|
|
Thanks, Bob
George - what Bob says. AeroElectric has good information and some good
products. The only thing I've really disagreed with Bob K is regarding
fuses vs circuit breakers. I favor Circuit breakers for all critical items,
but use fuses for non-critical, Bob K (AeroElectric) favors fuses for
everything. He makes a good case, but in my 2000 + hours of flying in the
military - I found numerous occasions where resetting a circuit breaker
returned power. Not every time by any means, but often enough to make me
prefer circuit breakers - resetting a circuit breaker may (or may not) help,
but try resetting a fuse {:>)
Ed
Ed Anderson
Rv-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com
http://www.andersonee.com
http://www.dmack.net/mazda/index.html
http://www.flyrotary.com/
http://members.cox.net/rogersda/rotary/configs.htm#N494BW
http://www.rotaryaviation.com/Rotorhead%20Truth.htm
-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Bob White
Sent: Friday, June 05, 2009 6:17 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Ed's Electrical System was Incident 5119
Hi George,
I'm not Ed, but what the heck.
http://www.matronics.com/Navigator/?AeroElectric-List to subscribe to
the AeroElectric list. You will get 20 - 30 messages per day.
http://www.aeroelectric.com/ is Bob's web site (It' really Bob N.)
Click on "Catalog of Products" to order his book and other stuff.
Bob knows his stuff. (Like Ed I prefer circuit breakers though.) Bob
is great at explaining his reasons for everything he says.
Bob W.
On Sat, 6 Jun 2009 07:39:40 +1000
"George Lendich" <lendich@aanet.com.au> wrote:
>
> Ed,
> Where do I find info on Bob K and the electronics mentioned?
> George (down under)
>
>
> Thanks, Bill
>
>
>
> Well, no doubt pot-shots will be taken by some, but for the most part,
folks are appreciative to have the facts (as best I know them) as it could
possibly happen to them - or some variation. Back when I first got started
(1992), I really did not know Bob K and his deserved reputation. In fact,
because of his view about fuses vs Circuit breakers - which I disagreed with
him about at least for crucial systems - may have influence my assessment of
his excellent wiring diagrams.
>
>
>
> You are correct about the alternator; I was somewhat surprised when I
discovered that once my alternator (auto) starts producing voltage, pulling
the field coil circuit breaker does not shut down the alternator. So your
suggestion to use a modified one makes good sense.
>
>
>
> I always say you "..Live and learn - provided you live!.." I am always
prepared to learn from my mistakes. So far I haven't committed the same one
twice.
>
>
>
> In any case, if my "full disclosure" reporting precludes even one person
from experiencing such excitement and leaves me with my "glider time" record
intact - that is payback enough {:>).
>
>
>
> Ed
>
>
>
> Ed Anderson
>
> Rv-6A N494BW Rotary Powered
>
> Matthews, NC
>
> eanderson@carolina.rr.com
>
> http://www.andersonee.com
>
> http://www.dmack.net/mazda/index.html
>
> http://www.flyrotary.com/
>
> http://members.cox.net/rogersda/rotary/configs.htm#N494BW
>
> http://www.rotaryaviation.com/Rotorhead%20Truth.htm
>
>
>
----------------------------------------------------------------------------
--
>
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of Ed Anderson
> Sent: Friday, June 05, 2009 2:04 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Ed's Electrical System was Incident 5119
>
>
>
> Hi David,
>
>
>
> You ever hear that old saying ".it seemed like a good idea at the time."
? {:>) I agree that Bob's stuff is a good place to start. I also realized
exactly what you point out. While I could isolate my battery from a failed
(or good for that matter {:>)) alternator - with my design, I could do
nothing to isolate my essential bus from a bad battery. The only reason I
can give you (10+ years later) is that I apparently viewed the alternator as
the likely cause of a problem, since I swap my batteries out every two
years. But, clearly a new battery short - an open circuit would not likely
pose a real problem - an no essential bus power.
>
>
>
> Along those same lines of thinking, is probably why I had the battery
voltage holding the master relay closed.
>
>
>
> Clearly pilot played major role in this incident from one 10 year point
to the next 10 year point.
>
>
>
>
>
> Regarding the "fancy" voltmeter switch, at the time since I had two
batteries and an alternator, it seemed like a good idea to be able to know
the state of the three power devices. Having it just to the main circuit
did not seem to provide any information on the voltage state of each
battery. I like, it did not case the problem, so I'll leave it in there.
No amp meter.
>
>
>
> I agree there is some rewiring in the very near future. I do find it
sort of Ironic that the very thing I put in to permit me to have sufficient
time (battery time) to get to an airfield - showed that it could do just
that {:>). The two year old 17AH battery showed it could easily provide 30
minutes of quality voltage. It did not start to get really nasty until
approx 50 minutes after launch (with two EFI and boost pumps running - I
turn one EFI and boost pump off at cruise altitude).
>
>
>
> Past 50 minutes, things were clearly going to Hades in a hand basket,
my EFISM showed the EC2 was still sending the correct pulse duration to
injectors (based on my fuel flow reading), however, there was simply not
enough voltage/power to pull the injectors completely open or for long
enough. All in all I was pleased how long things did stay functional.
Based on the measured voltage later on the ground (where it might have a
chance to recovery some) the battery was reading six volts. So things
probably continue to work/more or less down to around 7-8 volts.
>
>
>
>
>
> Some good suggestions David. One of the reasons for providing these
incidents is so that folks can learn from them (self included).
>
>
>
> Ed
>
>
>
> Ed Anderson
>
> Rv-6A N494BW Rotary Powered
>
> Matthews, NC
>
> eanderson@carolina.rr.com
>
> http://www.andersonee.com
>
> http://www.dmack.net/mazda/index.html
>
> http://www.flyrotary.com/
>
> http://members.cox.net/rogersda/rotary/configs.htm#N494BW
>
> http://www.rotaryaviation.com/Rotorhead%20Truth.htm
>
>
>
----------------------------------------------------------------------------
--
>
> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On
Behalf Of David Leonard
> Sent: Friday, June 05, 2009 1:03 PM
> To: Rotary motors in aircraft
> Subject: [FlyRotary] Re: Ed's Electrical System was Incident 5119
>
>
>
> Hi Ed,
>
>
>
> Great job handling the emergency! Very nice write up. I do have to
admit that you made some unusual decisions in the electrical system. None
of that stuff is new, electric Bob's advice is pretty sound. I think that
the "master" solenoid is often called the "battery" master for a reason - it
only isolates the battery. If you want to have another battery, have
another battery master that truly isolates that battery. In your system, if
either battery becomes a dead short - you have just taken out your essential
buss with no way to recover in flight! All your buses (essential or not)
should be on the other side of the 'master' solenoids. If you want to be
able to isolate the alternator, that is a separate system.
(crow-bar/solenoid/field switch/fuse link/breaker/whatever). I have come to
the opinion that sudden over-voltage that frys your avionics is exceedingly
unlikely. I have decided to only "isolate" my alternator with a fusible
link. - nice and simple that way. The alternator also connects to the buss
side of the battery master solenoids. To make one of the buses 'essential'
provide an alternate path around any perceived possible points of failure.
Batteries fail. I have seen it in cars, I'm sure you have too. Sure, it's
mostly the older type, but a good solid short across a SLA could fail it as
well.
>
>
>
> I also find it unusual that your voltmeter is not simply reading the
main buss voltage - no fancy switch. That way, you know what you are
getting, if you know what I mean. If you want to see how one or another
power source is doing, isolate the other sources from the master buss.
Lastly, what about you ammeter? Does it not measure current directly from
either the battery or the alternator?
>
>
>
> I'm not sure that a diode is the solution you are looking for. I think
what you really need is to re-do the big wires in your system altogether.
If you have settled on a one-battery system, get rid of all that extra
weight and do it according to the book. From what I know, you would use a
diode to 1) re-route field decay spikes back to the battery, or 2) provide
alternate path from a battery to an essential (always hot) buss. (i.e. If
you wanted to use a diodes, your essential buss would be connected to the
other side of the master contactors via diodes, and you would use a diode
from each battery to the essential buss.) So at a minimum you would want 2
diodes, one from the alternator and another from your single battery to the
essential buss.
>
>
>
> I know you are a WAY better gEEk than me (i cant even spell AC). So I
suspect that you already know what I am saying and you just need a kick in
the arse to bite the bullet and re-do the system.
>
>
>
> Highest regards as always,
>
>
>
> --
> David Leonard
>
> Turbo Rotary RV-6 N4VY
> http://N4VY.RotaryRoster.net
> http://RotaryRoster.net
>
> On Fri, Jun 5, 2009 at 4:47 AM, Ed Anderson <eanderson@carolina.rr.com>
wrote:
>
>
>
> Jim Maher was kind enough to convert the large DXF files of my
electrical
> system to JPG so perhaps more of you can examine it. Recall I have
removed
> the 2nd battery stuff - so ignore that on the diagrams. Also the
diagram
> does not show any of the detailed EC2/injector/ignition wiring - follow
> Tracy's recommendations on that.
>
> As you will note there is no "isolation" diode between alternator and
> battery and also that the battery voltage holds the master relay closed.
> That is another change I must make. I must have decided (10+ years ago)
> that the battery would never fail - only the alternator. Clearly (now),
> without battery voltage (in my design) to hold the master relay closed
-
> when the battery voltage fall to around 6-7 volts (in my case) the relay
> opens and all that good electrical power being produced by the perfectly
> good alternator - can not reach any part of the electrical system.
Clearly
> NOT good as I could have continued to fly perfectly well with just the
> alternator juice.
>
> Your design is not going to be any better than the accuracy of your
> assumptions. Clearly some of my assumptions make 10 years ago
definitely
> need revising.
>
> Ed
>
>
> The message is ready to be sent with the following file or link
attachments:
>
> DIAG_3B.jpg
> DIAG_2B.jpg
> DIAG_1B.jpg
>
>
> Note: To protect against computer viruses, e-mail programs may prevent
> sending or receiving certain types of file attachments. Check your
e-mail
> security settings to determine how attachments are handled.
>
>
> __________ Information from ESET NOD32 Antivirus, version of virus
signature
> database 3267 (20080714) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
>
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html
>
>
>
>
>
>
>
>
>
> __________ Information from ESET NOD32 Antivirus, version of virus
signature database 3267 (20080714) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com
>
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/
--
Homepage: http://www.flyrotary.com/
Archive and UnSub:
http://mail.lancaironline.net:81/lists/flyrotary/List.html
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 3267 (20080714) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
|
|