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Viking engine duel battery setup

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lgold(at)quantum-associat
Guest

Posted: Thu Jan 02, 2014 10:39 am Post subject: Viking engine duel battery setup

Hi Robert,

I know you have concerns about the Viking engine’s electrical system. But I purchased a Zenith aircraft with this engine and want to make the plane as safe as I can. The engine is an “aircraftized” Honda Fit with fuel injection. Since the engine will stop is a fuel pump fails Jan Eggenfeller specified duel redundant fuel pumps and the ability to switch pumps. However, there are no previsions for a duel battery circuit or a way to isolate the battery in case of an alternator fault. 

I would like to install two batteries that are both charged from the 55-Amp alternator and also be able to select the battery that powers the plane’s electricals and to isolate the batteries by disconnecting a faulty alternator in flight. I previously built a plane with a Rotax 912 using your wiring diagram, (after attending your great seminar). The Rotax diagram had battery isolation capabilities and was wondering of any of your wiring diagrams describe how to do this for my Viking engine or, if not, can you explain how I can do this properly or at least specify the diodes I need to install in the attached diagram.

Thank you for your help, 

Les Goldner  

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nuckolls.bob(at)aeroelect
Guest

Posted: Fri Jan 03, 2014 4:58 am Post subject: Viking engine duel battery setup

At 12:35 PM 1/2/2014, you wrote:



Hi Robert,



I know you have concerns about the Viking engine's electrical system.



    The Viking engine a derivative of

    the Eggenfellner venture which has

    suffered a checkered history from

    the perspectives of both business

    model and engineering . . .



http://tinyurl.com/qclebez



http://tinyurl.com/qclebez



    Yes, I have come 'concerns' that extend far beyond

    the 'electrical system'.



But I purchased a Zenith aircraft with this engine and want to make 

the plane as safe as I can. The engine is an "aircraftized" Honda Fit 

with fuel injection. Since the engine will stop is a fuel pump fails 

Jan Eggenfeller specified duel redundant fuel pumps and the ability 

to switch pumps. However, there are no previsions for a duel battery 

circuit or a way to isolate the battery in case of an alternator fault.



    Your premise for needing two batteries or needing

    to 'isolate them' from a faulted alternator begs

    more detailed examination. Alternator 'faults' are

    exceedingly rare these days and are generally limited

    to mechanical issues (belts and mounts) and wiring

    (the thing simply shuts down). There's a small risk

    for an overvoltage condition which is classically

    managed with a legacy o.v. sense and response system

    that has been part and parcel of aircraft alternator

    and generator systems for 60+ years.



    There is even a smaller probability of a shorted/

    open  diode array that will either (1) reduce the

    alternator's output severely or (2) short the battery

    to ground. The both cases will probably manifest with

    a low voltage warning with the second case opening

    the b-lead fuse.



    In other words, there are no demonstrated alternator

    faults that go beyond simple failure to function . . .

    a condition that does not propagate damage or operational

    stress to other parts of the system. Hence, no additional

    form of 'isolation' is indicated.



    There was some discussions and analysis conducted on

    the aviation special interest groups about 18 years

    ago concerning the use of diode isolation (ala RV

    and boat batteries) for dual batteries on airplanes.



http://tinyurl.com/oss5t4u

I would like to install two batteries that are both charged from the 

55-Amp alternator and also be able to select the battery that powers 

the plane's electricals and to isolate the batteries by disconnecting 

a faulty alternator in flight. I previously built a plane with a 

Rotax 912 using your wiring diagram, (after attending your great 

seminar). The Rotax diagram had battery isolation capabilities and 

was wondering of any of your wiring diagrams describe how to do this 

for my Viking engine or, if not, can you explain how I can do this 

properly or at least specify the diodes I need to install in the 

attached diagram.



    You would be well advised to search out, study,

    and understand all of the failure modes that

    might cause this engine to cease operation . . .

    both electrical AND mechanical.



    Then rank them in order of probability. Yes

    there will be a pile of "don't know" for

    probability but at least you have the item

    on the list.



    The only time I've seen an Eggenfellner

    design installed on an aircraft gave me an

    opportunity to take this picture . . .



http://tinyurl.com/p5dgz43



    The installation gives rise to concerns

    for gross complexity (failure risk proportional

    to parts count) as well as operational

    reliability. Relays generally don't find

    their way into the control of critical circuits

    on any engine installation, aviation or

    otherwise. The fact that this engine seemed

    to be 'blessed' with over a dozen such devices

    is cause for further examination and understanding.



    The point to being offered here is that past

    history for Eggenfellner designs suggests

    that there may be numerous failure modes

    that go beyond simple concerns for keeping

    the fuel pumps powered.



    We've had some discussions here recently on

    electrical system reliability for the electrically

    dependent engine . . . exploring the notion

    that a well maintained, single battery/alternator

    system has a very low failure rate on a par with

    other components that might cause engine failure.



    A new Z-figure . . .



http://tinyurl.com/kbn6bys



    . . . is in it's 5th refinement iteration

    and I'm pretty confident that it's final configuration

    will be suited to your installation as well without

    suffering the weight and cost of ownership penalties

    for carrying two batteries . . . just to address

    one of many failure modes.



    Are the wiring diagrams provided with your engine

    available on the 'net? If not, can you scan your

    documents for sharing?



  Bob . . .

kleh(at)dialupatcost.ca
Guest

Posted: Fri Jan 03, 2014 5:57 am Post subject: Viking engine duel battery setup

Minor point and I have not dealt with anything newer than 2002, but 

every EFI vehicle I've worked on had at least one relay that controlled 

essential engine circuits. My aircraft backup EFI does not have any 

relays but my primary oem soob efi has the same two as it had in the 

car.  As far as I could determine, the oem relays have outstanding 

reliability.



Have newer vehicles gone to solid state relays?



Ken

On 03/01/2014 7:57 AM, Robert L. Nuckolls, III wrote:

 	  Quote: 	
		   Relays generally don't find  their way into the control of critical

 > circuits on any engine installation, aviation or otherwise. The fact
	


 > that this engine seemed to be 'blessed' with over a dozen such

 > devices is cause for further examination and understanding.

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Jan 03, 2014 7:36 am Post subject: Viking engine duel battery setup

At 07:57 AM 1/3/2014, you wrote:

 	  Quote: 	
		  



Minor point and I have not dealt with anything newer than 2002, but 

every EFI vehicle I've worked on had at least one relay that 

controlled essential engine circuits. My aircraft backup EFI does 

not have any relays but my primary oem soob efi has the same two as 

it had in the car.  As far as I could determine, the oem relays have 

outstanding reliability.



Have newer vehicles gone to solid state relays?


	


   I don't know  . . . but it's coming. Waaayyyyy

   back when, I was finishing up the qualification

   paperwork for a pitch trim control system on the

   Lears. One of my colleagues was working the Mil-Hdbk-

   217 MTBF studies on the design.



   He had factored in all the jelly-beans, solder joints,

   integrated circuits, and transistors . . . so far so

   good . . . MTBF was running about 9,000 hours. THEN

   he factored in a mil-spec, hermetically sealed, power

   relay . . . whoops!  MTBF dropped to about 900 hours!



   Seems relays are not highly regarded devices in terms

   of impact on reliability. However, the study protocols

   did not consider the manner in which I was using the

   device . . . it was energized before any current was

   allowed to flow in the contacts . . . and de-energized

   after current flow ceased. In other words, it never

   SWITCHED a load, only carried a load but was available

   for responding to the Wheel-Master-Disconnect switch

   shutting system down in case of a runaway.



   To my knowledge, 30+ years later, no relays have ever

   been replaced. The speed control system has proven

   very robust also but the monitor system (4x parts count)

   and some mechanical environmental issues (box is

   mounted in vertical fin under the trim actuator)

   have required attention.



   Ergo, my statement about the use of relays was perhaps

   too broad . . . or at least lacking details. We attempt

   to reduce numbers of these things to a minimum . . . they

   are after all a mechanical device with moving, arcing

   parts. However, there are design concessions for de-rating,

   dry-switching, duty-cycle, etc. that go a long way toward

   boosting relay reliability.



   To be sure, nobody has more interest in component

   reliability than the automotive industry. An AD

   against an airplane generally involves fewer than

   100 airplanes . . . recalls on cars can number

   in the millions. I helped some guys qualify an

   automotive seat heater onto a Hawker some years

   back . . . the specs to which the seat had already

   been qualified were impressive! But you wanna put

   it on our airplane? Guess what? There's that 80v

   surge thingy . . .



   I helped them craft an automatic disconnect circuit

   that isolated their vulnerable components during

   the surge event.



   So your observation is on-point. Relays are not

   to be shunned out of hand . . . but consider also

   the lengths that talented users of relays will

   exercise to make them capable players in the

   game.



   Track records for the purveyors is important.

   Just because it's used on a car is not an automatic

   pass. A fuse block in my wife's AMC Pacer damned near

   set the car on fire . . . twice . . . before I

   replaced it.



   So let me re-qualify my original reaction to the

   photo of Eggenfellner's installation. Given the

   gross numbers of relays combined with his track

   record, I will suggest that there is cause for

   placing ALL of his intellectual and physical product

   under the microscope.



   Bob . . .

deej(at)deej.net
Guest

Posted: Fri Jan 03, 2014 8:51 am Post subject: Viking engine duel battery setup

On 1/3/2014 7:57 AM, Robert L. Nuckolls, III wrote:

 	  Quote: 	
		  

    The only time I've seen an Eggenfellner

    design installed on an aircraft gave me an

    opportunity to take this picture . . .



 http://tinyurl.com/p5dgz43


	




Are you sure that is a picture of an Eggenfellner installation?  It 

doesn't look like any Eggenfellner setups that I've seen, but it does 

resemble an older NSI setup that I saw at OSH or Sun-n-Fun some years back.



At any rate, it is certainly not typical of what is being installed to 

support Subaru engines (Eggenfellner or otherwise) these days. The 

Aeroelectric Connection is often used as a reference on the Subaru 

lists, but if you want to see the last recommended electrical design 

that came from Eggenfellner before they went out of business, you can 

download the installation guide from:



http://subenews.deej.net/wiki/index.php/EggH6



Click on the "Eggenfellner Engine Installation Guide" (top link under 

the under the Howto Guides section), and go to page 45, and page 51 has 

the electrical schematic.



Please note this is not an endorsement, just an informational posting.  



fyi



-Dj



-- 

Dj Merrill - N1JOV - VP EAA Chapter 87

Sportsman 2+2 Builder #7118 N421DJ - http://deej.net/sportsman/

Glastar Flyer N866RH - http://deej.net/glastar/

jluckey(at)pacbell.net
Guest

Posted: Fri Jan 03, 2014 9:29 am Post subject: Viking engine duel battery setup

It should be noted that the primary reason for such circuitry is to prevent paralleling the two independent batteries thru the charging system.

        From: Les Goldner <lgold(at)quantum-associates.com>

 To: Aeroelectric list <aeroelectric-list(at)matronics.com> 

 Sent: Thursday, January 2, 2014 10:35 AM

 Subject: Viking engine duel battery setup

 Hi Robert,

I know you have concerns about the Viking engineâ€™s electrical system. But I purchased a Zenith aircraft with this engine and want to make the plane as safe as I can. The engine is an â€œaircraftizedâ€ Honda Fit with fuel injection. Since the engine will stop is a fuel pump fails Jan Eggenfeller specified duel redundant fuel pumps and the ability to switch pumps. However, there are no previsions for a duel battery circuit or a way to isolate the battery in case of an alternator fault. 

I would like to install two batteries that are both charged from the 55-Amp alternator and also be able to select the battery that powers the planeâ€™s electricals and to isolate the batteries by disconnecting a faulty alternator in flight. I previously built a plane with a Rotax 912 using  your wiring diagram, (after attending your great seminar). The Rotax diagram had battery isolation capabilities and was wondering of any of your wiring diagrams describe how to do this for my Viking engine or, if not, can you explain how I can do this properly or at least specify the diodes I need to install in the attached diagram.

Thank you for your help, 

Les Goldner  

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nuckolls.bob(at)aeroelect
Guest

Posted: Fri Jan 03, 2014 10:13 am Post subject: Viking engine duel battery setup

At 11:28 AM 1/3/2014, you wrote:



 	  Quote: 	
		  It should be noted that the primary reason for such circuitry is to 

prevent paralleling the two independent batteries thru the charging system.


	


   Why would one want to do that?

   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Fri Jan 03, 2014 10:15 am Post subject: Viking engine duel battery setup

Are you sure that is a picture of an Eggenfellner installation?  It 

doesn't look like any Eggenfellner setups that I've seen, but it does 

resemble an older NSI setup that I saw at OSH or Sun-n-Fun some years back.



   Actually, I'm not. I saw the airplane on display

   at an airport where I was giving a weekend seminar.

   I snapped the picture to use in the seminar as an

   example of an installation that would benefit from

   some judicious review.



At any rate, it is certainly not typical of what is being installed 

to support Subaru engines (Eggenfellner or otherwise) these days. The 

Aeroelectric Connection is often used as a reference on the Subaru 

lists, but if you want to see the last recommended electrical design 

that came from Eggenfellner before they went out of business, you can 

download the installation guide from:



   Thanks for the heads-up! With all due respect

   to Jan's work, my apologies for any errors of

   attribution.



http://subenews.deej.net/wiki/index.php/EggH6



Click on the "Eggenfellner Engine Installation Guide" (top link under 

the under the Howto Guides section), and go to page 45, and page 51 

has the electrical schematic.



Please note this is not an endorsement, just an informational posting.



   And good information it is my friend. I'll study the drawings

   and incorporate the information into a follow-up posting. This

   dovetails nicely with the discussions we're having about

   Fred's incorporation of the ExpBus in his electrically dependent

   airplane.



   Fred provided some asked-for info on his installation

   which I've not yet had time to consider . . . but it's

   on the list.

   Bob . . .

lgold(at)quantum-associat
Guest

Posted: Fri Jan 03, 2014 10:30 am Post subject: Viking engine duel battery setup

Thanks for the information Robert. 

There is nothing in the Viking engine that looks anything as complex as the

picture you included in your last email. In fact, the physical electricals

provided with the Viking engine look very "clean".

You asked to see the Viking wiring diagrams so I attached two diagrams Jan

Eggenfeller provided for the Viking engine. The diagram named "Backup

System" is a very nice looking module provided with the Viking engine for

redundancy to control two fuel pumps (I think it also controls a duel ECUs)

in case one fails. The other diagram is more relevant to my questions to you

about having two batteries. It shows recommended  power provisions,

including a second battery. I would appreciate your comments about employing

this two-battery arrangement?  

Best regard,

Les

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teblejw

Joined: 19 Nov 2013
Posts: 14

Posted: Fri Jan 03, 2014 10:30 am Post subject: Viking engine duel battery setup

Bob,

 

You wrote: 

"There's a small risk

   for an overvoltage condition which is classically

   managed with a legacy o.v. sense and response system

   that has been part and parcel of aircraft alternator

   and generator systems for 60+ years."

Yes, but the Viking has an auto-based system, with an integrated regulator.  You make the comment:

"In other words, there are no demonstrated alternator

   faults that go beyond simple failure to function . . .

   a condition that does not propagate damage or operational

   stress to other parts of the system. Hence, no additional

   form of 'isolation' is indicated."

Is this true?  Is there some  recent information that suggests that the "runaway" auto regulator is too unlikely to be an issue.  I've been planning for a "crowbar" and an expensive contactor for this potential event.  Am I overreacting?  

Tom



 

[quote]     

   From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>

 To: aeroelectric-list(at)matronics.com 

 Sent: Friday, January 3, 2014 5:57 AM

 Subject: Re: Viking engine duel battery setup

  

 

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



At 12:35 PM 1/2/2014, you wrote:



Hi Robert,



I know you have concerns about the Viking engine's electrical system.



   The Viking engine a derivative of

   the Eggenfellner venture which has

   suffered a checkered history from

   the perspectives of both business

   model and engineering . . .



http://tinyurl.com/qclebez



http://tinyurl.com/qclebez



   Yes, I have come 'concerns' that extend far beyond

   the 'electrical system'.



But I purchased a Zenith aircraft with this engine and want to make the plane as safe as I can. The engine is an "aircraftized" Honda Fit with fuel injection. Since the  engine will stop is a fuel pump fails Jan Eggenfeller specified duel redundant fuel pumps and the ability to switch pumps. However, there are no previsions for a duel battery circuit or a way to isolate the battery in case of an alternator fault.



   Your premise for needing two batteries or needing

   to 'isolate them' from a faulted alternator begs

   more detailed examination. Alternator 'faults' are

   exceedingly rare these days and are generally limited

   to mechanical issues (belts and mounts) and wiring

   (the thing simply shuts down). There's a small risk

   for an overvoltage condition which is classically

   managed with a legacy o.v. sense and response system

   that has been part and parcel of aircraft alternator

   and generator systems for 60+ years.



   There is even a smaller probability of a shorted/

   open  diode array that  will either (1) reduce the

   alternator's output severely or (2) short the battery

   to ground. The both cases will probably manifest with

   a low voltage warning with the second case opening

   the b-lead fuse.



   In other words, there are no demonstrated alternator

   faults that go beyond simple failure to function . . .

   a condition that does not propagate damage or operational

   stress to other parts of the system. Hence, no additional

   form of 'isolation' is indicated.



   There was some discussions and analysis conducted on

   the aviation special interest groups about 18 years

   ago concerning the use of diode isolation (ala RV

   and boat batteries) for dual batteries on airplanes.



http://tinyurl.com/oss5t4u

I would like to install two batteries that are both charged from the 55-Amp alternator and  also be able to select the battery that powers the plane's electricals and to isolate the batteries by disconnecting a faulty alternator in flight. I previously built a plane with a Rotax 912 using your wiring diagram, (after attending your great seminar). The Rotax diagram had battery isolation capabilities and was wondering of any of your wiring diagrams describe how to do this for my Viking engine or, if not, can you explain how I can do this properly or at least specify the diodes I need to install in the attached diagram.



   You would be well advised to search out, study,

   and understand all of the failure modes that

   might cause this engine to cease operation . . .

   both electrical AND mechanical.



   Then rank them in order of probability. Yes

   there will be a pile of "don't know" for

   probability but at least you have the item

   on the list.



   The only  time I've seen an Eggenfellner

   design installed on an aircraft gave me an

   opportunity to take this picture . . .



http://tinyurl.com/p5dgz43



   The installation gives rise to concerns

   for gross complexity (failure risk proportional

   to parts count) as well as operational

   reliability. Relays generally don't find

   their way into the control of critical circuits

   on any engine installation, aviation or

   otherwise. The fact that this engine seemed

   to be 'blessed' with over a dozen such devices

   is cause for further examination and understanding.



   The point to being offered here is that past

   history for Eggenfellner designs suggests

   that there may be numerous failure modes

   that go beyond simple concerns for keeping

   the fuel pumps powered.



   We've had some discussions  here recently on

   electrical system reliability for the electrically

   dependent engine . . . exploring the notion

   that a well maintained, single battery/alternator

   system has a very low failure rate on a par with

   other components that might cause engine failure.



   A new Z-figure . . .



http://tinyurl.com/kbn6bys



   . . . is in it's 5th refinement iteration

   and I'm pretty confident that it's final configuration

   will be suited to your installation as well without

   suffering the weight and cost of ownership penalties

   for carrying two batteries . . . just to address

   one of many failure modes.



   Are the wiring diagrams provided with your engine

   available on the 'net? If not, can you scan your

   documents for sharing?



 ion" sp;                     &//www.matronics.com/Navigator?AeroElectric-List" target="_blank">http://w--> http://fo=======================

 

 

 [b]

jluckey(at)pacbell.net
Guest

Posted: Fri Jan 03, 2014 11:50 am Post subject: Viking engine duel battery setup

for many of the same reasons that (I imagine) you put a "buss tie" contactor in the Z-14 drawings.





        From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>

 To: aeroelectric-list(at)matronics.com 

 Sent: Friday, January 3, 2014 10:11 AM

 Subject: Re: Viking engine duel battery setup

  

 

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



At 11:28 AM 1/3/2014, you wrote:



 	  Quote: 	
		   It should be noted that the primary reason for such circuitry is to prevent paralleling the two independent batteries thru the charging system.


	


  Why would one want to do that? AeroElectric wwtarget="_blank" href="http://www.buildersbooks.com/">www.buildersbooks.bsp;  * My Pilot Store

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Jan 04, 2014 4:33 am Post subject: Viking engine duel battery setup

At 12:29 PM 1/3/2014, you wrote:

 	  Quote: 	
		    Bob,



You wrote:

   "There's a small risk

   for an overvoltage condition which is classically

   managed with a legacy o.v. sense and response system

   that has been part and parcel of aircraft alternator

   and generator systems for 60+ years."


	


 	  Quote: 	
		  Yes, but the Viking has an auto-based system, with an integrated 

regulator.  You make the comment:



   "In other words, there are no demonstrated alternator

   faults that go beyond simple failure to function . . .

   a condition that does not propagate damage or operational

   stress to other parts of the system. Hence, no additional

   form of 'isolation' is indicated."


	


 	  Quote: 	
		  Is this true?  Is there some recent information that suggests that 

the "runaway" auto regulator is too unlikely to be an issue.  I've 

been planning for a "crowbar" and an expensive contactor for this 

potential event.  Am I overreacting?


	


    The statements I made were in the context

    of the discussion for 'isolation diodes' in the b-lead.

    The incorporation of diodes external to the

    alternator for the purpose of 'isolation' has

    no foundation in the physics.



    OV conditions are another matter. There ARE

    failure modes within built in regulators which

    are not sufficiently detailed to allow

    incorporation of STOCK internally regulated

    alternators into aircraft under the LEGACY

    design goals.



    If one embraces those goals then some understanding

    of the options for ADDING ov protection to the

    system is necessary. See:



http://tinyurl.com/nexuekf



http://tinyurl.com/cx6426c



    There have been some interesting discussions

    about design goals for system robustness and

    the implementation of failure tolerance in

    OBAM aircraft over the years. Some positions

    were adopted by individuals unable to demonstrate

    an understanding of failure tolerant design goals

    . . .



http://tinyurl.com/7lhbbah



http://tinyurl.com/nexuekf



http://tinyurl.com/omnuypr



    My goals and those of my employers over

    the years has been to first reduce

    probability of malfunction with

    robust designs backed up by further reduction

    of risks with failure tolerant designs.



    Alternators are but one of many components

    with an ability to elevate your concerns

    while airborne . . . but easily managed.



   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Jan 04, 2014 5:15 am Post subject: Viking engine duel battery setup

At 01:49 PM 1/3/2014, you wrote:

 	  Quote: 	
		  for many of the same reasons that (I imagine) you put a "buss tie" 

contactor in the Z-14 drawings.


	


   But what might those reasons be? In other words, we

   add a component to a system to effect some desired

   functionality that figures into the overall performance,

   failure tolerance and risks.



   If diodes were incorporated in the manner suggested

   to feed the two batteries, how would we expect these

   to operate and for what purpose?



   I'm not trying to be obtuse here my friend. I

   AM encouraging all of my readers to understand

   the application of every component they choose

   to add to their system. Suppose I offered a description

   for the buss-tie contactor like, "This contactor

   offers pilot control of the phramistat to prevent

   inadvertent operation of the whatsadozit and

   potential damage to the dingusfuzzy."



   The inquiring builder would probably want some

   detailed expansion on that statement . . . un-

   fortunately, others will assume the statement

   correct and useful based on the reputation

   (deserved or otherwise) of the writer.



   I encourage yourself and others to KNOW why

   a part is included and UNDERSTAND what useful

   things it will do for you. Hence my question

   as to any value you perceive for having those

   diodes in place as suggested.

   Bob . . .

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Jan 04, 2014 6:10 am Post subject: Viking engine duel battery setup

Not a problem Bob...I'm busying myself attempting to master

 the techniques necessary to assemble a 25 pin D-sub w/ mostly shielded wires...Fred



    Okay, I presume you've looked at this piece on

    the website.



  http://tinyurl.com/87lea6o



    The shields do not have to come together inside

    the connector back-shell. If there are a lot of them,

    you can have a couple inches of un-shielded wires

    allowing all the shield terminations to happen

    outside the back-shell.



 

 

   Bob . . .     [quote][b]

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Jan 04, 2014 8:15 am Post subject: Viking engine duel battery setup

[img]cid:.0[/img]



 

 Okay, referring to the abbreviated power distribution diagram

 from the Viking installation literature, we see two batteries,

 both 'protected' buy current limiters and paralleled onto

 the system with independent contactors. One of the two batteries

 is fitted with an always hot feeder routed to a 4-pole engine power

 selection switch.



 Years ago, I proposed a similar two-battery system which

 could be automated to some degree with what was at that

 time called the Aux Battery Management Module.



  http://tinyurl.com/l353p5m



  http://tinyurl.com/mrxbrtw



 Back in those days, the notion was that at least one of

 two electronic ignition systems and perhaps a boost pump

 could be supported on an independent battery automatically

 isolated from the rest of the airplane when an alternator

 failure was detected (low voltage).



 Let's revisit those notions in light of the Viking installation

 documents that speak to a 'requirement' for a second battery

 capable of running the engine for a minimum of 30 minutes.



 First, how does one KNOW that battery #2 is capable of

 meeting that requirement? It has to be sized -AND- maintained

 such that the necessary energy available when needed.



 Okay, what conditions would FORCE the use of #2 battery?

 (a) no doubt the alternator is off line for what ever

 reason and (b) and we KNOW that #1 battery is not capable

 of carrying the engine + other endurance loads for at least

 30 minutes.



 Hmmmm . . . if we KNOW that #1 battery is overtaxed for 

 the task of supplied combined energy needs but that

 #1 plus #2 battery WILL rise to the occasion, then what

 is the value in having two batteries? Would a single

 battery with a KNOWN capacity for the combined loads not

 be a simpler, lighter and lower cost choice?



 In other words, what combination of conditions pose such

 risk that a second battery is needed to mitigate the risk?

 Two batteries DOUBLES your battery maintenance expenses

 and adds empty weight . . . all intended to mitigate a

 rather rare event . . . alternator failure.



 This line of reasoning is germane to the discussions

 we were having on Fred's Exp-Bus integration which prompted

 the crafting of Figure Z-7. It also applies to Les's question

 about diodes suitable for battery isolation. Obviously, the

 golden solution will include some assessment of loads over and

 above those required to run the engine . . . along with

 some decisions as to whether you're expecting to keep the panel all lit

 up . . . or have crafted a plan-B that matches your skills

 and confidence levels for getting down with a bare minimum

 of panel equipment combined perhaps with flight bag back-up

 hardware.



 If Figure Z-7 were substituted for the figure above, are

 there any unforeseen risks? Comments on the Viking drawing,

 Figure Z-7 and perceptions of your individual FMEAs are solicited . . .

 

   Bob . . .

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teblejw

Joined: 19 Nov 2013
Posts: 14

Posted: Sat Jan 04, 2014 10:20 am Post subject: Viking engine duel battery setup

Bob,

As someone who has a Viking engine and who has been looking to modify Z-7 for my electrical system, I'm very interested in this thread.  First, where did you get the diagram at the top of your last posting?  It's clearly different then the one sent by Les Goldner, which I also got from the Viking website.  It appears to be a system for Vikings unreleased turbo version.  

I hesitate to make the following comment, since you chose not to answer my last question about alternators running without batteries; but you asked for comments on Z-7 for this application.  Viking claims that the alternator can run with the batteries disconnected and I believe that the diagram provided by Les allows for that.  Your comment in an earlier thread that you wouldn't switch off the battery/batteries unless you were also disconnecting the alternator is a strong position.  I understand that batteries that are properly maintained don't usually fail in a catastrophic manner, but is that never?  Can we quantify?  Hard to separate failures due to inadequate maintenance and others.  In the absence of numbers but anecdotal experiences of failures (mine for one), why not have an allowance for running off the alternator only?  Seems prudent to me, so I'd like to understand why it isn't to you.  Thanks.

Tom



Sent from my iPad



On Jan 4, 2014, at 9:13 AM, "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

[quote]  <a6a5924.jpg>



 

 Okay, referring to the abbreviated power distribution diagram

 from the Viking installation literature, we see two batteries,

 both 'protected' buy current limiters and paralleled onto

 the system with independent contactors. One of the two batteries

 is fitted with an always hot feeder routed to a 4-pole engine power

 selection switch.



 Years ago, I proposed a similar two-battery system which

 could be automated to some degree with what was at that

 time called the Aux Battery Management Module.



  http://tinyurl.com/l353p5m



  http://tinyurl.com/mrxbrtw



 Back in those days, the notion was that at least one of

 two electronic ignition systems and perhaps a boost pump

 could be supported on an independent battery automatically

 isolated from the rest of the airplane when an alternator

 failure was detected (low voltage).



 Let's revisit those notions in light of the Viking installation

 documents that speak to a 'requirement' for a second battery

 capable of running the engine for a minimum of 30 minutes.



 First, how does one KNOW that battery #2 is capable of

 meeting that requirement? It has to be sized -AND- maintained

 such that the necessary energy available when needed.



 Okay, what conditions would FORCE the use of #2 battery?

 (a) no doubt the alternator is off line for what ever

 reason and (b) and we KNOW that #1 battery is not capable

 of carrying the engine + other endurance loads for at least

 30 minutes.



 Hmmmm . . . if we KNOW that #1 battery is overtaxed for 

 the task of supplied combined energy needs but that

 #1 plus #2 battery WILL rise to the occasion, then what

 is the value in having two batteries? Would a single

 battery with a KNOWN capacity for the combined loads not

 be a simpler, lighter and lower cost choice?



 In other words, what combination of conditions pose such

 risk that a second battery is needed to mitigate the risk?

 Two batteries DOUBLES your battery maintenance expenses

 and adds empty weight . . . all intended to mitigate a

 rather rare event . . . alternator failure.



 This line of reasoning is germane to the discussions

 we were having on Fred's Exp-Bus integration which prompted

 the crafting of Figure Z-7. It also applies to Les's question

 about diodes suitable for battery isolation. Obviously, the

 golden solution will include some assessment of loads over and

 above those required to run the engine . . . along with

 some decisions as to whether you're expecting to keep the panel all lit

 up . . . or have crafted a plan-B that matches your skills

 and confidence levels for getting down with a bare minimum

 of panel equipment combined perhaps with flight bag back-up

 hardware.



 If Figure Z-7 were substituted for the figure above, are

 there any unforeseen risks? Comments on the Viking drawing,

 Figure Z-7 and perceptions of your individual FMEAs are solicited . . .

 

   Bob . . .   

[b]

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Jan 04, 2014 3:28 pm Post subject: Viking engine duel battery setup

At 12:19 PM 1/4/2014, you wrote:

Bob,



As someone who has a Viking engine and who has been looking to modify 

Z-7 for my electrical system, I'm very interested in this 

thread.  First, where did you get the diagram at the top of your last 

posting?  It's clearly different then the one sent by Les Goldner, 

which I also got from the Viking website.  It appears to be a system 

for Vikings unreleased turbo version.



    I got it from the Viking website using a link forwarded to

    me by one of the list readers. The exact version is insignificant

    at the moment as the points to ponder deal with the rationale for

    two batteries as opposed to one.



I hesitate to make the following comment, since you chose not to 

answer my last question about alternators running without batteries; 

but you asked for comments on Z-7 for this application.



    My apologies . . . didn't mean to ignore your question.

    Never hesitate to jump right in the middle of my

    lap if you believe some important link of communication

    has broken. This list isn't about feelings, it's

    about ideas . . . and even though GMCJetpilot found the

    assertion incredible, I cannot be insulted and I welcome

    logical persuasion.



Viking claims that the alternator can run with the batteries 

disconnected and I believe that the diagram provided by Les allows for that.



    Okay, that doesn't surprise me. I'm wondering to what extent

    that operating mode has been tested.



Your comment in an earlier thread that you wouldn't switch off the 

battery/batteries unless you were also disconnecting the alternator 

is a strong position.



     . . . yes . . . based on the legacy design goals

     of yesteryear when the split-rocker master switch

     was king.



     But that was several generations ago in both alternator

     and battery design. Odds are that most airplanes will continue

     operating sans battery . . . but I suspect there are

     limits that should be explored. I had some plans to

     acquire a variable speed drive stand some years ago.

     The goal was to explore the new alternator-only

     paradigm.

I understand that batteries that are properly maintained don't 

usually fail in a catastrophic manner, but is that never?  Can we quantify?



    I'll have to ask Skip about that. Concorde has done

    countless failure analysis over the course of battery

    evolution in aircraft and can probably offer us some

    quantitative assessment.



Hard to separate failures due to inadequate maintenance and 

others.  In the absence of numbers but anecdotal experiences of 

failures (mine for one), why not have an allowance for running off 

the alternator only?  Seems prudent to me, so I'd like to understand 

why it isn't to you.  Thanks.



     I absolutely agree. But just as I was loath to

     RECOMMEND the internally regulated alternator some

     years back, my reluctance is not based on hard

     negative data but a lack of hard positive data.



     If Viking says they can run alternator only, I

     rather suspect that they have at least determined

     that the engine doesn't quit and the panel stays

     lit with the batteries OFF. I wonder to what extent

     any testing has been accomplished and documented upon

     which a gray beard stuck in such traditions

     can offer confident recommendation.



     Thanks for asking . . .

     Bob . . .

kearney

Joined: 20 Sep 2008
Posts: 563

Posted: Sat Jan 04, 2014 5:49 pm Post subject: Viking engine duel battery setup

Hi All

This is the Eggenfellner Aircraft Engines wiring diagram for a Subaru engine (turbo'd). This where the E6T engine reference comes from. 

Cheers

Les



Sent from my iPhone



On Jan 4, 2014, at 9:13 AM, "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com (nuckolls.bob(at)aeroelectric.com)> wrote:

[quote]  <a6a5924.jpg>



 

 Okay, referring to the abbreviated power distribution diagram

 from the Viking installation literature, we see two batteries,

 both 'protected' buy current limiters and paralleled onto

 the system with independent contactors. One of the two batteries

 is fitted with an always hot feeder routed to a 4-pole engine power

 selection switch.



 Years ago, I proposed a similar two-battery system which

 could be automated to some degree with what was at that

 time called the Aux Battery Management Module.



  http://tinyurl.com/l353p5m



  http://tinyurl.com/mrxbrtw



 Back in those days, the notion was that at least one of

 two electronic ignition systems and perhaps a boost pump

 could be supported on an independent battery automatically

 isolated from the rest of the airplane when an alternator

 failure was detected (low voltage).



 Let's revisit those notions in light of the Viking installation

 documents that speak to a 'requirement' for a second battery

 capable of running the engine for a minimum of 30 minutes.



 First, how does one KNOW that battery #2 is capable of

 meeting that requirement? It has to be sized -AND- maintained

 such that the necessary energy available when needed.



 Okay, what conditions would FORCE the use of #2 battery?

 (a) no doubt the alternator is off line for what ever

 reason and (b) and we KNOW that #1 battery is not capable

 of carrying the engine + other endurance loads for at least

 30 minutes.



 Hmmmm . . . if we KNOW that #1 battery is overtaxed for 

 the task of supplied combined energy needs but that

 #1 plus #2 battery WILL rise to the occasion, then what

 is the value in having two batteries? Would a single

 battery with a KNOWN capacity for the combined loads not

 be a simpler, lighter and lower cost choice?



 In other words, what combination of conditions pose such

 risk that a second battery is needed to mitigate the risk?

 Two batteries DOUBLES your battery maintenance expenses

 and adds empty weight . . . all intended to mitigate a

 rather rare event . . . alternator failure.



 This line of reasoning is germane to the discussions

 we were having on Fred's Exp-Bus integration which prompted

 the crafting of Figure Z-7. It also applies to Les's question

 about diodes suitable for battery isolation. Obviously, the

 golden solution will include some assessment of loads over and

 above those required to run the engine . . . along with

 some decisions as to whether you're expecting to keep the panel all lit

 up . . . or have crafted a plan-B that matches your skills

 and confidence levels for getting down with a bare minimum

 of panel equipment combined perhaps with flight bag back-up

 hardware.



 If Figure Z-7 were substituted for the figure above, are

 there any unforeseen risks? Comments on the Viking drawing,

 Figure Z-7 and perceptions of your individual FMEAs are solicited . . .

 

   Bob . . .   

[b]

jluckey(at)pacbell.net
Guest

Posted: Sun Jan 05, 2014 10:49 am Post subject: Viking engine duel battery setup

It occurs to me that this topic gets pretty design-specific in a hurry and without specifying a design, this will turn into an exercise in arm waving.  



Therefore, I have included some general comments sprinkled among Bob's remarks, below.



-Jeff        From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>

 To: aeroelectric-list(at)matronics.com 

 Sent: Saturday, January 4, 2014 5:15 AM

 Subject: Re: Viking engine duel battery setup

  

 

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



At 01:49 PM 1/3/2014, you wrote:

 	  Quote: 	
		   for many of the same reasons that (I imagine) you put a "buss tie" contactor in the Z-14 drawings.


	


  But what might those reasons be? In other words, we

  add a component to a system to effect some desired

  functionality that figures into the overall performance,

  failure tolerance and risks.



  If diodes were incorporated in the manner suggested

  to feed the two batteries, how would we expect these

  to operate and for what purpose?



The diodes are to isolate the batteries and their systems from each other.  If you simple run a wire from the alternator B terminal to batt A  and then to batt B you have paralleled the batteries when your intent was only to charge them.  It could be an unintended side-effect.  If your mission is to charge the batts then make sure your circuit does that.  If your mission is to parallel the batts then do that, but don't let one just happen as a side effect of the other.



  I'm not trying to be obtuse here my friend. I

  AM encouraging all of my readers to understand

  the application of every component they choose

  to add to their system. Suppose I offered a description

  for the buss-tie contactor like, "This contactor

  offers pilot control of the phramistat to prevent

  inadvertent operation of the whatsadozit and

  potential damage to the dingusfuzzy."



  The inquiring builder would probably want some

  detailed expansion on that statement . . . un-

  fortunately, others will  assume the statement

  correct and useful based on the reputation

  (deserved or otherwise) of the writer.



It is difficult to control the assumptions made by readers.



  I encourage yourself and others to KNOW why

  a part is included and UNDERSTAND what useful

  things it will do for you. Hence my question

  as to any value you perceive for having those

  diodes in place as suggested.

 

I know why - been there done that - and repaired the damage from some of those uninnd Get Some AWESOME FREE rget="_blank" href="http://www.aeroelectric.com/">www.aeroelectric.comwww.mypilots;                     &nb========================

nuckolls.bob(at)aeroelect
Guest

Posted: Sun Jan 05, 2014 12:51 pm Post subject: Viking engine duel battery setup

 	  Quote: 	
		  



   If diodes were incorporated in the manner suggested

   to feed the two batteries, how would we expect these

   to operate and for what purpose?



 The diodes are to isolate the batteries and their systems from each other.  If you simple run a wire from the alternator B terminal to batt A and then to batt B you have paralleled the batteries when your intent was only to charge them.  It could be an unintended side-effect.  If your mission is to charge the batts then make sure your circuit does that.  If your mission is to parallel the batts then do that, but don't let one just happen as a side effect of the other. 	


   Agreed. I can deduce no practical purpose for

   these diodes. As long as the alternator is

   operating normally, it charges both batteries.



   If alternator fails, you get a low-voltage

   warning light and you then separate the

   batteries onto their respective tasks.



   In other words, the system can service as many

   batteries in parallel as dictated by the

   alternator-out operating conditions. Simply

   parallel through hard contacts for normal ops;

   separate for alternator-out ops.



   A 'dead' battery will not accept 'charge' from

   a fully charged battery. If the batteries are

   remarkably different in size, the smaller one

   might want to be OFF during cranking.

   



 

   Bob . . .    [quote][b]

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