A little help with my Lakota.......Jerry!!!

[Off grid in Tonopah]

Hey Jerry and or others

    I was wondering since you are a Lakota dealer could you answer a couple of questions for me. First the long  short story of it all... I bought a used Lakota and have it up on my site and it's doing well, the issue is I have a 12 volt system and a 24 volt turbine. I plan to swap over soon to the higher voltage that's why I got the mis-matched mill. I've put some resistance in the DC line and it's brought the speed up on the unit to keep it out of stall but if I put to much it seems catch and look out! It's as though the turbine is going to over speed but it make much more power. So the question is, what speed is the Lakota supposed to run at? I can't seem to find a RPM spec anywhere. I want to get all I can out of it but don't want to over speed it either. Also do you know how many poles the Alt. on the Lakota has so I can use my HZ meter down tower to see the speed?    

                                                  Thanks Bob

[Nando]

BOB:

Can you tell what is the peak power and the furling point of the wind mill ?.

Do you have a power curve for 24 volts ?.

Nando

[Jerry]

Hi Bob.

My first Lakota was a used unit also. One of the first things I did with was a wind test in my S-10 PU.

I was disapointed in that first wind test. The genny was stalling bad. It took 15 mph just to brake it loose and get it going.

I Talked to the Lakota tech guy. He was a great help, he talked me through some things and sent me the large owners manual with more info then I thought posable.

The Lakota has 4 posable wireing scheems. Areomag calls these.

High wind wire conections (mod))0

Conenect the #1,#4,#5 and the #0 wires together

Phase 1: Connect the C and the #6 wires to one of the black leads going to the brushes.

Phase 2: Connect the B and the #3 wires to one of the black leads going to the brushes.

Phase 3: Connect the A and the #2 wires to one of the black leads going to the brushes.

Next.

Medium high wire connections (mod 1))0

Connect the #4,#5 and the 0 wires together.

1st Serial connection #1 and #2 wires.

Phase 1: Connect the C and the #6 wires to one of the black leads going to the brushes.

Phase 2: Connect the B and the #3 wires To one of the black leads going to the brushes.

Phase 3: Connect the A and the the last black wires going to the brushes.

Next.

Medium low wind wire connections (mod 2))0

Connect the #5 and the 0 wires together.

2nd Serial connection #3 and #4 wires.

Phase 1: connect the C and the #6 wires to one of the black leads going to the brushes.

Phase 2: connect the B wire and one of the black leads going to the brushes.

Phase 3: connect the A wire to the last black lead going to the brushes.

Next

Low wind wire connection (mod 3))0

Cap the 0 wire

1. st Serial connection #1 and #2 wires.
   
2. nd Serial connection #3 and #4 wires.
   
3. rd Serial connection #5 and #6 wires.
   
   

Phase 1: connect the C wire to one of the black leads going to the brushes.

Phase 2: connect the B wire to one of the black leads going to the brushes.

Phase 3: connect the A wire to one of the black leads going to the brushes.

I prefure the High wind connection. It has the easyest startup, It also will makes the most power. I had received the used alt set in the Low wind (mod 3))0 connection.

After reconfiguring it in the (mod 0))0 congiguration it started charging at 6 mph and by 20 mph it was doing 60 amps.

During one of our 50 mph wind storms (tower mounted) I was seeing well over 2000 watts from the Lakota. The furling is adjustable by the spring tesion adjusters.

Aeromag has stated the this unit has been tested to 120 mph. It resently survived our last 80 mph storm without a problem even though I locked the unit down so it could not furl out of the wind. I check just one phase ac with a clampon ac amp meter it was reading 58 amps. I knew the DC output after the rectifiers was much higher then that.

This alt is a 3 phase 8 pole. Curved NEOs. Those blades are a builtyfull thing. I used a set on one of my motor conversion and was seeing 2025 watts at 30 mph with cut in around 6 mph.

I will only use the high wind connection but the book says if you want to use the 24 volt for 48 volt try one of the lower wind connection.

I know if you short the leads it very hard to turn.

Sorry I don't have RPM info but now that you know pole #s you can take some HZ/ rpm readings.

Here are some color codes on those wires.

For high wind speed connection.

Blue#1

Orange#4

Gray#5.............Connect these to the Green #0 wire.

Black C and Gray #6 to a brush wire.

White B and orange #3 to a brush wire.

Red A and Blue#2 to a brush wire.

Blue and orange are used twice. Its been a long time but I think there #erd.

If not, take note of how and to what wires there connected to now and mark them.

Good luck.

Keep us posted.

                     JK TAS Jerry

 

[Flux]

It is not clear from the literature but they imply that the winding is different for the 3 voltages.

If this is so then you may still need the resistor to keep it out of stall at 12v,

If it is as Jerry implies then the connections may be all that decides which voltage it is.

Like you, I can't find any mention of speed but it is certainly not a low speed beast. If the connection change still leaves it stalled then you can add some resistance until you change to 24v. If you use just enough to avoid stall I don't think you need worry about speed. To manage the sort of power levels that Jerry has seen, it is not going to be low speed. If you measure frequency and find the cut in speed you will have some idea, you can reasonably expect it to run up to 3 times cut in speed and probably 4 times would not be unreasonable. If it runs faster than the point where it makes maximum power then you are too fast.

Such a small prop should not be bothered about 800rpm and I suspect the intended full speed is going to be over 1000rpm.

A simple way to check would be to add a temporary battery to reach 24v ( spare car battery or something). You could then check its intended speed directly with your frequency meter. 8 pole is 50Hz at 750 rpm.

Flux

[Off grid in Tonopah]

    Thanks for the feed back Jerry/Flux. My biggest concern was over speed on the turbine. By putting some resistance in the line as the amps go up the voltage drop across the resistor and the speed of the blades go up. It finally reaches a sweet spot and wow!!! the blades go the amps go up and I've seen voltage across the AC side up in the 70's

    Maybe what I'm seeing is the place were it should be running. I just wanted to be sure I wasn't going to over speed. I found some information on the True-North web site that leads me to believe that 500 to 600 rpm is ok and If as Flux was saying I should be good up to the 1000 rpm range than I may be just seeing the blades finally bite. I just got a little nervous because the transition is impressive!! I'll get some better speed readings now that I have the pole numbers, So thanks for the wiring information. Here's a question. Is it possible to over speed if I keep the machine loaded and the furling works as designed? Can you get to a position were the resistance in line gets the mill into a feedback loop of speed/voltage/amps increasing to the point of failure even if you are dumping the amp into a load?

    Also I'd have to agree the mill definitely has a lag coming out of startup. Once spilling it stays spinning though. Hopefully the change you suggested will fix this.

                              Again Thanks Everyone

                              Bob

[Flux]

Bob

Running a 24v  machine on 12v is rather naughty. It will stall very hard straight from cut in. Adding resistance will get it out but it needs more than would be desirable to clear stall later on in the speed curve.

As you have noticed it will be difficult to break clear and then it goes well clear once you have got it going.

Connect for the lowest voltage is the first thing to do. Then use the absolute minimum resistance to get it away in reasonable winds. You may have to leave it stalled in light winds.

Check your speed and as long as it doesn't go crazy I wouldn't worry, but you are certainly operating in a mode that it was not designed for. Your 70v does seem rather high but that alone is no great concern. As long as it furls within the current rating of the alternator you should be ok.

My only concern is that you may not normally see winds where it will furl and if a high wind does come when you are not about then you will not know if it is going to furl.

Ideally you need to add resistors in parallel with the first when it gets into higher winds but that becomes far too complicated for a temporary set up.

Flux

[Off grid in Tonopah]

Yea I might be pushing the envelope a little but one thing  for sure it's teaching me loads about the whole blade stall and matching blades to the generator thing. Nothing like first hand doing to make it all come clear after reading about it for the last few months. It looks as though I was operating less than 300 rpm which looked fast but nothing like500 that I'm running now. As you pointed out I'll have to keep an eye on things so it doesn't runaway from me with that whole amp / voltage drop across the resistor / speed increasing  feed back loop. Makes one wonder if some of the failures that have been reported on the board haven't been brought on be just such a situation if running some resistance in the line. Again thanks for  the help guys.

                                     Bob