Disaster!

[cdog]

My mill has been up two years and working great until  recemtly. I lowered it last weekend because of a strange noise that I Thought was a bad bearing that turned out to be loose stator nuts that let the mags chew it up! I would like to buy a new stator from our hosts but I need input as I want to use this opportunity to use windings ideal for the new midnite classic controller. My system is 24 volt with the 2x1x 1/2 mags, any advice out there? Many thanks as always, cdog.

[halfcrazy]

You would be fine with a 48 volt stator the Classic will down convert to the 24 volt battery you would want the 200 volt classic. The only thing the Classic needs is 5-7 volts above battery voltage so if you had a 24 volt bank I would want the stator to be made for 34 volts cut in at the minimum but just going with the standard 48volt stator will be fine.

[libra]

Re the problem with the stator nuts especially after two years.

How was it put together, lock nuts, nylock nuts, loctite, wired nuts?

More info would be appreciated so we can learn

Would you be able to use a 48v generator on a 24v system and how about the regulator?

Am not sure and would like more info here as well.

sorry to hear about the failure.

Libra

[cdog]

The mill had ss locknuts but I Think  I may not have set them up tight enough for worry of crushing the stator. I will be using nylock nuts this time and bruising up the threads as well. The only concern is how long will I Have to wait for a classic? I would think it would stall badly in the meantime with the 48 volt stator?

[hiker]

use some locktite as well-

or use some superglue-the brand i use is called [helping hand]..

strong and water proof-high heat as well-even boiling water dosent effect it..

only problem its a real hassle to take anything apart once you use the super glue on it. just my experance with it..................

[halfcrazy]

I don't want to promise a delivery date on the Classic any more but I am under the impression it will be early 2010. The first batch of beta units that where just built look real good hardware wise. So that is good news. boB spent a week here working on the solar tracking algorithms and things are coming together fast.

If one wanted to have the best of both worlds I would just raise the cut in voltage 5 vdc that way it would still operate without the MPPT but would be plenty optimized for it.

[cdog]

The 48volt hd stator has 105  turnrns of 15ga wire, would that be ok or would you have a better recomendation? My current stator has 72 turns of 14ga.

[halfcrazy]

You will have to decide the voltage based on the willingness to wait for the Classic. Whatever you decide get a hold of Dan and he can help you with that and make the stator for you I am sure.

The only real advantage to going with any voltage higher then 5 volts above battery is really just for wire size and losses other then that the Classic is not going to care as long as it has a few volts to play with. It will have a feature similar to Extended Play on the mx60 but I don't know if that will work with the wind turbine curves and Wind learning?

The one thing I will point out is boB and Robin are very accommodating and listen to every idea floated there way and that is where a lot of the good features come from.

[Ungrounded Lightning Rod]

Have you checked whether the magnets were harmed by friction heating?

[cdog]

Yes, the magnets are toast, I have another set to use.

[Volvo farmer]

Hey.. You're involved in this whole project that I have been following for years now..

What information do you have on the final cost of the Classic? It seems to be substantially more complex than an MX60. I was thinking maybe it would cost 2X a MX60 but maybe as much as 4X. Any news to report?  

[halfcrazy]

There will be 3 models of the Classic for now with 2 more in the future.

Classic 150 volt 80 amp output

Classic 200 volt 65 amp output

Classic 250 volt 55 amp output

The Classics output current really depends on the input voltage for example I had the 200 volt unit running with a Voc of 184vdc and a Vmpp of 155vdc and it was putting 65 amps into a 24 volt battery and still had room to go. but if I had been running a Voc of 90vdc I may have been able to go to 75-80 amps.

The cost of the Classic should be in the same range as the FM series the 150v being close to the FM60 and the 250v being close to the FM80

There will also be 2 models of the Clipper and I know they will range in price as well but not sure where they are at yet will keep you posted on that. The clipper will be an essential device to protect the Classic as well as other electronics. I recall a situation where Dan was helping someone hook up a trimetric and the turbine was still connected to the inverters and smoked a whole bunch of stuff. The Clipper would have prevented that.

Midnite Solar will of course fix Classics that have been overvoltaged with out a clipper for the cost of the parts and labor  

[cdog]

How about 78  turns of 14ga? Dan are you watching? I am at work on my cel and I cant email you. I you can do this for me I will call your office and send the loot!

[ghurd]

I do not follow this part,

"The Classics output current really depends on the input voltage for example I had the 200 volt unit running with a Voc of 184vdc and a Vmpp of 155vdc and it was putting 65 amps into a 24 volt battery and still had room to go. but if I had been running a Voc of 90vdc I may have been able to go to 75-80 amps."

It seems to go against MPPT concepts.

Unless that's what boB is working on.

G-

[halfcrazy]

What I was trying to say is the current limit I gave is based on the input voltage so if the 150 volt unit can handle 80 amps the 250 volt unit can handle 55 amps but that is at a high input voltage which makes more heat so if the 250 volt unit was run at a lower input voltage it would not get as hot therefore handling more current.

[halfcrazy]

I should have said the Classics Current limit is based on input voltage.

[ghurd]

OK, Now I 101% get it.

The limit is based on output Amps.  The model's voltage limit decides the output amps.

(And I should know better too!)

I personally have trouble explaining to people why amps are amps.

Some people vigorously insist if a 60A controller can deal with 60A at 48V, then it can handle 240A at 12V, and if a controller can deal with 1800W of 48V then it can deal with 1800W of 12V.

I try to explain amps is amps.  If the ratings were watts, then the units would be called '1800' instead of '60'.

Might consider wording it something like 'Output Amps is Output Amps'?

G-

[halfcrazy]

Close its Output Amp rating is based on its input voltage so even though it is a 250 volt Classic rated for 55 amps output it can do close to 80 amps output say if the input voltage is low like say 75 volts in instead of 250 volts in.

On any MPPT controller the higher the delta between the input and output voltage the hotter it will run so the unit is rated for say 60 amps this is based on the highest delta the unit will see.

[ghurd]

I understand that.

In more direct terms, it is firmly rated for 0-250V and somewhere between 0A, 55A and 80A?

I hope it is self current limited, at least in some fashion, which may account for the Clipper.

Does Robin still read here?

G-

[halfcrazy]

there will be 3 models the 150,200 and 250 volt these numbers represent the operational voltage limit but the controllers are safe to that voltage plus battery voltage roughly. they will shut off at the rated voltage though.

What Midnite is hoping to do is have the current limit High and then have it self regulate based on temperatures that way if you bought the 250 volt unit for the voltage cushion but only fed it lower voltage the Classic would allow you to go over 55 amps.  

Robin does not frequent this board or many others much as he is very busy with multiple projects at this moment.