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 

Dead battery
Goto page Previous  1, 2
 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List
View previous topic :: View next topic  
Author Message
ceengland7(at)gmail.com
Guest
PostPosted: Thu Jul 07, 2016 12:18 pm    Post subject: Dead battery Reply with quote
On 7/7/2016 12:21 PM, Robert L. Nuckolls, III wrote:

Quote:
At 10:48 AM 7/7/2016, you wrote:
Quote:
 
 
 
But all of the internally regulated alts I've seen need some form of external overvoltage protection (typically a series contactor in the B lead circuit) which implies the ability to control the alt's ability to feed the system. If the contactor control is 'downstream' of the master switch, you get the one-operation shutdown of the system
 
  I seem to recall a couple of years ago, Bob N. was working on a system
  to safely shut down an internally regulated alternator, and a simple series
  contactor was not the answer. 
 
  IIRC he never came up with a good recommendation for a circuit and
  procedure to do this.  Am I correct or did I miss the final answer???

  Yes, that idea was predicated on a bit of kerfuffle
  over some Van's alternators that eppeared to have
  gone belly up after having been switched on/off
  using the Figure Z-24 ov manager.

  To the best of my knowledge there was no failure
  analysis conducted on the damaged units. The
  general consensus amongst the best-guessers
  was that the alternators were switched under
  load . . . perhaps at rpms more than idle and
  the subsequent load-dump (automotive parlance
  load-dump) zapped the alternators.

  Nobody knew the pedigree of Van's offerings.
  Further, my visit to MPCA overhaul operations
  in San Diego/Tijuana demonstrated that a
  righteous/capable overhauler produces parts
  immune to such events (see chapter on alternators
  in the 'Connection).

  The more sophisticated controller was not
  pursued as probably unnecessary.  Even if
  the alternator is not so capably remanufactured,
  turning it on/off under load and running faster
  than idle is simply not necessary. Hence, Z-24
  has not be replaced or updated.




  Bob . . .
Bob,

My memory of those events is a bit different. At one time, there was a circuit in the book to provide overvoltage protection for 'one wire' (internally regulated) alternators. It used your overvoltage 'crowbar' module, but the crowbar was applied to the CB-protected power going to the coil of a contactor, which could open the B lead from the alternator.

As I remember it, numerous people running Van's small IR alternator (I think it was a Honda product; ~35amps) had alternator failures when they intentionally triggered the OV module with the alternator producing power (the infamous 'load dump'). Others were manually cycling the control to the contactor (thinking in legacy 'split master switch' a/c terms instead of 'new' automotive terms) while the alternator was under load, also resulting in alternator failure. FWIW, I actually had an alternator failure in an RV-4 using that old alternator, that apparently happened on the same flight that I cycled my master switch, working on a different electrical issue. I can't swear to cause & effect, but they were coincidental.

Again, as I remember it, you decided to pull the design to avoid the failure mode induced by misuse of the design. I hated to see it removed from the book, because I thought it was an elegant way to control inexpensive, readily available (any auto parts store), light weight alternators. I always thought that education would have been better than deletion. Smile

I still have a copy of the original circuit page from the book; I'm implementing it (twice) for my dual alternator equipped Mazda rotary on an RV-7.

Charlie

- 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
Back to top
ceengland7(at)gmail.com
Guest
PostPosted: Thu Jul 07, 2016 12:42 pm    Post subject: Dead battery Reply with quote
I'm not Roger, but I'm quoted in that message, so...

I suppose I should have been more specific. I was referring to 'off the shelf' internally regulated automotive alternators, being installed, unmodified, in an aircraft.

I think Roger's question would be at least partially answered by my response to Bob (sent a few minutes ago).

Charlie

On 7/7/2016 2:41 PM, John Tipton wrote:

Quote:
Roger


So you saying that the Plane-power alternators (as fitted to many RVs) need external over voltage protection


http://www.plane-power.com/pdf/internally%20regulated%20experimental%20alternator%20information.pdf


John

Sent from my iPad

     ----x--O--x----


On 7 Jul 2016, at 04:48 pm, Roger <rnjcurtis(at)charter.net (rnjcurtis(at)charter.net)> wrote:


Quote:

 
 
 

But all of the internally regulated alts I've seen need some form of external overvoltage protection (typically a series contactor in the B lead circuit) which implies the ability to control the alt's ability to feed the system. If the contactor control is 'downstream' of the master switch, you get the one-operation shutdown of the system

 




           I seem to recall a couple of years ago, Bob N. was working on a system
           to safely shut down an internally regulated alternator, and a simple series
           contactor was not the answer. 
 
           IIRC he never came up with a good recommendation for a circuit and
           procedure to do this.  Am I correct or did I miss the final answer???
 
           Roger
=================================== st">http://www.matronics.com/Navigator?AeroElectric-List =================================== cs.com =================================== om =================================== matronics.com/contribution ===================================


- 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
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List All times are GMT - 8 Hours
Goto page Previous  1, 2
Page 2 of 2

 
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