Electrical Load

Greetings all,
Anybody have the amp usage from the Rotax 912 ULS ignition? My analysis is pushing the 14 Amp threshold and need some good numbers.


I think I found my answer. The violet wire from the A and B modules are for starting, and the switches are grounded. So any power used would be during the start sequence and not normal operations. The alternator has seperate poles to keep the ignition isolated from the rest of the electrical system. So short of a total internal failure of the alternator, the engine should continue to operate even if the aircraft electrical system failed.
Does that sound correct?

Can't comment on the wire colors but conceptually you are correct, the engine will run in spite of an aircraft electrical system failure.

That is why God made magnetos. ;) Even with complete power failure, your engine should continue to run. I have lost two alternators in flight (bearings freeze, belt burns). The burning rubber was not what I wanted to be smelling at 8000'. This is a good reason to divide your electrical system into at least two circuits/ busses with one buss that you can isolate with "essential" loads. The other buss can then be shut down saving what battery power you have left to use for radios, etc.

Dan,
I agree, with an endurance buss powering the most needed items for flight, it affords some confidence. As long as the battery is up to the task. Working out the electrical system has been a good mental exercise while I await my return to the USA. The information at Aeroconnections has been very helpful. Our Aero Club here has 3 Cessnas, and even at 500 hrs, the magnetos look in good shape, but get sent out anyway for O/H. Some times technology of the past is hard to beat.