Hi,
I'm planning an upgrade to an all-glass setup, so I've been studying electrical systems in general and AeroElectric connection in general. I think I'll go with Z-12 (dual alternator, single battery setup). A diagram can be found here: http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z12M.pdf
It seems robust enough, but I have a question the answer to which I couldn't find. What if the master contactor gets disconnected in flight? It can happen due to a failure in the contactor itself, or in any wiring around it.
In this case both alternators get disconnected from the battery. Many people say that the alternators will still work with some ripple in the output voltage. But it is also plausible to think that OV protection will take both alternators out without any possibility of restarting them. It seems like this failure can defeat dual-alternator setup with a single failure around master contactor.
Also with automatic alternator failover setup (where backup alternator does not kick in until bus voltage drops below a certain voltage) is it possible that ripple amplitude will be large enough to trigger backup alternator? What would the consequences of this be?
Assuming alternators keep working after master is disconnected, everything is fine, but how do I test it without potentially frying a lot of expensive avionics?
I'm planning an upgrade to an all-glass setup, so I've been studying electrical systems in general and AeroElectric connection in general. I think I'll go with Z-12 (dual alternator, single battery setup). A diagram can be found here: http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z12M.pdf
It seems robust enough, but I have a question the answer to which I couldn't find. What if the master contactor gets disconnected in flight? It can happen due to a failure in the contactor itself, or in any wiring around it.
In this case both alternators get disconnected from the battery. Many people say that the alternators will still work with some ripple in the output voltage. But it is also plausible to think that OV protection will take both alternators out without any possibility of restarting them. It seems like this failure can defeat dual-alternator setup with a single failure around master contactor.
Also with automatic alternator failover setup (where backup alternator does not kick in until bus voltage drops below a certain voltage) is it possible that ripple amplitude will be large enough to trigger backup alternator? What would the consequences of this be?
Assuming alternators keep working after master is disconnected, everything is fine, but how do I test it without potentially frying a lot of expensive avionics?