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FandPwithPVC
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Joined: 09/09/2006
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Posts: 64

Posted: 09:13am 11 Jul 2008

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Hi All Using a 80SP in star with standard magnets ,24 volt bats and at 325 rpm we get 16 AMPS WITH CAPACITERS.
As we learn more about and understand the PRACTICAL effects of capaciters we decided to try something different.
Normally we connect our caps in delta but this time we put them in series. We had tried this before but had not used caps with high enough uF.(Learning all the time) The ones we used are not our regular ones but are from Jaycar Electronics Being small in physical size they are or were 100uf ,150uF and 220uF non polorized and 100 volts.
We used a protective safety shield and we were glad of it.From previous tests we had established that we would need a large uF so we crept up on it bit by bit.
The F and P kept very cool , the rectifiers got a litte warm and the caps were getting hot. This we put down to there size and after 15 minutes or so we got a very small bang and the blue smoke. This is is our first time for this.
Given these results it means building large size capaciter bank of 3 by 250 uf and seeing if it smokes too. Our current 5 blade Piggott with brushes goes better at our Pedlers Creek farm . It does not notice cogging or dead shorting it and is exceeding our exspectations. On closing our test bench does not show any problems in starting. Although it will run a little slower at times particularly if caps are connected and there is no bat load, Regards Dennis L

domwild
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Joined: 16/12/2005
Location: Australia
Posts: 873

Posted: 09:11am 12 Jul 2008

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Interesting try! Have already seen this adding on of caps several times. Pls explain what you mean by "adding caps on in series". Is it from each phase to star point?

Thanks.

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FandPwithPVC
Regular Member

Joined: 09/09/2006
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Posts: 64

Posted: 01:31am 13 Jul 2008

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Hi All
In your normal star output you have 3 wires from your F and P going separately into the rectifier.
The other3 wires at the F and P connect together and are not used.They however would be used for a delta output.
Putting capaciters in series is when you break each wire before the rectifiers.
Then you put the capaciters between each broken wire to form 3 wires again.
This is a star output with capaciters in series.
They are working extremely well but ONLY if you do it as explained in the notes.

Regards Dennis L

Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1343

Posted: 06:59am 13 Jul 2008

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Well dennis you were spot on saying theat 50uf won't be enough

. I put those 50uf caps in series and although I don't get any current increase the waveform is damn close to a pure sinewave before and after cutin. Shortly I'll get 6 of the 100uf caps and put them in and I can see test the cap theory in a real world setup ie: on my 100S f&P wire in delta. If I don't see increase it will be too easy to drop the tower and put the 80sp back on and that one was the one we tested on your testbench.

Cheers Bryan

P.S. Catch ya on Wednesday evening mate

herbnz

Senior Member

Joined: 18/02/2007
Location: New Zealand
Posts: 258

Posted: 09:13pm 13 Jul 2008

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removedEdited by herbnz 2008-07-18

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