Last night saw another 'event', at about 5:07am I was awoken by a huge gust of wind that shook the house which caused me to shut down the turbine.

Today when looking over my log files the turbine was putting out - well lets just say - well over 5kw... Ok I almost maxed out the inverter at 7540 watts. So needless to say I live in a bit of a violent place as far as wind goes, as the forecast only called for 17mph winds, and we experienced about 50mph.

I am looking into changing things a bit, Flux (from OtherPower.com) gave me an idea is to use the Tristar TS-60 as a straight forward diversion controller, and using a 'something voltage sensitive' to operate the contactor to shut the turbine down. What a simple stroke of genius that I had not thought of before!

In posting the information onto FieldLines.com discussion board, and as it turns out I misunderstood what it meant 'to have a sufficient diversion load'.

I had been using a .6 ohm 6kw diversion load, and I thought that it was sufficient. One misconception that I had was that the diversion controller only dumped excess power to the load. This is not true.

What I found out that a 'proper sized' diversion load means that you have to use Ohms law to calculate the amperage that the dump load has the capacity to draw at a given voltage. I have the diversion controller set to dump power at 57.6 volts using the formula:

(I = V / R) gives: 57.6 / .6 or 96amps.

The TS60 is rated at 60 amps, so what I really wanted is:

(R = V / I) 57.6 / 60 or .96 ohms for diversion load - and this is the minimum resistance that the load should be (still learning)!

So I can easily reconfigure my diversion load so that I have 1.2 ohms : allowing the load to draw 48 amps so as not to overload the controller.

In the past Glen developed a nice small diversion controller that he sells as kits and is making some modifications to it for me that will give me an automatic shutdown, here's how it works:

• The circuit triggers in a similar fashion as a diversion controller, at some preset voltage level.
• instead of diverting power it turns on a relay
• the relay will close my 3-phase contactor, engaging the electric brake (short 3-phases)
• once triggered it takes a manual reset to turn the turbine 'back on'
• it will have a manual override so that I can manually shut down the turbine

I'm ecstatic about this will give me a fall back in case the diversion controller fails (it has happened!).

With a significant emphasis on renewable energy technology deployment and job expansion, the bill improved upon the 2008 small wind tax credit by removing cost caps. This change allows consumers and small businesses to deduct from their tax liability 30% off the installed cost of a wind turbine. The 30% can be applied towards the *entire* installation costs!

If you put your wind turbine into service in 2008 then there is a $4000 cap, if put into service in 2009 there is no cap!

Let me get into the history first:
I have had 'issues' with the original Xantrex C-40 diversion controller. This device is not very responsive and on gusty days (when set to dump at about 58v) on many occasions allowed the battery voltage to climb to 64+volts.

This C-40 has since been replaced with a Tristar TS-60 controller - and is *far* superior to the C-40! Unfortunately for me I had my dump load mis-configured for .8 ohms (rather than 1.0+ ohms) and with some sort of interaction between the Xantrex XW inverter - made the TS-60 fail. Which means *no* dump controller.

The moral behind this story is that no electrical device is fail-proof and I wanted some fall back failure mechanism.

Glen Hurd (http://ghurd.info/) is one of the people on the OtherPower.com discussion board, and in the past he designed a very small diversion controller for small wind turbines (<400watt). In talking with Glen he agreed to modify his circuit board - rather than switch a diversion load, it would drive a relay that would close my 3-phase contactor switch, providing me an automatic turbine shutdown.

In addition he also agreed to do some further modifications so that the controller could exist in a 48v system (rather than 12/24v). As well as making the trigger voltage adjustable so I can raise/lower the voltage as needed.

The circuit works by monitoring the battery voltage, when it reaches a specific voltage the circuit energizes a solid state relay (SSR) which in turn switches on an electrical relay, which in turn engages my contactor switch. In addition once triggered it requires (optionally) a manual reset to re-engage the turbine. This manual reset is optional but I wanted it for heavy gusty days, my belief is that if it triggered in the first place then something must be wrong.....

Currently I have my TS-60 diversion controller set for 57.6v, and the auto-shutdown set for 59.0v. So if the diversion controller fails or a very heavy wind event happens this device should automatically shut down the wind turbine for me.

This am I noticed that the wind turbine had stopped spinning in a 10 mph winds, and it did so 2x in the last day - interesting.

While at the top of the tower I noticed that one side of the stator I could see the air gap, while the other side I could not. My immediate thoughts was that the stator had loosened up a bit and shifted, causing a slight rub between the magnets on one rotor and the stator. It does not take a lot of resistance to keep a wind turbine from spinning...

Finally by 2:00pm it warmed up to about 44 degrees Fahrenheit, and a moderate 8-10mph wind, so after about an hour of preparation up the tower I went and after about an hour I got the telescoping stub lowered..

Sure enough some of the nuts that hold the stator in place seemed to have loosened up. So with extra wrenches in hand (in case I dropped one) I got the stator roughly positioned in about the center between the rotors, and ensured that all of the stator nuts were tight.

Tower envy - what took me 3-1/2 hours to lower the telescoping stub, make adjustments, re-raise the telescoping stub and bring all equipment back to ground level. Something that persons with a tilting tower would probably have taken about 1 hr...

I did have one good thought - rather than using grease on the telescoping post use silicon wire lube that is used for pulling wires! This actually came out of necessity, as I did not have enough lube for the telescoping stub and as a last resort used a tube of pulling lube to get the telescoping stub re-raised. Nice thing about it is that when it dries it turns into a clean white powder - no muss, no fuss - much better than grease in the long run!! It's at least as slippery as grease and in the long run - less messy when you have to climb a tower. So I will continue to use it from now on!

Big recommendation of the day - use silicon pulling wire lube for telescoping tower stub - not grease!

I have to say that it is interesting having a fixed lattice tower, I can't say that I dislike it, as it is virtually maintenance free, and I don't have to worry about the farm animals loosening any guy wires. But you *do* have to be willing to climb, fun - not really, but still interesting in it's own right. After-all I am probably the only one within a 20 mi radius that is willing to climb the tower. After all the work it's really not that bad - just something you kinda have to get used to.

Sure enough I heard some occasional dreaded squeaking! But at least it was not squealing...

It appears that the original problem was probably not that the stator had shifted but more likely that the bearings had loosened up inside the hub and allowed the turbine to sag slightly, thus causing a stator ms-alignment.

This was pretty much confirmed by my log files as the turbine output was less than previously recorded.

So what I had hoped would wait till the end of summer I have to do sooner than later - that is take the turbine off the telescoping stub down to the ground.

I hope to do that within the next week, at least at that time I can do a total teardown and inspection. And when reassembling add some needed additional air-gap so that the turbine is not so stalled out.

I will probably also add some additional offset of the turbine which should help out with my furling issues, and possibly some lightening of the tail vane.

By the end of the day got everything back off the tower.

It also has optional step bolts, 3/8" steel lifeline, custom 12' telescoping stub and davit crane. Has 3 work platforms to stand on, room for two people at the top!

At current pricing tower lists for $5340.

It's value is easily $6.5k and can take up to 20' turbine. Currently setup for 17' wind turbine (not included)

Also comes with 2 electric hoists, one for the telescoping stub (30' cable) and one for the davit crane (90' cable).

Construction details can be seen Here

Will assist in disassembling and even give climbing lessons. Located in WV near intersections of PA/MD/WV, if within 150 miles I have trailer to transport.

Works great - excellent condition - in 6yrs I will be turning 60, and have to look at my physical restrictions and at that time just will be getting too old to climb for turbine maintenance... Replacing with guyed/hinged tower.

Make offer!

I still say that I don't care for the esthetics of guyed towers, and *love* my freestanding tower, I just have to look into the near future and my physical capabilities. Having said that I'm sure that I will adjust to the guys - hopefully I can get my tower sold and get this new one up before end of fall. To that end I am willing to cut a good deal for someone that wants a freestanding tower.

With a bit of time finally I was able to spend a couple of hours inspecting and disassembling the wind turbine. Good thing was that there were no real surprises. The main issue was that the main bearings had come loose (about 2/3 turn of the star nut) which made the rotor 'sag' thus causing the rotor to tilt - and allow the brake rotor to contact the brake shoes.

I was able to double check all dimensions and angles and they are pretty close to the specs of the 17'er on the OtherPower.com site, so at this point in time I don't think that I am going to increase the rotor offset like I originally thought that I might. Previously I reported that I thought that my air gap between rotors was .930", I remeasured using some calipers and it turns out to be 1.070".

With the smaller turbines people don't seem to use the rear seal for the hub/rotor, but I did on mine. It seemed like a little bit of water still got past the rear seal as there was a tiny bit of accumulated rust inside the hub.

I got all the old grease removed from inside the hub and replaced the bearings with a new set as well as new rear seal. I figured that it is cheap insurance to replace the bearings rather than risk reusing the old ones, I did notice a faint 'click' as the rotors were spun slowly by hand.

The rotors were wire brushed and cleaned up a bit, and fresh paint applied to both rotors and stator.

When it does come time to put the turbine back into service I decided that I was going to spin it using my lathe to get the new set of bearings to seat and then readjust the keeper nut. In addition I will be adding about .050" more air gap between the rotors to allow the turbine to spin a bit faster, while I have the turbine spinning I can again take some voltage readings to make sure the cut in speed is not going to be too high.

I am also going to leave off the auxiliary brake as I have been able to stop the turbine by shorting out the stator with no issues.

One last thing that I am doing is lightening up the tail a bit, I removed and weighed the 3/8" tail vane and it seems to weigh in at about 30 lbs. I am going to make a tail vane out of fiberglass/foam core and guessing that it should weigh in at about 15 lbs or so. The new tail vane will be made this week, my friend Paul Schreiner from PS Composites will be helping me since he has all the equipment necessary to vacuum bag it.

The new lift point is just off the centerline of the rotor shaft and as far forward as I could get it, and the cable support now should not be so obtrusive.

And here is the end of the tail which was also changed, end has lighter square tubing with 3 supports for tail vane:

I got the turbine all put back together yesterday and increased the air gap between the rotors by 0.050" using two extra stainless steel washers on all the studs. Then I put it on the lathe to spin it and take some voltage measurements:

Stator with about 1.070" air gap between rotors (previous measurement)

Stator with about 1.120" air gap between rotors (new measurement)

So the end result is that once the turbine is put back into service it should now spin a bit faster. I did not want to go overboard here and was conservative with the air gap, I'd rather have it a bit stalled rather than too loose and un-controlable..

I can always change it but would like to see what the actual turbine RPM's are at given wind speeds, I believe that I can expect about a 10% increase in speed.

I am going to drive the turbine and let it spin for a couple of hours today to help seat the bearings.

Paul is helping me (ok - I am actually helping him) make my fiberglass tail vane today. We are going to vacuum bag it. Previously I had cut out 2 sheets of masonite the shape of the tail vane - plus 1" extra all around. I waxed the mating sides using mold release and then Paul gave them two coats of PVA.

The layup that we will be using is glass cloth, glass matt, 1/8" foam core, glass matt and glass cloth. When completed it should be slightly less than 1/4" thick and extremely strong. In all we used about 1-1/2 gallons of resin, and put in white pigment for UV protection. When done I expect that it should weigh in at about 15lbs.

Here is a picture of the tail vane inside the vacuum bag at his shop you are actually looking at the backside of one of the sheets of masonite that we used (one on each side) to sandwich the layup - hence the brown color - the tail is pigmented white:

However rather than putting the seal into the hub and then mounting it onto the shaft, I did it a bit different in that I put the seal onto the rotor shaft first and then put on the hub with the rear rotor. Once the hub was on I was able to push the seal into the back side of the hub and it worked out ok. With the weight of the hub/rotor it is a bit heavy and hard to control, so I am glad that this worked.

Again chasing the outside rotor with a couple of nuts while assembling, made the whole assembly process much easier.

I used lock nuts, lock-tite (blue) and double nutted the studs that hold the stator in place.

The other week when I dis-assembled the turbine I noticed a slight rub on the front of the stator from the outside rotor. This rub was not at the bottom of the stator where you would think it would be due to the loosening of the bearings, but it was at the 3 o'clock position. This makes sense when you think about it, my turbine rotates CCW (looking at the front of it), and the wind causes lift and pushes at the 3 o'clock position trying to essentially skew it.

It's very strong but I think that if I were to make it over again I would add one layer of polyester cloth to each side to make it even stiffer yet while adding negligible weight to it - but what I have should work just fine.

The new tail vane weighs in at about 11lbs and is 1/4" thick, while the 3/8" plywood was about 30lbs, so it should help a lot with my furling issues. Worst case is that I always can easily add weight.

As I last left it when I took the turbine down, I noticed that I had an issue in lowering the boom crane. At first I figured that some paint chips had accumulated into the support structure. However when I went up to check it out it seemed a bit more...

Turns out that when lowering the turbine/yaw bearing to the ground when you stop/start the electric winch that it put a lot of stress on the vertical boom extension and had actually bent it.

So it took a couple of hours to actually extract the vertical portion and get it down to the ground. I ended up having to bring up an electric winch to pull the pipe through the two retaining collars as I pushed/pulled/turned the pipe manually, not an easy task especially when you are hanging off the side of the tower 60' in the air...

I had to turn the OD of the bar stock down and take about .010" off of it so that it would slide into the pipe easily, I also drilled a hole down the center of it so that water would not accumulate inside the pipe. This bar stock is centered where the pipe is pinned to the collar that allows it to rotate, this was the point in which it bent, so there should be ample support above and below this point. The solid bar stock is welded inside of the pipe so that it will not move.

Got all the 3/4" holes drilled out for the mounting pins, then drilled the slightly oversize and chamfered the holes so that it is easier to insert the pin when up on the tower.

One of the bigger issues is trying to balance out the turbine. Even though I put a new lift point on top of the yaw bearing there is still so much weight in the rotors that it was badly mis-balanced. I ended up putting a short length of chain on the back side of the hub where the threaded rod stuck through as the best compromise. Not great but hopefully more manageable when I am at the top of the tower trying to put the yaw bearing over the top of the stub...

Got the new davit crane boom lifted into place, went in just like I planned it all, had wife as ground crew and she controlled the rope as I eased it into the collars (no sexual connotation overtly implied here). Then got it raised enough to be able to engage the hand winch. Nice! For once every step came off without a hitch and perfectly as planned!

Came down from the tower after I got the davit crane all put back together including the top bar and the diagonal. Wind started picking up something fierce - a weather front started coming through and the wind (just above my rooftop) was measuring gusts to about 16mph so I waited a couple of hours.

Seemed like a little bit of a lull in the wind so brought out the electric winch and turbine out to the tower and again with my wife as ground crew got the turbine put on top of the stub. Hind-sight being what it is I am glad that I tried to balance out the turbine as much as possible, still was a bit of a handful, but easier than last time.

Definitely the added 1" to the height of the electric winch as well as the modification of the cable support closer to the top of the yaw bearing made a big difference and helped make everything go a lot smoother, in spite of the increased 20mph gusts of wind on the top of the tower. Unless my wife was yelling directly vertical I could not hear her over the sound of the wind...

But the turbine is at the top of the tower, and now the tower is not looking quite so empty. Hopefully after the rain passes tomorrow morning I can get the SO cable pulled through the yaw bearing and connected to the turbine. It is doubt full that tomorrow that I will be able to bring up the blades and tail, but taking things one step at a tme.

By not trying to do every thing all at once and spread the work across days it has made the whole process easier both physically and emotionally. Limit my climbs to four a day and limiting the time at the top of the tower has helped a lot to keep from being too fatigued.

The davit crane worked like a champ the little extra height that was added made lifting and positioning everything so much better. At this point I think that at least as far as the tower and davit crane is concerned I finally have everything just the way that I want it, and as such now believe that I am not going to sell it - I like it that much!

The next week the wind forecast is pretty moderate 8 -12 mph winds, so it will allow me to see how the turbine performs at this speed compared to before the last modifications.

In addition it will let me check my PowerDashboard software by having both the turbine and solar panels connected simultaneously and giving me output for each system! It's the only software available on the market that can do that!

So I closed the door and got out an extension ladder on the inside of the door to trace the wiring back to the main opener unit, this is where things went wrong...

Apparently some mice had chewed through the wiring (which made the button not work) and as soon as I wiggled the wires the door started to open - which would push the ladder past vertical. So hastily I scurried down the ladder as fast as I could, did not make it all the way when I finally jumped off the ladder just before it toppled over.

Well they seemed to be right at least on the pain part - initially I did not sleep for almost 3 days.

They put in three screws, each about 3" in length to hold my heel bone in place while mending, but otherwise surgery went pretty much as anticipated. I am required to stay in hospital overnight but by noon was allowed to go home.

Hindsight being what it is - had I taken the precaution of pulling the rope that releases the door from the lift mechanism the last couple of weeks would have been very different.

These graphs show the turbine with the .6ohm load resistor in-line. The anemometer that I am using is about 40' lower than the top of the tower so I figure that it is low at least by 15-20%.

With the new lighter weight tail I've seen it begin furling at about 17mph (realistically 20mph), however we have yet to have higher winds to allow complete furling.