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Super-whizzy energy management systems

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nuckolls.bob(at)aeroelect
Guest

Posted: Tue Apr 28, 2020 10:45 am Post subject: Super-whizzy energy management systems

I just became aware of an incident involving

complete loss of power from an electrically

dependent engine that occurred some years ago.



The accident airplane had a lot in common

with the narrative we have going with Ron.



I've posted a copy of a narrative at



https://tinyurl.com/y7xksy6v

While this narrative has a lot more data

than most 'dark-n-scarry-nite' stories

in the journals, it is still short of

critical information necessary to

ferret out root cause.



Fortunately, the pilot walked away. I'll

suggest this is a classic example of a system

that was too complex, would not yield to

a critical FMEA and may have suffered some

deficiencies in craftsmanship.



I'll let you guys read this thing first and

come up with questions one might ask if

you were on an accident investigation team.





   Bob . . .

ceengland7(at)gmail.com
Guest

Posted: Tue Apr 28, 2020 11:47 am Post subject: Super-whizzy energy management systems

On Tue, Apr 28, 2020 at 1:50 PM Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:



 	  Quote: 	
		  --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>

 

 I just became aware of an incident involving

 complete loss of power from an electrically

 dependent engine that occurred some years ago.

 

 The accident airplane had a lot in common

 with the narrative we have going with Ron.

 

 I've posted a copy of a narrative at

 

 https://tinyurl.com/y7xksy6v

 

 

 [snipped]

 

 I'll let you guys read this thing first and

 come up with questions one might ask if

 you were on an accident investigation team.

 

 

 

 

 Â  Â Bob . . . 



	
My 1st question is whether that alternator ground wire was the only connection between the engine and the airframe, as seems likely.

CharlieÂ

nuckolls.bob(at)aeroelect
Guest

Posted: Tue Apr 28, 2020 1:17 pm Post subject: Super-whizzy energy management systems

 	  Quote: 	
		   

  My 1st question is whether that alternator ground wire was the only connection between the engine and the airframe, as seems likely.



 Charlie 	


   Good one. Let's put that one on the table.



 

 

   Bob . . .

user9253

Joined: 28 Mar 2008
Posts: 1921
Location: Riley TWP Michigan

Posted: Tue Apr 28, 2020 4:26 pm Post subject: Re: Super-whizzy energy management systems

It seems that the engine quit because the electrical system voltage was too

high which damaged critical engine components, despite what  the 

manufacturer of the fuel injection and ignition systems stated.

  Factors that led to the high voltage include a poorly crimped cable, omission 

of an alternator on-off switch, lack of alternator over-voltage protection, and 

batteries that stop accepting charging current in case of high voltage, which 

allowed the voltage to climb even higher.

_________________
Joe Gores

johnbright

Joined: 14 Dec 2011
Posts: 165
Location: Newport News, VA

Posted: Tue Apr 28, 2020 5:30 pm Post subject: Re: Super-whizzy energy management systems

Did the alternator's integral regulator have overvoltage protection? Did it trip? What is it's trip voltage?



Were there any blown fuses or tripped circuit breakers supplying power to the ECUs or coilpacks?



What in the ignition system failed? ECUs? Coilpacks? Were they bench tested post accident? How do we know the ignitions systems failed?



What is the sample rate of the EMS? Could it miss a short spike in voltage that would destroy the ECU or coilpacks?



Is it possible for ECU programming to be affected by voltage transients such as from the loose alternator crimp?



Were there any other bad connections in the aircraft besides the alternator ground wire?



Is there a complete electrial power schematic for the aircraft? Does it match the implementation?



Was the alternator ground wire the only ground for the engine? Did the coilpacks require the engine to be grounded for them to receive power?

_________________
John Bright, RV-6A, at FWF, O-360
Z-101 single batt dual alt SDS EM-5-F.
john_s_bright@yahoo.com, Newport News, Va
N1921R links

Last edited by johnbright on Thu Apr 30, 2020 10:16 pm; edited 1 time in total

chaskuss(at)yahoo.com
Guest

Posted: Tue Apr 28, 2020 5:40 pm Post subject: Super-whizzy energy management systems

The pilot had an overcharge condition. Did his system have an over voltage warning system? The pilot's failure to install a breaker/switch for the alternator, left him with no way to disconnect the alternator. No other provisions are provided in his design to deal with an over voltage event. According to the supplied schematic, that would be his only option for protecting the batteries and making a safe continuation of the flight. Due to the design of the "Bus Manager" a [open circuit] failure of the internal diodes could leave the emergency power switch all but useless. Further, the pilot's choice of two LiFe batteries, left him with less of an electrical "sponge" to absorb the over voltage event, compared to using at least 1 flooded cell or AGM battery.



To me, both the pilot and the company who supplied the "bus manager" failed at making a safe system. The changes the pilot made, surely fall under the "major change" category. That would have required the pilot to make 5 hours of test flights in the vicinity of his home airport. Had this been done, most likely, he would have made it back to the runway safely.



Charlie Kuss

            

                                                                                        On Tuesday, 28 April 2020, 17:05:14 GMT-4, Robert L. Nuckolls, III <nuckolls.bob(at)aeroelectric.com> wrote:                

                



                



                --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)>



I just became aware of an incident involving



complete loss of power from an electrically



dependent engine that occurred some years ago.



The accident airplane had a lot in common



with the narrative we have going with Ron.



I've posted a copy of a narrative at



https://tinyurl.com/y7xksy6v



While this narrative has a lot more data



than most 'dark-n-scarry-nite' stories



in the journals, it is still short of



critical information necessary to



ferret out root cause.



Fortunately, the pilot walked away. I'll



suggest this is a classic example of a system



that was too complex, would not yield to



a critical FMEA and may have suffered some



deficiencies in craftsmanship.



I'll let you guys read this thing first and



come up with questions one might ask if



you were on an accident investigation team.



   Bob . . . 

<= the many List utilities such as List Un/Subscription,



http://www.matronics.com/Navigator?AeroElectric-List



http://forums.matronics.com



http://www.matronics.com/contribution[/url]

kenryan

Joined: 20 Oct 2009
Posts: 426

Posted: Tue Apr 28, 2020 5:56 pm Post subject: Super-whizzy energy management systems

16.3 volts just does not seem very high. It is hard to accept that 16.3 volts would fry these products, which seem to come from reputable vendors (SDS and FlyEFII).



On Tue, Apr 28, 2020 at 4:50 PM user9253 <fransew(at)gmail.com (fransew(at)gmail.com)> wrote:



 	  Quote: 	
		  --> AeroElectric-List message posted by: "user9253" <fransew(at)gmail.com (fransew(at)gmail.com)>

 

 It seems that the engine quit because the electrical system voltage was too

 high which damaged critical engine components, despite whatÂ  the 

 manufacturer of the fuel injection and ignition systems stated.

 Â  Factors that led to the high voltage include a poorly crimped cable, omission 

 of an alternator on-off switch, lack of alternator over-voltage protection, and 

 batteries that stop accepting charging current in case of high voltage, which 

 allowed the voltage to climb even higher.

 

 --------

 Joe Gores

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=496100#496100

 

 

 

 

 

 

 ===========

  -

 Electric-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List

 ===========

  FORUMS -

 eferrer" target="_blank">http://forums.matronics.com

 ===========

 WIKI -

 errer" target="_blank">http://wiki.matronics.com

 ===========

 b Site -

 Â  Â  Â  Â  Â  -Matt Dralle, List Admin.

 rel="noreferrer" target="_blank">http://www.matronics.com/contribution

 ===========

gilles(at)elixir-aircraft
Guest

Posted: Tue Apr 28, 2020 6:48 pm Post subject: Super-whizzy energy management systems

Le 29/04/2020 Ã  03:30, johnbright a Ã©critÂ :

 	  Quote: 	
		  

 Is there a complete electrial power schematic for the aircraft? Does it match the implementation?



 Was the alternator ground wire the only ground for the engine? Did the injectors or coilpacks require the engine to be grounded for them to receive power?



Hi all,
	




Found some schematic and installation instructions here :



https://www.flyefii.com/media/Bus_Manager_Installation_Instructions.pdf

-- 

Best regards,

Gilles

http://contrails.free.fr

http://lapierre.skunkworks.free.fr

finn.lassen(at)verizon.ne
Guest

Posted: Wed Apr 29, 2020 5:40 am Post subject: Super-whizzy energy management systems

The ProTek schematic does not specify how the power to ignition switch 

is supplied.



I don't see "Alternator charge isolation for two-battery system." That 

appears manual - pilot should be able to switch off alternator -- wrong 

circuit breaker.



"In this scenario, the battery does not disconnect but instead blocks 

the excess current/voltage into the battery." Doesn't make sense.



Obviously the cause was the faulty alternator grounding.



Secondary cause was wrong circuit breaker (and no OV protection).



Possibly wrong wiring of power to ignition switch.



Not sure I would want batteries that automatically disconnects.



Finn



On 4/28/2020 2:39 PM, Robert L. Nuckolls, III wrote:

 	  Quote: 	
		   

 <nuckolls.bob(at)aeroelectric.com>



 I just became aware of an incident involving

 complete loss of power from an electrically

 dependent engine that occurred some years ago.



 The accident airplane had a lot in common

 with the narrative we have going with Ron.



 I've posted a copy of a narrative at



 https://tinyurl.com/y7xksy6v

 While this narrative has a lot more data

 than most 'dark-n-scarry-nite' stories

 in the journals, it is still short of

 critical information necessary to

 ferret out root cause.



 Fortunately, the pilot walked away. I'll

 suggest this is a classic example of a system

 that was too complex, would not yield to

 a critical FMEA and may have suffered some

 deficiencies in craftsmanship.



 I'll let you guys read this thing first and

 come up with questions one might ask if

 you were on an accident investigation team.





 Â  Bob . . .

johnbright

Joined: 14 Dec 2011
Posts: 165
Location: Newport News, VA

Posted: Thu Apr 30, 2020 10:10 am Post subject: Re: Super-whizzy energy management systems

 	  gilles(at)elixir-aircraft wrote: 	
		  Found some schematic and installation instructions here:



... flyefii.com/media/Bus_Manager_Installation_Instructions.pdf



-- 

Best regards,

Gilles 	




EFII has an updated Bus Manager installation instruction. I have not studied it in detail but I see they eliminated one of the SPOFs in the fuel pump wiring, Dwg 3B.



https://www.flyefii.com/media/Bus-Manager-Installation-Instructions-1-6-20.pdf

_________________
John Bright, RV-6A, at FWF, O-360
Z-101 single batt dual alt SDS EM-5-F.
john_s_bright@yahoo.com, Newport News, Va
N1921R links

blues750

Joined: 06 Jun 2015
Posts: 56

Posted: Thu Apr 30, 2020 10:13 am Post subject: Re: Super-whizzy energy management systems

Great discussion so far...hits close to home as I have a similar configuration on my EAB though I have incorporated OVP and a disconnect from the PMA.  Additionally, the two EarthX batteries I have (ETX Hundred Series) are of the more recent BMS design which does not cut off available battery energy to systems, but does limit the charging current and voltage to the battery if the battery start receiving too much.  I think Mr Kuss brings up a valid point regarding failure of the internal diodes, though both diodes would have to fail to prevent either battery from providing power to the essential bus via the switch. I cannot say that the designer of the Bus Manager failed at making a "safe system" - how robust are the components?  Is the design flawed?  Obviously, highly interested in the overall discussion - but one of my first questions would be what EarthX battery Series did he have, then why no ALT disconnect.

gilles(at)elixir-aircraft
Guest

Posted: Thu Apr 30, 2020 10:39 am Post subject: Super-whizzy energy management systems

Le 30/04/2020 Ã  20:13, blues750 a Ã©critÂ :

 	  Quote: 	
		     I think Mr Kuss brings up a valid point regarding failure of the internal diodes, though both diodes would have to fail to prevent either battery from providing power to the essential bus via the switch. I cannot say that the designer of the Bus Manager failed at making a "safe system" - how robust are the components?  Is the design flawed?


	


Hi all,



Personnally I would prefer a means of disconnecting the alternator(s) 

from the ship, and wire the emergency power switch direct from the 

backup battery.



BTW, maybe I'm missing the obvious, but what is the point of having two 

batteries if they always connect and disconnect together, albeit through 

some diode array (part-count counts) ?



-- 

Best regards,

Gilles

http://contrails.free.fr

johnbright

Joined: 14 Dec 2011
Posts: 165
Location: Newport News, VA

Posted: Thu Apr 30, 2020 10:30 pm Post subject: Re: Super-whizzy energy management systems

In case folks are not familiar with EFI+I systems I made the attached schematic. "Elec Schem Generic EFI+I 4 Cylinder rev A.pdf"

Elec Schem Generic EFI+I 4 Cylinder rev A.pdf

Description:

Download

Filename:

Elec Schem Generic EFI+I 4 Cylinder rev A.pdf

Filesize:

380.74 KB

Downloaded:

316 Time(s)

_________________
John Bright, RV-6A, at FWF, O-360
Z-101 single batt dual alt SDS EM-5-F.
john_s_bright@yahoo.com, Newport News, Va
N1921R links

bcone1381

Joined: 25 Apr 2017
Posts: 42
Location: Southeast Michigan

Posted: Tue May 05, 2020 5:05 am Post subject: Re: Super-whizzy energy management systems

[/quote]My 1st question is whether that alternator ground wire was the only connection between the engine and the airframe, as seems likely.

CharlieÂ [/quote]



Throttle, mixture and prop cables will ground an engine.  Its a mystery what other grounds existed.

_________________
Brooks Cone
Bearhawk Patrol Kit Build

ceengland7(at)gmail.com
Guest

Posted: Tue May 05, 2020 4:24 pm Post subject: Super-whizzy energy management systems

On 5/5/2020 10:51 AM, Robert L.       Nuckolls, III wrote:

     

      	  Quote: 	
		                At 08:06 AM 5/5/2020, you wrote:

               	  Quote: 	
		  -->           AeroElectric-List message           posted by: "bcone1381" <bcone1964(at)gmail.com> (bcone1964(at)gmail.com)

           

           	
My 1st question is whether that alternator ground wire           was the           only connection between the engine and the airframe, as seems           likely.

           

           

           CharlieÂ 	


           

           Throttle, mixture and prop cables will ground an engine.  Its           a           mystery what other grounds existed.[/quote]       

         Yes . . . sort of . . . all those conductors

         are steel, long and terminate on various

         and widely separated mountings designed

         for mechanical integrity, not electrical

         conductivity.

       

         It is not uncommon for those 'ground paths'

         to suffer serious overheat events during

         engine cranking when a mechanic inadvertently

         fails to replace the crankcase-to-firewall

         bond strap during maintenance. This very

         event occurred on one of my rental airplanes

         back about 1990 but it was double grounded

         p-lead shields that smoked. This is why

         the z-figures show p-lead termination that

         is contrary to some legacy practice.

       

         A ground lead to an alternator case is

         not common practice. The crankcase-to-

         firewall ground strap is generally 2AWG

         equivalent or better and seeks good

         electrical conductivity at locations

         suited to that service.

       

         We don't know where the other end of

         the illustrated ground lead was terminated,

         nor do we know if it was in addition to

         another ground path. The overheating

         observed in the picture does suggest

         that the ground system on that engine

         was inadequate by design or compromised

         by error.

       

         I'm hoping to get back to our hip-pocket

         accident analysis but as participants

         will note, there are more questions

         than answers. Lacking a good schematic

         for how the airplane was wired, we'll

         never know how an engine became electrically

         starved (assuming that's true) while

         a data acquisition system RECORDED

         the presence of voltage in the system.

       

         This wasn't an electrical 'black out' . . .

       

         The alternator output went to zero

         but again, we're not privy to all the

         hardware between the alternator and

         the bus . . . the breaker was not open

         so something caused the alternator

         output to zero with what appears to

         be simultaneous engine failure.

       

                

             Bob . . .                     [/quote]     To the 'control cables will ground the engine': In the early 1970s,     I bought a brand new Fiat 128; the 1st commonly available front     wheel drive econobox in the USA. At some point, the dealership had     to do some work on it, and when I got it back, it would     intermittently fail to 'turn over' well, as if the battery was going     bad. I eventually quit driving it, having purchased a 124 (a lot     more fun). When a potential buyer showed interest in it, I tried to     get it running with a new battery mounted, and with the hood up, I     noticed smoke under the hood while the starter was trying to turn.     The car had a cable actuated clutch, and the clutch cable was trying     to go up in smoke. Looked under the car, and the engine's ground     strap was hanging loose on one end.

     

     If the discoloration in the 'alternator ground' terminal really is     due to poor termination-induced resistance heating, that's a strong     indicator (to me, anyway) that it was the only ground *wire*     connecting the engine to the airframe. I'd expect a properly sized     ground wire attached anywhere else on the engine to carry     effectively all the current, with the high resistance 'alternator     ground' being ignored by the a/c.

     

     The narrative of the engine shutting down *when the voltage climbed*     but the rest of the a/c continued to see battery voltage after the     alternator shut down really is....interesting.

     

     The investigation does seem very typical of NTSB/FAA handling of     experimental a/c incidents/accidents. The never have staff     experienced with homebuilts (especially 'alternative'     configurations), and very rarely even make an attempt to find     competent, knowledgeable consultants.  There's also rarely an     *objective* opinion sought. They frequently call on the mfgr of the     device, a/c, etc that's in question for failure analysis. If I built     the widget, am I likely to take responsibility for its failure in an     accident? 

     

     Charlie

     	          		Virus-free. www.avast.com 		 	 [url=#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2] [/url]

johnbright

Joined: 14 Dec 2011
Posts: 165
Location: Newport News, VA

Posted: Tue May 05, 2020 5:01 pm Post subject: Re: Super-whizzy energy management systems

Would/could the loose alternator/engine ground wire fool the regulator into raising the field current?

_________________
John Bright, RV-6A, at FWF, O-360
Z-101 single batt dual alt SDS EM-5-F.
john_s_bright@yahoo.com, Newport News, Va
N1921R links

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