Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Rotax 914, run fuel pump with no battery?

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Europa-List
View previous topic :: View next topic  
Author Message
rparigor(at)suffolk.lib.n
Guest





PostPosted: Wed Jan 25, 2006 8:47 am    Post subject: Rotax 914, run fuel pump with no battery? Reply with quote

Studying Rotax 914 schematic, the main fuel pump is wired to the B+ of the
regulator.

It appears if you open the alternator output switch, they expect the
alternator could run the fuel pump with no battery in circuit and act as a
true redundant pump???

Am I correct in my assumption that you could fly with a fuel pump running
off the alternator only with no battery connected?

In this configuration with no battery at all, is the alternator self
exciting to get things going?

Will testing often to make sure the pump will run in this configuration do
any harm to the regulator, alternator, pump or switch? Or should this be
used only in an emergency?

They do have a 22000mF capacitor from B+ to ground.

Thx.
Ron Parigoris


- The Matronics Europa-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List
Back to top
Gilles.Thesee(at)ac-greno
Guest





PostPosted: Wed Jan 25, 2006 9:31 am    Post subject: Rotax 914, run fuel pump with no battery? Reply with quote

rparigor(at)suffolk.lib.ny.us a crit :

Quote:


Studying Rotax 914 schematic, the main fuel pump is wired to the B+ of the
regulator.

It appears if you open the alternator output switch, they expect the
alternator could run the fuel pump with no battery in circuit and act as a
true redundant pump???

Am I correct in my assumption that you could fly with a fuel pump running
off the alternator only with no battery connected?

In this configuration with no battery at all, is the alternator self
exciting to get things going?

Will testing often to make sure the pump will run in this configuration do
any harm to the regulator, alternator, pump or switch? Or should this be
used only in an emergency?

They do have a 22000mF capacitor from B+ to ground.



Ron,


When designing our project's Rotax 914 electric circuit, I had the
opportunity to study the Rotax/Ducati alternator and regulator.
With the help of a friend who is doing electrical research at the
University, we performed some bench tests.

I am positive that the Rotax regulator will NOT start to life if not
connected to a properly charged battery or capacitor. You need
sufficient bus voltage to trigger it.
If your battery quits, or if you disconnect it in flight, you may
encounter difficulties trying to trigger the regulator again.
In my opinion, running the fuel pump direct from the regulator, as
suggested by Rotax, is definitely NOT a good idea.
Besides, the Rotax/Ducati exhibits an alarming high rate of failure.

So I decided to go the dual battery way, and resorted to a Schicke
regulator, which is self exciting. More info and diagrams on my
"Electricity" pages.
Within the next few weeks, I'll publish a summary of our research.

FWIW,
Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr


- The Matronics Europa-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List
Back to top
paul.mcallister



Joined: 09 Jan 2006
Posts: 177
Location: Waukesha, WI USA

PostPosted: Wed Jan 25, 2006 9:35 am    Post subject: Rotax 914, run fuel pump with no battery? Reply with quote

Ron,

Yes this is how it works on my aircraft and I have tested it.

Paul

--


- The Matronics Europa-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Europa-List
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Europa-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group