Today's Message Index:
----------------------
1. 02:59 AM - Re: out of town for a few days (GLEN MATEJCEK)
2. 05:56 AM - ORe: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Ron Burnett)
3. 06:12 AM - Re: ORe: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Kelly McMullen)
4. 06:59 AM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Charlie England)
5. 08:17 AM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Sebastien)
6. 08:54 AM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Charlie England)
7. 08:57 AM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (C&K)
8. 09:15 AM - Re: RV-10 Electrical Review with Electric AC and FlyEFII (user9253)
9. 09:26 AM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Charlie England)
10. 09:59 AM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Sebastien)
11. 10:47 AM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Charlie England)
12. 01:00 PM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Sebastien)
13. 02:11 PM - Re: Re: RV-10 Electrical Review with Electric AC and FlyEFII (Charlie England)
14. 02:37 PM - EFII System32 (Sebastien)
15. 05:40 PM - Re: EFII System32 (Charlie England)
Message 1
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| Subject: | Re: out of town for a few days |
>
>
> Have fun Bob!
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
Here is the bottom line,in this Marines opinion, having flown dual EFII and now
system 32 since 2017. If anything goes wrong, it is wise to land, rent a car,
call a friend, or whatever. Do you want yourself, let alone possibly 3 others
in jeopardy over your clever planning.
Initially I flew myRV-6A Subaru conversion with Ross Farnums system and then after
a piston failure and immediate return to my airport it took me 4 years to
get an O360 Lycoming with dual EFII flying. For a few months I have been flying
with the system 32. Have always had the Bus Manager. Now I have 270 hours on
the Lycoming, and dual Oddessey PC-680 batteries on the firewall. I buy one
new battery each year but if the alternator quits, personally I wouldnt fly more
than 20-30 minutes max.
Good luck, but remember there is always a weak link somewhere.
Ron Burnett
May you have the Lord's blessings today!
Sent from my iPad
> On Nov 9, 2021, at 9:52 PM, Sebastien S <cluros@gmail.com> wrote:
>
>
> Hello Michael,
>
> Im currently debugging a FLYEFII install on a Murphy Rebel. The fuel pumps are
definitely a conundrum. Fuel pump dependant aircraft are nothing new and for
a century the solution has been to run both the primary and the backup pump during
critical phases of flight. This doesnt seem to work well with the FLYEFII
system so they have that relay to enable only one pump at a time. If you install
their Bus Manager it includes a circuit to keep an eye on the fuel pressure
and switch to the backup pump if necessary. Without this system I see only
two options:
>
> 1. Create your own monitoring and automatic switching system,
>
> 2. Run both pumps during critical phases of flight. This will require careful
testing since it might cause problems in an effort to avoid a potentially catastrophic
one.
>
> As for your second battery, I would suggest putting it in the front. Youll need
to be careful not to overheat it and youll end up carrying ballast in the baggage
compartment when light, but when heavy youll have more useful load.
>
>> On Nov 9, 2021, at 18:49, melstien <michael@elstien.us> wrote:
>>
>>
>> Hello John,
>>
>> Yes, I like to keep track of my changes so I try to add revision tags. I don't
always remember.
>>
>> I will take a look at the failure modes and probably better align this to the
Z101 and also try to organize it so it makes physical sense. That will also
allow me to see where all my connection points should be. Currently it is just
electrically correct (or will be if people suggest good changes)
>>
>> I will add separate filed switches on the alternators. I was not sure and
that was one of my questions.
>>
>> The 40 Amp AC will be an experiment. I do not plan to add it to the alternator
load except during level flight at altitude and near an airport. AC is
a luxury. The Earthex batteries can draw at least 100 amps continuously so I
think they will pick up any sag and my IBBS batteries on critical avionics are
also meant to do that as well.
>>
>> Engine Bus answers:
>> 6 Cylinder as opposed to a 4 cylinder
>> Yes, everything will have its own power lead and the coil packs will have a
fusable link and a breaker
>> Injectors will have a fusible link only
>> I planned to not have the pump on automatice failover but to run them both during
takeoff, landing and fuel tank switch-overs but Robert at FLYEFII did not
suggest that. he thought it might cause cavitation on the inlet. My testing
using my actual fuel lines and pressure regulator indicated that running both
at the same time more than doubled the current draw (4.9 amps per pump solo)
and the fule flow increased marginally. I think they were both fighting
each other to supply pressure at the pump outlet and it was still only going through
qty 1 -3/8 inch hose.
>> I had thought about splicing each injector wire and coil pack power feed into
2 wires and feeding them off Engine Bus A and engine Bus B all with diode isolation.
The schematic looked cool but it introduced to many connections points
which would probably have increased failures.
>>
>> FLYEFII suggests a 10 Amp fuse for the for the pumps and my load testing indicates
they only use 4.9 when run separately. I can review the wires size I used
and see if it will support a 12 or 15 amp breaker.
>>
>> FlyEFII did not state what the coil pack would need when powered separately.
They have the coil packs and the injectors all being fed by 1 15 amp fuse.
I suspect that the coil packs will still need a 15 amp fuse per coil pack because
they all charge at different times, so splitting them into 3 does not reduce
the peak current, just the frequency it occurs. (I am a Mech Engineer so
I am looking for guidance on that.) I have reached out to FLY EFII and requested
guidance.
>>
>> FlyEFII informed me that the system at high RPM will consume 11 AMPs. That
is all I have to go on. to meet my 1 hour of reserve, I can always move up
the ETX 1200 battery. Its the same form factor and will carry an 18 amp load
for 80 minutes. If that is not enough there is always the ETX1600 (120Amp/hours).
Even two of the 1200's weight less than 1 PC680. Money is just the
issue. Not a place to skimp.
>>
>> Regarding the coil packs, cylinder 1-4 are spread across coil packs A and B
so they are redundant. If you lose A or B you still have 1 working plug per
cylinder 1-4. FLY EFII added the 3rd coil pack and both plugs for cylinders
5 and 6 are on the same pack. I have informed FLYEFII that I would suggest
a different arrangement so both plugs were not on the same coil pack. I do
know of a person who lost coil pack C and the engine ran without too much vibration,
but I need to check into that story.
>>
>> I have 2 LR3Ds and the higher output backup alternator. I just noticed they
come with an amber light. I will ties these outputs into my EFIS but a good
light is also nice. I Prefer LED for lower heat and better vibration and longer
life.
>>
>> OV Sense, so this is the contact that senses the buss voltage and is used to
increase or decrease the voltage ouput? I have them both going to the Main Bus,
but maybe the backup should go to the engine bus. There is a possibility
the main bus has power but the engine bus does not. Your thoughts?
>>
>> I reviewed your diagram and it is really what I intended mine to be, only with
the second battery.
>>
>> Thanks for the feedback. I appreciate it.
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=504060#504060
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
>
Message 3
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| Subject: | Re: RV-10 Electrical Review with Electric |
AC and FlyEFII
Besides your cautions the one other is weight and balance. The stock
RV-10 with stock battery location and weight needs ballast in baggage
compartment when flown with 2 upfront and no baggage, as in training
flight. Depending on where air conditioning components are and how they
affect the C.G.; battery placement and weight could be an issue. Going
with the latest lithium batteries to save weight may not be prudent for
c.g. location.
I don't think I would want to be managing a complex electrical
design(with electrically dependent engine) in IFR if one electrical
component fails. At least not for any extended period.
Kelly
On 11/10/2021 6:55 AM, Ron Burnett wrote:
>
> Here is the bottom line,in this Marines opinion, having flown dual EFII and now
system 32 since 2017. If anything goes wrong, it is wise to land, rent a car,
call a friend, or whatever. Do you want yourself, let alone possibly 3 others
in jeopardy over your clever planning.
>
> Initially I flew myRV-6A Subaru conversion with Ross Farnums system and then
after a piston failure and immediate return to my airport it took me 4 years to
get an O360 Lycoming with dual EFII flying. For a few months I have been flying
with the system 32. Have always had the Bus Manager. Now I have 270 hours
on the Lycoming, and dual Oddessey PC-680 batteries on the firewall. I buy one
new battery each year but if the alternator quits, personally I wouldnt fly
more than 20-30 minutes max.
>
> Good luck, but remember there is always a weak link somewhere.
>
> Ron Burnett
>
>
>
>
Message 4
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
The fuel pump symptoms you describe are totally normal. If you run both
pumps, they will each require their own full rated current while running.
Total fuel pressure shouldn't change more than a few PSI if the regulator
is sized properly. Excess fuel is bypassed by the regulator back to the
tank. Upside is that if one pump fails during a critical phase of flight,
fuel delivery doesn't even 'hiccup'.
Auto-switching of the pumps: If that's totally inside your 'black box', do
you *know* that black box doesn't have a single-point-of-failure inside?
Knowing means having the schematic for the guts of the black box, and a
full understanding of the circuit.
If you're using B&C regulators, I believe that the regulator is powered via
pin 6 ('bus'). The various pins and their functions are described in their
manual, here
<https://bandc.com/wp-content/uploads/2020/05/LR3D-Technical-Manual_RevIR_5-13-20.pdf>.
Not sure why they labeled pin 3 as 'OV' since the manual says overvoltage
is sensed at the supply pin (6). Pin 3 is a 'remote sense' line that the
regulator uses to accurately measure bus voltage so it can set proper
voltage, and does the secondary job of detecting *under* (low) voltage.
I can't specifically address the EFII system, but coil packs typically
consume fairly low current, compared to the injectors. Injectors can have
relatively high inrush current each time they fire.
This: "*They have the coil packs and the injectors all being fed by 1 15
amp fuse.*" just *screams* SINGLE POINT OF FAILURE at me. I could be
wrong, but I'd want to be absolutely certain about it. Play what if. Short
one wire to ground or short one coil internally to ground, etc, somewhere
downstream of that fuse. What happens to the engine?
Charlie
On Tue, Nov 9, 2021 at 8:48 PM melstien <michael@elstien.us> wrote:
>
> Hello John,
>
> Yes, I like to keep track of my changes so I try to add revision tags. I
> don't always remember.
>
> I will take a look at the failure modes and probably better align this to
> the Z101 and also try to organize it so it makes physical sense. That will
> also allow me to see where all my connection points should be. Currently
> it is just electrically correct (or will be if people suggest good changes)
>
> I will add separate filed switches on the alternators. I was not sure
> and that was one of my questions.
>
> The 40 Amp AC will be an experiment. I do not plan to add it to the
> alternator load except during level flight at altitude and near an
> airport. AC is a luxury. The Earthex batteries can draw at least 100
> amps continuously so I think they will pick up any sag and my IBBS
> batteries on critical avionics are also meant to do that as well.
>
> Engine Bus answers:
> 6 Cylinder as opposed to a 4 cylinder
> Yes, everything will have its own power lead and the coil packs will have
> a fusable link and a breaker
> Injectors will have a fusible link only
> I planned to not have the pump on automatice failover but to run them both
> during takeoff, landing and fuel tank switch-overs but Robert at FLYEFII
> did not suggest that. he thought it might cause cavitation on the inlet.
> My testing using my actual fuel lines and pressure regulator indicated
> that running both at the same time more than doubled the current draw (4.9
> amps per pump solo) and the fule flow increased marginally. I think they
> were both fighting each other to supply pressure at the pump outlet and it
> was still only going through qty 1 -3/8 inch hose.
> I had thought about splicing each injector wire and coil pack power feed
> into 2 wires and feeding them off Engine Bus A and engine Bus B all with
> diode isolation. The schematic looked cool but it introduced to many
> connections points which would probably have increased failures.
>
> FLYEFII suggests a 10 Amp fuse for the for the pumps and my load testing
> indicates they only use 4.9 when run separately. I can review the wires
> size I used and see if it will support a 12 or 15 amp breaker.
>
> FlyEFII did not state what the coil pack would need when powered
> separately. They have the coil packs and the injectors all being fed by 1
> 15 amp fuse. I suspect that the coil packs will still need a 15 amp fuse
> per coil pack because they all charge at different times, so splitting them
> into 3 does not reduce the peak current, just the frequency it occurs. (I
> am a Mech Engineer so I am looking for guidance on that.) I have reached
> out to FLY EFII and requested guidance.
>
> FlyEFII informed me that the system at high RPM will consume 11 AMPs.
> That is all I have to go on. to meet my 1 hour of reserve, I can always
> move up the ETX 1200 battery. Its the same form factor and will carry an
> 18 amp load for 80 minutes. If that is not enough there is always the
> ETX1600 (120Amp/hours). Even two of the 1200's weight less than 1 PC680.
> Money is just the issue. Not a place to skimp.
>
> Regarding the coil packs, cylinder 1-4 are spread across coil packs A and
> B so they are redundant. If you lose A or B you still have 1 working
> plug per cylinder 1-4. FLY EFII added the 3rd coil pack and both plugs
> for cylinders 5 and 6 are on the same pack. I have informed FLYEFII that
> I would suggest a different arrangement so both plugs were not on the same
> coil pack. I do know of a person who lost coil pack C and the engine ran
> without too much vibration, but I need to check into that story.
>
> I have 2 LR3Ds and the higher output backup alternator. I just noticed
> they come with an amber light. I will ties these outputs into my EFIS but
> a good light is also nice. I Prefer LED for lower heat and better
> vibration and longer life.
>
> OV Sense, so this is the contact that senses the buss voltage and is used
> to increase or decrease the voltage ouput? I have them both going to the
> Main Bus, but maybe the backup should go to the engine bus. There is a
> possibility the main bus has power but the engine bus does not. Your
> thoughts?
>
> I reviewed your diagram and it is really what I intended mine to be, only
> with the second battery.
>
> Thanks for the feedback. I appreciate it.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=504060#504060
>
>
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Message 5
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
Charlie if the "black box" that switches fuel pumps fails, the primary fuel
pump continues to run so no worries. The relay that switches pumps is NO
passing current to the primary pump, or energized and switching current to
the backup pump. I suppose the relay itself could be mechanically damaged
and shut off both pumps, but a fuel line could break cutting off fuel as
well.
The FLYEFII Bus Manager is expensive and requires two batteries, but it's
actually a pretty well thought out unit.
It just occurred to me that in our high wing we're not worried about
cavitating the pumps if we run both, but in an RV-10 it could be a concern.
So instead of fancy switching logic, install a *third* pump to feed the two
EFII pumps and run all three for takeoff :). Or just use different pumps
and run them in series (the way a legacy system is installed) instead of in
parallel with FLYEFII's manifold.
On Wed, Nov 10, 2021 at 7:11 AM Charlie England <ceengland7@gmail.com>
wrote:
> The fuel pump symptoms you describe are totally normal. If you run both
> pumps, they will each require their own full rated current while running.
> Total fuel pressure shouldn't change more than a few PSI if the regulator
> is sized properly. Excess fuel is bypassed by the regulator back to the
> tank. Upside is that if one pump fails during a critical phase of flight,
> fuel delivery doesn't even 'hiccup'.
>
> Auto-switching of the pumps: If that's totally inside your 'black box', do
> you *know* that black box doesn't have a single-point-of-failure inside?
> Knowing means having the schematic for the guts of the black box, and a
> full understanding of the circuit.
>
> If you're using B&C regulators, I believe that the regulator is powered
> via pin 6 ('bus'). The various pins and their functions are described in
> their manual, here
> <https://bandc.com/wp-content/uploads/2020/05/LR3D-Technical-Manual_RevIR_5-13-20.pdf>.
> Not sure why they labeled pin 3 as 'OV' since the manual says overvoltage
> is sensed at the supply pin (6). Pin 3 is a 'remote sense' line that the
> regulator uses to accurately measure bus voltage so it can set proper
> voltage, and does the secondary job of detecting *under* (low) voltage.
> I can't specifically address the EFII system, but coil packs typically
> consume fairly low current, compared to the injectors. Injectors can have
> relatively high inrush current each time they fire.
> This: "*They have the coil packs and the injectors all being fed by 1 15
> amp fuse.*" just *screams* SINGLE POINT OF FAILURE at me. I could be
> wrong, but I'd want to be absolutely certain about it. Play what if. Short
> one wire to ground or short one coil internally to ground, etc, somewhere
> downstream of that fuse. What happens to the engine?
>
> Charlie
>
>
> On Tue, Nov 9, 2021 at 8:48 PM melstien <michael@elstien.us> wrote:
>
>>
>> Hello John,
>>
>> Yes, I like to keep track of my changes so I try to add revision tags.
>> I don't always remember.
>>
>> I will take a look at the failure modes and probably better align this to
>> the Z101 and also try to organize it so it makes physical sense. That will
>> also allow me to see where all my connection points should be. Currently
>> it is just electrically correct (or will be if people suggest good changes)
>>
>> I will add separate filed switches on the alternators. I was not sure
>> and that was one of my questions.
>>
>> The 40 Amp AC will be an experiment. I do not plan to add it to the
>> alternator load except during level flight at altitude and near an
>> airport. AC is a luxury. The Earthex batteries can draw at least 100
>> amps continuously so I think they will pick up any sag and my IBBS
>> batteries on critical avionics are also meant to do that as well.
>>
>> Engine Bus answers:
>> 6 Cylinder as opposed to a 4 cylinder
>> Yes, everything will have its own power lead and the coil packs will have
>> a fusable link and a breaker
>> Injectors will have a fusible link only
>> I planned to not have the pump on automatice failover but to run them
>> both during takeoff, landing and fuel tank switch-overs but Robert at
>> FLYEFII did not suggest that. he thought it might cause cavitation on the
>> inlet. My testing using my actual fuel lines and pressure regulator
>> indicated that running both at the same time more than doubled the current
>> draw (4.9 amps per pump solo) and the fule flow increased marginally. I
>> think they were both fighting each other to supply pressure at the pump
>> outlet and it was still only going through qty 1 -3/8 inch hose.
>> I had thought about splicing each injector wire and coil pack power feed
>> into 2 wires and feeding them off Engine Bus A and engine Bus B all with
>> diode isolation. The schematic looked cool but it introduced to many
>> connections points which would probably have increased failures.
>>
>> FLYEFII suggests a 10 Amp fuse for the for the pumps and my load testing
>> indicates they only use 4.9 when run separately. I can review the wires
>> size I used and see if it will support a 12 or 15 amp breaker.
>>
>> FlyEFII did not state what the coil pack would need when powered
>> separately. They have the coil packs and the injectors all being fed by 1
>> 15 amp fuse. I suspect that the coil packs will still need a 15 amp fuse
>> per coil pack because they all charge at different times, so splitting them
>> into 3 does not reduce the peak current, just the frequency it occurs. (I
>> am a Mech Engineer so I am looking for guidance on that.) I have reached
>> out to FLY EFII and requested guidance.
>>
>> FlyEFII informed me that the system at high RPM will consume 11 AMPs.
>> That is all I have to go on. to meet my 1 hour of reserve, I can always
>> move up the ETX 1200 battery. Its the same form factor and will carry an
>> 18 amp load for 80 minutes. If that is not enough there is always the
>> ETX1600 (120Amp/hours). Even two of the 1200's weight less than 1 PC680.
>> Money is just the issue. Not a place to skimp.
>>
>> Regarding the coil packs, cylinder 1-4 are spread across coil packs A and
>> B so they are redundant. If you lose A or B you still have 1 working
>> plug per cylinder 1-4. FLY EFII added the 3rd coil pack and both plugs
>> for cylinders 5 and 6 are on the same pack. I have informed FLYEFII that
>> I would suggest a different arrangement so both plugs were not on the same
>> coil pack. I do know of a person who lost coil pack C and the engine ran
>> without too much vibration, but I need to check into that story.
>>
>> I have 2 LR3Ds and the higher output backup alternator. I just noticed
>> they come with an amber light. I will ties these outputs into my EFIS but
>> a good light is also nice. I Prefer LED for lower heat and better
>> vibration and longer life.
>>
>> OV Sense, so this is the contact that senses the buss voltage and is used
>> to increase or decrease the voltage ouput? I have them both going to the
>> Main Bus, but maybe the backup should go to the engine bus. There is a
>> possibility the main bus has power but the engine bus does not. Your
>> thoughts?
>>
>> I reviewed your diagram and it is really what I intended mine to be, only
>> with the second battery.
>>
>> Thanks for the feedback. I appreciate it.
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=504060#504060
>>
>>
>
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free.
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Message 6
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
Everyone sets their own comfort level when it comes to risk. If you're
happy *and you're fully informed about the risks*, then that's your
choice. I might make different choices, and some of mine on other
subjects might be unacceptable to you.
Do you *know* what's in the black box? Have you analyzed the failure
modes and their effects? A fuel line failure would be difficult to 'plan
around', except through careful and thoughtful installation work. But
electrical failure issues are relatively simple to plan for and to
implement backup systems for potential failures. I'm just trying to
point out that there are some whizbang gadgets that can introduce more
failure modes than they compensate for, and we need to know when that is
happening.
I'd have more confidence in a vendor's position if he told me that he
tested for a potential problem, rather than just speculation. For
instance, I asked one of the a/c fuel boost pump (for conventional fuel
injection) vendors about their technique of looping bypassed fuel back
to the inlet of the pump and the risks of vapor lock/cavitation. His
response was that they'd tested it, including at elevated fuel temps.
There's also the contrary data point that competitors' systems (using
very similar dual pump setups) work just fine when running both pumps
for takeoff & landing.
I really want to understand as well as possible any system I install
that's a departure from 'tradition', simply because failure modes will
be different and likely not as well documented. For instance, this:
Or just use different pumps and run them in series (the way a legacy
system is installed) instead of in parallel with FLYEFII's manifold.
As a FYI, the Walbro pumps shown on FLYEFII's web page are positive
displacement pumps. That means that if the pump isn't turning, no fuel
will move through that pump. See the problem with that thought path?
Charlie
On 11/10/2021 10:17 AM, Sebastien wrote:
> Charlie if the "black box" that switches fuel pumps fails, the primary
> fuel pump continues to run so no worries. The relay that switches
> pumps is NO passing current to the primary pump, or energized and
> switching current to the backup pump. I suppose the relay itself could
> be mechanically damaged and shut off both pumps, but a fuel line could
> break cutting off fuel as well.
>
> The FLYEFII Bus Manager is expensive and requires two batteries, but
> it's actually a pretty well thought out unit.
>
> It just occurred to me that in our high wing we're not worried about
> cavitating the pumps if we run both, but in an RV-10 it could be a
> concern. So instead of fancy switching logic, install a /third/pump
> to feed the two EFII pumps and run all three for takeoff :). Or just
> use different pumps and run them in series (the way a legacy system is
> installed) instead of in parallel with FLYEFII's manifold.
>
> On Wed, Nov 10, 2021 at 7:11 AM Charlie England <ceengland7@gmail.com>
> wrote:
>
> The fuel pump symptoms you describe are totally normal. If you run
> both pumps, they will each require their own full rated current
> while running. Total fuel pressure shouldn't change more than a
> few PSI if the regulator is sized properly. Excess fuel is
> bypassed by the regulator back to the tank. Upside is that if one
> pump fails during a critical phase of flight, fuel delivery
> doesn't even 'hiccup'.
>
> Auto-switching of the pumps: If that's totally inside your 'black
> box', do you *know* that black box doesn't have a
> single-point-of-failure inside? Knowing means having the schematic
> for the guts of the black box, and a full understanding of the
> circuit.
>
> If you're using B&C regulators, I believe that the regulator is
> powered via pin 6 ('bus'). The various pins and their functions
> are described in their manual, here
> <https://bandc.com/wp-content/uploads/2020/05/LR3D-Technical-Manual_RevIR_5-13-20.pdf>.
> Not sure why they labeled pin 3 as 'OV' since the manual says
> overvoltage is sensed at the supply pin (6). Pin 3 is a 'remote
> sense' line that the regulator uses to accurately measure bus
> voltage so it can set proper voltage, and does the secondary job
> of detecting *under* (low) voltage.
> I can't specifically address the EFII system, but coil packs
> typically consume fairly low current, compared to the injectors.
> Injectors can have relatively high inrush current each time they fire.
> This: "/They have the coil packs and the injectors all being fed
> by 1 15 amp fuse./" just *screams* SINGLE POINT OF FAILURE at me.
> I could be wrong, but I'd want to be absolutely certain about it.
> Play what if. Short one wire to ground or short one coil
> internally to ground,etc, somewhere downstream of that fuse. What
> happens to the engine?
>
> Charlie
>
>
> On Tue, Nov 9, 2021 at 8:48 PM melstien <michael@elstien.us> wrote:
>
> <michael@elstien.us>
>
> Hello John,
>
> Yes, I like to keep track of my changes so I try to add
> revision tags. I don't always remember.
>
> I will take a look at the failure modes and probably better
> align this to the Z101 and also try to organize it so it makes
> physical sense. That will also allow me to see where all my
> connection points should be. Currently it is just
> electrically correct (or will be if people suggest good changes)
>
> I will add separate filed switches on the alternators. I was
> not sure and that was one of my questions.
>
> The 40 Amp AC will be an experiment. I do not plan to add it
> to the alternator load except during level flight at altitude
> and near an airport. AC is a luxury. The Earthex batteries
> can draw at least 100 amps continuously so I think they will
> pick up any sag and my IBBS batteries on critical avionics are
> also meant to do that as well.
>
> Engine Bus answers:
> 6 Cylinder as opposed to a 4 cylinder
> Yes, everything will have its own power lead and the coil
> packs will have a fusable link and a breaker
> Injectors will have a fusible link only
> I planned to not have the pump on automatice failover but to
> run them both during takeoff, landing and fuel tank
> switch-overs but Robert at FLYEFII did not suggest that. he
> thought it might cause cavitation on the inlet. My testing
> using my actual fuel lines and pressure regulator indicated
> that running both at the same time more than doubled the
> current draw (4.9 amps per pump solo) and the fule flow
> increased marginally. I think they were both fighting each
> other to supply pressure at the pump outlet and it was still
> only going through qty 1 -3/8 inch hose.
> I had thought about splicing each injector wire and coil pack
> power feed into 2 wires and feeding them off Engine Bus A and
> engine Bus B all with diode isolation. The schematic looked
> cool but it introduced to many connections points which would
> probably have increased failures.
>
> FLYEFII suggests a 10 Amp fuse for the for the pumps and my
> load testing indicates they only use 4.9 when run separately.
> I can review the wires size I used and see if it will support
> a 12 or 15 amp breaker.
>
> FlyEFII did not state what the coil pack would need when
> powered separately. They have the coil packs and the
> injectors all being fed by 1 15 amp fuse. I suspect that the
> coil packs will still need a 15 amp fuse per coil pack because
> they all charge at different times, so splitting them into 3
> does not reduce the peak current, just the frequency it
> occurs. (I am a Mech Engineer so I am looking for guidance on
> that.) I have reached out to FLY EFII and requested guidance.
>
> FlyEFII informed me that the system at high RPM will consume
> 11 AMPs. That is all I have to go on. to meet my 1 hour
> of reserve, I can always move up the ETX 1200 battery. Its
> the same form factor and will carry an 18 amp load for 80
> minutes. If that is not enough there is always the ETX1600
> (120Amp/hours). Even two of the 1200's weight less than 1
> PC680. Money is just the issue. Not a place to skimp.
>
> Regarding the coil packs, cylinder 1-4 are spread across coil
> packs A and B so they are redundant. If you lose A or B you
> still have 1 working plug per cylinder 1-4. FLY EFII added
> the 3rd coil pack and both plugs for cylinders 5 and 6 are on
> the same pack. I have informed FLYEFII that I would suggest
> a different arrangement so both plugs were not on the same
> coil pack. I do know of a person who lost coil pack C and
> the engine ran without too much vibration, but I need to check
> into that story.
>
> I have 2 LR3Ds and the higher output backup alternator. I just
> noticed they come with an amber light. I will ties these
> outputs into my EFIS but a good light is also nice. I Prefer
> LED for lower heat and better vibration and longer life.
>
> OV Sense, so this is the contact that senses the buss voltage
> and is used to increase or decrease the voltage ouput? I have
> them both going to the Main Bus, but maybe the backup should
> go to the engine bus. There is a possibility the main bus
> has power but the engine bus does not. Your thoughts?
>
> I reviewed your diagram and it is really what I intended mine
> to be, only with the second battery.
>
> Thanks for the feedback. I appreciate it.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=504060#504060
>
>
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Message 7
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
Yes I've seen NO relays go high contact resistance and fail on EFI
systems. If you must use relays I'd recommend two of them.
There have been some issues with series pumps such as noise and
cavitation when the downstream pump only is running. They should have
one way bypass valves in case one fails in a restrictive way. Worst is
when they also have a check valve on a pump inlet. A third feed pump
can be another single point of failure. I prefer parallel pumps and
especially if mogas is involved but I still used external check valves
on their outputs.
Fluid leaks often show before a complete failure. Not so much with
electron leaks.
Also my automotive type port injectors draw less peak current than my
ignition coil packs. Both increase draw as rpm goes up.
Ken
On 10/11/2021 11:17 AM, Sebastien wrote:
> Charlie if the "black box" that switches fuel pumps fails, the primary
> fuel pump continues to run so no worries. The relay that switches
> pumps is NO passing current to the primary pump, or energized and
> switching current to the backup pump. I suppose the relay itself could
> be mechanically damaged and shut off both pumps, but a fuel line could
> break cutting off fuel as well.
>
> The FLYEFII Bus Manager is expensive and requires two batteries, but
> it's actually a pretty well thought out unit.
>
> It just occurred to me that in our high wing we're not worried about
> cavitating the pumps if we run both, but in an RV-10 it could be a
> concern. So instead of fancy switching logic, install a /third/pump
> to feed the two EFII pumps and run all three for takeoff :). Or just
> use different pumps and run them in series (the way a legacy system is
> installed) instead of in parallel with FLYEFII's manifold.
>
> On Wed, Nov 10, 2021 at 7:11 AM Charlie England <ceengland7@gmail.com
> <mailto:ceengland7@gmail.com>> wrote:
>
> The fuel pump symptoms you describe are totally normal. If you run
> both pumps, they will each require their own full rated current
> while running. Total fuel pressure shouldn't change more than a
> few PSI if the regulator is sized properly. Excess fuel is
> bypassed by the regulator back to the tank. Upside is that if one
> pump fails during a critical phase of flight, fuel delivery
> doesn't even 'hiccup'.
>
> Auto-switching of the pumps: If that's totally inside your 'black
> box', do you *know* that black box doesn't have a
> single-point-of-failure inside? Knowing means having the schematic
> for the guts of the black box, and a full understanding of the
> circuit.
>
> If you're using B&C regulators, I believe that the regulator is
> powered via pin 6 ('bus'). The various pins and their functions
> are described in their manual, here
> <https://bandc.com/wp-content/uploads/2020/05/LR3D-Technical-Manual_RevIR_5-13-20.pdf>.
> Not sure why they labeled pin 3 as 'OV' since the manual says
> overvoltage is sensed at the supply pin (6). Pin 3 is a 'remote
> sense' line that the regulator uses to accurately measure bus
> voltage so it can set proper voltage, and does the secondary job
> of detecting *under* (low) voltage.
> I can't specifically address the EFII system, but coil packs
> typically consume fairly low current, compared to the injectors.
> Injectors can have relatively high inrush current each time they fire.
> This: "/They have the coil packs and the injectors all being fed
> by 1 15 amp fuse./" just *screams* SINGLE POINT OF FAILURE at me.
> I could be wrong, but I'd want to be absolutely certain about it.
> Play what if. Short one wire to ground or short one coil
> internally to ground,etc, somewhere downstream of that fuse. What
> happens to the engine?
>
> Charlie
>
>
> On Tue, Nov 9, 2021 at 8:48 PM melstien <michael@elstien.us
> <mailto:michael@elstien.us>> wrote:
>
> <michael@elstien.us <mailto:michael@elstien.us>>
>
> Hello John,
>
> Yes, I like to keep track of my changes so I try to add
> revision tags. I don't always remember.
>
> I will take a look at the failure modes and probably better
> align this to the Z101 and also try to organize it so it makes
> physical sense. That will also allow me to see where all my
> connection points should be. Currently it is just
> electrically correct (or will be if people suggest good changes)
>
> I will add separate filed switches on the alternators. I was
> not sure and that was one of my questions.
>
> The 40 Amp AC will be an experiment. I do not plan to add it
> to the alternator load except during level flight at altitude
> and near an airport. AC is a luxury. The Earthex batteries
> can draw at least 100 amps continuously so I think they will
> pick up any sag and my IBBS batteries on critical avionics are
> also meant to do that as well.
>
> Engine Bus answers:
> 6 Cylinder as opposed to a 4 cylinder
> Yes, everything will have its own power lead and the coil
> packs will have a fusable link and a breaker
> Injectors will have a fusible link only
> I planned to not have the pump on automatice failover but to
> run them both during takeoff, landing and fuel tank
> switch-overs but Robert at FLYEFII did not suggest that. he
> thought it might cause cavitation on the inlet. My testing
> using my actual fuel lines and pressure regulator indicated
> that running both at the same time more than doubled the
> current draw (4.9 amps per pump solo) and the fule flow
> increased marginally. I think they were both fighting each
> other to supply pressure at the pump outlet and it was still
> only going through qty 1 -3/8 inch hose.
> I had thought about splicing each injector wire and coil pack
> power feed into 2 wires and feeding them off Engine Bus A and
> engine Bus B all with diode isolation. The schematic looked
> cool but it introduced to many connections points which would
> probably have increased failures.
>
> FLYEFII suggests a 10 Amp fuse for the for the pumps and my
> load testing indicates they only use 4.9 when run separately.
> I can review the wires size I used and see if it will support
> a 12 or 15 amp breaker.
>
> FlyEFII did not state what the coil pack would need when
> powered separately. They have the coil packs and the
> injectors all being fed by 1 15 amp fuse. I suspect that the
> coil packs will still need a 15 amp fuse per coil pack because
> they all charge at different times, so splitting them into 3
> does not reduce the peak current, just the frequency it
> occurs. (I am a Mech Engineer so I am looking for guidance on
> that.) I have reached out to FLY EFII and requested guidance.
>
> FlyEFII informed me that the system at high RPM will consume
> 11 AMPs. That is all I have to go on. to meet my 1 hour
> of reserve, I can always move up the ETX 1200 battery. Its
> the same form factor and will carry an 18 amp load for 80
> minutes. If that is not enough there is always the ETX1600
> (120Amp/hours). Even two of the 1200's weight less than 1
> PC680. Money is just the issue. Not a place to skimp.
>
> Regarding the coil packs, cylinder 1-4 are spread across coil
> packs A and B so they are redundant. If you lose A or B you
> still have 1 working plug per cylinder 1-4. FLY EFII added
> the 3rd coil pack and both plugs for cylinders 5 and 6 are on
> the same pack. I have informed FLYEFII that I would suggest
> a different arrangement so both plugs were not on the same
> coil pack. I do know of a person who lost coil pack C and
> the engine ran without too much vibration, but I need to check
> into that story.
>
> I have 2 LR3Ds and the higher output backup alternator. I just
> noticed they come with an amber light. I will ties these
> outputs into my EFIS but a good light is also nice. I Prefer
> LED for lower heat and better vibration and longer life.
>
> OV Sense, so this is the contact that senses the buss voltage
> and is used to increase or decrease the voltage ouput? I have
> them both going to the Main Bus, but maybe the backup should
> go to the engine bus. There is a possibility the main bus
> has power but the engine bus does not. Your thoughts?
>
> I reviewed your diagram and it is really what I intended mine
> to be, only with the second battery.
>
> Thanks for the feedback. I appreciate it.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=504060#504060
>
>
> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon>
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Message 8
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| Subject: | Re: RV-10 Electrical Review with Electric AC and FlyEFII |
There was a report on one of these forums (can't remember which) of a
newfangled black box failing due to a short circuit in a 5 volt portable device
that was plugged into the black box.
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=504150#504150
Message 9
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
Useful data point on coil vs injector power consumption. The stuff I've
worked with typically is reversed, so it's good to know that we shouldn't
make any assumptions without actual testing of the stuff we're actually
using.
Charlie
On Wed, Nov 10, 2021 at 11:01 AM C&K <yellowduckduo@gmail.com> wrote:
>
> Yes I've seen NO relays go high contact resistance and fail on EFI
> systems. If you must use relays I'd recommend two of them.
>
> There have been some issues with series pumps such as noise and
> cavitation when the downstream pump only is running. They should have
> one way bypass valves in case one fails in a restrictive way. Worst is
> when they also have a check valve on a pump inlet. A third feed pump
> can be another single point of failure. I prefer parallel pumps and
> especially if mogas is involved but I still used external check valves
> on their outputs.
>
> Fluid leaks often show before a complete failure. Not so much with
> electron leaks.
> Also my automotive type port injectors draw less peak current than my
> ignition coil packs. Both increase draw as rpm goes up.
> Ken
>
> On 10/11/2021 11:17 AM, Sebastien wrote:
> > Charlie if the "black box" that switches fuel pumps fails, the primary
> > fuel pump continues to run so no worries. The relay that switches
> > pumps is NO passing current to the primary pump, or energized and
> > switching current to the backup pump. I suppose the relay itself could
> > be mechanically damaged and shut off both pumps, but a fuel line could
> > break cutting off fuel as well.
> >
> > The FLYEFII Bus Manager is expensive and requires two batteries, but
> > it's actually a pretty well thought out unit.
> >
> > It just occurred to me that in our high wing we're not worried about
> > cavitating the pumps if we run both, but in an RV-10 it could be a
> > concern. So instead of fancy switching logic, install a /third/ pump
> > to feed the two EFII pumps and run all three for takeoff :). Or just
> > use different pumps and run them in series (the way a legacy system is
> > installed) instead of in parallel with FLYEFII's manifold.
> >
> > On Wed, Nov 10, 2021 at 7:11 AM Charlie England <ceengland7@gmail.com
> > <mailto:ceengland7@gmail.com>> wrote:
> >
> > The fuel pump symptoms you describe are totally normal. If you run
> > both pumps, they will each require their own full rated current
> > while running. Total fuel pressure shouldn't change more than a
> > few PSI if the regulator is sized properly. Excess fuel is
> > bypassed by the regulator back to the tank. Upside is that if one
> > pump fails during a critical phase of flight, fuel delivery
> > doesn't even 'hiccup'.
> >
> > Auto-switching of the pumps: If that's totally inside your 'black
> > box', do you *know* that black box doesn't have a
> > single-point-of-failure inside? Knowing means having the schematic
> > for the guts of the black box, and a full understanding of the
> > circuit.
> >
> > If you're using B&C regulators, I believe that the regulator is
> > powered via pin 6 ('bus'). The various pins and their functions
> > are described in their manual, here
> > <
> https://bandc.com/wp-content/uploads/2020/05/LR3D-Technical-Manual_RevIR_5-13-20.pdf
> >.
> > Not sure why they labeled pin 3 as 'OV' since the manual says
> > overvoltage is sensed at the supply pin (6). Pin 3 is a 'remote
> > sense' line that the regulator uses to accurately measure bus
> > voltage so it can set proper voltage, and does the secondary job
> > of detecting *under* (low) voltage.
> > I can't specifically address the EFII system, but coil packs
> > typically consume fairly low current, compared to the injectors.
> > Injectors can have relatively high inrush current each time they
> fire.
> > This: "/They have the coil packs and the injectors all being fed
> > by 1 15 amp fuse./" just *screams* SINGLE POINT OF FAILURE at me.
> > I could be wrong, but I'd want to be absolutely certain about it.
> > Play what if. Short one wire to ground or short one coil
> > internally to ground, etc, somewhere downstream of that fuse. What
> > happens to the engine?
> >
> > Charlie
> >
> >
> > On Tue, Nov 9, 2021 at 8:48 PM melstien <michael@elstien.us
> > <mailto:michael@elstien.us>> wrote:
> >
> > <michael@elstien.us <mailto:michael@elstien.us>>
> >
> > Hello John,
> >
> > Yes, I like to keep track of my changes so I try to add
> > revision tags. I don't always remember.
> >
> > I will take a look at the failure modes and probably better
> > align this to the Z101 and also try to organize it so it makes
> > physical sense. That will also allow me to see where all my
> > connection points should be. Currently it is just
> > electrically correct (or will be if people suggest good changes)
> >
> > I will add separate filed switches on the alternators. I was
> > not sure and that was one of my questions.
> >
> > The 40 Amp AC will be an experiment. I do not plan to add it
> > to the alternator load except during level flight at altitude
> > and near an airport. AC is a luxury. The Earthex batteries
> > can draw at least 100 amps continuously so I think they will
> > pick up any sag and my IBBS batteries on critical avionics are
> > also meant to do that as well.
> >
> > Engine Bus answers:
> > 6 Cylinder as opposed to a 4 cylinder
> > Yes, everything will have its own power lead and the coil
> > packs will have a fusable link and a breaker
> > Injectors will have a fusible link only
> > I planned to not have the pump on automatice failover but to
> > run them both during takeoff, landing and fuel tank
> > switch-overs but Robert at FLYEFII did not suggest that. he
> > thought it might cause cavitation on the inlet. My testing
> > using my actual fuel lines and pressure regulator indicated
> > that running both at the same time more than doubled the
> > current draw (4.9 amps per pump solo) and the fule flow
> > increased marginally. I think they were both fighting each
> > other to supply pressure at the pump outlet and it was still
> > only going through qty 1 -3/8 inch hose.
> > I had thought about splicing each injector wire and coil pack
> > power feed into 2 wires and feeding them off Engine Bus A and
> > engine Bus B all with diode isolation. The schematic looked
> > cool but it introduced to many connections points which would
> > probably have increased failures.
> >
> > FLYEFII suggests a 10 Amp fuse for the for the pumps and my
> > load testing indicates they only use 4.9 when run separately.
> > I can review the wires size I used and see if it will support
> > a 12 or 15 amp breaker.
> >
> > FlyEFII did not state what the coil pack would need when
> > powered separately. They have the coil packs and the
> > injectors all being fed by 1 15 amp fuse. I suspect that the
> > coil packs will still need a 15 amp fuse per coil pack because
> > they all charge at different times, so splitting them into 3
> > does not reduce the peak current, just the frequency it
> > occurs. (I am a Mech Engineer so I am looking for guidance on
> > that.) I have reached out to FLY EFII and requested guidance.
> >
> > FlyEFII informed me that the system at high RPM will consume
> > 11 AMPs. That is all I have to go on. to meet my 1 hour
> > of reserve, I can always move up the ETX 1200 battery. Its
> > the same form factor and will carry an 18 amp load for 80
> > minutes. If that is not enough there is always the ETX1600
> > (120Amp/hours). Even two of the 1200's weight less than 1
> > PC680. Money is just the issue. Not a place to skimp.
> >
> > Regarding the coil packs, cylinder 1-4 are spread across coil
> > packs A and B so they are redundant. If you lose A or B you
> > still have 1 working plug per cylinder 1-4. FLY EFII added
> > the 3rd coil pack and both plugs for cylinders 5 and 6 are on
> > the same pack. I have informed FLYEFII that I would suggest
> > a different arrangement so both plugs were not on the same
> > coil pack. I do know of a person who lost coil pack C and
> > the engine ran without too much vibration, but I need to check
> > into that story.
> >
> > I have 2 LR3Ds and the higher output backup alternator. I just
> > noticed they come with an amber light. I will ties these
> > outputs into my EFIS but a good light is also nice. I Prefer
> > LED for lower heat and better vibration and longer life.
> >
> > OV Sense, so this is the contact that senses the buss voltage
> > and is used to increase or decrease the voltage ouput? I have
> > them both going to the Main Bus, but maybe the backup should
> > go to the engine bus. There is a possibility the main bus
> > has power but the engine bus does not. Your thoughts?
> >
> > I reviewed your diagram and it is really what I intended mine
> > to be, only with the second battery.
> >
> > Thanks for the feedback. I appreciate it.
> >
>
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Message 10
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
>
> Or just use different pumps and run them in series (the way a legacy
> system is installed) instead of in parallel with FLYEFII's manifold.
> As a FYI, the Walbro pumps shown on FLYEFII's web page are positive
> displacement pumps. That means that if the pump isn't turning, no fuel will
> move through that pump. See the problem with that thought path?
I can't say that I do Charlie:
Or just *use different pumps* and run them in series (the way a legacy
> system is installed) instead of in parallel with FLYEFII's manifold.
When selecting fuel pumps, the ability to flow fuel when not turning has
been a basic requirement for series fuel pumps for about a century. The
fuel flow test performed before first flight will demonstrate whether or
not the correct pumps have been selected.
As for the black box, it is completely unnecessary to analyze the failure
modes and their effects since any failure of the box (including a bad
tempered Gremlin eating the box and leaving the wires dangling) will either
leave the relay powering the primary fuel pump as normal, or erroneously
switch to backup. The particular aircraft I've been working on has been
flying around with a failed black box since day one. The black box is in a
different country than the aircraft. The pump still runs.
Similarly the Mooney I fly has a complicated Garmin GNS Navigator and a
backup VOR/ILS. I have no need to analyse the different failure modes of
the Garmin in order to be confident that if it fails, I can use the other
VOR/ILS. I just tune, identify, switch HSI source, set course, and set the
desired autopilot mode.
However relay failures are something I know nothing about. If a likely
failure mode of this relay could leave both pumps unpowered then the
FLYEFII implementation is poor. I haven't seen any data to suggest this but
I'll ask them what research and testing they did next time I speak with
them.
On Wed, Nov 10, 2021 at 9:06 AM Charlie England <ceengland7@gmail.com>
wrote:
> Everyone sets their own comfort level when it comes to risk. If you're
> happy *and you're fully informed about the risks*, then that's your choice.
> I might make different choices, and some of mine on other subjects might be
> unacceptable to you.
>
> Do you *know* what's in the black box? Have you analyzed the failure modes
> and their effects? A fuel line failure would be difficult to 'plan around',
> except through careful and thoughtful installation work. But electrical
> failure issues are relatively simple to plan for and to implement backup
> systems for potential failures. I'm just trying to point out that there are
> some whizbang gadgets that can introduce more failure modes than they
> compensate for, and we need to know when that is happening.
>
> I'd have more confidence in a vendor's position if he told me that he
> tested for a potential problem, rather than just speculation. For instance,
> I asked one of the a/c fuel boost pump (for conventional fuel injection)
> vendors about their technique of looping bypassed fuel back to the inlet of
> the pump and the risks of vapor lock/cavitation. His response was that
> they'd tested it, including at elevated fuel temps. There's also the
> contrary data point that competitors' systems (using very similar dual pump
> setups) work just fine when running both pumps for takeoff & landing.
>
> I really want to understand as well as possible any system I install
> that's a departure from 'tradition', simply because failure modes will be
> different and likely not as well documented. For instance, this:
> Or just use different pumps and run them in series (the way a legacy
> system is installed) instead of in parallel with FLYEFII's manifold.
>
> As a FYI, the Walbro pumps shown on FLYEFII's web page are positive
> displacement pumps. That means that if the pump isn't turning, no fuel will
> move through that pump. See the problem with that thought path?
>
> Charlie
>
> On 11/10/2021 10:17 AM, Sebastien wrote:
>
> Charlie if the "black box" that switches fuel pumps fails, the primary
> fuel pump continues to run so no worries. The relay that switches pumps is
> NO passing current to the primary pump, or energized and switching current
> to the backup pump. I suppose the relay itself could be mechanically
> damaged and shut off both pumps, but a fuel line could break cutting off
> fuel as well.
>
> The FLYEFII Bus Manager is expensive and requires two batteries, but it's
> actually a pretty well thought out unit.
>
> It just occurred to me that in our high wing we're not worried about
> cavitating the pumps if we run both, but in an RV-10 it could be a concern.
> So instead of fancy switching logic, install a *third* pump to feed the
> two EFII pumps and run all three for takeoff :). Or just use different
> pumps and run them in series (the way a legacy system is installed) instead
> of in parallel with FLYEFII's manifold.
>
> On Wed, Nov 10, 2021 at 7:11 AM Charlie England <ceengland7@gmail.com>
> wrote:
>
>> The fuel pump symptoms you describe are totally normal. If you run both
>> pumps, they will each require their own full rated current while running.
>> Total fuel pressure shouldn't change more than a few PSI if the regulator
>> is sized properly. Excess fuel is bypassed by the regulator back to the
>> tank. Upside is that if one pump fails during a critical phase of flight,
>> fuel delivery doesn't even 'hiccup'.
>>
>> Auto-switching of the pumps: If that's totally inside your 'black box',
>> do you *know* that black box doesn't have a single-point-of-failure inside?
>> Knowing means having the schematic for the guts of the black box, and a
>> full understanding of the circuit.
>>
>> If you're using B&C regulators, I believe that the regulator is powered
>> via pin 6 ('bus'). The various pins and their functions are described in
>> their manual, here
>> <https://bandc.com/wp-content/uploads/2020/05/LR3D-Technical-Manual_RevIR_5-13-20.pdf>.
>> Not sure why they labeled pin 3 as 'OV' since the manual says overvoltage
>> is sensed at the supply pin (6). Pin 3 is a 'remote sense' line that the
>> regulator uses to accurately measure bus voltage so it can set proper
>> voltage, and does the secondary job of detecting *under* (low) voltage.
>> I can't specifically address the EFII system, but coil packs typically
>> consume fairly low current, compared to the injectors. Injectors can have
>> relatively high inrush current each time they fire.
>> This: "*They have the coil packs and the injectors all being fed by 1 15
>> amp fuse.*" just *screams* SINGLE POINT OF FAILURE at me. I could be
>> wrong, but I'd want to be absolutely certain about it. Play what if. Short
>> one wire to ground or short one coil internally to ground, etc, somewhere
>> downstream of that fuse. What happens to the engine?
>>
>> Charlie
>>
>>
>> On Tue, Nov 9, 2021 at 8:48 PM melstien <michael@elstien.us> wrote:
>>
>>>
>>> Hello John,
>>>
>>> Yes, I like to keep track of my changes so I try to add revision tags.
>>> I don't always remember.
>>>
>>> I will take a look at the failure modes and probably better align this
>>> to the Z101 and also try to organize it so it makes physical sense. That
>>> will also allow me to see where all my connection points should be.
>>> Currently it is just electrically correct (or will be if people suggest
>>> good changes)
>>>
>>> I will add separate filed switches on the alternators. I was not sure
>>> and that was one of my questions.
>>>
>>> The 40 Amp AC will be an experiment. I do not plan to add it to the
>>> alternator load except during level flight at altitude and near an
>>> airport. AC is a luxury. The Earthex batteries can draw at least 100
>>> amps continuously so I think they will pick up any sag and my IBBS
>>> batteries on critical avionics are also meant to do that as well.
>>>
>>> Engine Bus answers:
>>> 6 Cylinder as opposed to a 4 cylinder
>>> Yes, everything will have its own power lead and the coil packs will
>>> have a fusable link and a breaker
>>> Injectors will have a fusible link only
>>> I planned to not have the pump on automatice failover but to run them
>>> both during takeoff, landing and fuel tank switch-overs but Robert at
>>> FLYEFII did not suggest that. he thought it might cause cavitation on the
>>> inlet. My testing using my actual fuel lines and pressure regulator
>>> indicated that running both at the same time more than doubled the current
>>> draw (4.9 amps per pump solo) and the fule flow increased marginally. I
>>> think they were both fighting each other to supply pressure at the pump
>>> outlet and it was still only going through qty 1 -3/8 inch hose.
>>> I had thought about splicing each injector wire and coil pack power feed
>>> into 2 wires and feeding them off Engine Bus A and engine Bus B all with
>>> diode isolation. The schematic looked cool but it introduced to many
>>> connections points which would probably have increased failures.
>>>
>>> FLYEFII suggests a 10 Amp fuse for the for the pumps and my load testing
>>> indicates they only use 4.9 when run separately. I can review the wires
>>> size I used and see if it will support a 12 or 15 amp breaker.
>>>
>>> FlyEFII did not state what the coil pack would need when powered
>>> separately. They have the coil packs and the injectors all being fed by 1
>>> 15 amp fuse. I suspect that the coil packs will still need a 15 amp fuse
>>> per coil pack because they all charge at different times, so splitting them
>>> into 3 does not reduce the peak current, just the frequency it occurs. (I
>>> am a Mech Engineer so I am looking for guidance on that.) I have reached
>>> out to FLY EFII and requested guidance.
>>>
>>> FlyEFII informed me that the system at high RPM will consume 11 AMPs.
>>> That is all I have to go on. to meet my 1 hour of reserve, I can always
>>> move up the ETX 1200 battery. Its the same form factor and will carry an
>>> 18 amp load for 80 minutes. If that is not enough there is always the
>>> ETX1600 (120Amp/hours). Even two of the 1200's weight less than 1 PC680.
>>> Money is just the issue. Not a place to skimp.
>>>
>>> Regarding the coil packs, cylinder 1-4 are spread across coil packs A
>>> and B so they are redundant. If you lose A or B you still have 1 working
>>> plug per cylinder 1-4. FLY EFII added the 3rd coil pack and both plugs
>>> for cylinders 5 and 6 are on the same pack. I have informed FLYEFII that
>>> I would suggest a different arrangement so both plugs were not on the same
>>> coil pack. I do know of a person who lost coil pack C and the engine ran
>>> without too much vibration, but I need to check into that story.
>>>
>>> I have 2 LR3Ds and the higher output backup alternator. I just noticed
>>> they come with an amber light. I will ties these outputs into my EFIS but
>>> a good light is also nice. I Prefer LED for lower heat and better
>>> vibration and longer life.
>>>
>>> OV Sense, so this is the contact that senses the buss voltage and is
>>> used to increase or decrease the voltage ouput? I have them both going to
>>> the Main Bus, but maybe the backup should go to the engine bus. There is
>>> a possibility the main bus has power but the engine bus does not. Your
>>> thoughts?
>>>
>>> I reviewed your diagram and it is really what I intended mine to be,
>>> only with the second battery.
>>>
>>> Thanks for the feedback. I appreciate it.
>>>
>>>
>>>
>>>
>>> Read this topic online here:
>>>
>>> http://forums.matronics.com/viewtopic.php?p=504060#504060
>>>
>>>
>>
>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free.
>> www.avast.com
>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link>
>>
>
>
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
Your example of the GNS + VOR/ILS is the perfect example of proper 'what
if' thinking; if the GNS availability is down for any reason, you have
an independent method of accomplishing your goal. 'Black box' control of
the fuel pumps (or any other multiple device backup system) might or
might not meet those criteria. It's been demonstrated that some of them
do not accomplish this, and some have been demonstrated to have failure
modes that can take out *everything* they supply power to. I'm just
trying to point out that saying that it's worked for X hours or Y years
just says that you haven't seen a failure mode yet that could affect
both the primary and the backup. Without analyzing the circuits in the
box, you don't know the failure modes. Completely different situation
from two separate radio systems with separate power sources, antennas, etc.
My point about the fuel pumps is knowing the product when it isn't
'traditional'. The fuel pumps used by FLYEFII (and others) for
electronic injection are *not* like traditional fuel pumps. Unlike
traditional Lyc engine driven pumps, and unlike the traditional boost
pumps, those Walbro pumps will *not* pass fuel if they aren't running.
I don't know of any 'different pump' that you could run that would
supply the needed ~40 PSI and could still be run in series without any
issues. If you know of one, please share the info; it could well
simplify a lot of EFI installations.
Charlie
On 11/10/2021 11:58 AM, Sebastien wrote:
>
> Or just use different pumps and run them in series (the way a
> legacy system is installed) instead of in parallel with FLYEFII's
> manifold.
>
>
> As a FYI, the Walbro pumps shown on FLYEFII's web page are
> positive displacement pumps. That means that if the pump isn't
> turning, no fuel will move through that pump. See the problem with
> that thought path?
>
>
> I can't say that I do Charlie:
>
> Or just _use different pumps_ and run them in series (the way a
> legacy system is installed) instead of in parallel with FLYEFII's
> manifold.
>
>
> When selecting fuel pumps, the ability to flow fuel when not turning
> has been a basic requirement for series fuel pumps for about a
> century. The fuel flow test performed before first flight will
> demonstrate whether or not the correct pumps have been selected.
>
> As for the black box, it is completely unnecessary to analyze the
> failure modes and their effects since any failure of the box
> (including a bad tempered Gremlin eating the box and leaving the wires
> dangling) will either leave the relay powering the primary fuel pump
> as normal,or erroneously switch to backup. The particular aircraft
> I've been working on has been flying around with a failed black box
> since day one. The black box is in a different country than the
> aircraft. The pump still runs.
>
> Similarly the Mooney I fly has a complicated Garmin GNS Navigator and
> a backup VOR/ILS. I have no need to analyse the different failure
> modes of the Garmin in order to be confident that if it fails, I can
> use the other VOR/ILS. I just tune, identify, switch HSI source, set
> course, and set the desired autopilot mode.
>
> However relay failures are something I know nothing about. If a likely
> failure mode of this relay could leave both pumps unpowered then the
> FLYEFII implementation is poor. I haven't seen any data to suggest
> this but I'll ask them what research and testing they did next time I
> speak with them.
>
> On Wed, Nov 10, 2021 at 9:06 AM Charlie England <ceengland7@gmail.com>
> wrote:
>
> Everyone sets their own comfort level when it comes to risk. If
> you're happy *and you're fully informed about the risks*, then
> that's your choice. I might make different choices, and some of
> mine on other subjects might be unacceptable to you.
>
> Do you *know* what's in the black box? Have you analyzed the
> failure modes and their effects? A fuel line failure would be
> difficult to 'plan around', except through careful and thoughtful
> installation work. But electrical failure issues are relatively
> simple to plan for and to implement backup systems for potential
> failures. I'm just trying to point out that there are some
> whizbang gadgets that can introduce more failure modes than they
> compensate for, and we need to know when that is happening.
>
> I'd have more confidence in a vendor's position if he told me that
> he tested for a potential problem, rather than just speculation.
> For instance, I asked one of the a/c fuel boost pump (for
> conventional fuel injection) vendors about their technique of
> looping bypassed fuel back to the inlet of the pump and the risks
> of vapor lock/cavitation. His response was that they'd tested it,
> including at elevated fuel temps. There's also the contrary data
> point that competitors' systems (using very similar dual pump
> setups) work just fine when running both pumps for takeoff & landing.
>
> I really want to understand as well as possible any system I
> install that's a departure from 'tradition', simply because
> failure modes will be different and likely not as well documented.
> For instance, this:
> Or just use different pumps and run them in series (the way a
> legacy system is installed) instead of in parallel with FLYEFII's
> manifold.
>
> As a FYI, the Walbro pumps shown on FLYEFII's web page are
> positive displacement pumps. That means that if the pump isn't
> turning, no fuel will move through that pump. See the problem with
> that thought path?
>
> Charlie
>
> On 11/10/2021 10:17 AM, Sebastien wrote:
>> Charlie if the "black box" that switches fuel pumps fails, the
>> primary fuel pump continues to run so no worries. The relay that
>> switches pumps is NO passing current to the primary pump, or
>> energized and switching current to the backup pump. I suppose the
>> relay itself could be mechanically damaged and shut off both
>> pumps, but a fuel line could break cutting off fuel as well.
>>
>> The FLYEFII Bus Manager is expensive and requires two batteries,
>> but it's actually a pretty well thought out unit.
>>
>> It just occurred to me that in our high wing we're not worried
>> about cavitating the pumps if we run both, but in an RV-10 it
>> could be a concern. So instead of fancy switching logic, install
>> a /third/pump to feed the two EFII pumps and run all three for
>> takeoff :). Or just use different pumps and run them in series
>> (the way a legacy system is installed) instead of in parallel
>> with FLYEFII's manifold.
>>
>> On Wed, Nov 10, 2021 at 7:11 AM Charlie England
>> <ceengland7@gmail.com> wrote:
>>
>> The fuel pump symptoms you describe are totally normal. If
>> you run both pumps, they will each require their own full
>> rated current while running. Total fuel pressure shouldn't
>> change more than a few PSI if the regulator is sized
>> properly. Excess fuel is bypassed by the regulator back to
>> the tank. Upside is that if one pump fails during a critical
>> phase of flight, fuel delivery doesn't even 'hiccup'.
>>
>> Auto-switching of the pumps: If that's totally inside your
>> 'black box', do you *know* that black box doesn't have a
>> single-point-of-failure inside? Knowing means having the
>> schematic for the guts of the black box, and a full
>> understanding of the circuit.
>>
>> If you're using B&C regulators, I believe that the regulator
>> is powered via pin 6 ('bus'). The various pins and their
>> functions are described in their manual, here
>> <https://bandc.com/wp-content/uploads/2020/05/LR3D-Technical-Manual_RevIR_5-13-20.pdf>.
>> Not sure why they labeled pin 3 as 'OV' since the manual says
>> overvoltage is sensed at the supply pin (6). Pin 3 is a
>> 'remote sense' line that the regulator uses to accurately
>> measure bus voltage so it can set proper voltage, and does
>> the secondary job of detecting *under* (low) voltage.
>> I can't specifically address the EFII system, but coil packs
>> typically consume fairly low current, compared to the
>> injectors. Injectors can have relatively high inrush current
>> each time they fire.
>> This: "/They have the coil packs and the injectors all being
>> fed by 1 15 amp fuse./" just *screams* SINGLE POINT OF
>> FAILURE at me. I could be wrong, but I'd want to be
>> absolutely certain about it. Play what if. Short one wire to
>> ground or short one coil internally to ground,etc, somewhere
>> downstream of that fuse. What happens to the engine?
>>
>> Charlie
>>
>>
>> On Tue, Nov 9, 2021 at 8:48 PM melstien <michael@elstien.us>
>> wrote:
>>
>> <michael@elstien.us>
>>
>> Hello John,
>>
>> Yes, I like to keep track of my changes so I try to add
>> revision tags. I don't always remember.
>>
>> I will take a look at the failure modes and probably
>> better align this to the Z101 and also try to organize it
>> so it makes physical sense. That will also allow me to
>> see where all my connection points should be. Currently
>> it is just electrically correct (or will be if people
>> suggest good changes)
>>
>> I will add separate filed switches on the alternators.
>> I was not sure and that was one of my questions.
>>
>> The 40 Amp AC will be an experiment. I do not plan to
>> add it to the alternator load except during level flight
>> at altitude and near an airport. AC is a luxury. The
>> Earthex batteries can draw at least 100 amps continuously
>> so I think they will pick up any sag and my IBBS
>> batteries on critical avionics are also meant to do that
>> as well.
>>
>> Engine Bus answers:
>> 6 Cylinder as opposed to a 4 cylinder
>> Yes, everything will have its own power lead and the coil
>> packs will have a fusable link and a breaker
>> Injectors will have a fusible link only
>> I planned to not have the pump on automatice failover but
>> to run them both during takeoff, landing and fuel tank
>> switch-overs but Robert at FLYEFII did not suggest that.
>> he thought it might cause cavitation on the inlet. My
>> testing using my actual fuel lines and pressure regulator
>> indicated that running both at the same time more than
>> doubled the current draw (4.9 amps per pump solo) and the
>> fule flow increased marginally. I think they were both
>> fighting each other to supply pressure at the pump
>> outlet and it was still only going through qty 1 -3/8
>> inch hose.
>> I had thought about splicing each injector wire and coil
>> pack power feed into 2 wires and feeding them off Engine
>> Bus A and engine Bus B all with diode isolation. The
>> schematic looked cool but it introduced to many
>> connections points which would probably have increased
>> failures.
>>
>> FLYEFII suggests a 10 Amp fuse for the for the pumps and
>> my load testing indicates they only use 4.9 when run
>> separately. I can review the wires size I used and see
>> if it will support a 12 or 15 amp breaker.
>>
>> FlyEFII did not state what the coil pack would need when
>> powered separately. They have the coil packs and the
>> injectors all being fed by 1 15 amp fuse. I suspect
>> that the coil packs will still need a 15 amp fuse per
>> coil pack because they all charge at different times, so
>> splitting them into 3 does not reduce the peak current,
>> just the frequency it occurs. (I am a Mech Engineer so I
>> am looking for guidance on that.) I have reached out to
>> FLY EFII and requested guidance.
>>
>> FlyEFII informed me that the system at high RPM will
>> consume 11 AMPs. That is all I have to go on. to
>> meet my 1 hour of reserve, I can always move up the ETX
>> 1200 battery. Its the same form factor and will carry an
>> 18 amp load for 80 minutes. If that is not enough there
>> is always the ETX1600 (120Amp/hours). Even two of the
>> 1200's weight less than 1 PC680. Money is just the
>> issue. Not a place to skimp.
>>
>> Regarding the coil packs, cylinder 1-4 are spread across
>> coil packs A and B so they are redundant. If you lose
>> A or B you still have 1 working plug per cylinder 1-4.
>> FLY EFII added the 3rd coil pack and both plugs for
>> cylinders 5 and 6 are on the same pack. I have informed
>> FLYEFII that I would suggest a different arrangement so
>> both plugs were not on the same coil pack. I do know of
>> a person who lost coil pack C and the engine ran without
>> too much vibration, but I need to check into that story.
>>
>> I have 2 LR3Ds and the higher output backup alternator.
>> I just noticed they come with an amber light. I will
>> ties these outputs into my EFIS but a good light is also
>> nice. I Prefer LED for lower heat and better vibration
>> and longer life.
>>
>> OV Sense, so this is the contact that senses the buss
>> voltage and is used to increase or decrease the voltage
>> ouput? I have them both going to the Main Bus, but maybe
>> the backup should go to the engine bus. There is a
>> possibility the main bus has power but the engine bus
>> does not. Your thoughts?
>>
>> I reviewed your diagram and it is really what I intended
>> mine to be, only with the second battery.
>>
>> Thanks for the feedback. I appreciate it.
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=504060#504060
>>
>>
>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon>
>> Virus-free. www.avast.com
>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link>
>>
>>
>
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Message 12
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
No argument about other black boxes Charlie, I was just trying to point out
that the EFII fuel pump black box is a control circuit, not a power
circuit. The output to the fuel pump relay is one wire. If the black box
end of that wire goes to ground, or open, or 15v, or whatever, the fuel
pump keeps running.
As for inline fuel pumps, I hadn't run into that problem yet. Would this
not work?
Andair Products <http://www.andair.co.uk/product/boost-pump-px500-tc/>
On Wed, Nov 10, 2021 at 10:51 AM Charlie England <ceengland7@gmail.com>
wrote:
> Your example of the GNS + VOR/ILS is the perfect example of proper 'what
> if' thinking; if the GNS availability is down for any reason, you have an
> independent method of accomplishing your goal. 'Black box' control of the
> fuel pumps (or any other multiple device backup system) might or might not
> meet those criteria. It's been demonstrated that some of them do not
> accomplish this, and some have been demonstrated to have failure modes that
> can take out *everything* they supply power to. I'm just trying to point
> out that saying that it's worked for X hours or Y years just says that you
> haven't seen a failure mode yet that could affect both the primary and the
> backup. Without analyzing the circuits in the box, you don't know the
> failure modes. Completely different situation from two separate radio
> systems with separate power sources, antennas, etc.
>
> My point about the fuel pumps is knowing the product when it isn't
> 'traditional'. The fuel pumps used by FLYEFII (and others) for electronic
> injection are *not* like traditional fuel pumps. Unlike traditional Lyc
> engine driven pumps, and unlike the traditional boost pumps, those Walbro
> pumps will *not* pass fuel if they aren't running.
>
> I don't know of any 'different pump' that you could run that would supply
> the needed ~40 PSI and could still be run in series without any issues. If
> you know of one, please share the info; it could well simplify a lot of EFI
> installations.
>
> Charlie
>
>
> On 11/10/2021 11:58 AM, Sebastien wrote:
>
> Or just use different pumps and run them in series (the way a legacy
>> system is installed) instead of in parallel with FLYEFII's manifold.
>
>
>> As a FYI, the Walbro pumps shown on FLYEFII's web page are positive
>> displacement pumps. That means that if the pump isn't turning, no fuel will
>> move through that pump. See the problem with that thought path?
>
>
> I can't say that I do Charlie:
>
> Or just *use different pumps* and run them in series (the way a legacy
>> system is installed) instead of in parallel with FLYEFII's manifold.
>
>
> When selecting fuel pumps, the ability to flow fuel when not turning has
> been a basic requirement for series fuel pumps for about a century. The
> fuel flow test performed before first flight will demonstrate whether or
> not the correct pumps have been selected.
>
> As for the black box, it is completely unnecessary to analyze the failure
> modes and their effects since any failure of the box (including a bad
> tempered Gremlin eating the box and leaving the wires dangling) will either
> leave the relay powering the primary fuel pump as normal, or erroneously
> switch to backup. The particular aircraft I've been working on has been
> flying around with a failed black box since day one. The black box is in a
> different country than the aircraft. The pump still runs.
>
> Similarly the Mooney I fly has a complicated Garmin GNS Navigator and a
> backup VOR/ILS. I have no need to analyse the different failure modes of
> the Garmin in order to be confident that if it fails, I can use the other
> VOR/ILS. I just tune, identify, switch HSI source, set course, and set the
> desired autopilot mode.
>
> However relay failures are something I know nothing about. If a likely
> failure mode of this relay could leave both pumps unpowered then the
> FLYEFII implementation is poor. I haven't seen any data to suggest this but
> I'll ask them what research and testing they did next time I speak with
> them.
>
> On Wed, Nov 10, 2021 at 9:06 AM Charlie England <ceengland7@gmail.com>
> wrote:
>
>> Everyone sets their own comfort level when it comes to risk. If you're
>> happy *and you're fully informed about the risks*, then that's your choice.
>> I might make different choices, and some of mine on other subjects might be
>> unacceptable to you.
>>
>> Do you *know* what's in the black box? Have you analyzed the failure
>> modes and their effects? A fuel line failure would be difficult to 'plan
>> around', except through careful and thoughtful installation work. But
>> electrical failure issues are relatively simple to plan for and to
>> implement backup systems for potential failures. I'm just trying to point
>> out that there are some whizbang gadgets that can introduce more failure
>> modes than they compensate for, and we need to know when that is happening.
>>
>> I'd have more confidence in a vendor's position if he told me that he
>> tested for a potential problem, rather than just speculation. For instance,
>> I asked one of the a/c fuel boost pump (for conventional fuel injection)
>> vendors about their technique of looping bypassed fuel back to the inlet of
>> the pump and the risks of vapor lock/cavitation. His response was that
>> they'd tested it, including at elevated fuel temps. There's also the
>> contrary data point that competitors' systems (using very similar dual pump
>> setups) work just fine when running both pumps for takeoff & landing.
>>
>> I really want to understand as well as possible any system I install
>> that's a departure from 'tradition', simply because failure modes will be
>> different and likely not as well documented. For instance, this:
>> Or just use different pumps and run them in series (the way a legacy
>> system is installed) instead of in parallel with FLYEFII's manifold.
>>
>> As a FYI, the Walbro pumps shown on FLYEFII's web page are positive
>> displacement pumps. That means that if the pump isn't turning, no fuel will
>> move through that pump. See the problem with that thought path?
>>
>> Charlie
>>
>> On 11/10/2021 10:17 AM, Sebastien wrote:
>>
>> Charlie if the "black box" that switches fuel pumps fails, the primary
>> fuel pump continues to run so no worries. The relay that switches pumps is
>> NO passing current to the primary pump, or energized and switching current
>> to the backup pump. I suppose the relay itself could be mechanically
>> damaged and shut off both pumps, but a fuel line could break cutting off
>> fuel as well.
>>
>> The FLYEFII Bus Manager is expensive and requires two batteries, but it's
>> actually a pretty well thought out unit.
>>
>> It just occurred to me that in our high wing we're not worried about
>> cavitating the pumps if we run both, but in an RV-10 it could be a concern.
>> So instead of fancy switching logic, install a *third* pump to feed the
>> two EFII pumps and run all three for takeoff :). Or just use different
>> pumps and run them in series (the way a legacy system is installed) instead
>> of in parallel with FLYEFII's manifold.
>>
>> On Wed, Nov 10, 2021 at 7:11 AM Charlie England <ceengland7@gmail.com>
>> wrote:
>>
>>> The fuel pump symptoms you describe are totally normal. If you run both
>>> pumps, they will each require their own full rated current while running.
>>> Total fuel pressure shouldn't change more than a few PSI if the regulator
>>> is sized properly. Excess fuel is bypassed by the regulator back to the
>>> tank. Upside is that if one pump fails during a critical phase of flight,
>>> fuel delivery doesn't even 'hiccup'.
>>>
>>> Auto-switching of the pumps: If that's totally inside your 'black box',
>>> do you *know* that black box doesn't have a single-point-of-failure inside?
>>> Knowing means having the schematic for the guts of the black box, and a
>>> full understanding of the circuit.
>>>
>>> If you're using B&C regulators, I believe that the regulator is powered
>>> via pin 6 ('bus'). The various pins and their functions are described in
>>> their manual, here
>>> <https://bandc.com/wp-content/uploads/2020/05/LR3D-Technical-Manual_RevIR_5-13-20.pdf>.
>>> Not sure why they labeled pin 3 as 'OV' since the manual says overvoltage
>>> is sensed at the supply pin (6). Pin 3 is a 'remote sense' line that the
>>> regulator uses to accurately measure bus voltage so it can set proper
>>> voltage, and does the secondary job of detecting *under* (low) voltage.
>>> I can't specifically address the EFII system, but coil packs typically
>>> consume fairly low current, compared to the injectors. Injectors can have
>>> relatively high inrush current each time they fire.
>>> This: "*They have the coil packs and the injectors all being fed by 1
>>> 15 amp fuse.*" just *screams* SINGLE POINT OF FAILURE at me. I could
>>> be wrong, but I'd want to be absolutely certain about it. Play what if.
>>> Short one wire to ground or short one coil internally to ground, etc,
>>> somewhere downstream of that fuse. What happens to the engine?
>>>
>>> Charlie
>>>
>>>
>>> On Tue, Nov 9, 2021 at 8:48 PM melstien <michael@elstien.us> wrote:
>>>
>>>> >
>>>>
>>>> Hello John,
>>>>
>>>> Yes, I like to keep track of my changes so I try to add revision tags.
>>>> I don't always remember.
>>>>
>>>> I will take a look at the failure modes and probably better align this
>>>> to the Z101 and also try to organize it so it makes physical sense. That
>>>> will also allow me to see where all my connection points should be.
>>>> Currently it is just electrically correct (or will be if people suggest
>>>> good changes)
>>>>
>>>> I will add separate filed switches on the alternators. I was not
>>>> sure and that was one of my questions.
>>>>
>>>> The 40 Amp AC will be an experiment. I do not plan to add it to the
>>>> alternator load except during level flight at altitude and near an
>>>> airport. AC is a luxury. The Earthex batteries can draw at least 100
>>>> amps continuously so I think they will pick up any sag and my IBBS
>>>> batteries on critical avionics are also meant to do that as well.
>>>>
>>>> Engine Bus answers:
>>>> 6 Cylinder as opposed to a 4 cylinder
>>>> Yes, everything will have its own power lead and the coil packs will
>>>> have a fusable link and a breaker
>>>> Injectors will have a fusible link only
>>>> I planned to not have the pump on automatice failover but to run them
>>>> both during takeoff, landing and fuel tank switch-overs but Robert at
>>>> FLYEFII did not suggest that. he thought it might cause cavitation on the
>>>> inlet. My testing using my actual fuel lines and pressure regulator
>>>> indicated that running both at the same time more than doubled the current
>>>> draw (4.9 amps per pump solo) and the fule flow increased marginally. I
>>>> think they were both fighting each other to supply pressure at the pump
>>>> outlet and it was still only going through qty 1 -3/8 inch hose.
>>>> I had thought about splicing each injector wire and coil pack power
>>>> feed into 2 wires and feeding them off Engine Bus A and engine Bus B all
>>>> with diode isolation. The schematic looked cool but it introduced to many
>>>> connections points which would probably have increased failures.
>>>>
>>>> FLYEFII suggests a 10 Amp fuse for the for the pumps and my load
>>>> testing indicates they only use 4.9 when run separately. I can review the
>>>> wires size I used and see if it will support a 12 or 15 amp breaker.
>>>>
>>>> FlyEFII did not state what the coil pack would need when powered
>>>> separately. They have the coil packs and the injectors all being fed by 1
>>>> 15 amp fuse. I suspect that the coil packs will still need a 15 amp fuse
>>>> per coil pack because they all charge at different times, so splitting them
>>>> into 3 does not reduce the peak current, just the frequency it occurs. (I
>>>> am a Mech Engineer so I am looking for guidance on that.) I have reached
>>>> out to FLY EFII and requested guidance.
>>>>
>>>> FlyEFII informed me that the system at high RPM will consume 11 AMPs.
>>>> That is all I have to go on. to meet my 1 hour of reserve, I can always
>>>> move up the ETX 1200 battery. Its the same form factor and will carry an
>>>> 18 amp load for 80 minutes. If that is not enough there is always the
>>>> ETX1600 (120Amp/hours). Even two of the 1200's weight less than 1 PC680.
>>>> Money is just the issue. Not a place to skimp.
>>>>
>>>> Regarding the coil packs, cylinder 1-4 are spread across coil packs A
>>>> and B so they are redundant. If you lose A or B you still have 1 working
>>>> plug per cylinder 1-4. FLY EFII added the 3rd coil pack and both plugs
>>>> for cylinders 5 and 6 are on the same pack. I have informed FLYEFII that
>>>> I would suggest a different arrangement so both plugs were not on the same
>>>> coil pack. I do know of a person who lost coil pack C and the engine ran
>>>> without too much vibration, but I need to check into that story.
>>>>
>>>> I have 2 LR3Ds and the higher output backup alternator. I just noticed
>>>> they come with an amber light. I will ties these outputs into my EFIS but
>>>> a good light is also nice. I Prefer LED for lower heat and better
>>>> vibration and longer life.
>>>>
>>>> OV Sense, so this is the contact that senses the buss voltage and is
>>>> used to increase or decrease the voltage ouput? I have them both going to
>>>> the Main Bus, but maybe the backup should go to the engine bus. There is
>>>> a possibility the main bus has power but the engine bus does not. Your
>>>> thoughts?
>>>>
>>>> I reviewed your diagram and it is really what I intended mine to be,
>>>> only with the second battery.
>>>>
>>>> Thanks for the feedback. I appreciate it.
>>>>
>>>>
>>>>
>>>>
>>>> Read this topic online here:
>>>>
>>>> http://forums.matronics.com/viewtopic.php?p=504060#504060
>>>>
>>>>
>>>
>>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon> Virus-free.
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>>
>>
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| Subject: | Re: RV-10 Electrical Review with Electric AC and |
FlyEFII
It *might* work, if you could dial the pressure up to electronic
injection levels. The pump is possibly capable of that much pressure;
but I just don't know if Andair would configure it that way. There's
also the issue of additive pressure, though I suppose that if you kept
the bypass regulator between the 2nd pump & the engine, it would
probably work. I'd want test data; either my own or the pump mfgr's
before installing that kind of setup.
I just downloaded the System32 install manual and scrolled down to the
power wiring page. I tried to find the Bus Manager install manual (ref
by the NOTE on this page), but couldn't find it on their web site.
Comments are based on what I can see, with available docs from the mfgr
that I could find.
Looking at the diagram, I see three (3) (scratch that; at least 6;
likely quite a few more if I could see inside the box) single points of
failure, on this one page, any one of which *would* stop the engine.
Depending on how you count failures, I can see closer to a dozen. All of
those failure modes are hardware related; they don't count control logic
(inside the 'black boxes'), which I can't see. Now some of them are
quite unlikely, but some have a much higher probability of occurring,
and there are relatively simple fixes for all of them. (Doing FMEA
doesn't really look at probabilities; it looks at /Effects/.) I keep
coming back to the mantra of: if it's nearly impossible to make
redundant (like the wing spar, or only one throttle body on the engine),
I'll evaluate and likely accept the risk, but if it's relatively easy to
provide a backup for flight critical items, I'm going to find a way to
do it.
Please believe me when I say I'm truly not trying to be insulting, but I
would not want to fly in a plane wired like that. There's just not a
diplomatic way to tell someone that an easily corrected thing could kill
them if not corrected. If I haven't offended you System32 users too much
and you're interested, we can discuss some of the failure modes and
ideas to fix them.
Charlie
On 11/10/2021 2:59 PM, Sebastien wrote:
> No argument about other black boxes Charlie, I was just trying to
> point out that the EFII fuel pump black box is a control circuit, not
> a power circuit. The output to the fuel pump relay is one wire. If the
> black box end of that wire goes to ground, or open, or 15v, or
> whatever, the fuel pump keeps running.
>
> As for inline fuel pumps, I hadn't run into that problem yet. Would
> this not work?
>
> Andair Products <http://www.andair.co.uk/product/boost-pump-px500-tc/>
>
>
> On Wed, Nov 10, 2021 at 10:51 AM Charlie England
> <ceengland7@gmail.com> wrote:
>
> Your example of the GNS + VOR/ILS is the perfect example of proper
> 'what if' thinking; if the GNS availability is down for any
> reason, you have an independent method of accomplishing your goal.
> 'Black box' control of the fuel pumps (or any other multiple
> device backup system) might or might not meet those criteria. It's
> been demonstrated that some of them do not accomplish this, and
> some have been demonstrated to have failure modes that can take
> out *everything* they supply power to. I'm just trying to point
> out that saying that it's worked for X hours or Y years just says
> that you haven't seen a failure mode yet that could affect both
> the primary and the backup. Without analyzing the circuits in the
> box, you don't know the failure modes. Completely different
> situation from two separate radio systems with separate power
> sources, antennas, etc.
>
> My point about the fuel pumps is knowing the product when it isn't
> 'traditional'. The fuel pumps used by FLYEFII (and others) for
> electronic injection are *not* like traditional fuel pumps. Unlike
> traditional Lyc engine driven pumps, and unlike the traditional
> boost pumps, those Walbro pumps will *not* pass fuel if they
> aren't running.
>
> I don't know of any 'different pump' that you could run that would
> supply the needed ~40 PSI and could still be run in series without
> any issues. If you know of one, please share the info; it could
> well simplify a lot of EFI installations.
>
> Charlie
>
>
> On 11/10/2021 11:58 AM, Sebastien wrote:
>>
>> Or just use different pumps and run them in series (the way a
>> legacy system is installed) instead of in parallel with
>> FLYEFII's manifold.
>>
>>
>> As a FYI, the Walbro pumps shown on FLYEFII's web page are
>> positive displacement pumps. That means that if the pump
>> isn't turning, no fuel will move through that pump. See the
>> problem with that thought path?
>>
>>
>> I can't say that I do Charlie:
>>
>> Or just _use different pumps_ and run them in series (the way
>> a legacy system is installed) instead of in parallel with
>> FLYEFII's manifold.
>>
>>
>> When selecting fuel pumps, the ability to flow fuel when not
>> turning has been a basic requirement for series fuel pumps for
>> about a century. The fuel flow test performed before first flight
>> will demonstrate whether or not the correct pumps have been selected.
>>
>> As for the black box, it is completely unnecessary to analyze the
>> failure modes and their effects since any failure of the box
>> (including a bad tempered Gremlin eating the box and leaving the
>> wires dangling) will either leave the relay powering the primary
>> fuel pump as normal,or erroneously switch to backup. The
>> particular aircraft I've been working on has been flying around
>> with a failed black box since day one. The black box is in a
>> different country than the aircraft. The pump still runs.
>>
>> Similarly the Mooney I fly has a complicated Garmin GNS Navigator
>> and a backup VOR/ILS. I have no need to analyse the different
>> failure modes of the Garmin in order to be confident that if it
>> fails, I can use the other VOR/ILS. I just tune, identify, switch
>> HSI source, set course, and set the desired autopilot mode.
>>
>> However relay failures are something I know nothing about. If a
>> likely failure mode of this relay could leave both pumps
>> unpowered then the FLYEFII implementation is poor. I haven't seen
>> any data to suggest this but I'll ask them what research and
>> testing they did next time I speak with them.
>>
>> On Wed, Nov 10, 2021 at 9:06 AM Charlie England
>> <ceengland7@gmail.com> wrote:
>>
>> Everyone sets their own comfort level when it comes to risk.
>> If you're happy *and you're fully informed about the risks*,
>> then that's your choice. I might make different choices, and
>> some of mine on other subjects might be unacceptable to you.
>>
>> Do you *know* what's in the black box? Have you analyzed the
>> failure modes and their effects? A fuel line failure would be
>> difficult to 'plan around', except through careful and
>> thoughtful installation work. But electrical failure issues
>> are relatively simple to plan for and to implement backup
>> systems for potential failures. I'm just trying to point out
>> that there are some whizbang gadgets that can introduce more
>> failure modes than they compensate for, and we need to know
>> when that is happening.
>>
>> I'd have more confidence in a vendor's position if he told me
>> that he tested for a potential problem, rather than just
>> speculation. For instance, I asked one of the a/c fuel boost
>> pump (for conventional fuel injection) vendors about their
>> technique of looping bypassed fuel back to the inlet of the
>> pump and the risks of vapor lock/cavitation. His response was
>> that they'd tested it, including at elevated fuel temps.
>> There's also the contrary data point that competitors'
>> systems (using very similar dual pump setups) work just fine
>> when running both pumps for takeoff & landing.
>>
>> I really want to understand as well as possible any system I
>> install that's a departure from 'tradition', simply because
>> failure modes will be different and likely not as well
>> documented. For instance, this:
>> Or just use different pumps and run them in series (the way a
>> legacy system is installed) instead of in parallel with
>> FLYEFII's manifold.
>>
>> As a FYI, the Walbro pumps shown on FLYEFII's web page are
>> positive displacement pumps. That means that if the pump
>> isn't turning, no fuel will move through that pump. See the
>> problem with that thought path?
>>
>> Charlie
>>
>> On 11/10/2021 10:17 AM, Sebastien wrote:
>>> Charlie if the "black box" that switches fuel pumps fails,
>>> the primary fuel pump continues to run so no worries. The
>>> relay that switches pumps is NO passing current to the
>>> primary pump, or energized and switching current to the
>>> backup pump. I suppose the relay itself could be
>>> mechanically damaged and shut off both pumps, but a fuel
>>> line could break cutting off fuel as well.
>>>
>>> The FLYEFII Bus Manager is expensive and requires two
>>> batteries, but it's actually a pretty well thought out unit.
>>>
>>> It just occurred to me that in our high wing we're not
>>> worried about cavitating the pumps if we run both, but in an
>>> RV-10 it could be a concern. So instead of fancy switching
>>> logic, install a /third/pump to feed the two EFII pumps and
>>> run all three for takeoff :). Or just use different pumps
>>> and run them in series (the way a legacy system is
>>> installed) instead of in parallel with FLYEFII's manifold.
>>>
>>> On Wed, Nov 10, 2021 at 7:11 AM Charlie England
>>> <ceengland7@gmail.com> wrote:
>>>
>>> The fuel pump symptoms you describe are totally normal.
>>> If you run both pumps, they will each require their own
>>> full rated current while running. Total fuel pressure
>>> shouldn't change more than a few PSI if the regulator is
>>> sized properly. Excess fuel is bypassed by the regulator
>>> back to the tank. Upside is that if one pump fails
>>> during a critical phase of flight, fuel delivery doesn't
>>> even 'hiccup'.
>>>
>>> Auto-switching of the pumps: If that's totally inside
>>> your 'black box', do you *know* that black box doesn't
>>> have a single-point-of-failure inside? Knowing means
>>> having the schematic for the guts of the black box, and
>>> a full understanding of the circuit.
>>>
>>> If you're using B&C regulators, I believe that the
>>> regulator is powered via pin 6 ('bus'). The various pins
>>> and their functions are described in their manual, here
>>> <https://bandc.com/wp-content/uploads/2020/05/LR3D-Technical-Manual_RevIR_5-13-20.pdf>.
>>> Not sure why they labeled pin 3 as 'OV' since the manual
>>> says overvoltage is sensed at the supply pin (6). Pin 3
>>> is a 'remote sense' line that the regulator uses to
>>> accurately measure bus voltage so it can set proper
>>> voltage, and does the secondary job of detecting *under*
>>> (low) voltage.
>>> I can't specifically address the EFII system, but coil
>>> packs typically consume fairly low current, compared to
>>> the injectors. Injectors can have relatively high inrush
>>> current each time they fire.
>>> This: "/They have the coil packs and the injectors all
>>> being fed by 1 15 amp fuse./" just *screams* SINGLE
>>> POINT OF FAILURE at me. I could be wrong, but I'd want
>>> to be absolutely certain about it. Play what if. Short
>>> one wire to ground or short one coil internally to
>>> ground,etc, somewhere downstream of that fuse. What
>>> happens to the engine?
>>>
>>> Charlie
>>>
>>>
>>> On Tue, Nov 9, 2021 at 8:48 PM melstien
>>> <michael@elstien.us> wrote:
>>>
>>> <michael@elstien.us>
>>>
>>> Hello John,
>>>
>>> Yes, I like to keep track of my changes so I try to
>>> add revision tags. I don't always remember.
>>>
>>> I will take a look at the failure modes and probably
>>> better align this to the Z101 and also try to
>>> organize it so it makes physical sense. That will
>>> also allow me to see where all my connection points
>>> should be. Currently it is just electrically
>>> correct (or will be if people suggest good changes)
>>>
>>> I will add separate filed switches on the
>>> alternators. I was not sure and that was one of
>>> my questions.
>>>
>>> The 40 Amp AC will be an experiment. I do not plan
>>> to add it to the alternator load except during level
>>> flight at altitude and near an airport. AC is a
>>> luxury. The Earthex batteries can draw at least 100
>>> amps continuously so I think they will pick up any
>>> sag and my IBBS batteries on critical avionics are
>>> also meant to do that as well.
>>>
>>> Engine Bus answers:
>>> 6 Cylinder as opposed to a 4 cylinder
>>> Yes, everything will have its own power lead and the
>>> coil packs will have a fusable link and a breaker
>>> Injectors will have a fusible link only
>>> I planned to not have the pump on automatice
>>> failover but to run them both during takeoff,
>>> landing and fuel tank switch-overs but Robert at
>>> FLYEFII did not suggest that. he thought it might
>>> cause cavitation on the inlet. My testing using my
>>> actual fuel lines and pressure regulator indicated
>>> that running both at the same time more than doubled
>>> the current draw (4.9 amps per pump solo) and the
>>> fule flow increased marginally. I think they were
>>> both fighting each other to supply pressure at the
>>> pump outlet and it was still only going through qty
>>> 1 -3/8 inch hose.
>>> I had thought about splicing each injector wire and
>>> coil pack power feed into 2 wires and feeding them
>>> off Engine Bus A and engine Bus B all with diode
>>> isolation. The schematic looked cool but it
>>> introduced to many connections points which would
>>> probably have increased failures.
>>>
>>> FLYEFII suggests a 10 Amp fuse for the for the pumps
>>> and my load testing indicates they only use 4.9 when
>>> run separately. I can review the wires size I used
>>> and see if it will support a 12 or 15 amp breaker.
>>>
>>> FlyEFII did not state what the coil pack would need
>>> when powered separately. They have the coil packs
>>> and the injectors all being fed by 1 15 amp fuse.
>>> I suspect that the coil packs will still need a 15
>>> amp fuse per coil pack because they all charge at
>>> different times, so splitting them into 3 does not
>>> reduce the peak current, just the frequency it
>>> occurs. (I am a Mech Engineer so I am looking for
>>> guidance on that.) I have reached out to FLY EFII
>>> and requested guidance.
>>>
>>> FlyEFII informed me that the system at high RPM will
>>> consume 11 AMPs. That is all I have to go on.
>>> to meet my 1 hour of reserve, I can always move up
>>> the ETX 1200 battery. Its the same form factor and
>>> will carry an 18 amp load for 80 minutes. If that
>>> is not enough there is always the ETX1600
>>> (120Amp/hours). Even two of the 1200's weight less
>>> than 1 PC680. Money is just the issue. Not a
>>> place to skimp.
>>>
>>> Regarding the coil packs, cylinder 1-4 are spread
>>> across coil packs A and B so they are redundant.
>>> If you lose A or B you still have 1 working plug per
>>> cylinder 1-4. FLY EFII added the 3rd coil pack
>>> and both plugs for cylinders 5 and 6 are on the same
>>> pack. I have informed FLYEFII that I would suggest
>>> a different arrangement so both plugs were not on
>>> the same coil pack. I do know of a person who lost
>>> coil pack C and the engine ran without too much
>>> vibration, but I need to check into that story.
>>>
>>> I have 2 LR3Ds and the higher output backup
>>> alternator. I just noticed they come with an amber
>>> light. I will ties these outputs into my EFIS but a
>>> good light is also nice. I Prefer LED for lower
>>> heat and better vibration and longer life.
>>>
>>> OV Sense, so this is the contact that senses the
>>> buss voltage and is used to increase or decrease the
>>> voltage ouput? I have them both going to the Main
>>> Bus, but maybe the backup should go to the engine
>>> bus. There is a possibility the main bus has power
>>> but the engine bus does not. Your thoughts?
>>>
>>> I reviewed your diagram and it is really what I
>>> intended mine to be, only with the second battery.
>>>
>>> Thanks for the feedback. I appreciate it.
>>>
>>>
>>>
>>>
>>> Read this topic online here:
>>>
>>> http://forums.matronics.com/viewtopic.php?p=504060#504060
>>>
>>>
>>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=icon>
>>> Virus-free. www.avast.com
>>> <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=webmail&utm_term=link>
>>>
>>>
>>
>
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In a belated attempt to not derail Michael's electrical system thread, I'm
starting this one to ask Charlie for more details on the possible problems
with EFII's System32 fuel injection and ignition system when the electrical
system architecture is based on the EFII Bus Manager.
I have been hired to test fly an aircraft with this system. Haven't been
able to get off the ground yet due to multiple setup problems and wiring
mistakes but none of these were related to the Bus Manager.
Charlie I would be very interested to hear anything you have to say FMEA
wise about this system.
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| Subject: | Re: EFII System32 |
On 11/10/2021 4:35 PM, Sebastien wrote:
> In a belated attempt to not derail Michael's electrical system thread,
> I'm starting this one to ask Charlie for more details on the possible
> problems with EFII'sSystem32 fuel injection and ignition system when
> the electrical system architecture is based on the EFII Bus Manager.
>
> I have been hired to test fly an aircraft with this system. Haven't
> been able to get off the ground yet due to multiple setup problems and
> wiring mistakes but none of these were related to the Bus Manager.
>
> Charlie I would be very interested to hear anything you have to say
> FMEA wise about this system.
OK, for a start, here's a marked up copy of that page from the install
manual. I've likely overlooked some stuff in the quick run-through I
did, and could be more accurate with an internal schematic + board
layout of the Bus Manager. But I've marked six ways the system can kill
the engine, and highlighted a seventh *possible* way; I'd want to see
exactly how up to twelve fusible links are installed within the
backshell of the BM connector. Fusible links may or may not generate
enough heat to be a factor in any wire near them. They're typically
thermally insulated to protect other wires around them but they're
typically not tightly confined in an enclosure (the backshell, in this
case).
As I said, it's difficult to completely evaluate the system without the
BM info. The drawing shows an external 'daisy chain' connection path
(circled in red) to the various components, but the yellow circled text
seems to indicate that path is inside the BM. Having said that, things
like the ECU select switch are likely to be external.
Hope that's at least some food for thought, and maybe others will have
some input, as well.
Charlie
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