John,

I forgot to answer your question.  Each battery is connected independently to its own alternator through an individual contactor.  If one alt fails, I can shut it off by opening the field (good argument for external regulated alt) and close the x-feed contactor to connect both batteries in parallel.  So, a failed alternator should be a non-event… just open the field on the failed alt, flip the x-feed switch and continue on to my destination.

 

Mark S. 

 

 

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of Mark R Steitle
Sent: Tuesday, January 24, 2006 8:21 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Two Alternators?

Doug,

I have dual alternators and dual batteries per Aero-Electric Z-14 architecture.  I’m using the small 55amp ND units.  They weigh about half of what the Mazda alternator weighs, so I rationalized that there was very little weight penalty to using two alternators, but a significant safety improvement.  With an electrically dependent engine and all electric panel, I decided this was the way to go for me.  The cross-feed contactor connects both Odyssey batteries during starting, so I am able to use smaller batteries than would be required to start the 3-rotor with only one battery.  Every annual, I plan on replacing the main battery, rotating the 1 year old main battery to the aux position, and move the 2 year old aux battery to my Goldwing motorcycle.  That way the main battery will be less than one year old, the aux battery will be 1 - 2 years old, and the motorcycle battery will be 2-3 years old.  I’ll send you a picture off-line. 

 

Mark S.

 

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From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of DLOMHEIM@aol.com
Sent: Tuesday, January 24, 2006 6:11 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Two Alternators?

 

I am debating the future use of two batteries vs. two alternators and I was wondering if anyone in the group has mounted a second alternator and if so if they had any pictures of its mounting location, etc.

 

Thanks for the information.

 

Doug Lomheim    RV-9A / 13B

OK City, OK