Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

An Architecture Question - Z13

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List
View previous topic :: View next topic  
Author Message
trichmond(at)obermeyer.co
Guest





PostPosted: Fri Feb 24, 2006 7:11 am    Post subject: An Architecture Question - Z13 Reply with quote

All,



I have been reading the AeroElectric posts for several weeks now and find
the forum extremely useful as I begin designing the electrical system for my
RV-7A (that and re-reading the AeroElectric Connection several times). I am
planning an all electric airplane based on the Grand Rapids EFIS/EIS system,
Garmin 430, E-Mag / P-Mag combo and all the other little gizmos I can fit
(afford). At this point, I'm basing my architecture on the Z-13 with a 60
Amp alternator and SD-20 auxiliary alternator.



So my first question is this. do I need an e-bus? The only reason I can
figure is that without the e-bus, the master battery contactor becomes a
single point of failure. If true, could I simply wire two battery
contactors in parallel and run them via a 2-10 switch? To me the advantage
of this approach is that in case of an alternator failure, I can simply
switch to the auxiliary alternator and systematically reduce my loads until
the alternator is picking up the full load without worrying what is attached
to each bus.



My second question is would it make sense to wire both alternators to a DP3T
switch? My thought being that this approach ensures only one alternator may
be operating at a time and thus would prevent them from inadvertently
fighting one another.



Any input is gratefully appreciated.



Todd R. Richmond

RV-7A Wings

<mailto:trichmond(at)obermeyer.com> trichmond(at)obermeyer.com


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
frank.hinde(at)hp.com
Guest





PostPosted: Fri Feb 24, 2006 7:42 am    Post subject: An Architecture Question - Z13 Reply with quote

Remember switches fail too and if I read your proposal correctly you
have mentioned two additional points of failure in your design...I
would'nt do it put it that way.

If you look at Bobs Z figures you will see that single points of failure
are not an issue, the back fed e bus is quite elaegant in this regard.

Frank

--


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
BigD(at)DaveMorris.com
Guest





PostPosted: Fri Feb 24, 2006 8:36 am    Post subject: An Architecture Question - Z13 Reply with quote

If I understand your point correctly, you probably should think through the
scenario wherein you would feel comfortable doing that level of detective
work in a potentially busy cockpit. The beauty of the e-bus is that you
just flip a switch (or it gets flipped for you), and then you have a known
quantity of time remaining before you need to think about landing. No
systematic reduction of things, no long division in your head, no thinking
required. Just flip the switch and go to Plan B.

Dave Morris

At 09:09 AM 2/24/2006, you wrote:
Quote:
in case of an alternator failure, I can simply
switch to the auxiliary alternator and systematically reduce my loads until
the alternator is picking up the full load without worrying what is attached
to each bus.


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
nuckollsr(at)cox.net
Guest





PostPosted: Fri Feb 24, 2006 9:54 am    Post subject: An Architecture Question - Z13 Reply with quote

At 08:09 AM 2/24/2006 -0700, you wrote:

Quote:

<trichmond(at)obermeyer.com>

All,

I have been reading the AeroElectric posts for several weeks now and find
the forum extremely useful as I begin designing the electrical system for my
RV-7A (that and re-reading the AeroElectric Connection several times). I am
planning an all electric airplane based on the Grand Rapids EFIS/EIS system,
Garmin 430, E-Mag / P-Mag combo and all the other little gizmos I can fit
(afford). At this point, I'm basing my architecture on the Z-13 with a 60
Amp alternator and SD-20 auxiliary alternator.

Why so much snort? 'lectric toe heaters? Hot prop? Air conditioning?
Where does Z-13/8 fall short of your requirements for operational power?
Quote:


So my first question is this. do I need an e-bus? The only reason I can
figure is that without the e-bus, the master battery contactor becomes a
single point of failure. If true, could I simply wire two battery
contactors in parallel and run them via a 2-10 switch? To me the advantage
of this approach is that in case of an alternator failure, I can simply
switch to the auxiliary alternator and systematically reduce my loads until
the alternator is picking up the full load without worrying what is attached
to each bus.

It would be presumptuous of us to tell you what you 'need'.
After a review of chapter 17, what are your power requirements
to continue flight sweat-free in spite of any single failure?
One should never "worry" about any aspect of operating your
electrical system. This isn't a jazz combo where one should
be prepared to improvise an impressive new rift at a moment's
notice.

EVERYTHING you might expect to encounter is 100% predictable
which includes loads, numbers and sizes of available energy
sources and combinations of sources and loads really useful
for the various phases of flight.

Quote:
My second question is would it make sense to wire both alternators to a DP3T
switch? My thought being that this approach ensures only one alternator may
be operating at a time and thus would prevent them from inadvertently
fighting one another.

Any input is gratefully appreciated.

Keep in mind that the Z-figures have been crafted over 15 years
of sifting the options. The features shown all have reasons
for their incorporation. I'll respectfully suggest that
you do a load analysis first. How much snort is necessary
for normal en-route operations, how much is necessary for
alternator-out operations and for how long. Answers to these
questions drive sizing of alternator(s) and battery(ies).

Then pick a Z-figure that seems closest to your NEEDS and
then tell us how that figure falls short of some perceived
NEED. I'm not suggesting for a moment that the z-figures are
"golden" . . . but at the same time, if any figure is deficient
in some feature that makes sense, I'd be pleased to revise the
the drawing or create a new one. That's how new figures find their
way into the book.

You are presently at the stage where it's important to know
the difference between what's needed and what's simply cool
(wanted). We wouldn't presume to tell you that what you want
shouldn't be considered either . . . but it's important that
you have those two buckets understood. A watchword of system
reliability is simplicity. Keep parts count down, avoid single
points of failure, keep operational options down (ZERO probability
of in-flight worries).

Bob . . .


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
trichmond(at)obermeyer.co
Guest





PostPosted: Fri Feb 24, 2006 11:38 am    Post subject: An Architecture Question - Z13 Reply with quote

All good points, which lead to two operational questions assuming the
Z-13/8. First, I would assume that normal operations would include closing
the alternate feed switch to the e-bus, true? And second, is there a risk
of damage should the SD-8 inadvertently become activated while the primary
alternator is running?

Hopefully these aren't ignorant questions. Thanks.

Todd R. Richmond
trichmond(at)obermeyer.com

--


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
armywrights(at)adelphia.n
Guest





PostPosted: Fri Feb 24, 2006 7:19 pm    Post subject: An Architecture Question - Z13 Reply with quote

A thought I keep having during these double alternator discussions is:
What's wrong with having two alternators online at the same time, with the
standby set to a volt less than the main? The standby would only then
support the load of the bus it's attached to if the main went offline (this
assumes that a "nonessential" bus goes away automatically when the main alt
fails).

Rob

--


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
endspeed(at)yahoo.com
Guest





PostPosted: Fri Feb 24, 2006 8:45 pm    Post subject: An Architecture Question - Z13 Reply with quote

Todd,
In regards to the e-bus question, it is not just to
protect against a contactor failure. Let me
illustrate this with a real live incident that
happened to a roommate of mine. Picture being IFR in
solid clag when you smell smoke and see thick smoke
instantly start billowing from under the bottom of
your instrument panel. A quick flip to off with the
master switch makes the smoke start to lessen. Now,
you have no radios working though your radio stack is
probably o.k. Your electrical system is now caput.
Nada, zilch. Now remember you are in the clag. What
will you do? At any rate, with the e-bus, you turn
off the master and then energize the e-bus to maintain
whatever you have determined is required for safety of
flight in your flight regime. If it is IFR I would
have one navcom with an ils hopefully still available.
You get the gist and this really did happen. The guy
did get the rental aircraft down safely but he was a
real solid CFI II MEI and you name it he had it for a
rating. More importantly he was proficient. I prefer
the e-bus method to avoid this superior display of
airmanship.

Take care.
Bob Sultzbach

Quote:
I have been reading the AeroElectric posts for
several weeks now and find
the forum extremely useful as I begin designing the
electrical system for my
RV-7A (that and re-reading the AeroElectric
Connection several times). I am
planning an all electric airplane based on the Grand
Rapids EFIS/EIS system,
Garmin 430, E-Mag / P-Mag combo and all the other
little gizmos I can fit
(afford). At this point, I'm basing my architecture
on the Z-13 with a 60
Amp alternator and SD-20 auxiliary alternator.



So my first question is this. do I need an e-bus?
The only reason I can
figure is that without the e-bus, the master battery
contactor becomes a
single point of failure. If true, could I simply
wire two battery
contactors in parallel and run them via a 2-10
switch? To me the advantage
of this approach is that in case of an alternator
failure, I can simply
switch to the auxiliary alternator and
systematically reduce my loads until
the alternator is picking up the full load without
worrying what is attached
to each bus.



My second question is would it make sense to wire
both alternators to a DP3T
switch? My thought being that this approach ensures
only one alternator may
be operating at a time and thus would prevent them
from inadvertently
fighting one another.



Any input is gratefully appreciated.



Todd R. Richmond

RV-7A Wings

<mailto:trichmond(at)obermeyer.com>
trichmond(at)obermeyer.com




















browse
Subscriptions page,
FAQ,
http://www.matronics.com/Navigator?AeroElectric-List

Admin.













- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
nuckollsr(at)cox.net
Guest





PostPosted: Sat Feb 25, 2006 1:39 pm    Post subject: An Architecture Question - Z13 Reply with quote

At 12:35 PM 2/24/2006 -0700, you wrote:

Quote:

<trichmond(at)obermeyer.com>

All good points, which lead to two operational questions assuming the
Z-13/8. First, I would assume that normal operations would include closing
the alternate feed switch to the e-bus, true?

No. It's crafted to be open except when needed for independent
power of goodies on the e-bus during alternator out operations in
the endurance mode.

Quote:
And second, is there a risk
of damage should the SD-8 inadvertently become activated while the primary
alternator is running?

There is no risk for damage to either alternator by having it
on line with the other alternator. Neither is there a guarantee
of performance with respect to these alternators performing in
concert with each other in some predictable sharing of loads.

Quote:
Hopefully these aren't ignorant questions. Thanks.

Not at all . . . but perhaps not very useful answers if we're ignorant
of the conditions that raised the questions. You can help us help
you by describing more of what your goals are and by sharing
the circumstances that raised your questions than by simply
posting the questions.

What caused you to believe that a 60/20 combination of engine
driven power sources was the most useful/practical? What operational
consideration raises questions in the ability of one of the Z-figures
to handle as presently configured?

Bob . . .


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
nuckollsr(at)cox.net
Guest





PostPosted: Sat Feb 25, 2006 2:36 pm    Post subject: An Architecture Question - Z13 Reply with quote

At 09:17 PM 2/24/2006 -0600, you wrote:

Quote:

<armywrights(at)adelphia.net>

A thought I keep having during these double alternator discussions is:
What's wrong with having two alternators online at the same time, with the
standby set to a volt less than the main? The standby would only then
support the load of the bus it's attached to if the main went offline (this
assumes that a "nonessential" bus goes away automatically when the main alt
fails).

Rob

Not a bit. That's what Z-12 is all about. That system is now installed
in a whole boat load of Bonanzas, big Pipers and Mooneys. If the features
illustrated in that configuration are attractive to you, there's nobody here
on the list who would discourage you from doing it. Incorporation
of automatic switching of buses is problematic. When an alternator quits,
the airplane does not immediately roll over and head for the ground
trailing black smoke. If the interval between notification of low voltage
and re-configuration of the system for plan-b operations were 60 seconds
or 120 seconds, or . . . the probable outcome of the flight is not highly
dependent on reaction to the failure.

It's seems better to have plan-b in your check list (and adequate
notification
that plan-b is now the order of the day) than to add complexity and cost of
ownership for automatic changes of configuration. Z-13/8 is, in my never
humble opinion, very cost effective and offers not only a plan-B but a
plan-C
alternative to looking for someplace very close to set down. My personal
goal
is to craft systems and ways to use them where a limit to endurance is
determined
only by fuel aboard and not on unknowns or poorly planned design and
maintenance
of an electrical system.

Read chapter 17, look over the Z-figures. If there are any perceived
short comings of any of the suggested architectures that prompt useful
changes, bring them up. There's always room for improvement.

Bob . . .


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
jetfr8t(at)hotmail.com
Guest





PostPosted: Sat Feb 25, 2006 3:02 pm    Post subject: An Architecture Question - Z13 Reply with quote

Bob,

Are you going to be at Sun'N'Fun, and if so, are you going as a spectator or
a presenter?

Craig

On the road to retirement? Check out MSN Life Events for advice on how to
get there! http://lifeevents.msn.com/category.aspx?cid=Retirement


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
nuckollsr(at)cox.net
Guest





PostPosted: Sat Feb 25, 2006 3:38 pm    Post subject: An Architecture Question - Z13 Reply with quote

At 05:02 PM 2/25/2006 -0600, you wrote:

Quote:

<jetfr8t(at)hotmail.com>


Bob,

Are you going to be at Sun'N'Fun, and if so, are you going as a spectator or
a presenter?

Craig

Sorry, I don't do the big shows any more. The cost of being there
far outweighs the revenues generated by attending. We went to OSH
a couple of years ago (the first time in about 8 years after having
been there 12-years running). It was fun, interesting, and not terribly
expensive (we had use of a hotel room that wasn't needed by an exhibitor
over the weekend).

Sun'N'Fun is a very long way from here and generated even less revenue.
I went only once. There's only so much money I can spend just to have
fun . . . I'd rather spend it on new tools (or products to buy and
evaluate).

Bob . . .

< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
scott(at)randolphs.net
Guest





PostPosted: Sat Feb 25, 2006 4:57 pm    Post subject: An Architecture Question - Z13 Reply with quote

I find myself thinking along very similar lines to Todd. I like the idea of
having options and turning off things to shed load doesn't seem like a big
problem. I've drawn up something with a 2nd master switch that engages a
2nd contactor and in it's 2nd position brings the 2nd alternator into the
system. The point about smoke in the cockpit is a good one I'll give some
though to, however. It brings up a nagging conern of my about the e-bus,
though. With my Garmin 430 drawing 3A for the GPS side and 10A for the
radio (when transmitting) it seems to me that it would blow the e-bus feed
fuse if I hit the transmit button. Now I fully realize that transmitting is
not the best way to conserve battery, but a quick word to let ATC know
what's up or even an accidental (habitual?) bump of the transmit switch
having the potential to take down what remains of my electical system
through that fuse seems scary. Just the GPS and my EFIS and my Transponder
add up to about 7.5 Amps without the transmitter! If I go to a contactor
for the e-bus feed, then it might as well be another master it seems like,
no?


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
scott(at)randolphs.net
Guest





PostPosted: Tue Feb 28, 2006 11:44 pm    Post subject: An Architecture Question - Z13 Reply with quote

Quote:
What caused you to believe that a 60/20 combination of engine
driven power sources was the most useful/practical? What operational
consideration raises questions in the ability of one of the Z-figures
to handle as presently configured?

Can't speak for Todd, but my thought pattern which arrived at a point
similar to his was:
I know that my alternator can't quite keep up with everything on while
taxing at relatively low RPM. A little extra help would be nice. I'd also
like to give the standby a little exercise as a way to ensure it's running.
If it's always in standby it would be easy for it to fail and not be noticed
-- until it was needed.


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
nuckollsr(at)cox.net
Guest





PostPosted: Wed Mar 01, 2006 6:43 am    Post subject: An Architecture Question - Z13 Reply with quote

At 11:38 PM 2/28/2006 -0800, you wrote:

Quote:


> What caused you to believe that a 60/20 combination of engine
> driven power sources was the most useful/practical? What operational
> consideration raises questions in the ability of one of the Z-figures
> to handle as presently configured?

Can't speak for Todd, but my thought pattern which arrived at a point
similar to his was:
I know that my alternator can't quite keep up with everything on while
taxing at relatively low RPM. A little extra help would be nice. I'd also
like to give the standby a little exercise as a way to ensure it's running.
If it's always in standby it would be easy for it to fail and not be noticed
-- until it was needed.

A bigger alternator doesn't automatically translate into
more snort at low rpm. If your modern, light weight
alternator is installed like B&C's with the stock 2.5" pulley
then you should be able to get nearly full output at taxi
RPMs.

Alternator sizing should be a function of your load analysis
for various cruising flight conditions. A 60/20 combo is
REALLY big, expensive and heavy comparted to 40/8. I'm not
suggesting you'll never need such capability, only that I'm
skeptical of most builder's plans to install this system without
also having evaluated system requirements in detail.

Bob . . .


- The Matronics AeroElectric-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?AeroElectric-List
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> AeroElectric-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group