Posted: 10:17pm 05 Jan 2006

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I drew up 4 diagrammes to show the difference between star and delta connections on the F&P. Its gets a bit messy, especially the last one, but if you follow the red wires you should be ok.

Each coil has a start and end connection, the start connection is the wire that disappears under the coil ( it is the start or first layer of the winding ), and the end connection is the wire at the end of the winding, or the wire on top. Think of each coil as a little battery with its polarity swapping from end to end as the magnets go past. Its when we connect these little batteries together, is important to make sure we get the start and end connections the correct way around, or we end up shorting the coils out.

Star connection: the start wires of coil 1, coil 2 and coil3 are connected together. The ends of each coil make our 3 phase power.

Delta connection: the end of coil 1 connects to the start of coil 2. The end of coil 2 connects to the start of coil 3. The end of coil 3 connects the the start of coil 1.

This is a Star wired as 14 poles, good for 100 series stators in strong winds.

This one is a star 7 poles, the most common converstion and good all rounder!

Now we get fancy with a delta 14 pole. If you have VERY strong winds, like F&P Murray , this is the one to go for.

And this is a delta 7 pole, less current, more volts than above.

As a rule, delta give more current but less volts, so delta is good for high winds.

Glenn

Posted: 05:44am 08 Jan 2006

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Hi Glenn and thanks for talking to me the other day i finally worked out my problem with the 14 pole delta, a very very small piece of metal had been lodged deep between 2 coils ( this was the stator taken literally from the jaws of a scrap crane ) i unwound both coils repaired the areas and rewound both by hand, a five beer job, now the unit is ready to go up on saturday meanwhile the current stator is a 14 pole star and is doing well, my nieghbour convinced me to let him have an older star mill and it turns out he is in the fibreglass industry and will look at making up a mould for new blades, he then gave me a tip ion an 8 metre mast thats wide at the base and tapers a bit to the top for $120 well that will be mast number 3. Having had time to think a bit while at the block and have come up with a new hub setup that is adjustable i will make one up this week and post a couple of photos by friday. The tall 13 metre mast has come down and been reduced to 6.5 metres, it was just too dangerous to raise and lower, so now i will have 2 x 6.5 metre masts that will be delta 14 pole and 1 x 8 metre that will be star 14 pole the new setup is easy for me to lower and i can even climb the large ladder to do small jobs. The new 900mm blades just dont cut it as well as the 1200mm ones but a 900mm blade with a much wider blade to the wind might be ok ill make up a couple sets this week and test them.

Bob from Murray Bridge

Posted: 09:43am 08 Jan 2006

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Hi Wayne from Canada, and welcome to the board.

I'm not sure on the best configuration for a VAWT. I played around with one but the large surface area was making to much noise, the F&P's vibrate as they turn. VAWT's turn slow, but have heaps of torque ( depending on what type of VAWT you are building ), so you mights have to use other combinations than the standard 14 or 7 pole. 2 poles ( stator divided in two ) could be an option, you would need to try a few options to see what gives the best results, but thats the fun of it all.

As F&P's would be pretty rare up in Canada, I would suggest you make your stator so it can be easily reconfigured. This can be done by adding screw terminals to each of the 42 poles. I have seen this done, but cant find the photo, so drew this diagram....

This way you can play around with different combinations without the risk of damage to the windings. But even if you do damage a coil, they can be rewound, see Murrays message above.

Sorry to hear you are ill, hope you can get back into action soon.

Glenn

Posted: 09:54am 08 Jan 2006

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Hi Bob.

Glad to see you found the problem. Those shorts can be hard to find.

You should see if your friend wants to make fibre glass blades for the DIY windmill builders. I've been building a CNC router to make blades on, as well as other stuff. I fired it up today to check the motion systems, all ok but needs some tuning to get the speed up. The bed size is 1200 * 600, so its big enough to make a set of 3 blades in one go. I still need to buy a router for it, trying to find one thats quiet, a set of blades would take a couple of hours to rout, thats a long time to have a router screaming its head off.

I'm tempted to rip the milling attachment off my lathe . Its quiet and I never use it.

Glenn

Posted: 09:40pm 09 Jan 2006

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Hi Wayne

Yeah you are right, This page http://www.thebackshed.com/Windmill/FPRewire.asp has more details. I've got the terminology mixed up a bit in the drawings.

Glenn