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danko12
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Joined: 23/01/2012
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Posted: 07:53am 23 Jan 2012

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Hi some one know this wiring metod called fractional slot ???

im from italy i bought from china an vawt 1 kw turbine 48 volt
now after more test it dosen't produce power under hight wind
all is ok batteries controllers and cables

when the rotor spinn and arrive at cut in speed about 48 volt

look like backed and dont produce any amperage only voltage throu2012-01-23_175134_diagrham__real_061.rar 2012-01-23_175158_DSC03315.rar 2012-01-23_175221_DSC03359.rar 2012-01-23_175249_DSC03376.rar the phases

I disassamble the alternator inside and find 8 poles and 33 slot ??

the connection is three phases but i found other unknow three other connection

now i think the operator who wired the stator maybe wrong some position

the factory says the rotor is wired as fractional slot

some know the fractional slot how it works??

Gizmo

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Joined: 05/06/2004
Location: Australia
Posts: 5078

Posted: 08:51am 23 Jan 2012

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Hi Danko

Those images you tried to upload are RAR files. Can you upload them as plain images or Zip files?

Glenn

The best time to plant a tree was twenty years ago, the second best time is right now.
JAQ

danko12
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Joined: 23/01/2012
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Posted: 11:09am 23 Jan 2012

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hi mate i have only rar

Gizmo

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Posted: 12:46pm 23 Jan 2012

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I've un-rar'd them and posted here. Using RAR files mean most people cant open the files.

The best time to plant a tree was twenty years ago, the second best time is right now.
JAQ

BobMann

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Joined: 30/06/2011
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Posted: 01:30pm 23 Jan 2012

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Hello on the wireing I thing it was build for a 6 phase unit . Then was made into a VAWT.
I would bring all six down to try to work with you must Ohm out all 6 wire ends to see if the are all open ended if so it was to let you do a star or delta wiring setup??

If it was like the pic it had 12 wire ends and 6 are grouped to make 2 star phases
you could play with just 1 phase at a time for some power testing.

I would pull the motor and install in a lathe for a few bench tests to come up with a power curve.

I do not think you will not see much power from it China realy over rates this kind of thing.
You may wish to ask over at
USVAWTS

We ae 99% VAWTs
Bob Mann

danko12
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Posted: 04:23pm 23 Jan 2012

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thanks mate the factory says the wiring is " fractioned slot " y connection

danko12
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Posted: 06:00pm 23 Jan 2012

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danko12
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Posted: 06:03pm 23 Jan 2012

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this is the actual diagram some know this particular " fractioned slot "???

the coil are spaced from 5 slots !!

BobMann

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Posted: 07:50pm 23 Jan 2012

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danko12 said

this is the actual diagram some know this particular " fractioned slot "???

the coil are spaced from 5 slots !!

The term used fractioned slots means I think for that the magnets are not lined up to the stator at a unifed degree like magnet 1 is at 0 degree magnet 2 is at 22 degree magnet 3 is at 27 degree and so on . So to lower cogging the winding have no part to the fractioned slot.

Bob Mann

danko12
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Posted: 09:52pm 23 Jan 2012

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thanks bob the mag trhu the rotor are perfect equal distance they are at 45�

im waiting an unwhere from the china factory but now all china is on holiday !!

danko12
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Posted: 10:01pm 23 Jan 2012

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any way im find some pepole who bought the same vawt ctturbine 1 kw to share info
thanks

yahoo2

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Joined: 05/04/2011
Location: Australia
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Posted: 04:51am 24 Jan 2012

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I cant see clearly from the photo, it looks like there are two coils per slot.

If that is right that would make it a "constant fractional pitch odd slot 8 pole 3 phase hookup"

The six wires together has me confused, if they were not there, I would say it is wired delta.

I'm confused, no wait... maybe I'm not...

danko12
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Posted: 11:46am 24 Jan 2012

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the wiring of the coil i suppose is with two line of coopper !
thanks

BobMann

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Posted: 01:10pm 24 Jan 2012

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yahoo2 said I cant see clearly from the photo, it looks like there are two coils per slot.

If that is right that would make it a "constant fractional pitch odd slot 8 pole 3 phase hookup"

The six wires together has me confused, if they were not there, I would say it is wired delta.

As I said it is a china build this PMA or motor was designed for some other use.
and they used some of the stator to make up a VAWT.

If it was build by this company in china take a good look at the failed part.
China failed VAWT

Bob Mann

danko12
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Posted: 02:58pm 24 Jan 2012

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the factory is http://www.ctturbine.com/

in the wole structure the vawt is a strong material

but there is this problem

the fractional slot how it works ??

yahoo2

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Posted: 03:42pm 24 Jan 2012

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fractional pitch means the degrees of angle two sides of a single coil is smaller than the degrees of angle that two poles of the rotor make.

poles 360 degrees / 8 poles = 45 degrees
coils 4 slots apart 43.5 degrees

the odd number of slots is something to do with reducing harmonics in motors, it could reduce cogging when used as a alternator.

looks to me like there are 11 coils per phase with a constant overlap.

polyphase motor/ generator

I'm confused, no wait... maybe I'm not...

danko12
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Posted: 04:46pm 24 Jan 2012

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HI MATE YAHOO2 THE COILS ARE EVERY 5 SLOT

I WILL BE CRAZY WITH THIS WIRING

danko12
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Posted: 05:05pm 24 Jan 2012

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this is the spacers bitwin the coils and slots

the whole slot are 33 !!

yahoo2

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Posted: 11:54pm 24 Jan 2012

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Could it be possible that they have cut one coil off the end of each phase giving us 30 coils.
10 coils per phase, then wired each phase parallel as 5+5 to lower the output voltage and keep the coils balanced.

That would make the 6 wires the parallel star connection and the 3 pairs the output wires. The 3 single wires would be the original high voltage star output wires.

That would mean there are 3 more cut wire ends hiding somewhere in all that copper, that is the other ends of the coils that have been cut out of the circuit.

yahoo

that's the best I can come up with , sorry

I'm confused, no wait... maybe I'm not...

danko12
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Posted: 08:19am 26 Jan 2012

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hi this is the replay from the factory for the wiring diagrham !!!

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