so much for that winter output! problem w/ 4' piggott.

[defed]

after a cpl of really good days of production from the 4', there seems to be a problem.  i had some really good winds the last 2 days, and it just wouldn't kick up to speed.  it would turn slowly and get up to maybe 1/4 speed at times, but never hit its stride.

today, there is ALOT of good wind, and it still won't go.  ok, i figure bearing nut tightened up (happened once before), some water got into my plug and shorted the phases, etc.  lower it down, nut feels ok.  loosen and retighten.  spin it by hand, smooth but still tight.  put the short plug in, seems harder to turn as expected.  it was always a little on the hard side to spin, so put it back up.  still spins slowly but won't take off.  open up the plug.  everything looks ok.  unplugged from the batts, still won't take off.  let it get up as fast as it will go, insert shorting plug.  little difference.  i left the short plug in, and it seems to spin a little slower in high winds than w/o...so my guess is i have a short somewhere...and since there is only 20' of cord from the plug to stator....my guess is leaning towards the stator.  i don't see any signs of damage to it (burning, rubbing), but i haven't taken the magnet disk off yet.  also need to try running some volts back up each phase and see if i can find something grossly out of whack.

i guess the fact the 4' blades still turn while shorted means i have some pretty good wind today.  not to mention it's like 30F out, which always makes troubleshooting fun!

[TomW]

You might try disconnecting the turbine from the rectifiers / bridge near as you can get to the turbine.

You may have shorted a rectifier or something.

If it spins up unloaded you will know it is not mechanical and then you can go from there to sort the problem.

That is where I would start.

Good luck.

Tom

[defed]

1st thing i did was disconnect it at the base, w/ shorting plug at the ready in case it spun up.  it didn't change.  it is so hard to tell if it changes speed from full short to full open because the winds change so fast.  i ran 12v up each 2 phase combination and measured the amps and they all came out the same.  so my guess is on that test that nothing is shorted or all 3 are!  i just watched it in a massive gust, shorted, and it didn't seem to pick up as much as it would have if open (or to rectifier).  the other thing i want to try is cutting the plug off at the base in case there is something wrong w/ it, but i don't have another handy to put on.

the bearing feels ok...can't imagine the the grease thickening in the cold would hold it back, since it turns fully shorted.

[defed]

had a good constant wind, pulled short plug, it got to a fair speed, put the plug in, and it slowed down quite a bit.  pulled plug and it started to pick back up.  i guess that means that its not fully shorted, and since my amp readings on backfeed were all the same, 2 phases probably aren't shorted.  will have to lower it back down when the wind dies down and take the rotor off and see what's going on.

too bad, would probably be up to 3kwh produced in the last 2 days if it had been working right.

[TomW]

Not sure I follow your logic?

If it slows connected to the bridge / rectifier then I suspect the bridge / rectifier.

Especially if you disconnect the battery side of it and it still slows.

Remote troubleshooting is troublesome at best.

Deliberate elimination of possible fault sources is the only method that will work.

This exact thing happened to me a few weeks ago and it was a shorted bridge following a couple days of large output.

Tom

[defed]

setup is as follows:

turbine stator, 30' cord down the tower to a female plug, male plug to rectifier, rectifier to batts.

when it wasn't turning well, i disconnected the plug at the base....removing everything beyond the tower from the equation and free wheeling the turbine.  this made no difference.  so i know it is either my female plug at the base is shorted, the stator is shorted, or the bearing is bad/seized.  i have a male  shorting plug that i can insert into the female plug at the base.  after working in some constant winds, the shorting plug DOES make a difference.

i removed the rotor and brought it in the house.  i used a rear hub/spindle from a front wheel drive car.  the bearings are kind of weird, not your typical wheel bearings.  there is 2 stacked and that slips over the spindle.  the front bearing is smooth and easy to turn.  the rear bearing is smooth and hard to turn.  doesn't feel like it has gone bad, it's just tight.  i'm going to let it sit in the house for a bit and see if it loosens up as it warms up.  if so, it will be a big problem for the rest of the winter!  hard to believe that the grease would get that thick, and not loosen up when it's spinning at 100 rpm (needs 300 for cut in).  not sure how these bearing are inserted (or removed) from the hub, but they aren't like typical front wheel bearings that i am familiar with.  not sure if i can remove them and change grease.

[ghurd]

"Cord"?
Any chance the cord is damaged at the top?
That could make for varying and intermittent issues.
G-

[defed]

yea, it's just a piece of rubber coated 10/3.  it passes thru a piece of heavy garden hose where is comes thru the turbine frame to avoid rubbing on the steel.  it is possible that it got damaged if the hose moved.  i am going to look at this bearing 1st, since one is 'tighter' than the other.  it was always a hard starter, and maybe this is why.  i don't recall noticing that one bearing was harder to turn than the other tho.

[defed]

also, it's never had a problem going when the winds were high enough to get it to kick on (and stay running in lower winds once it got started)...but then it's never been windy enough to go when it's been this cold (20F-30F).

[Norm]

bearing is smooth and hard to turn.  doesn't feel like it has gone bad, it's just tight.  i'm going to let it sit in the house for a bit and see if it loosens up as it warms up.  if so, it will be a big problem for the rest of the winter!  hard to believe that the grease would get that thick, and not loosen up when it's spinning at 100 rpm (needs 300 for cut in).  not sure how these bearing are inserted (or removed) from the hub, but they aren't like typical front wheel bearings that i am familiar with.  not sure if i can remove them and change grease.

Sounds like a challenge....surely you could drill into the side of the bearing if it is
permanently sealed and squirt solvent into to dissolve the old caked grease to some extent
and then squirt in some faily light oil   
My own personal experience....a small blowtorch works wonders not directly as to destroy the seal
or bearing but indirectly on the shaft so as to conduct the heat to the bearing just sitting in a warm
room doesn't make it.
lmay be better replies than this but.....
Luck,
Norm.

[defed]

sitting in the house won't be a permanent solution, but it should be enough to see if it will run up to speed (presuming the winds stay high before it gets cold again).  i mean, it ran good when it was 50F, besides the hard start up.  if this makes it 'go', then i will have to figure out something permanent.  it is only a test mill, which is why i used this car hub, it was free.  even in the summer, it never spun too well by hand.  grabbing a blade and 'whipping' it, only would turn a cpl revolutions.  i should have expected it to get worse in the winter.

[defed]

put it back out, took shorting plug out, away it went.  got it back on the rectifier and it's running like a champ.  so it's the bearing.  probably been the bearing all along causing my problems!  now i really feel like a dope!  i knew it was a little tight, but didn't think it would cause so much havoc.  now i'll have to figure out a way to fix it or i'll get no output for the winter once it stops.  with the speeds it spins, not sure if getting the grease out and oiling, as Norm mentioned, will be good enough?  may have to try and replace them.

[Rover]

Good news.  . lets hope that was it and that just movig it around didn't just void any short activity. (why did I even mention that?...couldn't be... never mind.. forget that statement)

I'd be interest though in the ouptu you are seeing on the 4'

[defed]

i'm confident now that there was no short.  i just didn't want to think it was the bearing when it has been somewhat problematic all along.

i did learn something tho, while looking for a replacement bearing...i thought that there was 2 bearings, a front and rear, but apparently it is just one.  it looks like this:





there is a groove in the center, and the top and bottom halves move independently, which is why i thought there was 2.  changing it might not be too easy w/ the magnets attached to the hub tho!

[ghurd]

Being really lazy, I would change it.
Must be easier than screwing around with it repeatedly, raising and lowering repeatedly in the cold,
then finding out it needs changed anyway.
G-

[defed]

I'd be interest though in the output you are seeing on the 4'

i don't have my anemometer up right now.  it was on the turbine post, but my guy wires (ratchet straps) were vibrating the tower too much and shaking the anemometer.  so i removed it.  i did take some readings while the anemometer was up tho, and i was getting (roughly) 25w @ 12 mph, 50w @ 17mph, 140w @ 24mph, 170w @ 25mph.  these are not 100% accurate, and i know i made almost 1kwh in under 8hrs and the amps never exceeded 12.  turbine is 24v, and when it gets going really good, will go over 30v.  last time i was watching it (last kwh day), i was seeing 30v quite a lot and between 4-10 amps.  all time peak was 476w @ 16.5a, but don't know what the wind speed was.

there were 2 days the last wk where i made almost 1kwh, but i was at work, so i don't know when it started to know how long it was running.  the one day, it wasn't going when i left for work, so it was less than 8 hrs.  i haven't opened my outdoor battery box to see what it is doing now, but my guess is a pretty constant 3-5 amps and jumping to near 10 in the gusts.  the last 30 hrs or so have been really good wind, but i was problems so got nothing!  the winds i am having now are typical of my winter winds, especially overnight.  so i'm hoping that i get good production overnight when the solar is asleep.  this is also on an 18' tower.  i have a freestanding 50' ready for a future 10 footer.

when it works, it works REALLY well...just have to iron out the bearing issue for winter, before it gets replaced by a bigger machine.

[defed]

Being really lazy, I would change it.
Must be easier than screwing around with it repeatedly, raising and lowering repeatedly in the cold,
then finding out it needs changed anyway.
G-

yea, you are right.  i forgot to get the bearing # off of it, so it has to at least come down again for that...but once it stops running, it probably won't go again after the bearing cools down anyway.

[jaskiainen]

Hi!

I had same kind of a situation a week ago. My small test mill hardly spin at all even in big gusts.
I took it down and took it in to a workshop (warm place) and did some adjustment for where i thought
the problem was. I put it back in air and yes, it spun like never before.
After awhile i looked it again and it was completely stopped even if there was wind available.
Took it down again and took it completely apart.
The problem was my front bearing. There was some water in it and when it was up in air it freezed
and when i took it inside warm room it spun very well. So i just dry it out and greased it again.
Now it spins like never before...

So there might be some water inside that bearing. Or bad grease for wintertime.

[Rover]

Def, Impressive numbers for a 4' ....Cool, thanks

[defed]

Def, Impressive numbers for a 4' ....Cool, thanks

when it's running, yea....but there are alot of 0's in between!   

[ruddycrazy]

Hi defed,
             That bearing you showed is a sealed dual ball bearing and the bearing number will either start with 52 or 32 depending on the brand of the bearing. I fitted as the rear bearing on my 2hp motor conversion and it's still going great years later with a 3 metre prop hanging off the genny. The seals on that bearing will cause some drag as they rub on the inner race to provide a full seal.

Cheers Bryan

[defed]

Hi defed,
             That bearing you showed is a sealed dual ball bearing and the bearing number will either start with 52 or 32 depending on the brand of the bearing. I fitted as the rear bearing on my 2hp motor conversion and it's still going great years later with a 3 metre prop hanging off the genny. The seals on that bearing will cause some drag as they rub on the inner race to provide a full seal.

Cheers Bryan

thanks for the info.  when i was looking at the hub, i didn't notice an obvious way to take remove the bearing.  when i look at the bearings online, most indicate that there are snap rings on the ends to hold them in.  seems to me, snap rings would be obvious, but i didn't notice them.  i will have to look it over again when i bring it down.  there is alot of drag on on of the 2 halves of the bearing.  not sure how much is normal and how much is wear, bad/no grease, moisture penetration etc.  i just know 1 half spins easy, the other does not.  i wonder if your prop is better w/ that type due to the size vs weight ratio.  my blades are so light and small, seems like it would be harder for them to overcome this.

[Norm]

As Ghurd says easier to just replace.....even at $25-35 well worth it as your
machine and putting it up and down probably far exceeds the cost of the
bearing.
Norm.

[defed]

i took it down again to get a bearing number, and while it was down, i had my dad look at it.  he is a mechanic/machinist/hvac tech etc.  he said the bearing was fine.  the drag is mostly being caused by the seal, as Ruddycrazy said.  he pulled the spring out from around the seal and put it back on the stator.  he had me tighten it as i normally would, then he checked it and thought it was too tight.  so he messed w/ it and got it to where he liked it.  put it back up.  seems to be working alot better.  seems to start up at lower winds.  i was probably making it too tight, especially after it heated up, and taking the spring out loosed up the drag a little.  i'll just keep watching it and see how it goes, especially in the cold.