Today's Message Index:
----------------------
1. 05:04 AM - Re: Dual battery, single master switch problem (Michel Therrien)
2. 11:29 AM - Re: LED as blown fuse indicator (Robert L. Nuckolls, III)
3. 07:03 PM - Re: Essential Bus Alt Feed Wire Protection (Robert L. Nuckolls, III)
4. 07:04 PM - SD-8 Feeding E-Bus (Don Boardman)
5. 07:07 PM - Re: Essential Bus Alt Feed Wire Protection (Robert L. Nuckolls, III)
6. 07:14 PM - Courtesy Light Timer (Don Boardman)
7. 07:44 PM - Re: 11051 Lesher (Robert L. Nuckolls, III)
8. 07:59 PM - Re: Buttsplice vs. Solder Heatshrink? (Robert L. Nuckolls, III)
9. 09:16 PM - Brass Instrument Screws for MicroAir avionics (Rick Fogerson)
10. 09:16 PM - Re: Courtesy Light Timer (Larry Bowen)
11. 09:25 PM - Grand Rapids EIS 4000 MAP sensor (Rick Fogerson)
12. 10:11 PM - Wire bundling for minimum avionics noise (Rick Fogerson)
13. 10:34 PM - Re: RV-List: Brass Instrument Screws for MicroAir avionics (Dan Checkoway)
14. 10:36 PM - Re: RV-List: Brass Instrument Screws for MicroAir avionics (Dan Checkoway)
Message 1
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| Subject: | Re: Dual battery, single master switch problem |
--> AeroElectric-List message posted by: Michel Therrien <mtherr@yahoo.com>
I slept on this problem last night and realized that I
already made the electrical system more complex than
it needs to be and than it is in the AeroElectric's
diagram. Instead of adding more components, I decided
to remove the split master switch and go with a pair
of toggle master switches (one DPDT for Bat1/Alt and
the other one for Bat 2).
For those who copied on my diagram, I suggest you
reflect on this too. The issue is when there is a
charged battery and a discharged battery in the system
(this could happen if you are running on the essential
bus for a long period, as an example and both
batteries don't discharge at the same rate). Then,
because the two ground side of the master relay coils
are attached together, this creates a circuits whereby
the coils can be activated, closing the master relays.
Having two separate master switches as per Bob's
diagrams eliminate this possibility.
Michel
--- Michel Therrien <mtherr@yahoo.com> wrote:
> --> AeroElectric-List message posted by: Michel
> Therrien <mtherr@yahoo.com>
>
> Bob,
>
> You may remember a while ago, I mentioned I wanted
> to
> have a single master switch to operate both
> electrical
> circuits (both contactors). I installed normally
> closed momentary switches to test the contactors
> independtly, but I use a split master switch for
> both
> contactors and for the alternator. (see diagram at
> http://pages.infinit.net/mthobby/misc/electprob.gif
> ).
>
> This evening, I found a bizzare behavior when one
> battery goes weak. It appears that when one battery
> is weak and I turn on the radio, something happens.
> At least one of the contactor closes. I think this
> is
> because the weak battery creates a closed circuit
> using the two contactor coils (which are joined at
> my
> contactor test switches).
>
> Now I see that having two separate master switches
> would resolve this problem as the two contactor
> coils
> would not be linked together.
>
> I wonder if I could also solve this problem by
> inserting diodes between the contactor coil (ground
> side) and the contactor test switch. This, I think
> would prevent the second battery from feeding the
> first contactor coil (and vice versa).
>
> Please let me know if you think this would work.
>
> Thanks!
>
> Michel
=====
----------------------------
Michel Therrien CH601-HD, C-GZGQ
http://mthobby.pcperfect.com/ch601
http://www.zenithair.com/bldrlist/profiles/mthobby
http://pages.infinit.net/mthobby
__________________________________
http://hotjobs.sweepstakes.yahoo.com/signingbonus
Message 2
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| Subject: | Re: LED as blown fuse indicator |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:31 AM 1/12/2004 -0800, you wrote:
>Bob,
>A friend has told me about using LED's as blown fuse indicators. Do you
>have any thoughts on that and would you have any hook-up info? ( What
>LED's to use & how wired)
>
>Thanks,
>Wayne Berg
This has been discussed many times on the AeroElectric List.
You can buy fuses with LED's built into them . . . but consider:
How often do you need to find/replace fuses in your car? In
your total flying experience, how often have you had to troubleshoot
a blowing breaker problem? These are such very rare events that
adding leds as a troubleshooting enhancement offers little or
no return on investment of $time$.
You can certainly do this in an experimental airplane. If
you've got time and dollars to spare it's no big deal one
way or another . . . but if you're realling wanting to get
first light under the wheels as soon as practical, I'd rather
see you spend resources on more useful activities that run
toward that goal.
Bob . . .
-----------------------------------------
( Experience and common sense cannot be )
( replaced with policy and procedures. )
( R. L. Nuckolls III )
-----------------------------------------
Message 3
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| Subject: | Re: Essential Bus Alt Feed Wire Protection |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:59 AM 1/9/2004 -0800, you wrote:
>--> AeroElectric-List message posted by: Brett Ferrell <bferrell@123mail.net>
>
>
>Quoting "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>:
>
> > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> > <bob.nuckolls@cox.net>
> > >Bob - are you recommending this in-lieu of using a switch-breaker? I'm
> >
> > >using the SD-20 for my all-electric Velocity as was planning on using a
> >
> > >20A Switchbreaker to activate the backfeed, and then take the master
> > >off-line if needed.
> >
> > We're talking about the E-Bus alternate feed being
> > a long, relatively fat wire and needing to be made-cold
> > when all switches are OFF.
> >
> > Controlling the SD-20 is another issue. I'm not sure what
> > you're proposing here. Which Z-Figure are you considering?
> >
> > Bob . . .
>
>Bob - I'm using Z12 with the SD-20 low voltage controller bringing the
>second alt online, and wire to the E-Bus is not particularly long, but it
>will be reasonably fat since I'm going to use an EFIS and all electric IFR
>instruments, so instead of the depicted switch I was going to use a switch
>breaker to control the altnerate feed source from the battery bus.
I'd use a relay at the battery bus to control any e-bus feed over 7A.
The FAA would make me do it for any feed over 5A on a certified ship.
Bob . . .
Message 4
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| Subject: | SD-8 Feeding E-Bus |
--> AeroElectric-List message posted by: Don Boardman <dboardm3@twcny.rr.com>
Hi Bob,
Hope you had fun at your weekend seminar and all went well.
In figure (Z-13) The SD-8 section shows a #12 wire running from the
regulator via the capacitor to a 701 relay. There is no need to protect this
wire?
The relay has the OVM-14 connected. No Diode needed?
The #12 wire running form the always hot side of the battery contactor up to
the relay to grab the juice from the SD-8 is protected by a #16 fuselink.
I understand why the protection. My contactor is under the co-pilot's seat,
with the battery and the battery bus, and the SD-8's relay is planned for
behind the panel. Does this leave an always hot wire protected with a #16
fuselink which would be over the 5A guideline for maximizing crash safety?
Would the following alternative routing work? In my case I think the
following would facilitate wire installation.
My alternate feed for the e-bus is via #12 wire and a 701 relay located at
the battery bus under the seat, fused at 15 amps. Instead of bringing the
#12 feed from the SD-8's 701 relay to the under seat contactor, could I
feed the system via the e-bus located behind the panel?
At the e-bus I would use a #16 fuselink or a fuse slot from the e-bus.
My thought is that the juice from the SD-8 with its "14v" would take the
following path back to the battery.
Regulator via capacitor to the relay, relay to e-bus, run back though the
#12 e-bus feed, though the feed relay to the battery bus, to the contactor
and finally to the battery. Boy the life of an electron!.
If the above works, my conclusion is, that when both Master and E-bus
switches are off in the case of a potential
$#&
%%*&
*&$
the #12 wire
from the SD-8's relay is dead along with the relayed e-bus feed from the
battery bus.
As always thank you for your time and knowledge shared,
Don B.
Message 5
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| Subject: | Re: Essential Bus Alt Feed Wire Protection |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:50 AM 1/9/2004 -0800, you wrote:
>--> AeroElectric-List message posted by: Michel Therrien <mtherr@yahoo.com>
>
>Nice! But thinking about it.... is this really
>required?
>
>What I mean is that while I was testing my electrical
>system, I used a fused battery connected to my system
>with aligator clips. Every so often, the clip
>connected to the contactor dropped in the fuselage and
>the 20-amp fuse blew away. I never noticed any noise,
>spark or damages.
>
>I cannot call that experience above anything that
>would make me an expert; so, I wonder what kind of
>failure would make the wire go hot without the fuse
>burning.
>
>I see one potential issue with my setup... the 12awg
>wire is switched behind the panel. If there would be
>a contact to ground from the e-Bus wire at the switch,
>I think it could drain a lot of current on the
>unprotected segment of wire through the main bus. (the
>wire from switch to e-Bus post is not protected from
>the e-Bus)
It's not a mater of getting wires hot for crash safety
but a matter of how big the sparks are while the airplane
is disassembling itself on the rocks. I've never been able
to find any definitive testing offered for the 5A rule . . . this
is especially curious since they don't make a distinction
between fuses and breakers on the 5A limited feeder. The
sparks downstream of the breaker are 10 to 100x bigger
than sparks from a faster fuse . . .
It's one of those things 99.9% of us will never have
to test in real life. Bottom line for OBAM aircraft
is do what ever makes YOU most comfortable.
Bob . . .
Message 6
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| Subject: | Courtesy Light Timer |
--> AeroElectric-List message posted by: Don Boardman <dboardm3@twcny.rr.com>
Hi Bob,
A while back you talked about wiring a courtesy light(s) from the battery
bus. You mentioned putting the light(s) on a timer. Great idea! Turn on the
light without switching on the master and with a timer, no fear of
accidentally leaving a light on to kill the battery.
I certainly have never done that !
#
%*&&)(+!.
At the time of the post you did not elaborate, no particulars, about the
timer itself. How would one go about incorporating such an "automatic" timer
on such a circuit?
Thanks,
Don B.
Message 7
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| Subject: | Re: 11051 Lesher |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 04:08 AM 1/8/2004 +0000, you wrote:
>Below is the result of your inquiry. It was submitted by
>Lee Lesher (leelesher@cs.com) on Wednesday, January 7, 2004 at 20:08:04
>
>Wednesday, January 7, 2004
>
>Lee Lesher
>
>,
>Email: leelesher@cs.com
>Comments/Questions: Bob,
>
>I have installed a KX-125 in my RV-8 with a Flightcom 403
>intercom. Everything works normally but when I push to talk with either
>the front or rear button The Van's ammeter pegs negatively and the
>instrument lights and the trim indicator dim. Any ideas?
>
>Thanks, Lee Lesher, Colorado Springs, CO
It sounds as if these accessories are both sensitive
to strong radio frequency energy from your transmitter . . .
which suggests further that there is an abnormal
amount of RF energy in the cockpit. I'd look for a
coax shield that has not been properly terminated
in the connector at the back of the radio tray. This
can cause your coax feedline to become an emitter
of transmitter energy into wiring behind the panel.
I will invite you to join us on the AeroElectric List
to continue this and similar discussions. It's useful to
share the information with as many folks as possible.
A further benefit can be realized with membership on
the list. . . there are lots of technically capable folks
on the list who can offer suggestions too. You can
join at . . .
http://www.matronics.com/subscribe/
Thanks!
Bob . . .
--------------------------------------------
( Knowing about a thing is different than )
( understanding it. One can know a lot )
( and still understand nothing. )
( C.F. Kettering )
--------------------------------------------
Message 8
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| Subject: | Re: Buttsplice vs. Solder Heatshrink? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 08:50 AM 1/8/2004 -0500, you wrote:
>--> AeroElectric-List message posted by: "LarryRobertHelming"
><lhelming@sigecom.net>
>
>Nothing wrong with that approach. If you have several to do, don't do them
>all at the same spot but space them out so you can later shrink over the
>whole bunch and not look like a snake that swallowed an egg. Another thing
>to consider is using the machined d-sub pins. After you put a pin on each
>joining wire, you slide a hear shrink on and shrink it down after plugging
>together. Works nice on the wires that might need to come back apart at a
>later time but costs more. But for things like the panel where there are
>lots of connections, you should consider Bob's suggestion that was posted
>yesterday of using the D-sub connector with machined pins using safety wire
>to hold the two halves together.
>
>Keep in mind solder does make a hard connection and that needs some relief
>with the heat shrink and other supports.
As do crimped joints as well. Insulation support adjacent
to the electrical joint is automatically provided by the
PIDG style terminal technology.
Raychem makes solder butt splices that depend on nothing
but solder for the mechanical and electrical connection
with the final assembly being supported by a rather stiff
cover of heatshrink for anti-flexure support.
See
http://www.raychem.com/US/datasheets/1654025_Sec_8/8-6_8-11.pdf
So, if doing this with $1.00/pop solder sleeves is a good
thing to do, I don't see why you couldn't use a similar
technique using off-the-shelf solder and heatshrink.
Bob . . .
-----------------------------------------
( Experience and common sense cannot be )
( replaced with policy and procedures. )
( R. L. Nuckolls III )
-----------------------------------------
Message 9
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| Subject: | Brass Instrument Screws for MicroAir avionics |
--> AeroElectric-List message posted by: "Rick Fogerson" <rickf@cableone.net>
The MicroAir radio and xpdr use 8-36 thread screws which is not common. Does anyone
know of a source for these. I need 8 and would prefer countersunk brass
screws but might have to consider other if forced to.
Thanks for help,
Rick Fogerson
RV3 wiring
Boise, ID
Message 10
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| Subject: | Courtesy Light Timer |
--> AeroElectric-List message posted by: "Larry Bowen" <Larry@BowenAero.com>
That reminds me of this interesting, but overpriced, fuse block I saw in
Gall's catelog. It has a timer.
http://www.galls.com/style.html?style=SE007&assort=general_catalog
-
Larry Bowen
Larry@BowenAero.com
http://BowenAero.com
> -----Original Message-----
> From: Don Boardman [mailto:dboardm3@twcny.rr.com]
> Sent: Monday, January 12, 2004 10:15 PM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Courtesy Light Timer
>
>
> --> AeroElectric-List message posted by: Don Boardman
> --> <dboardm3@twcny.rr.com>
>
> Hi Bob,
>
> A while back you talked about wiring a courtesy light(s) from
> the battery bus. You mentioned putting the light(s) on a
> timer. Great idea! Turn on the light without switching on the
> master and with a timer, no fear of accidentally leaving a
> light on to kill the battery. I certainly have never done
> that ! # %*&&)(+!.
>
> At the time of the post you did not elaborate, no
> particulars, about the timer itself. How would one go about
> incorporating such an "automatic" timer on such a circuit?
>
>
> Thanks,
> Don B.
>
Message 11
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| Subject: | Grand Rapids EIS 4000 MAP sensor |
--> AeroElectric-List message posted by: "Rick Fogerson" <rickf@cableone.net>
Grand Rapids recommends placing the MAP sensor in the cockpit because it uses a
plastic case. I'm not going to because I've gone to a lot of effort and some
$'s to protect the cockpit from engine fires. Placing the sensor in the cockpit
means you would have to bring a manifold pressure hose through the firewall.
Has anyone else had any good or bad experience with this sensor in the engine
compartment.
thanks,
Rick Fogerson
Boise, ID
RV3 wiring
Message 12
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| Subject: | Wire bundling for minimum avionics noise |
--> AeroElectric-List message posted by: "Rick Fogerson" <rickf@cableone.net>
Hi Bob,
I've read your book Re what wires can be bundled together several times and I'm
not completely sure if what I have done will avoid noise in the avionics. Could
you take a look and see if it appears okay? I have an RV3 with 2 batteries,
battery buses, contactors, and dual Electonic Ignition relays in the back.
Essentially there are three bundles in question as follows:
1) Starter power (2AWG), all ground block wires, and all LR-3 voltage reg. wires
bundled.
2) All engine sensor wires (EGT, CHT, Oil Temp/Press, Fuel Press, and MAP) bundled.
3) Avionics, pump, and auto pilot power and ground wires, Ess Bus sw, MicroAir
radio and xpdr shielded/twisted pairs and PTT twisted pair to head phones and
microphones. I'm most uncertain of this one!
Thanks Bob for all your help. I'm just about finished with wiring and couldn't
have done it with out you!
Rick Fogerson
RV3 wiring almost completed
Boise, ID
Message 13
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| Subject: | Re: RV-List: Brass Instrument Screws for MicroAir avionics |
--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
McMaster Carr sells 8-36 screws, but only in the socket head cap form
factor, not a pan-head machine screw. See page 2898 of McMaster's online
catalog. For example, part #91251A494. http://www.mcmaster.com
)_( Dan
RV-7 N714D
http://www.rvproject.com
----- Original Message -----
From: "Rick Fogerson" <rickf@cableone.net>
Subject: RV-List: Brass Instrument Screws for MicroAir avionics
> --> RV-List message posted by: "Rick Fogerson" <rickf@cableone.net>
>
> The MicroAir radio and xpdr use 8-36 thread screws which is not common.
Does anyone know of a source for these. I need 8 and would prefer
countersunk brass screws but might have to consider other if forced to.
> Thanks for help,
> Rick Fogerson
> RV3 wiring
> Boise, ID
>
>
Message 14
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| Subject: | Re: RV-List: Brass Instrument Screws for MicroAir avionics |
--> AeroElectric-List message posted by: "Dan Checkoway" <dan@rvproject.com>
Ah...found what you're looking for:
http://www.wicksaircraft.com/gotopage.php?page=94
)_( Dan
----- Original Message -----
From: "Dan Checkoway" <dan@rvproject.com>
Subject: Re: RV-List: Brass Instrument Screws for MicroAir avionics
> McMaster Carr sells 8-36 screws, but only in the socket head cap form
> factor, not a pan-head machine screw. See page 2898 of McMaster's online
> catalog. For example, part #91251A494. http://www.mcmaster.com
>
> )_( Dan
> RV-7 N714D
> http://www.rvproject.com
>
> ----- Original Message -----
> From: "Rick Fogerson" <rickf@cableone.net>
> To: "RV List" <rv-list@matronics.com>; <aeroelectric-list@matronics.com>
> Sent: Monday, January 12, 2004 9:18 PM
> Subject: RV-List: Brass Instrument Screws for MicroAir avionics
>
>
> > --> RV-List message posted by: "Rick Fogerson" <rickf@cableone.net>
> >
> > The MicroAir radio and xpdr use 8-36 thread screws which is not common.
> Does anyone know of a source for these. I need 8 and would prefer
> countersunk brass screws but might have to consider other if forced to.
> > Thanks for help,
> > Rick Fogerson
> > RV3 wiring
> > Boise, ID
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
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