Same stator 12v or 24 v?

[snuffy]

My original idea was 12vdc Jerry wired.  Since then I've aquired 24vdc ups's and need to change my base voltage.

This will be turned by a 3 meter 4 bladed prop set up for low wind conditions. (6 degrees at the tips and wide blades)

1st setup:

 Dual rotor 12/9 - 18 awg, 3 phase with N35 wedge mags.

 I get 12.5 vdc wired Jerry rigged, open circuit at 110 rpm.  (slightly low of my original target)  

2nd setup:

 Same stator and rotors.

 Wired in star I get 25 vdc open circuit at 132 rpm.  

Question:

  Will this work with reasonable success wired star for a 24 vdc system or am I missing some important detail?

[Devo]

By my calculations your star Voltage should be a little higher like 28 volts at the same rpm as the 12.5 volts jerry rigged.

I would think it would work ok at 24 volt, how many in hand is the 18 gauge? you don't specify magnet size or rotor so it's hard to know if the stator is a good match (won't burn out)with that size prop.

Devo  

[snuffy]

Sorry for my omission.  The 18 awg is 100 turns one in hand.  Wedge magnets are 3/16" thick x 2 inches long.  Rotors are 10.25. One is a Volvo brake disk and the other is a cement cutting blade.

[Flux]

Yes the star connection will work perfectly well for 24v, the cut in is slow but should be ok with your low speed prop.

You have incredibly low flux density, probably your stator is very thick for the magnet thickness and this may not be helped by choosing a saw blade for one rotor disc. The end result is that you have had to use thinner wire and you will need to make sure you furl real early to prevent burn out. If it is a low wind area and you produce most of your power in the lower winds then it shouldn't matter if you have to limit peak output to about 300W.

Flux

[snuffy]

Yes I was figuring 300-400 watts to be about max, and would like to furl before 20 mph.  (don't get much of that anyway).  The saw blade doesn't appear to have any flux leakage behind it so I was hoping it would be sufficient.  Yes, the stator is 1/2 inch thick.  I molded this before the discussions about 2 or more in hand.  

My summer wind is pretty steady daytime around 10-15 mph but winter is less average with gusts during storms. A gust to 40 mph will hit the news channel. Then we have weeks of fog and no wind.

[Devo]

I would be leaning towards 300 watts max , 250 normal.300 watts at 24 volts thats 12.5 amps,well past 18 gauge's "normal" operating range(50 % over) it should do short spurts there but 400 watts may be leaning to trouble-(just my opinion)

A 3 meter prop could easily run away with that thin of wire, furl early..

Devo

[snuffy]

OK, I get the message, believe your right.  I will see what I can do to keep it under control.  My tail isn't very long or heavy and I have plenty of offset so I should be able to keep it down. I'm really not very power greedy.  At this time it's as much a toy as anything, hoping to use the power for part of my shop lighting.

[ghurd]

Greedy never pays?  Good point!

If the hurricane force winds show up, the battery is full well before that.

Before the hurricane force winds arrive, the battery is already dumping.

G-