal particles getting on slip rings/magnets, etc.)...

    It will not fix itself. (I do not have any experience with wind turbines--just mechanical stuff in general). 3 years sounds (depending on your average winds--I would guess) sounds like a normal life for standard bearings...

    Take car alternator. Lasts 200,000+ miles. Average speed is about 35 mph (have GPS that measured my average speed for the last 20,000+ miles)...

    200,000 miles / 35 mph = 5,700 hours of operation.

    So, 5-10,000 hours of operation sounds approximately correct for sealed ball bearings (if that is what they are). How many hours are on your unit?

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Ralph DayRalph Day Solar Expert Posts: 985 ✭✭✭✭
    Re: anyone with H80 problems?

    Good question, i used to keep daily, then weekly, now monthly (when i remember) track of KWhrs in from sun, wind and genset. Now, i notice when things aren't right...internalized a lot of cues about the system. For instance, if your nightly battery discharge is more than "normal", look for lights left on in garage, uv timer "on" all the time...such like that.

    I think i'll drop the tilt up tower this weekend and give the turbine a wiggle to check play in bearings. Maintenance is cheaper than replacement.

    ralph
  • BB.BB. Super Moderators, Administrators Posts: 32,741 admin
    Re: anyone with H80 problems?

    If you have the tilt-up tower--it sounds like the thing to do.

    I always wondered about installations where you have to rent a crane for service--seems to eat most of the savings that wind power may offer.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: anyone with H80 problems?

    tiltup towers are so expensive. wish i had a few.:D
  • System2System2 Posts: 6,290 admin
    Re: anyone with H80 problems?

    Ralph,

    Is your H-80 still able to make 800-1000 watts?
  • Ralph DayRalph Day Solar Expert Posts: 985 ✭✭✭✭
    Re: anyone with H80 problems?

    I dropped the tower and replaced the original blades (which i'd shortened) with a new set which SWWP had sent me last year. Once the wind picked up again there was still a little transitions shudder, but not as noticable as before. Think i'll sit tight and see how things go.

    There was a little play in the pivot bushing, but not a great deal. No discernable play in the thrust bearing (which the rotor rides on/with).

    ralph

    ps the turbine still provides peaks of 1200 watts, sustained 800-900 when the wind if whistling.
  • Solar GuppySolar Guppy Solar Expert Posts: 1,989 ✭✭✭
    Re: anyone with H80 problems?

    The blade you cut down, unless balanced would be what caused your bearing issues. VERY importaint for any type of rotating mass
  • Ralph DayRalph Day Solar Expert Posts: 985 ✭✭✭✭
    Re: anyone with H80 problems?

    SG,
    the blades were weighed to within 1 gram of each other when cut down from original length, but that is only total weight. If the roots of the blades were different in thickness, and i removed weight by cutting off the tips (as i did), then there could have been problems during rotation due to where the mass was...root vs tip.

    I'll update as the fall progresses and the winds increase, hopefully there won't be any fallout from the time there was vibrations in the unit.

    ralplh
  • BB.BB. Super Moderators, Administrators Posts: 32,741 admin
    Re: anyone with H80 problems?

    Also look for signs of rust stains/red-black powder (fretting) around the bearings, shafts, and housings. It is possible to see this before you can feel the bearing going bad.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Ralph DayRalph Day Solar Expert Posts: 985 ✭✭✭✭
    Re: anyone with H80 problems?

    Thanks for the pointers Bill, but even when the power head is in your lap you can't see anything without taking it apart. I long for the Bergey yearly maintenance...go out, look up, if it's turning you're OK. Unfortunately Bergey didn't/doesn't make a 1kw 48v model.

    ralp[h
  • System2System2 Posts: 6,290 admin
    Re: anyone with H80 problems?

    Ralph:
    I am currently flying one H40 (Sn0003) and three H80/W200;s or whatever they call them this week. I have close to 10 years run time on the H40 and have seem several bearing failures all of which were replaced at the factory. 10 years of wind data shows a 10.2 average at 30' but a recent addition of a anomometer at 62' on a 80' tower has initial data showing close to 12.5mph.
    If the question is does anyone with H80/W200's have problems my answer is yes. On a 80' LMWS 4" tilt tower my new W200 has vibration problems that I feel are more than the usual start up vibrations. I feel the 10' NRG crosspiece holding the anomometer and the jello like transmission capabilities of my 150% over spec tundra mounted anchors merely magnify the inherent vibration characteristics of the Whisper series. The vibration seems to increase with the windspeed and furling of the unit. Any input would be appreciated.
    092407-3.jpg
  • BB.BB. Super Moderators, Administrators Posts: 32,741 admin
    Re: anyone with H80 problems?

    I will give it a shot... But I don't think I have any magic solutions...

    Problem is you have a thin metal rod, and lots of metal guy wires. All of these are marvelous springs with virtually zero damping. Any spring will want to vibrate at frequencies related to its size, mass, and "springy-ness" (modules of elasticity--if I recall correctly). And there are only several ways to address those problems.

    1. Reduce the energy input--hopefully your rotors are balanced and you have at least three bladed props.

    There is a possibility--although it may be unlikely, that you could be getting vibration in the pole or on the guy wires directly from the wind... If so, try wrapping a cheap large diameter rope (like 1/2" or bigger???) around the pole from top to bottom in a spiral. It can prevent the wind from forming large eddy currents (look at the antenna on a modern car--it is not a pure cylindrical shape anymore but uses a spiral shape to prevent whistling).

    2. Change the natural frequency of resonance... Perhaps tighten or loosen the guy wires a bit. Bolt a weight up towards the middle of a few of the guy wires. That 10' cross bar--shorten it (or remove it), lighten it to reduce bending moment (try adding a light guy and pull the cross bar one direction, just a bit, to prevent it naturally winding back and forth in the wind). If you need the cross bar, try adding two light guy wires to prevent it swinging back and forth.

    Add additional guy wires and guy collars between those collars already installed.

    3. Take the energy out of the system--I am not sure what to do here--normally one would use the equivalent of shock absorbers and rubber bushings to dissipate excess energy as heat. And large free standing wind turbines may have hydraulic tanks where they can pump water back and forth to kill vibrations (not practical here).

    From what I can tell of your pictures--other than the cross piece--it seems you have plenty of guy wires and my suggestions of adding a spiral rope up the pole probably would not do any good--probably not enough energy at the right frequency to be causing your problem).

    From a quick search of the internet, you are not alone with these problems and if somebody came up with an easy solution they could make good money.

    If you can identify the actual problem vibration (there may be more than one mode)--is it bending where you could add guy wires at the middle. Is it twisting (perhaps adding a collar with an arm/cross piece sticking out--and adding two wires to prevent twisting), etc....

    If you have a good mechanical engineer in your area (looks like a beautiful piece of property in the middle of nowhere)--they good give you some better ideas.

    Sorry,
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • System2System2 Posts: 6,290 admin
    Re: anyone with H80 problems?

    Bill
    Thank you for taking the time to provide a very good "shot" at the issue. The first problem I have is how to determine if I really have a problem because I can find no way to specifically express the amount of vibration. Everyone agrees that the Whisper series has start-up vibration visible in the tail feathers or at least I do on all four I am flying. The issue to me is how much is designed into the product and how much is magnified by my conditions.
    I am experimenting with movie clips with a still camera but have not been successful yet. I believe once I capture that anyone would concur that the vibration past start-up is excessive and will lead to future problems. The ends of the crosspiece will vibrate at least an estimated 3" at the extremities and all four guy wires will have that much travel in the center.
    Your description of the pole/guys as a splendid combination of vibration enhancing springs is spot on. I have tried tuning the guys within the number of oscillations spec from LMWS that has a different time period for 20 oscillations for each level of guy wire but there is not much latitude and it is not an exact science. I have tightened it to the point where the tower pipe sections begin to bow then I back off. All of this while maintaining some sort of plumb is a challenge. All I do for plumb is use a 6' level on the lower pipe then eyeball the upper three sections for plumb by viewing from different angles from the base. Add in the effect of a varying wind speed and it becomes interesting trying to maintain the oscillation spec and plumb. I have a good friend who puts nothing but data gathering towers for big wind and he claims he tensions the guys by nothing but feel but I don't know if I am there yet.
    Before I venture further into tower rocket science thing I would like to be more confident my problem is not the turbine/blades creating a unique problem that is being magnified by my conditions. When I first contacted LMWS about this issue they said they have the identical tower running the same turbine without vibration issues. We revisited the guy wire tuning described above and they concurred that they were within spec and that I should fix the turbine. When I contacted SWW we checked the transition to braking in hopes of seeing a vibration but saw a smooth transition which led them to conclude the controller was a possible problem when transitioning to regulate mode etc. I replaced the controller(which had several other issues) and it resolved nothing. It is I think noteworthy that my vibrations can be characterized as evident throughout the entire rpm range but more noticeable at higher rpm. Furling complicates this by making it more visible above furling speed but the problem is still there below furling speed. SWW also asked me to lower the tower again and measure blade end tip distance to ensure balance. I am all for that and anything else that could be done to identify a out of balance condition. If a delta in blade tip measurement was found the only contributors I can see are the blades themselves or mounting bolt hole placement on the hub. I don't know if I have a accurate enough scale to weigh them with but will try. Since my bride and I are in our mid sixties and alone with just a grip hoist I would prefer to keep the tower raising/lowering to a minimum and have asked SWW to send me set of blades/hardware to try. After doing that and double/double checking the rest of usual suspects I think it is time to try some of your suggestions with the tower. Are you aware of any links that have the basics of aerodynamics concerning airflow around a tower with a blade revolving in front? Just curious to know how it interacts.
    My hopes in posting here was to find out what if any vibration issues are evident on other 80' Whispers and to solicit ideas like yours on how to minimize my vibration. Thanks again for the input
  • Ralph DayRalph Day Solar Expert Posts: 985 ✭✭✭✭
    Re: anyone with H80 problems?

    UBOB,
    How are your anchors fixed? My guy cables are tightened as much as i can by hand, that's pulling down with one hand and up with the other and the spouse tightens the cable u bolt. There's quite a bit of "belly" in each cable, maybe from base to tower...8-10 inches (tough to guestimate). Each pair of cables are tightened equally (or almost) to keep the tower straight.

    The guys are anchored with expansion anchors which are drilled into limestone 4 feet, the rod is then tightened into the expansion chuck and goes nowhere. How do you anchor in permafrost, or do you stay above it? What happens as the permafrost melts, seasonally and as the climate warms? I know what kind of forces act on the turbine and tower...i try not to watch the top 5 feet bend over in heavy winds (40mph and over).

    Oh, and we don't brake anymore. I was wakened one night by the blade tip flutter (aka farts of the gods) when the turbine was braked...no damage mainly because the wire run is about 400 feet of #6 wire. But since then, we don't bother, that and SWWP sent me new, stiffer, 9'diameter rotor blades. There must have been enough customer complaints about the noises. With your number of turbines, you must have some sleepless windy nights!

    ralph
  • BB.BB. Super Moderators, Administrators Posts: 32,741 admin
    Re: anyone with H80 problems?

    Can you remove your hub and blades (keep attached) and have a "through" hole in the hub?

    If so, you can use a prop balancer to check your blades and see if they are balanced when installed (just weighing the blades is not good enough).

    You can probably build one if you have a small lathe (quick article describing the basics), or if you have a local airplane mechanic--check to see if he has a prop balancer setup. You would have to find out from SWWP on how they add/remove weight from a blade when they balance (file end, paint, sand, etc.).

    Otherwise--just adding more guy wires in the middle of un-guyed sections is all I can think of off hand...

    Good Luck!
    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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