Author Topic: shorted coil?  (Read 7783 times)

0 Members and 1 Guest are viewing this topic.

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
shorted coil?
« on: September 07, 2014, 12:31:20 PM »
I have a five phase hugh piggott 500 watt turbine.  It is ten coil, with all the coil starts connected and all the coil finish wires connected to 5 rectifiers.  When building it, I had to add a solder splice to two coils to get the proper amount of turns. 

This turbine is currently on  a 40' utility pole.  I thought it was shorted at the yaw bearing as I had to lower the turbine once before due to pinching the wire at the yaw bearing.  One thing makes me question this.

I unhooked the wires going to the battery and the turbine still was shorted and when I went to short the wires at the battery for safty, incase the turbine turned and unshorted it's self, it threw a very small spark.  This leads me to think the whole turbine might not be shorted but maby just one coil.

I know I will find the true answer when I lower the turbine.  I was curious anyway about a couple of things.

One;  If it is a shorted coil, What would happen if I just unhooked that coil from the rectifyer?

Two;  Since my rectifiers are at the top or the tower,  How would I know if I ever had a bad rectifier?

Just curious.
Thanks
gww

Flux

  • Super Hero Member Plus
  • *******
  • Posts: 6275
Re: shorted coil?
« Reply #1 on: September 07, 2014, 01:45:05 PM »
The only way is to disconnect the coils from the rectifier. If the problem is the rectifier the drag will vanish, if it is a coil the drag will stay.

Flux

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #2 on: September 07, 2014, 02:23:59 PM »
Flux
Thanks, that put it into perspective for me.  My brain some times needs a bump, for thing I should know, to make sence to me.

If you feel like it,  a couple more questions. 

One;  If it was a coil, Is there a way to locate which coil it is?

Two;  It is a 48 volt turbine,  say 1 amp per coil at rated wind speed,  If it were a coil and I broke into the stator and cut the start and finish wires so the coils was no longer part of the turbine, What would be the end result?

Three;  I lost an inverter and my internet connection (dish) during a storm.  I don't think there was a direct hit and I had the turbine shorted at the yaw bearing before. Then all I did was pull more wire out and tape the heck out of it.   Does emf or whatever affect thing like diodes/rectifiers?
Thanks
gww

madlabs

  • Hero Member
  • *****
  • Posts: 686
  • Country: us
Re: shorted coil?
« Reply #3 on: September 07, 2014, 05:50:45 PM »
For sensing which coil, try a compass? If that doesn't work, a cheap Hall effect sensor and a voltmeter should do the trick, like the Allegro A1104 or the like. That is a simple switch type and should work. They also make ones that are actual sensors and you can read them in mv/gauss or the like with a voltmeter, A1321 being one. I've played with these a bunch and they are sensitive and easy to use. All you need to do is feed 'em VSS and ground, read the third leg with a volt meter.

Jonathan

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #4 on: September 07, 2014, 08:39:01 PM »
jonathan
The compass I understand, the other stuff, I am going to have to look up.  As you can see, my knowladge is minimal.  I mostly survive by copying other poeples doings.  I will do an internet search for the items you mentioned and then see if I can learn anything.  The turbine may just be shorted at the bearing but even so it won't hurt to learn more stuff. 
Thanks
gww

Flux

  • Super Hero Member Plus
  • *******
  • Posts: 6275
Re: shorted coil?
« Reply #5 on: September 08, 2014, 03:50:10 AM »
If you had a lightning event nearby that could have caused the problem, more likely to be a rectifier in that case but could take a coil out. Need not be even very close to do damage, a direct strike would be more dramatic.

If it is not a rectifier, finding a shorted coil depends on the severity, if it shorted and continued running it will be obviously burnt.

If not obvious then it is more difficult to locate, you may find it by resistance measurement ( can you get at the star point?).

If you get to the stage where you know it is a coil but can't find it we can discuss that later, there are a few tricks that help.

You can run with one coil missing but not with it having a short, if there are shorted turns within the coil you can't fix it by cutting the connecting leads, You could cut it out with a dremel tool or similar. If the stator is still mechanically strong enough it will work. It may run faster, may or may not match the prop as well and you must expect a bit less output but it will still do the job.

Flux

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #6 on: September 08, 2014, 04:27:57 AM »
Flux
I can't get to the star point without cutting.  I rapped a wire around all ten coils and connected each coil to it and incased it in stator.  I have a starting point and am not sure when I will get to it.  I also have anouther one on an 80' tower that I made 9' blades to replace the eight foot ones on it.  That is probly the bigger job and I think I will tackle it first.

I may come back and ask more when I get the turbine down but in my mind I have enough info to atleast look at it first. 

I always love the way you communicate where even dummies like me half-assed understand.
Thanks
gww

PS I did have a lightning event that took out an inverter and blew a 125 amp dc fuse.  I beleive the fuse blew due to dead short in the inverter.  I shorted out the turbines and eight days later when I fliped the turbine shutdown breakers to let them run again, the one never took off.
« Last Edit: September 08, 2014, 04:37:42 AM by gww »

madlabs

  • Hero Member
  • *****
  • Posts: 686
  • Country: us
Re: shorted coil?
« Reply #7 on: September 08, 2014, 11:01:41 AM »
Gww,

It's easy to use one of the Hall effect sensors. They have three legs, like a transistor. One leg is power +, one is ground and the other is the output. If you use a sensor like the A1321, the output will vary with the strength of the magnetic field. So connect some voltage to the coils and then use the sensor connected to a voltmeter to detect the magnetic field strength. Try to place the sensor in the exact same spot on each coil. They are very sensitive to placement. You should, with careful placement and measuring even be able to see a partially shot coil.

If you use the switch type like the A1104 it will just allow current to flow if there is enough magnetic flux.  So there will be no voltage and then when you send current to the coil it will turn on fully. Not as sensitive but cheaper.

Jonathan




 

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #8 on: September 08, 2014, 11:50:29 AM »
johnathan
I am writing this so you know I have seen your post.  I am taking my wife somewhere today but when I get time I am going to type my perspective of what you are saying and see if I am getting an understanding.
Thank you
gww

hiker

  • Hero Member
  • *****
  • Posts: 1661
  • BIG DOG
Re: shorted coil?
« Reply #9 on: September 08, 2014, 01:20:20 PM »
if you have access to the star point--a simple way to find your shorted coil would be to hook up a battery charger or batt to each phase one at a time..just hook one lead from the batt. to the star point other lead from batt to a single phase--then hold a mag in your hand and run it over each coil in that phase--weak one will be the shorted coil !! do that for each phase...do this rather quick because your coils will heat up rapidly..you could hook up a 50watt. headlite in series with one of the battery leads to cut down on the amps. good luck..........
WILD in ALASKA

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #10 on: September 08, 2014, 09:06:29 PM »
Johnatan
Nope, I still don't get it.  Is the hall senser like a shunt in paralell to the positive.  Sorry,  I am a high-school drop out.  I also have no experiance with transisters.  In my defence I did build a gheurd charge controller That seemed to work fine but I just soldered and couldn't tell you why it worked even though Glen tried to explain some of it to me.  I still intend to look for a hall senser in use on the net.  hopefully with pictures or on youtube. I only have 5 gigabites of data use connection so I try and space my usage on need at the time. but still intend to get to this.
Thanks for the explinations and its me not you that has problims understanding.

Hiker
Again my turbine has one wire circling the coils with all coil starts connected to it.  To do what you say, I dig to that wire and then bare it leaving all coils hooked to it and then at the wires pluged into the five rectifiers add power to each wire and test the  respective coil.  as all coils are connected coil circle wire, will the magnet trick still work?   

I loved building these turbines due to the ease of wiring the stator.  Hugh hasn't kept it around  ( I think due to rectifiers on tower)  so I guess it isn't that great but I still really like the simplistic layout.  I built the 6 coil 8 magnet rotors and brought all the coil wires out and it wasn't that hard.  I used salvage microwave wire and used way to many turns for neo's.  It had wires everywhere.  If I do anouther I want to dismantle the eight magnet and one of these turbines and make a twelve or fourteen foot turbine.  I only have one tall tower up 80' but have enough lattice tower sections to go even higher if I can figure how to raise it as it is so much heavier.  I also don't want to spend any money as solar is better then wind in my area.   This is the tall tower and the turbine on the small tower is the one shorted.
[ Attachment Invalid Or Does Not Exist ] [ Attachment Invalid Or Does Not Exist ]

Thanks
gww

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #11 on: September 08, 2014, 09:21:44 PM »


thanks
gww

I don't get it.

« Last Edit: September 08, 2014, 09:34:33 PM by gww »

madlabs

  • Hero Member
  • *****
  • Posts: 686
  • Country: us
Re: shorted coil?
« Reply #12 on: September 08, 2014, 10:54:29 PM »
Gww,

Don't worry about shunts or anything. All you need is the sensor and three test wires with aligator clips. And a voltmeter. You can use a battery or whatever to power the sensor. Looking at the data sheet will tell you which lead is which. I don't know how all this works, I never finished high school either. But I do know if you hold the sensor close to something with a magnetic field you volt meter will read more juice. I feel quite certain that if you get ine you will make it work. Feel free to ask more question, here or in pm. Also happy to shoot you my phone number if you like.

Jonathan

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #13 on: September 08, 2014, 11:56:05 PM »
Johnathan
I have the aligator clips and volt meter.  I will look for the hall sensors you posted.  My hope is the turbin is shorted at yaw bearing or bad retifyer.  If it isn't I will probly be pm-ing you.  I thank you for the offer and although I usually need more help then I can give,  If you ever think I can help, the same offer you gave me including phone number is open for you also.  I will always do my best to be a help as long as you know I lead myself down wrong paths even when "I know" I am right. 
Thanks
gww

Flux

  • Super Hero Member Plus
  • *******
  • Posts: 6275
Re: shorted coil?
« Reply #14 on: September 09, 2014, 03:13:46 AM »
In view of the fact that this was lightning induced I would wait until you have checked the rectifier before worrying about the coils.

If it does turn out to be the coils then there are fairly easy ways to find it if you can get to the star point at any part of that ring. If not then it can still be done but will take longer and could be more confusing.

Flux

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #15 on: September 09, 2014, 07:17:14 AM »
Thanks Flux
gww

jlt

  • Sr. Member
  • ****
  • Posts: 368
Re: shorted coil?
« Reply #16 on: September 10, 2014, 05:02:46 PM »
I still have of the 10coil 12 pole up and running 7years I think.
All of the coils are in parallel so removing one coil would not affect it much.
to find the bad coil disconnect all rectifiers and spin it with a large drill.
 The shorted coil will show up very quick.and start to smoke.
remove that coil and your done.

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #17 on: September 10, 2014, 08:10:42 PM »
Jilt
Thank you,  I really enjoyed building them.  Have you stuck with the eight foot blade?  Did you run small or large wire from the turbine to battery?  Mine are 48 volts, Yours?   I have mixed feelings about the larger blade as the turbines have been through so heavy winds and have survived thus far.
Thanks for the post.
gww

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #18 on: September 18, 2014, 09:10:55 PM »
Update
I lowered the turbine today.  It has five rectifiers and it turned out to be the last one that I checked, of course.  I am happy that is what it ended up being and a bit surprised as it is a 35 amp rectifier and only has about 2 amps going through it at 500 watts rated power.

Thanks for all the help
gww

joestue

  • Hero Member
  • *****
  • Posts: 1759
  • Country: 00
Re: shorted coil?
« Reply #19 on: September 18, 2014, 09:36:24 PM »
Could very well be lightning induced over voltage failure.
I would replace all of them, and add a handful of  MOV's on the DC side of the rectifier, not the ac side.

there is no reason to buy  600 or 1200 volt rectifiers, they have a higher forward voltage drop.
and if the price is too good to be true, it probably is.
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #20 on: September 18, 2014, 10:05:39 PM »
joestue
I am not sure what movs are. 

I will probly fly it, till the next problim. 

My next project is to lower the 80' tower and replace the eight foot blades with 9' ones. 

Then I need to figure out how to raise a lattice tower which will be much heavier then the pole one. 

Then I wan't to take one of these apart and a different 12 volt turbine and use the magnets for maby hughs 14' turbine. 

I got chickens and am going to start bees.   I wan't some more fruit trees and would like to end up with 9 more solar panels so I can max out my charge controllers and combiner box. 

I don't know what I will actually get to but really apretiate all comments and try to keep them in my mind as I get to thing.  Every year my mind get a bit worse for keeping things in it but I will try to remember helpful suggestions.

Thanks
gww

PS  The couch aint bad either.

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #21 on: September 18, 2014, 10:19:48 PM »
I live in a wind zone 2 and these turbines are in my mind only putting out about half of what I would expect of them altough I have seen an instatainous 2700 watts out of them together.  I don't know why I mess with wind but I still like doing it a bit.  My highest production was 6 kwh one day.  The next highest was around 4 kwh.  Most times it is nothing to a couple hundred watts.  Last month I made about 2 kwh for the month.  I am new enough that I don't know if it is working right or not.  I can't wait to see if the 9' blade improves it, "or not".
Wind bag aint I?
Cheers
gww

PS this site is really acting weird when I try to post.
« Last Edit: September 18, 2014, 10:28:09 PM by gww »

joestue

  • Hero Member
  • *****
  • Posts: 1759
  • Country: 00
My wife says I'm not just a different colored rubik's cube, i am a rubik's knot in a cage.

Flux

  • Super Hero Member Plus
  • *******
  • Posts: 6275
Re: shorted coil?
« Reply #23 on: September 19, 2014, 04:43:20 AM »
Production depend on your local wind speed, site and turbine heigh tas well as the type and size of turbine.

Just to give you a rough guide I have found figures I kept on a 8ft 6" turbine on a poor site. The average wind speed for the area is only 8mph and the tower was only 25ft so the machine never saw winds from some directions. The maximum output was 1kW and we only saw that on a few occasions a year.

The highest recorded figure was over 100kwh one February. The lowest was about 4kwh one July.

Typically the average winter month figures was 40kwh and something like 10kwh during the summer months.

This is well below the theoretical for that site and if mounted at 100ft the results would have been much better. This was not a true mppt machine but it was not stall limited either. With true mppt you may get double, with a direct connected stall limited machine it may have been half this.

I don't know how your class 2 wind regime compares with this, but with your high tower you ought to be above this.

This is only a very rough guide, every site is different and some machines are significantly better than others.

Flux

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #24 on: September 19, 2014, 08:26:15 AM »
joestue

What does a mov do and how do I know which one to get?
gww

Flux
I would say my turbine is stall limited now but I am not sure.  My production with two of them going through a doc wattson  is about 17kwh winter month and 2 kwh last month. I have writen it down on a calender for since last jan.  The 40' high one is fairly sheltered and the 80' high one is only about 26' above the closest tree.  I ran out of pipe.   I have 8 gage wire with about 25 extra 12 gage wire from tall turbine to battery and 12 awg going to 10 awg on the short one.  I am going to try the 9' blade .  I have not adjusted the gap but believe they might be wide enough due to a very small amount of stator warping.  All these are things that hugh has mentioned as posible improvements to this turbine design.  My problim is I never know if I am going forward or back ward as I try the (improvements) untill I try them.  It may end up that I should have went to smaller blades and thicker wire.  One thing I am pretty sure of is I will know more when I am done.
Thanks
gww

madlabs

  • Hero Member
  • *****
  • Posts: 686
  • Country: us
Re: shorted coil?
« Reply #25 on: September 19, 2014, 11:01:01 AM »
MOV's are little things that are non-conductive until a certain voltage is reached, but when that voltage is reached it begins to conduct. So if you see a MOV rated for 100V then it will begin to conduct at 100V, but below that will not. So, they are often used for over voltage protection. When put in series their turn on voltage adds, so two 100V MOVs in series will conduct at 200V. The Midnite lightning protectors I use have MOV's in 'em.

I have bees, just harvested 3.5 gallons of honey. One thing about having bees though, now that there aren't many things blooming they come and "vampire" my rasberries, sucking 'em dry. Still love them though.

Jonathan

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #26 on: September 19, 2014, 11:26:15 AM »
Johnathan
I still don't understand how movs help.  Also I am really a cheepskate, even though it cost more sometimes.  I saw some of the lightning arresters but they where like 80 bucks apiece.  I just lost an inverter ($500 repair) and whatever the retifier for the turbine cost.  Its like insurance and deciding how much you should have. Depends on how lucky you are on whether the decision was good or bad. 

Bees, I am going to try to buy or capture some come spring.  My cheepness:  I built seven medium supers and one top bar hive, including about 90 foundationless frames, out of used lumber.  It took a lot longer then I thought it would to build.

I notice the bees drain grapes in the same fassion as your berries.  Some of that is yellow jackets also.

Thanks for the explination on movs.  I am still not sure how/why to use them.
gww

madlabs

  • Hero Member
  • *****
  • Posts: 686
  • Country: us
Re: shorted coil?
« Reply #27 on: September 19, 2014, 11:58:42 AM »
I believe the OP was referring to using the MOV's to protect your diodes. You would put your MOV string across the diodes, with the voltage of the MOVs adding up to a little less then the max voltage rating of the diode. Then, if a surge happens, the MOV's will conduct the surge to ground, saving the lives your diodes.

And not only am I cheap, I'm poor too! But I ante'd up for lightning protection on my system. I'm too poor to buy more equipment and I'm too busy either working for a pittance or getting ready for winter to spend time fixing stuff. My Grandma used to say "you're too poor to buy cheap". I believe that

Jonathana

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #28 on: September 19, 2014, 02:12:57 PM »
I half agree with your grandma,  I bought a cheep harbor fraite wire welder,  I don't weld long enough to time it out very often, my dad has a thousand dollar one that we don't know how to use.  I bought two cheep riding mowers and wore them out.  I bought my first stick welder to fix the deck of the craftman over and over.  I now have a commercial zero turn mower.  It is a monster and very fast, I will never go back.  I fixed a spendle on the cheep one and on the commercial.  It was like $17 for the cheep one and $250 for the comecial one. 

I figure somebody gets my money in the end.  I do have one thing that is disapearing in america.  I have a pension.  It is about 50% of what I would have made if I kept working.  I have less money but much more time to piddle.  Best trade ever made possible for some.  I don't know how people will fare with 401's and the stock market but I hope most are smarter then me. 

Above putting the aray in I couldn't believe how much it cost to just ground the aray.  I will never pay for my system if it works for 100 years and I am glad I reconize this as an expensive hobby. 

I am not discounting the advice but apparently set on learning things the hard way.  I may also get it done.  I didn't know anyone who had did any of this stuff when I started and you guys have been a godsend for me to get this far.

Thanks
gww

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #29 on: September 20, 2014, 09:32:41 PM »
I got the 80' tower lowered today so I can try to put londer blades on it. 

I need a front loader tractor to make it easeir.  My gen pole is 4" inside pipe about 28 feet long and heavy as hell. 

I have it low enough to remove the blades easy enough but will probly have to ask some one for help cause I can't lift it from the tower to the test stand and can't figure out how to balance them on the tower.  There was a time I could move it by myself but I guess all the couch time is catching up with me.
I hate asking for help,"except from you guys".

Well now you know as much about my doings as I do.

Cheers
gww

Ungrounded Lightning Rod

  • SuperHero Member
  • ******
  • Posts: 2865
Re: shorted coil?
« Reply #30 on: September 21, 2014, 02:33:01 AM »
At the risk of being redundant:

 - MOV = Metal Oxide Varistor.  As described, it doesn't conduct significantly below a well-defined applied voltage and conducts heavily if the voltage rises above that threshold, .thus "clamping" the voltage to the threshold.  They protect electronics from moderately short electrical high-voltage spikes, like those you get when lightning strikes nearby, by conducting heavily when the voltage is higher than their threshold, which you pick to be lower than the rated voltage of the protected device.  Semiconductors, like your mill's rectifiers, have a "peak reverse voltage", and if the voltage rises above that they die.  So you hook a varistor (or string of them) across the output, with the threshold voltage somewhere above runaway-mill-max and below the peak-reverse.  If you get a surge induced in the wiring between the mill and your house/battery/whatever, they MAY protect the diodes.  (They may also die, themselves, in the process, and need replacing, or disconnection until you get a replacement, to get things running again.)

A hall effect sensor is a magnetic field detector.  The sensor proper produces a small signal and the module has an amplifier to produce either an output voltage proportional to the field or a voltage that jumps up or down if the field is above a below a certain value.  You want the proportional type.  You don't hook it into your mill's wiring.  You hook a battery to the power input pin, a meter to the output pin, and the other side of both to the common/ground pin.  Then you use the sensor as a probe to measure the field from your coils, reading the field strength on your meter.  (Or you would if you hadn't already found out the coils were OK.)  The sensor measures the component of the magnetic field penetrating it along a particular axis.  So not only do you have to put it in the equivalent location on each coil, but you also have to orient it the same way, preferably with the sensor axis aligned with the line through the middle of the coil.  Shorted turns don't contribute to the field, so if you feed a given DC current into each coil, a coil that has a short across 20% of the turns will only produce 80% of the field produced by an unshorted coil of the same number of turns.

My ranch house is being painted, an a couple weeks ago the painter discovered a large beehive on the outside.  It was entirely on the outside beams under the roof overhang (a rare occurrence).  Of course it had to be removed so the painting could be finished before the weather changes.  Rather than have it killed off, I contacted a local bee breeder who wanted them for his post-colony-collapse breeding program, which is based on the feral bees in the region.  The bees in the problem hive were very productive (going from nothing to a basketball-sized hive in less than three months) and non-aggressive (not bothering the painter while he took picktures from a couple feet away).  The breeder is trading removal service, a small bottle of their honey, and a "nuc" from his program next spring, for the bees and their comb.  (A "nuc" is the nucleus of a new hive:  A few combs on frames with a queen and a starter set of workers.)

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #31 on: September 21, 2014, 02:41:44 PM »
Underground lightning.  I understand the how to use the movs now.  Do they affect voltage like a diode?  does amprage have to be worried about as they seem rather thin?  Since my rectifiers are on the tower,  Would connecting them on the ground prior to the batteries work or do they need to be against the rectifiers?

Believe me, I need redundancy.

I will probly forgo the hall senser, at least untill my next problim.  Thank you for the explination.

Bees.  There is a guy that lives about 60 miles from me who is going to fill my mediam super with a couple brode comb and a queen and a few workers if needed next spring.  He thinks he can get me started for $50/$75 compared to the $150 it would cost to buy a package.  I am also going to tell my mushroom hunting freinds to be on the lookout for a swarm and I am going to make traps out of my unused supers and set them at the deer stands at my dads.  Should give me about 6 traps.  If all else fails I won't have bees till the following spring.  With my homade bee suit and my homade smoker I may find I am unprepared anyway.  Time will tell.  I just did it cause my son in law seemed interested and I am not above bribery to keep them coming to my house.

I put my turbine back in the air today with the 9' blades.  I did see it furling a bit and it seems to be producing a bit better but I won't know intill the batteries are low and by watching it for some time.
There is some fear of high winds coming that the eight foot blade made it through. 

I balance the blades while the turbine was hanging on the end of the tower and in a breeze.  I had the turbine shorted out when I raised it and tought it wasn't stalling very well at all.  It speeded up when I threw the kill switch off.  It then got fast enough that it sounded like the blades were hitting a guy wire.  I looked and knew they wern't.  So I though "my god the blades are way out of balance.

Turns out he connection at the pole was knocked lose and the turbine was running free.  I re-connected it and under load the turbine is running quite smothly.  It funny the wind was slow enough that the turbine seemed stalled untill I let it lose and then took off.  That is what confused me for a bit.

Oh well, I got my finger crossed that it all works out.
gww

gww

  • Hero Member
  • *****
  • Posts: 762
  • Country: us
Re: shorted coil?
« Reply #32 on: September 21, 2014, 02:54:22 PM »
PS
My turbines are 48 volt and the most I ever saw one run was 100 volts unloaded.  My battery voltage is 48 volts.  What mov would I need or mov voltage should I shoot for?
Thanks
gww