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longg(at)pjm.com
Guest

Posted: Thu May 08, 2008 8:19 am Post subject: Z-19 Item Clarification

Thanks for converting Larry.



Scott, you broke the simplification rule, but not the experimental one.

Starting from the grip, wow that's a bit lazy  Looks good, thanks for

posting. The always hot deal for the fuel pumps/EFI/ECU is not a bad

thing on these Subes. Do you have a layout of your panel switches?



Glenn



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sshook(at)cox.net
Guest

Posted: Thu May 08, 2008 8:30 am Post subject: Z-19 Item Clarification

Here is the PDF



				

Scott R. Shook

RV-7A (Building)

N696JS (Reserved)



--

N696JS_-_Electrical_Layout.pdf

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sshook(at)cox.net
Guest

Posted: Thu May 08, 2008 9:34 am Post subject: Z-19 Item Clarification

I am confused...Simplification rule starting from the grip?  Are you talking

about my use of the infinity grips?



				

Scott R. Shook

RV-7A (Building)

N696JS (Reserved)



--

Allen Fulmer

Joined: 10 Jan 2006
Posts: 79
Location: Alexander City, AL

Posted: Thu May 08, 2008 10:22 am Post subject: Z-19 Item Clarification

Scott,



I feel a little inadequate to make any comments except that I am trying to

do the approximately the same thing you are (RV7 with Egg Subaru) and I

might as well go public with my questions now.



These are in no order of importance and are just my first questions after

looking over the drawing:

(I have sort of ignored the annunciator part of the diagram as I have not

thought much about how I might do those.)



1. The extra starter solenoid is required only because you will have a

little bitty pushbutton on the grip.  I used to think that would be a good

idea so you didn't have to take your hand off the stick when starting but I

think with our automotive engines it probably is not a problem to reach for

a pushbutton on the panel.  Egg manual notes that it is not necessary

(additional starter relay) unless you have a wimpy key switch or stick push

button like you plan.  I have seen it suggested to put an "ARM" switch on

the panel so you are not inadvertently pushing the little button when the

engine is already running, etc.  I "want badly" (for unknown reason) to have

an automotive style key switch to energize the starter but may finally go

with the panel mounted 20 amp push button.



2. As I understand the function of the LV Monitor module, it is wired up on

Z19RB to energize the Engine/AUX Battery Contactor (not the MAIN Battery

Contactor) but only when the Engine/Bat Off/On/Auto is in the AUTO position.

I think you need a switch like Bob depicts on Z19RB to accomplish this.  As

you have it now the contactor will always be energized if you have your

switch in the up position (connected to ground) and the LV Monitor module

will do nothing.



2. (continued) I think I have decided that since we are adopting a somewhat

more manual system of switching batteries using the Egg recommended (Engine)

Bus Master Switch we can manually open the Main Battery Switch and close the

Aux/Engine Battery switch and not even worry about the LV Monitor module.

We would still want a "genius" light (as Bob calls them) to alert us when

the bus voltage drops below 13 Volts (or whatever his stuff recommends) so

we know the Alternator is off line.



3. I guess you are calling your Endurance Bus the Avionics Bus but it

appears to me that if you lose the Main bus ALL your avionics are without a

source of power.  Notice that Bob has an Ebus Alt Feed switch that powers a

S-704-1 relay to feed the Endurance Bus (Avionics Bus in your case) from the

always hot Main Battery Bus.  Similar to the way we use 4NT1-1 Engine Bus

Master switch select the "alternate feed" from the always hot side of the

AUX Battery.



4. One of the things I am wrestling with is how to power the engine

instruments (GRT EIS4000 in my case; AFS3500 EMS in yours) so ONLY it comes

on when the Engine Bus Master Switch is placed in either ON position. (To

check oil pressure light working and to see the oil pressure come up when

engine starts.)  That may require an Avionics Switch/Relay since the starter

requires/prefers to have both Battery Contactors energized.  Still thinking

about that issue.



So there; now I have exposed some of my ignorance for the world to see.



Keep talking, Scott.



Allen Fulmer

RV7 Subaru E6Ti hanging

Working on wiring/avionics

Alexander City, AL



[quote]>>--

_________________
RV7 QB Fuselage
Eggenfellner H6 on orde
N808AF reserved
Alexander City, AL

klehman(at)albedo.net
Guest

Posted: Thu May 08, 2008 1:07 pm Post subject: Z-19 Item Clarification

FWIW you might consider that you simply don't have the oil pressure 

issues that air cooled engines have with single grade oil. I run 5W50 

synthetic and I pretty much ignore the oil pressure just like most car 

drivers. If it doesn't come up or if it goes out of limits, the EIS will 

bring it to my attention. The chances of a secondary failure where the 

EIS would be helpful, at the same time as an alternator failure, have 

got to to be very small. Keeping it simple has advantages. Do you really 

care if the EIS works after an alternator failure? Will it help you fly 

the airplane or just be a distraction?

Ken



Allen Fulmer wrote:

 	  Quote: 	
		  snip

 4. One of the things I am wrestling with is how to power the engine

 instruments (GRT EIS4000 in my case; AFS3500 EMS in yours) so ONLY it comes

 on when the Engine Bus Master Switch is placed in either ON position. (To

 check oil pressure light working and to see the oil pressure come up when

 engine starts.)  That may require an Avionics Switch/Relay since the starter

 requires/prefers to have both Battery Contactors energized.  Still thinking

 about that issue.

Allen Fulmer

Joined: 10 Jan 2006
Posts: 79
Location: Alexander City, AL

Posted: Thu May 08, 2008 1:36 pm Post subject: Z-19 Item Clarification

Thanks Ken,



One of the reasons for turning on the EIS before starting the engine is to

make sure the oil pressure sensor DOES work like it is supposed to.  But you

make a good point.  Maybe the light could be checked when shutting DOWN the

engine before the EIS is turned OFF?  Thoughts?



Allen



[quote]>>--

_________________
RV7 QB Fuselage
Eggenfellner H6 on orde
N808AF reserved
Alexander City, AL

bbradburry(at)bellsouth.n
Guest

Posted: Thu May 08, 2008 2:44 pm Post subject: Z-19 Item Clarification

Scott, I am the last person who should be talking about someone else's

electrical design....

But, I can see your reason for the 200ANLs in front of the batteries, but

you are also protecting the "B" lead of a 60A alternator with a 200ANL...are

you thinking that the alternator itself might somehow short to ground?  I

think that ANL is to protect against a runaway alternator and if so, 60A is

all you need.

Also, is that low voltage module just supposed to turn on a light?  I think

that relay is to automatically turn on your aux battery in case of low

voltage, if so, I think that the way you have it wired will turn your main

battery contactor back on when you turn it off???  I am willing to be wrong

about this as I speak electric only through an interpreter. :>) 



Bill B



--

sshook(at)cox.net
Guest

Posted: Thu May 08, 2008 3:23 pm Post subject: Z-19 Item Clarification

I see what you are saying.  I was under the impression that the low voltage

module was to measure and warn of low voltage only.  I was not aware that

activating the contactor was a function.  If that is the case, you are

correct - I would not be able to isolate the Main Battery.



This is precisely the reason I am asking for reviews.



				

Scott R. Shook

RV-7A (Building)

N696JS (Reserved)



--

klehman(at)albedo.net
Guest

Posted: Thu May 08, 2008 6:36 pm Post subject: Z-19 Item Clarification

Allen



My EIS comes on any time the master switch is on so it is on before 

startup. However I elected not to provide any other power source for it 

so it does go dead if I turn off the master switch.



The warning light flashes for everything outside of spec which means you 

can cancel them one at a time to confirm they are working. However I 

normally just start the engine which removes all the warnings except low 

coolant pressure.



At shutdown the warnings come back on for low voltage and low oil 

pressure which can again be canceled one at a time as you suggest. 

However if the oil pressure indicated normal at any time while the 

engine was running, it is very unlikely that the low pressure warning 

will not work from the EIS. You can also set the low oil pressure 

warning such that it will come on at slow idle just before shutdown (if 

the oil is up to temperature). In my case I also wired a small light to 

the low pressure switch that was already installed in my stock engine. 

The engine is my own conversion and I run a modified Z-14 architecture 

with two small alternators and two very small 8AH batteries. The system 

actually weighs less than many single alternator single battery 

installations.

Ken

Allen Fulmer wrote:

[quote] 

 

 Thanks Ken,

 

 One of the reasons for turning on the EIS before starting the engine is to

 make sure the oil pressure sensor DOES work like it is supposed to.  But you

 make a good point.  Maybe the light could be checked when shutting DOWN the

 engine before the EIS is turned OFF?  Thoughts?

 

 Allen

 

>>> --

Allen Fulmer

Joined: 10 Jan 2006
Posts: 79
Location: Alexander City, AL

Posted: Fri May 09, 2008 7:46 am Post subject: Z-19 Item Clarification

Thanks Ken,



If your panel contains EFIS display units, are they on when your "master

switch" is turned on?  Keeping them off until the engine is started is my

desire.  I think BobN says it is not an issue with modern day electronics

but I seem to remember that GRT (at least) recommends that you not expose

the display units to the potential voltage drop during engine start.

(Actually, I seriously doubt starting the Subaru with it's geared starter is

going to create much of a drop but . . ..)



Allen



[quote]>>--

_________________
RV7 QB Fuselage
Eggenfellner H6 on orde
N808AF reserved
Alexander City, AL

Mark Sletten

Joined: 10 Jan 2006
Posts: 43
Location: St. Jacob, IL (Near St. Louis, MO)

Posted: Fri May 09, 2008 7:56 am Post subject: Re: Z-19 Item Clarification

 	  sshook(at)cox.net wrote: 	
		  For my Z19/Egg Hybrid wiring, I used all of Jan's recommendations for supplying electrical power to the engine ECU, prop, and fuel pumps.-- 	




Ok, I'll be the first to bite... why run power to all critical engine components thru a single point of failure, specifically the four-pole switch? While you have redundant sources feeding redundant poles on the feed side of the switch, the failure of a single pole on the feed side of the switch (bad connection, poor crimp, broken wire, etc.) results in engine shut down. 



Additionally, you have both fuel pumps feeding off a single pole on the switch. This seems like a single-point of failure added to a single-point of failure. If this one pole of the switch fails you lose both fuel pumps.



In my mind, the whole point of redundant power supplies is to avoid single points of failure.



Regards,

_________________
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com

sshook(at)cox.net
Guest

Posted: Fri May 09, 2008 8:47 am Post subject: Z-19 Item Clarification

I hear what you are saying with the 4P3T switch.  I just don't see any other

alternatives to switching bus power while still staying within the

recommendations/requirements of Eggenfellner.



Certainly, if someone has a suggestion or recommendation for me - I am

always ready to hear it.



Eventually, all roads in our redundant electrical systems lead to a single

point of failure - the power wire for the component we are powering.  That

will always be a single point of failure as I do not know of many components

that have independent, redundant power sources.



				

Scott R. Shook

RV-7A (Building)

N696JS (Reserved)



--

Allen Fulmer

Joined: 10 Jan 2006
Posts: 79
Location: Alexander City, AL

Posted: Fri May 09, 2008 8:59 am Post subject: Z-19 Item Clarification

Mark and all interested in the Z19/Eggenfellner Subaru electrical system

design discussion:



See if this link works to the thread titled: "Diode verses Switches 101"



http://forums.matronics.com/viewtopic.php?p=169493#169493



Allen Fulmer



[quote]>>--

_________________
RV7 QB Fuselage
Eggenfellner H6 on orde
N808AF reserved
Alexander City, AL

harley(at)AgelessWings.co
Guest

Posted: Fri May 09, 2008 9:54 am Post subject: Z-19 Item Clarification

>>I do not know of many components that have independent, redundant power sources.<<

 

 The P-Mag for one...electrically, anyway

 

 Harley

 

 Scott R. Shook wrote: [quote]   [quote]--> AeroElectric-List message posted by: "Scott R. Shook" <sshook(at)cox.net> (sshook(at)cox.net)  I hear what you are saying with the 4P3T switch.  I just don't see any other alternatives to switching bus power while still staying within the recommendations/requirements of Eggenfellner.  Certainly, if someone has a suggestion or recommendation for me - I am always ready to hear it.  Eventually, all roads in our redundant electrical systems lead to a single point of failure - the power wire for the component we are powering.  That will always be a single point of failure as I do not know of many components that have independent, redundant power sources.  				 Scott R. Shook RV-7A (Building) N696JS (Reserved)  --

klehman(at)albedo.net
Guest

Posted: Fri May 09, 2008 2:17 pm Post subject: Z-19 Item Clarification

Hello Allen

No I do not have an EFIS, just a six pack of conventional flight 

instruments on my bird.

Computers make wonderful monitoring tools though and my Grand Rapids EIS 

(engine instruments only) is always powered during start up. It does not 

reboot as far as I know but it wouldn't matter anyway as it comes up 

pretty much instantly when turned on. It has survived several hundred 

startups so far   Thanks to the crowbar overvoltage module, it has 

also survived a voltage regulator failure that drove the voltage up.

Ken



Allen Fulmer wrote:

 	  Quote: 	
		   

 

 Thanks Ken,

 

 If your panel contains EFIS display units, are they on when your "master

 switch" is turned on?  Keeping them off until the engine is started is my

 desire.  I think BobN says it is not an issue with modern day electronics

 but I seem to remember that GRT (at least) recommends that you not expose

 the display units to the potential voltage drop during engine start.

 (Actually, I seriously doubt starting the Subaru with it's geared starter is

 going to create much of a drop but . . ..)

 

 Allen

Mark Sletten

Joined: 10 Jan 2006
Posts: 43
Location: St. Jacob, IL (Near St. Louis, MO)

Posted: Sat May 10, 2008 6:57 pm Post subject: Re: Z-19 Item Clarification

 	  sshook(at)cox.net wrote: 	
		  I hear what you are saying with the 4P3T switch.  I just don't see any other alternatives to switching bus power while still staying within the recommendations/requirements of Eggenfellner. 	


I've read the Eggenfellner install manual. There IS a schematic depicting what the manual refers to as "one way to wire your system" using the switch to which you refer. I couldn't find anything stating the switch as a "requirement." As far as I can see, the ONLY benefit this switch provides is the ability to switch between power supplies with a single switch.



Other than the drawing in the manual, which specific recommendation(s) from Eggenfellner require you to incorporate a single point of failure in your electrical system? Maybe a better question might be how has Eggenfellner justified the recommendation(s) you feel compelled to follow? 



 	  sshook(at)cox.net wrote: 	
		  Eventually, all roads in our redundant electrical systems lead to a single point of failure - the power wire for the component we are powering.  That will always be a single point of failure as I do not know of many components that have independent, redundant power sources. 	




Comparing a single, unbroken wire connected at either end with a switch incorporating 12 external connecting points and a multitude of moving parts manipulating several internal contacts is a bit of a stretch...

Even if you are convinced of the invincibility of the switch, what design philosophy drives connecting both fuel pumps to a single pole of the switch?



Regards,

_________________
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com

sshook(at)cox.net
Guest

Posted: Sun May 11, 2008 4:09 pm Post subject: Z-19 Item Clarification

The "requirement" I spoke of came about from an off-field incident in March

which Eggenfellner said that they will not support bridge rectifiers being

used for their engines.



				

Scott R. Shook

RV-7A (Building)

N696JS (Reserved)



--

ZuluZephyr

Joined: 12 Mar 2008
Posts: 6
Location: Upland CA

Posted: Sun May 11, 2008 8:52 pm Post subject: Re: Z-19 Item Clarification

Scott,



The failure that you mention was due to an incorrectly sized rectifier or diode that was not designed to carry the load that was applied.  Not because the basic design is faulty.  All designs have advantages and disadvantages.



Eggenfellner's design solves certain potential problems and creates others.



Ultimately, it is your plane and your risks.  The trick is to make fully informed decisions about the trade-offs in design and decide what your risk tolerance is for the various design options.

Rocky Morrison

Sportsman / H6

Mark Sletten

Joined: 10 Jan 2006
Posts: 43
Location: St. Jacob, IL (Near St. Louis, MO)

Posted: Mon May 12, 2008 5:59 am Post subject: Re: Z-19 Item Clarification

 	  sshook(at)cox.net wrote: 	
		  The "requirement" I spoke of came about from an off-field incident in March which Eggenfellner said that they will not support bridge rectifiers being used for their engines. 	




Scott,



1. The NTSB has not completed its investigation of this accident yet. I would hesitate to base design decisions on speculation regarding ANY accident -- especially if the speculation comes from a party with an interest in the results of that investigation.

2. I do not believe the accident aircraft to which you refer incorporated a bridge rectifier in the power path to the critical engine components.

3. If you are leery about using bridge rectifiers there are other products capable of controlling power routing besides them.



Regards,

_________________
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com

longg(at)pjm.com
Guest

Posted: Mon May 12, 2008 7:23 am Post subject: Z-19 Item Clarification

I spoke with two Legacy builders from Princeton, NJ on Saturday. One of

their fellow builders was flying their RV-9 and Egg Sube when a $20.00

switch or diode failed. You can have all the batteries and busses you

like, the Sube ignition maintains a single point of failure. That's why

they call it Experimental. 



The crash pilot escaped with a mangled foot and broken leg. He is

re-building and now a favorite customer at Lycoming. BTW - If he had

turned right off after take-off there are smoother fields available for

landing. As Murphy would have it, he went left towards the trees. 



Performance goes far beyond switches. Nothing is perfect, but Lycoming

still offers the Briggs and Stratton reliability to bring you home again

and again. 



Keep it smart; wire for reliability not convenience. 



The result:



http://www.ntsb.gov/ntsb/brief.asp?ev_id 080319X00337&key=1



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