Rotax in Highlander electrics???

[Meatball]

Hi all! I’m planning my build for an Edge Performance 912STi which means electronic injection and dual electronic ignition. I’m fairly certain I’ll need an external alternator to help power especially if I add a heater for the cockpit. Can I please get some examples of how folks wired their planes up? I’ve been over and over diagrams in the install manuals for 912/914 and in Aeroelectric Connection, but I seem to get more confused. How do you wire the alternators while being able to disconnect them and still keeping the engine fuel pumps running?

Any info would help

Thank you!!
Rob

[danerazz]

I can’t speak specifically for Rotax, but if you lose an alternator (and do not have a backup generator source) you will be on battery power. You want to make sure your amp-hour (ampacity) is enough for you to land safely if you lose an alternator while still running important stuff like critical fuel pumps, electronic ignition, etc. Ideally you have the “must have or I am a glider” (and some instruments and navigation if you are IFR) stuff on an emergency or essential bus.

This is outlined in the aero electric guides. Do you have the “book” or just looking at the website?

This book is available here and has detailed diagrams and descriptions. Lots of good info.

It is free to download, but is very large (300-ish pages, lots of chapters). Or buy a hard copy for $30.

If you download the appendix Z it has the diagrams, and there are chapters that discuss them in dtail.

https://matronics.com/aeroelectric/Catalog/pub/pub.html


Anyway, you would have a diode protected e-bus, with its OWN battery, that powers the really important stuff. The capacity of this battery is enough that you can run for at least 30-60 minutes on this as sole power. There will be a switch that can isolate or connect this bus as required as well, but with the diode protection it is essentially an automatic transfer. This allows isolation should a “non-essential” item short, thus not taking your e-bus with it.

[Meatball]

Thanks Dane! It’s slowly coming along but there’s soooo much thought that goes into it. I’m glad I’m not building an IFR airplane!