Today's Message Index:
----------------------
1. 03:21 AM - Re: Z-19 Function (Justin Jones)
2. 03:38 AM - Re: Z-19 Function (Justin Jones)
3. 07:00 AM - Re: Z-19 Function (Robert L. Nuckolls, III)
4. 10:11 AM - Re: Z-19 Function (Ken Ryan)
5. 10:36 AM - Re: Z-19 Function (Justin Jones)
6. 10:42 AM - Re: Z-19 Function (Justin Jones)
7. 11:50 AM - Re: Z-19 Function (Jeff Luckey)
8. 03:26 PM - Re: Z-19 Function (Robert L. Nuckolls, III)
9. 07:44 PM - Real life lessons in wire ratings . . . (Robert L. Nuckolls, III)
10. 07:52 PM - Dynon D-180 & flickering LEDs (user9253)
Message 1
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| Subject: | Re: Z-19 Function |
Thanks fit the input Jeff. I appreciate it. I like the way redundancy in the
system you drew.
You are correct that a single 10A breaker for both coils is a single point o
f failure and I don't like it. If a 4-diode rectifier were used with an inpu
t from both battery buses, it would solve the issue. Then a single breaker w
ould be powering it them from 2 different power sources.
On Aug 17, 2014, at 20:06, Jeff Luckey <jluckey@pacbell.net> wrote:
> Justin,
>
> ... I have also learned that a single 10A breaker feeds both coils. I wo
uld think the 4-diode rectifier with power from the engine battery bus and t
he main battery bus would solve the single-point of failure issue with a sin
gle power source...
>
> Without looking a schematic it is difficult to get a clear picture of what
you are describing but a single breaker for both coils? Is that not the de
finition of a single point of failure?
>
>
> ... I feel that with a dual battery system and a way to isolate the batte
ries from each other during flight, a higher level of safety is achieved.
>
> Agree.
>
>
> ... The pilot would simply isolate the batteries and shut off all items t
hat are drawing a load from that battery bus. ....
>
> The drawing that I posted yesterday does the isolation you are talking abo
ut but it does so automatically without any interruption of current flow and
requires no pilot interaction.
>
>
> The challenge is to engineer a reliable and redundant 12V system that will
allow for safe and reliable operation regardless of individual component, c
omplete bus, or even power source failure.
>
> This wheel has been invented many times over. Between Bob N's Z drawing(s
) and the one I posted, you should be able accomplish your goals.
>
>
> -Jeff
>
>
> On Sunday, August 17, 2014 8:37 PM, Justin Jones <jmjones2000@mindspring.c
om> wrote:
>
>
> Here is the link to the downloadable instruction manual. http://flyefii.co
m/customer_projects/EFII_Ignition_Instruction_sheet_rev9-13.pdf
>
> There is a Dual ECU addendum at the end of the instructions that deal with
the installation of the dual ECUs. Through numerous emails that I have exc
hanged with Robert, I have learned that there the entire system (both ECUs a
nd IGN coils) draws 2.4 amps. I have also learned that a single 10A breaker
feeds both coils. I would think the 4-diode rectifier with power from the e
ngine battery bus and the main battery bus would solve the single-point of f
ailure issue with a single power source. The system requires 5 breakers. 2-
5A breakers for the ECUs, 1- 10A breaker for the IGN Coils, and 2- 10A brea
kers for the fuel pumps (one each).
>
> The reason for installing the electrically dependent system is for the per
formance gains and the flexibility of using MOGAS. The system draws very li
ttle current, and WHEN the alternator fails (and it will at some point), the
pilot will be notified (low voltage and low amperage warnings). At this po
int the pilot must shed the loads to protect the remaining battery power. T
he EFII system will run as low as 6 volts. I feel that with a dual battery s
ystem and a way to isolate the batteries from each other during flight, a hi
gher level of safety is achieved. The pilot would simply isolate the batter
ies and shut off all items that are drawing a load from that battery bus. W
hen and if the primary battery=99s voltage gets too low, the pilot sim
ply switches to the other battery and lands as soon as POSSIBLE.
>
> The challenge is to engineer a reliable and redundant 12V system that will
allow for safe and reliable operation regardless of individual component, c
omplete bus, or even power source failure.
>
> Any thoughts and tips are much appreciated. I have some experience in 12VD
C systems but am by no means an engineer.
>
> Thanks again for the help!
>
> Justin
>
>
> On Aug 17, 2014, at 12:02 PM, Robert L. Nuckolls, III <nuckolls.bob@aeroel
ectric.com> wrote:
>
>> The system requires that both ECUs and both IGN coils are powered all the
time . . .
>>
>> Okay, suppose one of these four items doesn't get power
>> while the other three do . . . what happens?
>>
>> Suppose half of the system ECU and IGN get a momentary
>> power interruption, what happens?
>>
>> Suppose there's complete interruption of power to all
>> engine support which is 'fixed' in a few seconds,
>> what happens?
>>
>> The legacy design philosophy we've applied to all
>> systems intended for use in unforgiving environments
>> is the failure mode effects analysis. FMEA looks at
>> every component of the system and asks:
>>
>> How can this part fail?
>> If it does fail, how will I become aware of it?
>> If not immediately noticed or annunciated by
>> warning system, is it pre-flight detectable?
>> If it does fail, how is probable outcome of
>> the flight affected?
>> If it is necessary for comfortable continuation
>> of flight, what are my alternatives?
>>
>> Here's my personal notions that go to the topic
>> of system reliability
>>
>> Nuckolls' first law of airplane systems design sez: "Things break"
>>
>> The second: "Systems shall be designed so that when things break, no imme
diate hazard is created."
>>
>> The third: "Failure tolerant design dictates that items needed for
>> comfortable termination of flight are backed up with Plan-B alternatives.
"
>>
>> The forth: "Upgrading the quality, reliability, longevity, or
>> capability of a part shall be because you're tired of replacing it
>> or want some new operating feature, not because it damned near
>> got you killed."
>>
>> Before you march off to craft a never fails power
>> source(s) . . . it seems prudent to ASSUME there
>> WILL be failures . . . and craft a system that is
>> comfortably tolerant of such failures.
>>
>> Your query to the List cited an imperative for everything
>> that supports engine operations to be powered at all
>> times . . . if this is strictly true, then are you
>> sure that you want to install it on your airplane?
>>
>>
>>
>> Bob . . .
>>
>>
>> href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.
matronics.com/Navigator?AeroElectric-List
>> href="http://forums.matronics.com/">http://forums.matronics.com
>> href="http://www.matronics.com/contribution">http://www.matronics.com/c
ontribution
>>
>
> -->
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
Message 2
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| Subject: | Re: Z-19 Function |
I guess I should have said that 2 single breakers would be powering the
coils from 2 different power sources.
On Aug 18, 2014, at 2:19 AM, Justin Jones <jmjones2000@mindspring.com>
wrote:
> Thanks fit the input Jeff. I appreciate it. I like the way redundancy
in the system you drew.
>
> You are correct that a single 10A breaker for both coils is a single
point of failure and I don't like it. If a 4-diode rectifier were used
with an input from both battery buses, it would solve the issue. Then a
single breaker would be powering it them from 2 different power sources.
>
>
>
> On Aug 17, 2014, at 20:06, Jeff Luckey <jluckey@pacbell.net> wrote:
>
>> Justin,
>>
>> ... I have also learned that a single 10A breaker feeds both coils.
I would think the 4-diode rectifier with power from the engine battery
bus and the main battery bus would solve the single-point of failure
issue with a single power source...
>>
>> Without looking a schematic it is difficult to get a clear picture of
what you are describing but a single breaker for both coils? Is that
not the definition of a single point of failure?
>>
>>
>> ... I feel that with a dual battery system and a way to isolate the
batteries from each other during flight, a higher level of safety is
achieved.
>>
>> Agree.
>>
>>
>> ... The pilot would simply isolate the batteries and shut off all
items that are drawing a load from that battery bus. ....
>>
>> The drawing that I posted yesterday does the isolation you are
talking about but it does so automatically without any interruption of
current flow and requires no pilot interaction.
>>
>>
>> The challenge is to engineer a reliable and redundant 12V system that
will allow for safe and reliable operation regardless of individual
component, complete bus, or even power source failure.
>>
>> This wheel has been invented many times over. Between Bob N's Z
drawing(s) and the one I posted, you should be able accomplish your
goals.
>>
>>
>> -Jeff
>>
>>
>> On Sunday, August 17, 2014 8:37 PM, Justin Jones
<jmjones2000@mindspring.com> wrote:
>>
>>
>> Here is the link to the downloadable instruction manual.
http://flyefii.com/customer_projects/EFII_Ignition_Instruction_sheet_rev9-
13.pdf
>>
>> There is a Dual ECU addendum at the end of the instructions that deal
with the installation of the dual ECUs. Through numerous emails that I
have exchanged with Robert, I have learned that there the entire system
(both ECUs and IGN coils) draws 2.4 amps. I have also learned that a
single 10A breaker feeds both coils. I would think the 4-diode
rectifier with power from the engine battery bus and the main battery
bus would solve the single-point of failure issue with a single power
source. The system requires 5 breakers. 2- 5A breakers for the ECUs, 1-
10A breaker for the IGN Coils, and 2- 10A breakers for the fuel pumps
(one each).
>>
>> The reason for installing the electrically dependent system is for
the performance gains and the flexibility of using MOGAS. The system
draws very little current, and WHEN the alternator fails (and it will at
some point), the pilot will be notified (low voltage and low amperage
warnings). At this point the pilot must shed the loads to protect the
remaining battery power. The EFII system will run as low as 6 volts. I
feel that with a dual battery system and a way to isolate the batteries
from each other during flight, a higher level of safety is achieved.
The pilot would simply isolate the batteries and shut off all items that
are drawing a load from that battery bus. When and if the primary
battery=92s voltage gets too low, the pilot simply switches to the other
battery and lands as soon as POSSIBLE.
>>
>> The challenge is to engineer a reliable and redundant 12V system that
will allow for safe and reliable operation regardless of individual
component, complete bus, or even power source failure.
>>
>> Any thoughts and tips are much appreciated. I have some experience in
12VDC systems but am by no means an engineer.
>>
>> Thanks again for the help!
>>
>> Justin
>>
>>
>> On Aug 17, 2014, at 12:02 PM, Robert L. Nuckolls, III
<nuckolls.bob@aeroelectric.com> wrote:
>>
>>> The system requires that both ECUs and both IGN coils are powered
all the time . . .
>>>
>>> Okay, suppose one of these four items doesn't get power
>>> while the other three do . . . what happens?
>>>
>>> Suppose half of the system ECU and IGN get a momentary
>>> power interruption, what happens?
>>>
>>> Suppose there's complete interruption of power to all
>>> engine support which is 'fixed' in a few seconds,
>>> what happens?
>>>
>>> The legacy design philosophy we've applied to all
>>> systems intended for use in unforgiving environments
>>> is the failure mode effects analysis. FMEA looks at
>>> every component of the system and asks:
>>>
>>> How can this part fail?
>>> If it does fail, how will I become aware of it?
>>> If not immediately noticed or annunciated by
>>> warning system, is it pre-flight detectable?
>>> If it does fail, how is probable outcome of
>>> the flight affected?
>>> If it is necessary for comfortable continuation
>>> of flight, what are my alternatives?
>>>
>>> Here's my personal notions that go to the topic
>>> of system reliability
>>>
>>> Nuckolls' first law of airplane systems design sez: "Things break"
>>>
>>> The second: "Systems shall be designed so that when things break, no
immediate hazard is created."
>>>
>>> The third: "Failure tolerant design dictates that items needed for
>>> comfortable termination of flight are backed up with Plan-B
alternatives."
>>>
>>> The forth: "Upgrading the quality, reliability, longevity, or
>>> capability of a part shall be because you're tired of replacing it
>>> or want some new operating feature, not because it damned near
>>> got you killed."
>>>
>>> Before you march off to craft a never fails power
>>> source(s) . . . it seems prudent to ASSUME there
>>> WILL be failures . . . and craft a system that is
>>> comfortably tolerant of such failures.
>>>
>>> Your query to the List cited an imperative for everything
>>> that supports engine operations to be powered at all
>>> times . . . if this is strictly true, then are you
>>> sure that you want to install it on your airplane?
>>>
>>>
>>>
>>> Bob . . .
>>>
>>>
>>>
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.m
atronics.com/Navigator?AeroElectric-List
>>> href="http://forums.matronics.com/">http://forums.matronics.com
>>>
href="http://www.matronics.com/contribution">http://www.matronics.com/co
ntribution
>>>
>>
>> -->
>>
>>
>> ========================
>> courier
new,courier">http://www.matronics.com/Navigator?AeroElectric-List
>> ========================
>> cs.com
>> ========================
>> matronics.com/contribution
>> ========================
>>
>
>
>
Message 3
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| Subject: | Re: Z-19 Function |
At 12:53 AM 8/18/2014, you wrote:
><http://www.flyefii.com/customer_projects/EFII_Installation_Manual_rev9-13.pdf>http://www.flyefii.com/customer_projects/EFII_Installation_Manual_rev9-13.pdf
Hmmmm . . . These systems probably perform as advertised . . .
but the supplier has not served their customer well in
terms of system integration data. In particular, their treatment
of electrical systems architecture and failure modes is
sketchy to non-existent. The word 'fail' appears three
times . . . not in the context of a system integrator's
work instruction or pilot's operating manual . . . but of
a marketing brochure.
I went back into the series of Justin's postings . . . the first
one showed up in February of this year. It seems that by the
time he first came to the List, drawings were made, parts bought,
holes drilled and a lot of decisions already under the bridge
were being 'fine tuned'.
I am not pleased to note that this project is probably way
too complex for reasons not well defined. If the supplier
of this system has offered nothing more than the documents
cited, then he is . . . well. Suffice it to say that
if I walked into some airframe OEM attempting to sell this
hardware on no better data . . . I wouldn't get past the
purchasing agents.
Just because our airplanes are relatively unregulated and
'experimental' does not relieve any supplier of a duty
to reduce costs and risk. This is especially true when the product is
being offered to a non-professional marketplace.
I have often opined here on the List that every electrical
system . . . ESPECIALLY one with the potential for complexity
as this one . . . should start with the bus-by-bus load analysis.
This exercise starts the thinking processes that guide hardware
sizing and architecture decisions that go to the elegant (read
frugal) design.
I've been struggling with a task for a client to refine
requirements documents on a system that has already been
built. It DOES function as advertised . . . but its schematic
has the appearance of a bucket full of parts stirred
vigorously with a paint mixer until desired functionality was
achieved.
The problem I'm wrestling with is whether or not I want
to continue to pursue the task for the client. Once the
documentation is completed, do I want to sign the
author's signature line? Doing so would add my own
credential to an activity which (in my never humble
opinion) does not serve the end-user well for cost of
ownership and mitigation of risk.
Justin's project presents a similar conundrum. I'm recalling
a conversation with a builder about 20 years ago who said,
"I shielded all the wires and installed filters here, there,
and a few over there . . . what else do I need?"
I asked, "Gee, do you have a noise problem?"
"Oh no . . . I haven't flown the airplane yet."
Justin has not been well served by his suppliers
and is struggling with issues that should have
been put to bed before he made his decision to
purchase the system.
It's not clear to what advice we can offer that
would markedly refine a system that's already
built.
Justin,
One thing I gleaned from the data package:
With the exception of fuel injectors, the two systems
are entirely redundant. Should one of the systems
become unusable for any reason, including loss of
power, then the other system can be pressed into
service with no significant loss of engine performance.
The manufacturer's citation of breaker sizes tells
us NOTHING about this system's energy needs. You
would do well to approach them with questions
that go to ENERGY that moves through each breaker
and under what conditions.
I apologize for pushing this off on you . . . but
these guys need to understand the problems THEIR
customers are wrestling with. I could write and ask
for the same data . . . but I would not be surprised
if they don't really know the answers. This study
needs to start with a customer . . . and you're
the only one I know.
If inquiring minds seek to be helpful, then
it's something we need to know. If their answers
seem less than confident, suggest that they contact
me . . . or better yet, join the AeroElectric-List.
There is no better opportunity for teaching
responsible consumerism than to carry out our
conversations with the supplier in open forum.
Bob . . .
Message 4
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| Subject: | Re: Z-19 Function |
Justin,
Have you considered using Robert's Bus Manager? It allows for two
batteries, isolated for charging. Either or both batteries can be used for
starting, and there is great redundancy for power to the essential bus.
Also, it will monitor fuel pressure and automatically switch to the
auxiliary pump if pressure is lost.
Ken
On Sun, Aug 17, 2014 at 7:25 PM, Justin Jones <jmjones2000@mindspring.com>
wrote:
> Here is the link to the downloadable instruction manual.
> http://flyefii.com/customer_projects/EFII_Ignition_Instruction_sheet_rev9
-13.pdf
>
> There is a Dual ECU addendum at the end of the instructions that deal wit
h
> the installation of the dual ECUs. Through numerous emails that I have
> exchanged with Robert, I have learned that there the entire system (both
> ECUs and IGN coils) draws 2.4 amps. I have also learned that a single 10
A
> breaker feeds both coils. I would think the 4-diode rectifier with power
> from the engine battery bus and the main battery bus would solve the
> single-point of failure issue with a single power source. The system
> requires 5 breakers. 2- 5A breakers for the ECUs, 1- 10A breaker for the
> IGN Coils, and 2- 10A breakers for the fuel pumps (one each).
>
> The reason for installing the electrically dependent system is for the
> performance gains and the flexibility of using MOGAS. The system draws
> very little current, and WHEN the alternator fails (and it will at some
> point), the pilot will be notified (low voltage and low amperage warnings
).
> At this point the pilot must shed the loads to protect the remaining
> battery power. The EFII system will run as low as 6 volts. I feel that
> with a dual battery system and a way to isolate the batteries from each
> other during flight, a higher level of safety is achieved. The pilot wou
ld
> simply isolate the batteries and shut off all items that are drawing a lo
ad
> from that battery bus. When and if the primary battery=99s voltage
gets too
> low, the pilot simply switches to the other battery and lands as soon as
> POSSIBLE.
>
> The challenge is to engineer a reliable and redundant 12V system that wil
l
> allow for safe and reliable operation regardless of individual component,
> complete bus, or even power source failure.
>
> Any thoughts and tips are much appreciated. I have some experience in
> 12VDC systems but am by no means an engineer.
>
> Thanks again for the help!
>
> Justin
>
>
> On Aug 17, 2014, at 12:02 PM, Robert L. Nuckolls, III <
> nuckolls.bob@aeroelectric.com> wrote:
>
> The system requires that both ECUs and both IGN coils are powered all th
e
> time . . .
>
> Okay, suppose one of these four items doesn't get power
> while the other three do . . . what happens?
>
> Suppose half of the system ECU and IGN get a momentary
> power interruption, what happens?
>
> Suppose there's complete interruption of power to all
> engine support which is 'fixed' in a few seconds,
> what happens?
>
> The legacy design philosophy we've applied to all
> systems intended for use in unforgiving environments
> is the failure mode effects analysis. FMEA looks at
> every component of the system and asks:
>
>
> *How can this part fail? *
> *If it does fail, how will I become aware of it? **If not immediately
> noticed or annunciated by *
> *warning system, is it pre-flight detectable? **If it does fail, how is
> probable outcome of *
> *the flight affected? **If it is necessary for comfortable continuation *
>
> *of flight, what are my alternatives?* Here's my personal notions that
> go to the topic
> of system reliability
>
> *Nuckolls' first law of airplane systems design sez:* "Things break" *
The
> second:* "Systems shall be designed so that when things break, no
> immediate hazard is created." *The third:* "Failure tolerant design
> dictates that items needed for comfortable termination of flight are
> backed up with Plan-B alternatives." *The forth:* "Upgrading the
> quality, reliability, longevity, or capability of a part shall be because
> you're tired of replacing it or want some new operating feature, not
> because it damned near got you killed."
>
> Before you march off to craft a never fails power
> source(s) . . . it seems prudent to ASSUME there
> WILL be failures . . . and craft a system that is
> comfortably tolerant of such failures.
>
> Your query to the List cited an imperative for everything
> that supports engine operations to be powered at all
> times . . . if this is strictly true, then are you
> sure that you want to install it on your airplane?
>
>
> Bob . . .
>
> *
>
> href="http://www.matronics.com/Navigator?AeroElectric-List <http://www.
matronics.com/Navigator?AeroElectric-List>">http://www.matronics.com/Naviga
tor?AeroElectric-List <http://www.matronics.com/Navigator?AeroElectric-List
>
> href="http://forums.matronics.com/ <http://forums.matronics.com/>">http
://forums.matronics.com <http://forums.matronics.com>
> href="http://www.matronics.com/contribution <http://www.matronics.com/c
ontribution>">http://www.matronics.com/contribution <http://www.matronics.c
om/contribution>
>
> *
>
>
> *
>
===========
www.matronics.com/Navigator?AeroElectric-List>
===========
===========
om/contribution>
===========
>
> *
>
>
Message 5
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| Subject: | Re: Z-19 Function |
Bob,
I appreciate your help and opinion with this matter. I will approach
Robert about this and find out the specifics of the electrical demands
of his system. I have heard great things about his customer service and
the folks using his system in their running aircraft have nothing but
great things to say about it and him. He is a very knowledgable A&P and
has deep knowledge of his system.
Thank you again.
Justin
On Aug 18, 2014, at 5:59 AM, Robert L. Nuckolls, III
<nuckolls.bob@aeroelectric.com> wrote:
> At 12:53 AM 8/18/2014, you wrote:
>
>>
http://www.flyefii.com/customer_projects/EFII_Installation_Manual_rev9-13.
pdf
>
> Hmmmm . . . These systems probably perform as advertised . . .
> but the supplier has not served their customer well in
> terms of system integration data. In particular, their treatment
> of electrical systems architecture and failure modes is
> sketchy to non-existent. The word 'fail' appears three
> times . . . not in the context of a system integrator's
> work instruction or pilot's operating manual . . . but of
> a marketing brochure.
>
> I went back into the series of Justin's postings . . . the first
> one showed up in February of this year. It seems that by the
> time he first came to the List, drawings were made, parts bought,
> holes drilled and a lot of decisions already under the bridge
> were being 'fine tuned'.
>
> I am not pleased to note that this project is probably way
> too complex for reasons not well defined. If the supplier
> of this system has offered nothing more than the documents
> cited, then he is . . . well. Suffice it to say that
> if I walked into some airframe OEM attempting to sell this
> hardware on no better data . . . I wouldn't get past the
> purchasing agents.
>
> Just because our airplanes are relatively unregulated and
> 'experimental' does not relieve any supplier of a duty
> to reduce costs and risk. This is especially true when the product
is
> being offered to a non-professional marketplace.
>
> I have often opined here on the List that every electrical
> system . . . ESPECIALLY one with the potential for complexity
> as this one . . . should start with the bus-by-bus load analysis.
> This exercise starts the thinking processes that guide hardware
> sizing and architecture decisions that go to the elegant (read
> frugal) design.
>
> I've been struggling with a task for a client to refine
> requirements documents on a system that has already been
> built. It DOES function as advertised . . . but its schematic
> has the appearance of a bucket full of parts stirred
> vigorously with a paint mixer until desired functionality was
> achieved.
>
> The problem I'm wrestling with is whether or not I want
> to continue to pursue the task for the client. Once the
> documentation is completed, do I want to sign the
> author's signature line? Doing so would add my own
> credential to an activity which (in my never humble
> opinion) does not serve the end-user well for cost of
> ownership and mitigation of risk.
>
> Justin's project presents a similar conundrum. I'm recalling
> a conversation with a builder about 20 years ago who said,
> "I shielded all the wires and installed filters here, there,
> and a few over there . . . what else do I need?"
>
> I asked, "Gee, do you have a noise problem?"
>
> "Oh no . . . I haven't flown the airplane yet."
>
> Justin has not been well served by his suppliers
> and is struggling with issues that should have
> been put to bed before he made his decision to
> purchase the system.
>
> It's not clear to what advice we can offer that
> would markedly refine a system that's already
> built.
>
> Justin,
>
> One thing I gleaned from the data package:
> With the exception of fuel injectors, the two systems
> are entirely redundant. Should one of the systems
> become unusable for any reason, including loss of
> power, then the other system can be pressed into
> service with no significant loss of engine performance.
>
> The manufacturer's citation of breaker sizes tells
> us NOTHING about this system's energy needs. You
> would do well to approach them with questions
> that go to ENERGY that moves through each breaker
> and under what conditions.
>
> I apologize for pushing this off on you . . . but
> these guys need to understand the problems THEIR
> customers are wrestling with. I could write and ask
> for the same data . . . but I would not be surprised
> if they don't really know the answers. This study
> needs to start with a customer . . . and you're
> the only one I know.
>
> If inquiring minds seek to be helpful, then
> it's something we need to know. If their answers
> seem less than confident, suggest that they contact
> me . . . or better yet, join the AeroElectric-List.
> There is no better opportunity for teaching
> responsible consumerism than to carry out our
> conversations with the supplier in open forum.
>
> Bob . . .
>
>
>
>
Message 6
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| Subject: | Re: Z-19 Function |
Ken,
I have considered using it. I am left wondering if his system has the
same functions of Bob=92s Z-19 diagram, and his other diagrams for
electrically dependent engines. If it does (and it seems to) it seems
that it would be an added cost for no good reason.
Here is the link to the Bus Manager Installation instructions.
http://flyefii.com/bus_manager/Bus_Manager_Installation_Instructions.pdf
Maybe Bob can weigh in on the Bus Manager?
Thanks
Justin
On Aug 18, 2014, at 9:09 AM, Ken Ryan <keninalaska@gmail.com> wrote:
> Justin,
>
> Have you considered using Robert's Bus Manager? It allows for two
batteries, isolated for charging. Either or both batteries can be used
for starting, and there is great redundancy for power to the essential
bus. Also, it will monitor fuel pressure and automatically switch to the
auxiliary pump if pressure is lost.
>
> Ken
>
>
> On Sun, Aug 17, 2014 at 7:25 PM, Justin Jones
<jmjones2000@mindspring.com> wrote:
> Here is the link to the downloadable instruction manual.
http://flyefii.com/customer_projects/EFII_Ignition_Instruction_sheet_rev9-
13.pdf
>
> There is a Dual ECU addendum at the end of the instructions that deal
with the installation of the dual ECUs. Through numerous emails that I
have exchanged with Robert, I have learned that there the entire system
(both ECUs and IGN coils) draws 2.4 amps. I have also learned that a
single 10A breaker feeds both coils. I would think the 4-diode
rectifier with power from the engine battery bus and the main battery
bus would solve the single-point of failure issue with a single power
source. The system requires 5 breakers. 2- 5A breakers for the ECUs, 1-
10A breaker for the IGN Coils, and 2- 10A breakers for the fuel pumps
(one each).
>
> The reason for installing the electrically dependent system is for the
performance gains and the flexibility of using MOGAS. The system draws
very little current, and WHEN the alternator fails (and it will at some
point), the pilot will be notified (low voltage and low amperage
warnings). At this point the pilot must shed the loads to protect the
remaining battery power. The EFII system will run as low as 6 volts. I
feel that with a dual battery system and a way to isolate the batteries
from each other during flight, a higher level of safety is achieved.
The pilot would simply isolate the batteries and shut off all items that
are drawing a load from that battery bus. When and if the primary
battery=92s voltage gets too low, the pilot simply switches to the other
battery and lands as soon as POSSIBLE.
>
> The challenge is to engineer a reliable and redundant 12V system that
will allow for safe and reliable operation regardless of individual
component, complete bus, or even power source failure.
>
> Any thoughts and tips are much appreciated. I have some experience in
12VDC systems but am by no means an engineer.
>
> Thanks again for the help!
>
> Justin
>
>
> On Aug 17, 2014, at 12:02 PM, Robert L. Nuckolls, III
<nuckolls.bob@aeroelectric.com> wrote:
>
>> The system requires that both ECUs and both IGN coils are powered all
the time . . .
>>
>> Okay, suppose one of these four items doesn't get power
>> while the other three do . . . what happens?
>>
>> Suppose half of the system ECU and IGN get a momentary
>> power interruption, what happens?
>>
>> Suppose there's complete interruption of power to all
>> engine support which is 'fixed' in a few seconds,
>> what happens?
>>
>> The legacy design philosophy we've applied to all
>> systems intended for use in unforgiving environments
>> is the failure mode effects analysis. FMEA looks at
>> every component of the system and asks:
>>
>> How can this part fail?
>> If it does fail, how will I become aware of it?
>> If not immediately noticed or annunciated by
>> warning system, is it pre-flight detectable?
>> If it does fail, how is probable outcome of
>> the flight affected?
>> If it is necessary for comfortable continuation
>> of flight, what are my alternatives?
>>
>> Here's my personal notions that go to the topic
>> of system reliability
>>
>> Nuckolls' first law of airplane systems design sez: "Things break"
>>
>> The second: "Systems shall be designed so that when things break, no
immediate hazard is created."
>>
>> The third: "Failure tolerant design dictates that items needed for
>> comfortable termination of flight are backed up with Plan-B
alternatives."
>>
>> The forth: "Upgrading the quality, reliability, longevity, or
>> capability of a part shall be because you're tired of replacing it
>> or want some new operating feature, not because it damned near
>> got you killed."
>>
>> Before you march off to craft a never fails power
>> source(s) . . . it seems prudent to ASSUME there
>> WILL be failures . . . and craft a system that is
>> comfortably tolerant of such failures.
>>
>> Your query to the List cited an imperative for everything
>> that supports engine operations to be powered at all
>> times . . . if this is strictly true, then are you
>> sure that you want to install it on your airplane?
>>
>>
>>
>> Bob . . .
>>
>>
>>
>>
href="http://www.matronics.com/Navigator?AeroElectric-List">http://www.m
atronics.com/Navigator?AeroElectric-List
>> href="http://forums.matronics.com/">http://forums.matronics.com
>>
href="http://www.matronics.com/contribution">http://www.matronics.com/co
ntribution
>>
>
>
>
> ist"
target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
> tp://forums.matronics.com
> _blank">http://www.matronics.com/contribution
>
>
>
>
>
Message 7
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| Subject: | Re: Z-19 Function |
Justin,=0A=0ASomeone mentioned the Bus Manager product. I am not privy to i
ts design but that same functionality is provided in the system design that
I posted, except for the fuel pump management.=0A=0A-Jeff=0A=0A=0A=0AOn Mo
nday, August 18, 2014 10:56 AM, Justin Jones <jmjones2000@mindspring.com> w
rote:=0A =0A=0A=0ABob,=0A=0AI appreciate your help and opinion with this ma
tter. -I will approach Robert about this and find out the specifics of th
e electrical demands of his system. -I have heard great things about his
customer service and the folks using his system in their running aircraft h
ave nothing but great things to say about it and him. -He is a very knowl
edgable A&P and has deep knowledge of his system.=0A=0AThank you again.=0A
=0AJustin-=0A=0A=0A=0AOn Aug 18, 2014, at 5:59 AM, Robert L. Nuckolls, II
I <nuckolls.bob@aeroelectric.com> wrote:=0A=0AAt 12:53 AM 8/18/2014, you wr
ote:=0A>=0A>=0A>http://www.flyefii.com/customer_projects/EFII_Installation_
Manual_rev9-13.pdf =0A>-- Hmmmm . . . These systems probably perform as
advertised . .=0A.=0A>-- but the supplier has not served their custome
r well in=0A>-- terms of system integration data. In particular, their
=0Atreatment=0A>-- of electrical systems architecture and failure modes
is=0A>-- sketchy to non-existent. The word 'fail' appears three=0A>-
- times . . . not in the context of a system integrator's=0A>-- work
instruction or pilot's operating manual . . . but=0Aof=0A>-- a marketin
g brochure. =0A>=0A>-- I went back into the series of Justin's postings
. . . the=0Afirst=0A>-- one showed up in February of this year. It see
ms that by=0Athe=0A>-- time he first came to the List, drawings were ma
de, parts=0Abought,=0A>-- holes drilled and a lot of decisions already
under the=0Abridge=0A>-- were being 'fine tuned'.=0A>=0A>-- I am no
t pleased to note that this project is probably=0Away=0A>-- too complex
for reasons not well defined. If the=0Asupplier=0A>-- of this system h
as offered nothing more than the=0Adocuments=0A>-- cited, then he is .
. . well. Suffice it to say that=0A>-- if I walked into some airframe O
EM attempting to sell=0Athis=0A>-- hardware on no better data . . . I w
ouldn't get past=0Athe=0A>-- purchasing agents.=0A>=0A>-- Just beca
use our airplanes are relatively unregulated=0Aand=0A>-- 'experimental'
does not relieve any supplier of a duty=0A>-- to reduce costs and risk
. This is especially true when the=0Aproduct is=0A>-- being offered to
a non-professional marketplace.=0A>=0A>-- I have often opined here on t
he List that every=0Aelectrical=0A>-- system . . . ESPECIALLY one with
the potential for=0Acomplexity=0A>-- as this one . . . should start wit
h the bus-by-bus load=0Aanalysis.=0A>-- This exercise starts the thinki
ng processes that guide=0Ahardware=0A>-- sizing and architecture decisi
ons that go to the elegant=0A(read=0A>-- frugal) design.=0A>=0A>--
I've been struggling with a task for a client to refine=0A>-- requireme
nts documents on a system that has already=0Abeen=0A>-- built. It DOES
function as advertised . . . but its=0Aschematic=0A>-- has the appearan
ce of a bucket full of parts stirred=0A>-- vigorously with a paint mixe
r until desired functionality=0Awas=0A>-- achieved.=0A>=0A>-- The p
roblem I'm wrestling with is whether or not I want=0A>-- to continue to
pursue the task for the client. Once the=0A>-- documentation is comple
ted, do I want to sign the=0A>-- author's signature line? Doing so woul
d add my own=0A>-- credential to an activity which (in my never humble
=0A>-- opinion) does not serve the end-user well for cost of=0A>--
ownership and mitigation of risk.=0A>=0A>-- Justin's project presents a
similar conundrum. I'm=0Arecalling=0A>-- a conversation with a builder
about 20 years ago who=0Asaid,=0A>-- "I shielded all the wires and ins
talled filters here,=0Athere,=0A>-- and a few over there . . . what els
e do I=0Aneed?"=0A>=0A>-- I asked, "Gee, do you have a noise=0Aproblem?
"=0A>=0A>-- "Oh no . . . I haven't flown the airplane=0Ayet."=0A>=0A>
-- Justin has not been well served by his suppliers=0A>-- and is st
ruggling with issues that should have=0A>-- been put to bed before he m
ade his decision to=0A>-- purchase the system.=0A>=0A>-- It's not c
lear to what advice we can offer that=0A>-- would markedly refine a sys
tem that's already=0A>-- built.=0A>=0A>-- Justin, =0A>=0A>-- On
e thing I gleaned from the data package: =0A>-- With the exception of f
uel injectors, the two systems=0A>-- are entirely redundant. Should one
of the systems=0A>-- become unusable for any reason, including loss of
=0A>-- power, then the other system can be pressed into=0A>-- servi
ce with no significant loss of engine=0Aperformance.=0A>=0A>-- The manu
facturer's citation of breaker sizes tells=0A>-- us NOTHING about this
system's energy needs. You=0A>-- would do well to approach them with qu
estions=0A>-- that go to ENERGY that moves through each breaker=0A>-
- and under what conditions.=0A>=0A>-- I apologize for pushing this o
ff on you . . . but=0A>-- these guys need to understand the problems TH
EIR=0A>-- customers are wrestling with. I could write and ask=0A>--
for the same data . . . but I would not be surprised=0A>-- if they don
't really know the answers. This study=0A>-- needs to start with a cust
omer . . . and you're=0A>-- the only one I know.=0A>=0A>-- If inqui
ring minds seek to be helpful, then=0A>-- it's something we need to kno
w. If their answers=0A>-- seem less than confident, suggest that they c
ontact=0A>-- me . . . or better yet, join the AeroElectric-List.=0A>-
- There is no better opportunity for teaching =0A>-- responsible cons
umerism than to carry out our=0A>-- conversations with the supplier in
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D
Message 8
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| Subject: | Re: Z-19 Function |
At 01:49 PM 8/18/2014, you wrote:
>Justin,
>
>Someone mentioned the Bus Manager product. I am not privy to its
>design but that same functionality is provided in the system design
>that I posted, except for the fuel pump management.
>
>-Jeff
This might well be marching off in the wrong direction.
Given what I understand about the engine accessories
now, it's not clear that this installation's optimum
configuration would not be well served with Z-13/8 or
at worst, Z-12 with a 20A s/b alternator and one
battery.
Z-19 was tailored to engines that could not conveniently
drive two alternators.
Bob . . .
Message 9
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| Subject: | Real life lessons in wire ratings . . . |
Last weekend, Dr. Dee and I spent Friday/Saturday
supporting our son's shaved ice and cotton candy
business during "Old Settlers Days" in Mulvane, KS.
Temperature in upper 90s. Shaved ice trailer with
lights, rooftop a/c, freezer and shaved ice machine
running on ac mains through 100', 12AWG extension
cord not unlike that pictured below. Total current
draw on the order of 13 amps.
Emacs!
Approximately 70' of cord was spooled out leaving about
30' still coiled on the reel. After 3 or 4 hours operation,
a vendor on the row behind us asked if that 'smoke and
bad smell' was something to be concerned about.
I swapped out the smoking cord for a spare.
I un-spooled the rest of the cord and discovered that
when not allowed the benefits of cooling air, the wrapped
up coils got pretty hot. The cord that was spooled out
was warmer than ambient but not markedly so. Voltage
at plug end under load was 124 volts . . . inside trailer
it was 117 volts for a round trip drop of about 7 volts.
Nonetheless, insulation on the poorly cooled wires
inside the yellow jacket fused together. In some places
the yellow jacket was breached and/or fused to adjacent
turns.
This cord reel is designed to encourage rolling out only
that cordage which is needed . . . but if you're going
to load it to near max ratings, then it's a good idea
to un-spool the entire length.
A profound demonstration of how temp rise on
a wire is exacerbated by constriction of free air cooling.
I cut off the damaged 30', installed a new plug and
left the full in-service length of cord laid out on
the ground for the rest of the event. Voltage drop
went down to just over 5 volts on the shortened cord.
Bob . . .
Message 10
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| Subject: | Dynon D-180 & flickering LEDs |
I have been corresponding with a RV-12 owner in TX. His Dynon D-180 has a problem with LEDs that flicker when they should be on steady. The D-180 supplies negative PWM voltage to LEDs which are external to the D-180. Download the D-180 Installation Manual http://www.dynonavionics.com/downloads/Install_Guides/FlightDEK-D180_Installation_Guide_Rev_H.pdf
and read about "External EMS Warning Light" on page 4-10. The aircraft owner did
some experiments. Here are the results:
With the engine off and the D-180 powered by the aircraft battery, the LEDs are
on steady. With the engine running, the LEDs flicker. With the engine still
running, if the avionics switch is shut off, the D-180 reverts to its internal
backup battery and the LEDs illuminate steadily. Engine still running and the
avionics switch is turned back on, the LEDs flicker again. This experiment
was repeated and the results are consistent. From these experiments I conclude
that the D-180 puts out a steady PWM voltage when operating on battery power
(whether aircraft battery or internal backup battery). And when operating off
the alternator, the D-180 puts out an intermittent PWM voltage which causes
LED flicker.
With the engine running, the D-180 indicates a system voltage of 13.7 which is
normal for RV-12s. All E-LSA RV-12s have a 22,000 microfarad capacitor connected
to the output of the Rotax rectifier/regualtor. If that capacitor is bad,
could that cause the D-180 to output an unsteady PWM voltage to the the LEDs?
Or should the D-180 be able to function even if the aircraft electrical power
is dirty and not pure DC?
Thanks, Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=428713#428713
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