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Alternator Parallel/Series Windings

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New Member
Joined: 5 years ago
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Hiello  Looking to get any information about pros/cons of upgrading the Jabiru 3300 alternator to improve output at lower engine speeds as described in the paper Doug wrote in 2013 to convert from 12 pole parallel (2 x 6 pole) to 12 pole series (AVDALSR087-2).  Looks like a winner.  Anyone had any experience of running a modified unit?  Is there any downside to doing it?  I notice the JEM0002-7 table 12 specifies both 12 pole parallel and 12 pole series type alternators.  Is the series wound a factory option/fit now?

Thanks. Chris.  3300A2556

New Member
Joined: 2 years ago
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According to this if the alternator is operating in parallel it reduces the overall operating cost. You should read for more because of ensuring greater security and help you to generate alternative in parallel services.  

New Member
Joined: 3 years ago
Posts: 2

I changed mine with the Rotec kit, and am beyond happy…but there are several things to account for->>>your engine tach derives it’s rpm indication from the ripple in the factory alternator. So, you need to address this…. The Rotec alternator ( off the shelf at any good alternator shop )has a built in regular, so the only thing coming out of the DC power connector is ripple free DC. (And you no longer need your external regulator BTW)

So you need to pick up your tach data from elsewhere because the ripple is now within the alternator, not external

If u ‘’look closely at the Jabaru 3300 manual you will see two hall except sensors available, one that takes its tack from the flywheel teeth. You don’t want that one, far too flimsy..

The other one Jabaru provides is a VASTLY more rugged Hall effect pick-up and a small bracket to pick up the indicator from the large flywheel magnets 

In fact they even give you the machining diagram which any machine shop with a Bridgeport can fabricate in less than a hour’s time, along with the exact AN parts designations and the sender ( who’s is insanely well constructed to Mil-spec standards..)

And the best thing is that the Hall effect sensor connects directly to your EFIS without having to tell the EFIS a new pulse rate, since the output pulse count has changed..

And one last thing to remember —> the Rotec kit uses a generator that produces energy at FAR fewer RPM than the Jabaru, which means you can now taxi with 7 planes in front of you while in low idle using fewer RPM to stay ahead of the the equipment load/depkdtion of your battery.

And that is a home run, using extremely rugged parts to solve the problem..     

Peter Virdee reacted