Matronics Email Lists :: View topic - 14V alternator producing 28V?

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

14V alternator producing 28V?

Matronics Email Lists Forum Index -> AeroElectric-List

View previous topic :: View next topic

Author Message

a.s.elliott(at)cox.net
Guest

Posted: Tue Apr 14, 2015 6:38 am Post subject: 14V alternator producing 28V?

In the airplane I just bought, there is a truly *arcane* mixed 12V/24V electrical system that I will need to rationalize in the coming months.  But here is the first question:

  The plane has a 24V battery and a 24V starter.  The alternator is clearly marked “14V” however.  Now with my admittedly limited understanding of how alternators and regulators work together, I realized that an alternator can provide pretty much any voltage that the regulator asks for, up to maybe 150V or so.

  So my questions are:  How are the voltage ratings and amperage ratings for alternators decided? And what are the issues with setting up a declared “14V” alternator to run with a 24V regulator?  Is it nothing more than using higher capacity diodes?

  Thanks,

Andy Elliott

new owner of GP-4 N729LS

 

 

   [quote][b]

- The Matronics AeroElectric-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?AeroElectric-List

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Apr 14, 2015 3:12 pm Post subject: 14V alternator producing 28V?

At 09:36 2015-04-14, you wrote:

  	  Quote: 	
		    In the airplane I just bought, there is a truly *arcane* mixed 12V/24V electrical system that I will need to rationalize in the coming months.  But here is the first question:  The plane has a 24V battery and a 24V starter.  The alternator is clearly marked “14V” however.  Now with my admittedly limited understanding of how alternators and regulators work together, I realized that an alternator can provide pretty much any voltage that the regulator asks for, up to maybe 150V or so.

   So my questions are:  How are the voltage ratings and amperage ratings for alternators decided? And what are the issues with setting up a declared “14V” alternator to run with a 24V regulator?  Is it nothing more than using higher capacity diodes? 	


    The B&C SD-20 series OBAM and TC aviation alternators

    are 14v devices. Using the standard line of 14v alternator

    controllers, this device produces 20+ amps at 14v.



    It can be used in a 28V system but only with a special

    regulator designed to limit field voltage to 15 volts.

    You're correct, an alternator is capable of a wide

    range of voltages depending on RPM, field voltage and

    loads. It may be characterized at some voltage like 14

    or 28v . . . but it's not necessarily limited to working

    in the one system.



    Where is your alternator mounted? Belt or pad driven?

    What is the make and model number of the alternator

    regulator. My suspicions are that you have a 28v

    system . . . not a mixture of two systems.



 

 

   Bob . . .    [quote][b]

- The Matronics AeroElectric-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?AeroElectric-List

Display posts from previous:

	Matronics Email Lists Forum Index -> AeroElectric-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