Today's Message Index:
----------------------
1. 01:11 AM - Re: Tailwind Electrical System Drawing and Power Analysis (Peter Pengilly)
2. 06:53 AM - PMag power requirements (Robert L. Nuckolls, III)
3. 07:12 AM - Re[2]: Tailwind Electrical System Drawing and Power Analysis (Gerry van Dyk)
4. 07:30 AM - Re: Re: Fusible links (Christopher Cee Stone)
5. 08:12 AM - Re: Re: Fusible links (ashleysc@broadstripe.net)
6. 09:45 AM - Re: Plane Power alternator $$$$ (Coastflyer)
7. 10:59 AM - Re: Re: Plane Power alternator $$$$ (Robert L. Nuckolls, III)
8. 11:18 AM - Re[3]: Tailwind Electrical System Drawing and Power Analysis (Gerry van Dyk)
9. 11:34 AM - Re: Re: Plane Power alternator $$$$ (Charlie England)
10. 11:44 AM - Re: Re[3]: Tailwind Electrical System Drawing and Power Analysis (Peter Pengilly)
11. 11:57 AM - Re[5]: Tailwind Electrical System Drawing and Power Analysis (Gerry van Dyk)
12. 12:29 PM - Re: Plane Power alternator $$$$ (Coastflyer)
13. 01:45 PM - Re: Re[3]: Tailwind Electrical System Drawing and Power Analysis (M Wilson)
14. 02:57 PM - Re: Re: Fusible links (Robert L. Nuckolls, III)
15. 04:54 PM - Re: Re[3]: Tailwind Electrical System Drawing and Power Analysi (user9253)
16. 05:34 PM - Re: Re: Fusible links (Finn Lassen)
Message 1
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| Subject: | Tailwind Electrical System Drawing and Power Analysis |
Why do you want to switch the SD-8 alternator?
Why switch battery power to the bus twice?
Use an externally regulated main alternator to avoid having to switch
the alternator output.
Provide a method to connect the battery directly to the bus.
Do not use a diode in the feed to the essential bus.
There are a number of services connected directly to the battery just
waiting to flatten it
If the voltage of the SD8 is set (say) 0.2v lower than the main
alternator it will not produce power if the main is on line. If the main
fails it takes up the load.
For my liking you have too many relays between the battery and the bus
bar.
If you use an externally regulated main alternator then initially only
switch on the SD8 on start up. Then power up the main alternator
regulator and bring that on line.
Install a switch that powers up the essential (or main) bus directly
from the battery, if the switch is a double pole use the second pole to
disable the starter.
The large diode in the feed line to the essential bus will always drop
the voltage by an amount. The benefit is auto load shedding but do you
need that with 2 alternators? If you really want to shed the main bus
use a large switch and ensure there is a path to the essential bus
directly from the battery. I used to have a feed diode and would not use
one again.
A diode is very beneficial on the starter contactor.
Having a low voltage waring that is independent of the EFIS is useful.
It is possible you will get immune to EFIS warnings
Peter
From: owner-aeroelectric-list-server@matronics.com
<owner-aeroelectric-list-server@matronics.com> On Behalf Of Gerry van
Dyk
Sent: Thursday, December 28, 2023 11:32 PM
Subject: AeroElectric-List: Tailwind Electrical System Drawing and Power
Analysis
Hello again all
Well, I think I'm ready for a good critique on my proposed electrical
system for my Tailwind project. For the most part it's based on Z13/8,
we're using a Plane Power AL12-E160 primary alternator, and of course
the B&C SD-8 backup alternator. The E160 is internally regulated, and
also has an internal crowbar system and alt-out panel light output,
which I intend to use. The SD-8 has their older PMR1 regulator, so
we've got the external crowbar module and no voltage sensing. I've
drawn these items as shown on their respective install instructions call
for.
As I mentioned earlier, I intended to start the engine on the endurance
bus, and check the SD-8 operation during the startup procedure. I had
neglected to think about where the starter was going to get power from,
so the idea has forced an additional switch and relay (a rather robust
one at that) to run the main bus. The battery contactor would be closed
for startup, then the SD-8 operation checked and finally the main bus
would be brought up to begin normal operation.
I'm a little uneasy about this extra switching, as I know this group is
inclined toward fewer failure points, and with good reason. As I look
at the 'textbook' Z13/8 drawing, with my dual EFIS, IFR capable panel in
mind, it seems to me that a startup would bring the entire panel up with
the main bus, then with the engine running I'd have to close the E-bus
switch, open the battery contactor, dropping out half the instrument
panel. Then check the backup alternator operation, and finally reboot
the rest of the panel again. It just really feels rather clunky to me.
Bob, have I missed something with the original architecture concept? Is
there a way to check the backup alternator function while the main bus
is up and running? It would certainly help me simplify my system.
I'd appreciate if you good folks would give my drawing a good review.
Questions, comments and critiques are all welcome.
Thanks again
Gerry van Dyk
Tailwind C-GVDZ
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| Subject: | PMag power requirements |
At 09:19 PM 12/28/2023, you wrote:
>Hi Bob,
>
>I would answer on Aeroelectric List if I could. I get the postings
>by email but I can't answer due to longstanding technical issues
>with the forum. My next try at a resolution will be a postal letter
>to Matt Dralle.
>
>Re your post 19 at
><http://forums.matronics.com/viewtopic.php?t=16781981>http://forums.matronics.com/viewtopic.php?t=16781981
>
>I'm writing because I believe it is incorrect that the Pmag bus
>power feeder is "about 0.04A". I have no idea where you got that
>number. This feeder is EI power for starting and in case of Pmag internal
You are correct. Emag specs and installation sheets are not
satisfyingly clear on their electrical requirements.
Had to dig around in some older EMag literature
to come up with the attached illustration:
That 0.04A number was for bus supply loads
under normal operation above 1800 rpm or
so on a PMag. Obviously, should the internal alternator
fail (exceedingly unlikely) demands from
ship's bus will be on the order of 0.3 to 0.7A
depending on rpm.
NOTE: the attached figure is exemplar data
captured from EMagair literature from
some years back.
This thread illustrates an oft ignored
hazard for not having manufacturer's
published data. I've not spoken with
the guys for some years. I'll call them
tomorrow to renew acquaintance. I'm
planning on a trip to Ft. Worth in March . . .
will plan on visiting them.
I'll suggest some updating of their
electrical performance data would be
helpful.
In the mean time, I'll update my suggestion
to utilize a "Polyswitch" . . . a solid
state, self-resetting fault limiter.
https://tinyurl.com/yu2tjncu
I've used these in numerous applications over
the years. These are NOT a universal replacement
for fuses/breakers/limiters BUT in this case
I think it will fill the bill. I've added
some to an order from Digikey. I want to
do a bit of bench testing. I'll have some
to 'donate to the cause'.
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
In the interest of creative evolution
of the-best-we-know-how-to-do based
on physics and good practice.
Message 3
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| Subject: | Tailwind Electrical System Drawing and Power |
Analysis
Hi Peter, thanks for your thoughts.
Why do you want to switch the SD-8 alternator?
because it is shown on the original Z-13/8 drawing. I'm working from
rev T 1/07/14. Is there a later revision with this switch removed?
Why switch battery power to the bus twice?
As I mentioned, I want to start the engine on the E-bus. I need to
supply power to the starter, but leave the main bus un-powered, in order
to check the function of SD-8. Supplying starting power through the
E-bus seems impractical.
Use an externally regulated main alternator to avoid having to switch
the alternator output.
Yeah, I'm hamstringing myself a little bit here. I bought the AL
12-E160 alt several years ago, I don't have a spare couple thousand
dollars to buy another. I'll have to think about it better, but on the
face of it, having a separate regulator doesn't seem to change how the
alternator is controlled. Mr. Nuckolls has mentioned on many occasions
that we want to have definite control of the alternator output with a
switch in the cockpit. Z12/8 shows this switch in the center of the
drawing.
Provide a method to connect the battery directly to the bus. (I presume
your're talking about the main bus here.)
Perhaps I'm being foolish here. I'm placing an absolute requirement to
check the operation of the backup alternator at the beginning of every
flight. My life will depend on it should the main alternator fail.
With the main bus and main alternator connected directly to the battery
contactor they will be running at startup. As yet I don't see a way to
check the backup alternator operation with the main's running. I'd like
to do so without turning half the panel on-off-on during startup.
Do not use a diode in the feed to the essential bus.
This diode is called for by B&C on their installation drawing 504-500,
and they provide it in the kit. What would be the reason to remove it?
There are a number of services connected directly to the battery just
waiting to flatten it
Quite right, and this duplicates what's shown on Z13-8. They are a
couple of conveniences, loading the baggage compartment, charging a
phone etc, without having to turn on the battery master and it's
relatively large current draw. In building my panel, all switches will
be down=off, and they're all in two rows so visually obvious when left
on. I'll have to have a quick scan of the panel when leaving the
airplane, and if I flatten the battery by mistake, my fault.
If the voltage of the SD8 is set (say) 0.2v lower than the main
alternator it will not produce power if the main is on line. If the main
fails it takes up the load.
I presume you are making another case for removing the backup alt
switch. Again, it is called for on Z13/8, but your point is well taken.
For my liking you have too many relays between the battery and the bus
bar.
I absolutely agree, I haven't yet come up with an elegant solution to
check the backup alternator without cycling the avionics.
If you use an externally regulated main alternator then initially only
switch on the SD8 on start up. Then power up the main alternator
regulator and bring that on line.
I think we've covered this already. In order to start the engine I need
to switch on the battery contactor, which would also bring the main bus
and main alt online. I could move the starter wire to the always-hot
side of the battery contactor, so the mains are still inop, but with
that wire permanently hot, and 2 gauge wire at that, it violates the
idea of making the electrical system as inert as possible in a forced
landing. Again, I don't see the difference between an externally or
internally regulated alternator. The red wire to lead 1 on the alt
connector is the equivalent of the A wire on an external regulator, the
jumper is the same as one to the S wire, and the F wire is internal.
Peter, writing this is making me think about separating the main alt
control to a separate switch. Let me think that through a bit and I'll
report back later.
Install a switch that powers up the essential (or main) bus directly
from the battery, if the switch is a double pole use the second pole to
disable the starter.
Interesting, I'll think that out as well.
The large diode in the feed line to the essential bus will always drop
the voltage by an amount. The benefit is auto load shedding but do you
need that with 2 alternators? If you really want to shed the main bus
use a large switch and ensure there is a path to the essential bus
directly from the battery. I used to have a feed diode and would not use
one again.
Yes, I believe it is necessary. 8 amps will not power the entire panel,
so the load shedding is still valid. Incidentally, I discovered on the
SD-8 literature that a Lycoming will need to run at 2500 rpm to get the
full 8 amps out of the SD-8. it's looking like about 6.8 amps at 2300
rpm. Your suggestion will mean both main and E-bus need to be switched
on for normal operations. Bob has made note on many of his drawings
that "all buses are on when the main is on". I've had that in mind when
drawing this up. Having the E-bus switched on for normal ops means the
backup alternator is always running, though as you've suggested it can
be set lower than the main, and loaf along in the background. I need to
get my head around this idea.
A diode is very beneficial on the starter contactor.
That's a whoops, should have added it to the drawing, I'll get it on
there.
Having a low voltage waring that is independent of the EFIS is useful.
It is possible you will get immune to EFIS warnings
Yes, I do agree here. I was hoping the 'alt out light' function of the
main alternator would be a 'low voltage monitor' as B&C does on their
newer AVC regulator. After exchanging a couple of emails with Tim at
Plane Power, it indeed only sees the output within the alternator,
nothing outside. I've already got the Dynon EMS with all the engine
sensors, so it makes some sense to use what I've got. My thinking is if
it becomes annoying I can add the separate voltage monitoring system
after the fact. Tim at PP did mention that he regularly sees OBAM guys
using the EFIS for voltage monitoring, and all too often they've got
parameters set way too stringent, and get many nuisance warnings. As
yet I haven't investigated what parameters and settings I can work with,
so the external LV warning is always on the table.
Thanks very much for the thoughts Peter. It's very useful to think
through the questions and comments.
Cheers
Gerry
------ Original Message ------
>From "Peter Pengilly" <peter@sportingaero.com>
To aeroelectric-list@matronics.com
Date 2023-12-29 2:11:12 AM
Subject RE: AeroElectric-List: Tailwind Electrical System Drawing and
Power Analysis
>Why do you want to switch the SD-8 alternator?
>
>Why switch battery power to the bus twice?
>
>Use an externally regulated main alternator to avoid having to switch
>the alternator output.
>
>Provide a method to connect the battery directly to the bus.
>
>Do not use a diode in the feed to the essential bus.
>
>There are a number of services connected directly to the battery just
>waiting to flatten it
>
>
>If the voltage of the SD8 is set (say) 0.2v lower than the main
>alternator it will not produce power if the main is on line. If the
>main fails it takes up the load.
>
>For my liking you have too many relays between the battery and the bus
>bar.
>
>If you use an externally regulated main alternator then initially only
>switch on the SD8 on start up. Then power up the main alternator
>regulator and bring that on line.
>
>Install a switch that powers up the essential (or main) bus directly
>from the battery, if the switch is a double pole use the second pole to
>disable the starter.
>
>The large diode in the feed line to the essential bus will always drop
>the voltage by an amount. The benefit is auto load shedding but do you
>need that with 2 alternators? If you really want to shed the main bus
>use a large switch and ensure there is a path to the essential bus
>directly from the battery. I used to have a feed diode and would not
>use one again.
>
>A diode is very beneficial on the starter contactor.
>
>Having a low voltage waring that is independent of the EFIS is useful.
>It is possible you will get immune to EFIS warnings
>
>
>Peter
>
>
>From:owner-aeroelectric-list-server@matronics.com
><owner-aeroelectric-list-server@matronics.com> On Behalf Of Gerry van
>Dyk
>Sent: Thursday, December 28, 2023 11:32 PM
>To:aeroelectric-list@matronics.com
>Subject: AeroElectric-List: Tailwind Electrical System Drawing and
>Power Analysis
>
>
>Hello again all
>
>Well, I think I'm ready for a good critique on my proposed electrical
>system for my Tailwind project. For the most part it's based on Z13/8,
>we're using a Plane Power AL12-E160 primary alternator, and of course
>the B&C SD-8 backup alternator. The E160 is internally regulated, and
>also has an internal crowbar system and alt-out panel light output,
>which I intend to use. The SD-8 has their older PMR1 regulator, so
>we've got the external crowbar module and no voltage sensing. I've
>drawn these items as shown on their respective install instructions
>call for.
>
>
>As I mentioned earlier, I intended to start the engine on the endurance
>bus, and check the SD-8 operation during the startup procedure. I had
>neglected to think about where the starter was going to get power from,
>so the idea has forced an additional switch and relay (a rather robust
>one at that) to run the main bus. The battery contactor would be
>closed for startup, then the SD-8 operation checked and finally the
>main bus would be brought up to begin normal operation.
>
>
>I'm a little uneasy about this extra switching, as I know this group is
>inclined toward fewer failure points, and with good reason. As I look
>at the 'textbook' Z13/8 drawing, with my dual EFIS, IFR capable panel
>in mind, it seems to me that a startup would bring the entire panel up
>with the main bus, then with the engine running I'd have to close the
>E-bus switch, open the battery contactor, dropping out half the
>instrument panel. Then check the backup alternator operation, and
>finally reboot the rest of the panel again. It just really feels
>rather clunky to me.
>
>
>Bob, have I missed something with the original architecture concept?
>Is there a way to check the backup alternator function while the main
>bus is up and running? It would certainly help me simplify my system.
>
>
>I'd appreciate if you good folks would give my drawing a good review.
>Questions, comments and critiques are all welcome.
>
>
>Thanks again
>
>Gerry van Dyk
>
>Tailwind C-GVDZ
>
Message 4
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| Subject: | Re: Fusible links |
My very basic test rig with somewhat empirical results- no measured data.
Objective: observe failure of fusible links of various lengths when
subjected to a high current short circuit event.
12V wet cell, new, fully charged battery
Knife switch
18 ga tefzel feeder, 20" length x2
PIDG style butt splices (red)
Camera
DUT: 2", 6", 13" lengths 24 ga tefzel FL (M22759/16)
Procedure:
Fabricate fusible links of 2, 6 an 13 inch lengths
Crimp w/ AMP PIDG crimper to
Feeder 20" 18 ga tefzel
Clamp feeders to B+ Knife switch and B- battery terminal
Start camera video
Rabidly close switch
Two inch FL setup
[image: 2InchSetup.jpg]
Crimp tool and butt splice
[image: AmpCrimpTool.jpg]
results:
http://tinyurl.com/mryadbfx
No fiberglas sleeve was used so that failure could be observed.
Comments, questions, critique!
...chris
On Sat, Dec 23, 2023 at 8:02=AFAM Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> At 09:31 AM 12/23/2023, you wrote:
>
> Back to the original question of the length of a fusible link. That is th
e
> length of smaller gauge wire comprising=C3=82 the 'link'.
>
>
> Had to do some 'digging' to see if I could
> find where that 3-6 inch citation came from.
> No joy.
>
> Actually, 6" is the minimum. 9" is more typical,
> 10" not unheard of. 3" is too short . . .
>
> . . . and INSULATED with material resistant to
> energy released by clearing the fault.
>
> See: http://tinyurl.com/4vnzdjpc
>
>
> Bob . . .
>
> ////
> (o o)
> ===========o00o=(_)=o00o======
==
> < Go ahead, make my day . . . >
> < show me where I'm wrong. >
> =======================
=========
>
> In the interest of creative evolution
> of the-best-we-know-how-to-do based
> on physics and good practice.
>
Message 5
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| Subject: | Re: Fusible links |
Hi Chris;
Hi All;
That's a great demonstration Chris.
And it evidences exactly why I would not use fusible links in an aircraft,
or automobile for that matter.
There's smoke, there's fire, and there's molten metal!
With most fuses the burned wire, smoke, and fire are contained.
Cheers! Stu.
From: "Christopher Cee Stone" <rv8iator@gmail.com>
Sent: Friday, December 29, 2023 7:30:01 AM
Subject: Re: AeroElectric-List: Re: Fusible links
My very basic test rig with somewhat empirical results- no measured data.
Objective: observe failure of fusible links of various lengths when subject
ed to a high current short circuit event.
12V wet cell, new, fully charged battery
Knife switch
18 ga tefzel feeder, 20" length x2
PIDG style butt splices (red)
Camera
DUT: 2", 6", 13" lengths 24 ga tefzel FL (M22759/16)
Procedure:
Fabricate fusible links of 2, 6 an 13 inch lengths
Crimp w/ AMP PIDG crimper to
Feeder 20" 18 ga tefzel
Clamp feeders to B+ Knife switch and B- battery terminal
Start camera video
Rabidly close switch
Two inch FL setup
Crimp tool and butt splice
results:
[ http://tinyurl.com/mryadbfx | http://tinyurl.com/mryadbfx ]
No fiberglas sleeve was used so that failure could be observed.
Comments, questions, critique!
...chris
On Sat, Dec 23, 2023 at 8:02 AM Robert L. Nuckolls, III < [ mailto:nuckolls
.bob@aeroelectric.com | nuckolls.bob@aeroelectric.com ] > wrote:
At 09:31 AM 12/23/2023, you wrote:
BQ_BEGIN
Back to the original question of the length of a fusible link. That is the
length of smaller gauge wire comprising=C3=82 the 'link'.
Had to do some 'digging' to see if I could
find where that 3-6 inch citation came from.
No joy.
Actually, 6" is the minimum. 9" is more typical,
10" not unheard of. 3" is too short . . .
. . . and INSULATED with material resistant to
energy released by clearing the fault.
See: [ http://tinyurl.com/4vnzdjpc |
http://tinyurl.com/4vnzdjpc
]
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
=
< Go ahead, make my day . . . >
< show me where I'm wrong. >
========
In the interest of creative evolution
of the-best-we-know-how-to-do based
on physics and good practice.
BQ_END
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| Subject: | Re: Plane Power alternator $$$$ |
Thats ok Bob, I wanted to replace the battery anyway. I do appreciate your analysis.
I took some video yesterday, still with the old battery.
https://youtu.be/1TluvrVBLJo?si=IkUwgLP910Cht7Kt
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=512976#512976
Message 7
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| Subject: | Re: Plane Power alternator $$$$ |
At 11:44 AM 12/29/2023, you wrote:
<jessejenks72@gmail.com>
>
>That=99s ok Bob, I wanted to replace the battery
>anyway. I do appreciate your analysis.
>I took some video yesterday, still with the old battery.
>
>https://youtu.be/1TluvrVBLJo?si=IkUwgLP910Cht7Kt
That's interesting. The period of oscillation
is too long to be a regulation issue especially
since the voltage is not similarly afflicted.
It will be interesting to see if it persists
with the new battery.
How old is the present battery? Have
you recently cap-checked it?
It's a strong suggestion of some accessory
load . . . but what? This began after
installation of the new alternator?
Bob . . .
////
(o o)
===========o00o=(_)=o00o=======
=
< Go ahead, make my day . . . >
< show me where I'm wrong. >
========================
========
In the interest of creative evolution
of the-best-we-know-how-to-do based
on physics and good practice.
Message 8
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| Subject: | Tailwind Electrical System Drawing and Power |
Analysis
Hello again all
Peter I'll follow-up here on those couple of points...
I've attached the latest revision to my architecture. Thinking about
what you've suggested, separating the main alternator to it's own
switch, I've done so, and it cleans up both the drawing and the
electrical system quite a bit. Effectively what we've done is separate
the "battery / alt / DC power" switch shown on the Z13/8 drawing into
two. I've got a keyed switch which I want for some basic theft
deterrence, and then the main alt switch.
In operation we'll turn on the main bus, which will mean the entire
panel will be up. The big consumers will of course be off, pitot heat,
exterior lighting, AP servos, boost fuel pump, and the radios will be in
passive receive mode. At this point we'd close the ebus / aux alt
switch and start the engine. Dynon says this will not bring down the
EFIS's so with the EMS operating we should see the aux alternator bump
the voltage, I'd flip the switch on and off if need be to see this
change. Satisfied that the aux alternator is operating we'll then bring
the main alternator online and turn the e-bus / aux alt switch off. Or
I may come around on leaving it on for normal operations.
For alternator-out condition: turn the e-bus / aux alt switch on, open
the main battery switch, dropping out the battery contactor and therefor
the main bus. If the main alt has failed or thrown the belt, it won't
matter much if we turn off the main alt switch or not.
What are your thoughts on this layout? I known I haven't used all your
suggestions, I hope you take no offense to it, I think some were moving
away from the original Z13/8 philosophy which I do rather agree with.
Best regards
Gerry
------ Original Message ------
>From "Gerry van Dyk" <gerry.vandyk@eastlink.ca>
To aeroelectric-list@matronics.com
Date 2023-12-29 8:12:00 AM
Subject Re[2]: AeroElectric-List: Tailwind Electrical System Drawing and
Power Analysis
>Hi Peter, thanks for your thoughts.
>Why do you want to switch the SD-8 alternator?
>because it is shown on the original Z-13/8 drawing. I'm working from
>rev T 1/07/14. Is there a later revision with this switch removed?
>Why switch battery power to the bus twice?
>As I mentioned, I want to start the engine on the E-bus. I need to
>supply power to the starter, but leave the main bus un-powered, in
>order to check the function of SD-8. Supplying starting power through
>the E-bus seems impractical.
>Use an externally regulated main alternator to avoid having to switch
>the alternator output.
>Yeah, I'm hamstringing myself a little bit here. I bought the AL
>12-E160 alt several years ago, I don't have a spare couple thousand
>dollars to buy another. I'll have to think about it better, but on the
>face of it, having a separate regulator doesn't seem to change how the
>alternator is controlled. Mr. Nuckolls has mentioned on many occasions
>that we want to have definite control of the alternator output with a
>switch in the cockpit. Z12/8 shows this switch in the center of the
>drawing.
>Provide a method to connect the battery directly to the bus. (I
>presume your're talking about the main bus here.)
>Perhaps I'm being foolish here. I'm placing an absolute requirement to
>check the operation of the backup alternator at the beginning of every
>flight. My life will depend on it should the main alternator fail.
>With the main bus and main alternator connected directly to the battery
>contactor they will be running at startup. As yet I don't see a way to
>check the backup alternator operation with the main's running. I'd
>like to do so without turning half the panel on-off-on during startup.
>Do not use a diode in the feed to the essential bus.
>This diode is called for by B&C on their installation drawing 504-500,
>and they provide it in the kit. What would be the reason to remove it?
>There are a number of services connected directly to the battery just
>waiting to flatten it
>Quite right, and this duplicates what's shown on Z13-8. They are a
>couple of conveniences, loading the baggage compartment, charging a
>phone etc, without having to turn on the battery master and it's
>relatively large current draw. In building my panel, all switches will
>be down=off, and they're all in two rows so visually obvious when left
>on. I'll have to have a quick scan of the panel when leaving the
>airplane, and if I flatten the battery by mistake, my fault.
>If the voltage of the SD8 is set (say) 0.2v lower than the main
>alternator it will not produce power if the main is on line. If the
>main fails it takes up the load.
>I presume you are making another case for removing the backup alt
>switch. Again, it is called for on Z13/8, but your point is well
>taken.
>For my liking you have too many relays between the battery and the bus
>bar.
>I absolutely agree, I haven't yet come up with an elegant solution to
>check the backup alternator without cycling the avionics.
>If you use an externally regulated main alternator then initially only
>switch on the SD8 on start up. Then power up the main alternator
>regulator and bring that on line.
>I think we've covered this already. In order to start the engine I
>need to switch on the battery contactor, which would also bring the
>main bus and main alt online. I could move the starter wire to the
>always-hot side of the battery contactor, so the mains are still inop,
>but with that wire permanently hot, and 2 gauge wire at that, it
>violates the idea of making the electrical system as inert as possible
>in a forced landing. Again, I don't see the difference between an
>externally or internally regulated alternator. The red wire to lead 1
>on the alt connector is the equivalent of the A wire on an external
>regulator, the jumper is the same as one to the S wire, and the F wire
>is internal.
>Peter, writing this is making me think about separating the main alt
>control to a separate switch. Let me think that through a bit and I'll
>report back later.
>Install a switch that powers up the essential (or main) bus directly
>from the battery, if the switch is a double pole use the second pole to
>disable the starter.
>Interesting, I'll think that out as well.
>The large diode in the feed line to the essential bus will always drop
>the voltage by an amount. The benefit is auto load shedding but do you
>need that with 2 alternators? If you really want to shed the main bus
>use a large switch and ensure there is a path to the essential bus
>directly from the battery. I used to have a feed diode and would not
>use one again.
>Yes, I believe it is necessary. 8 amps will not power the entire
>panel, so the load shedding is still valid. Incidentally, I discovered
>on the SD-8 literature that a Lycoming will need to run at 2500 rpm to
>get the full 8 amps out of the SD-8. it's looking like about 6.8 amps
>at 2300 rpm. Your suggestion will mean both main and E-bus need to be
>switched on for normal operations. Bob has made note on many of his
>drawings that "all buses are on when the main is on". I've had that in
>mind when drawing this up. Having the E-bus switched on for normal ops
>means the backup alternator is always running, though as you've
>suggested it can be set lower than the main, and loaf along in the
>background. I need to get my head around this idea.
>A diode is very beneficial on the starter contactor.
>That's a whoops, should have added it to the drawing, I'll get it on
>there.
>Having a low voltage waring that is independent of the EFIS is useful.
>It is possible you will get immune to EFIS warnings
>Yes, I do agree here. I was hoping the 'alt out light' function of the
>main alternator would be a 'low voltage monitor' as B&C does on their
>newer AVC regulator. After exchanging a couple of emails with Tim at
>Plane Power, it indeed only sees the output within the alternator,
>nothing outside. I've already got the Dynon EMS with all the engine
>sensors, so it makes some sense to use what I've got. My thinking is
>if it becomes annoying I can add the separate voltage monitoring system
>after the fact. Tim at PP did mention that he regularly sees OBAM guys
>using the EFIS for voltage monitoring, and all too often they've got
>parameters set way too stringent, and get many nuisance warnings. As
>yet I haven't investigated what parameters and settings I can work
>with, so the external LV warning is always on the table.
>
>Thanks very much for the thoughts Peter. It's very useful to think
>through the questions and comments.
>
>Cheers
>Gerry
>
>
>------ Original Message ------
>From "Peter Pengilly" <peter@sportingaero.com>
>To aeroelectric-list@matronics.com
>Date 2023-12-29 2:11:12 AM
>Subject RE: AeroElectric-List: Tailwind Electrical System Drawing and
>Power Analysis
>
>>Why do you want to switch the SD-8 alternator?
>>
>>Why switch battery power to the bus twice?
>>
>>Use an externally regulated main alternator to avoid having to switch
>>the alternator output.
>>
>>Provide a method to connect the battery directly to the bus.
>>
>>Do not use a diode in the feed to the essential bus.
>>
>>There are a number of services connected directly to the battery just
>>waiting to flatten it
>>
>>
>>
>>If the voltage of the SD8 is set (say) 0.2v lower than the main
>>alternator it will not produce power if the main is on line. If the
>>main fails it takes up the load.
>>
>>For my liking you have too many relays between the battery and the bus
>>bar.
>>
>>If you use an externally regulated main alternator then initially only
>>switch on the SD8 on start up. Then power up the main alternator
>>regulator and bring that on line.
>>
>>Install a switch that powers up the essential (or main) bus directly
>>from the battery, if the switch is a double pole use the second pole
>>to disable the starter.
>>
>>The large diode in the feed line to the essential bus will always drop
>>the voltage by an amount. The benefit is auto load shedding but do you
>>need that with 2 alternators? If you really want to shed the main bus
>>use a large switch and ensure there is a path to the essential bus
>>directly from the battery. I used to have a feed diode and would not
>>use one again.
>>
>>A diode is very beneficial on the starter contactor.
>>
>>Having a low voltage waring that is independent of the EFIS is useful.
>>It is possible you will get immune to EFIS warnings
>>
>>
>>
>>Peter
>>
>>
>>
>>From:owner-aeroelectric-list-server@matronics.com
>><owner-aeroelectric-list-server@matronics.com> On Behalf Of Gerry van
>>Dyk
>>Sent: Thursday, December 28, 2023 11:32 PM
>>To:aeroelectric-list@matronics.com
>>Subject: AeroElectric-List: Tailwind Electrical System Drawing and
>>Power Analysis
>>
>>
>>
>>Hello again all
>>
>>Well, I think I'm ready for a good critique on my proposed electrical
>>system for my Tailwind project. For the most part it's based on
>>Z13/8, we're using a Plane Power AL12-E160 primary alternator, and of
>>course the B&C SD-8 backup alternator. The E160 is internally
>>regulated, and also has an internal crowbar system and alt-out panel
>>light output, which I intend to use. The SD-8 has their older PMR1
>>regulator, so we've got the external crowbar module and no voltage
>>sensing. I've drawn these items as shown on their respective install
>>instructions call for.
>>
>>
>>
>>As I mentioned earlier, I intended to start the engine on the
>>endurance bus, and check the SD-8 operation during the startup
>>procedure. I had neglected to think about where the starter was going
>>to get power from, so the idea has forced an additional switch and
>>relay (a rather robust one at that) to run the main bus. The battery
>>contactor would be closed for startup, then the SD-8 operation checked
>>and finally the main bus would be brought up to begin normal
>>operation.
>>
>>
>>
>>I'm a little uneasy about this extra switching, as I know this group
>>is inclined toward fewer failure points, and with good reason. As I
>>look at the 'textbook' Z13/8 drawing, with my dual EFIS, IFR capable
>>panel in mind, it seems to me that a startup would bring the entire
>>panel up with the main bus, then with the engine running I'd have to
>>close the E-bus switch, open the battery contactor, dropping out half
>>the instrument panel. Then check the backup alternator operation, and
>>finally reboot the rest of the panel again. It just really feels
>>rather clunky to me.
>>
>>
>>
>>Bob, have I missed something with the original architecture concept?
>>Is there a way to check the backup alternator function while the main
>>bus is up and running? It would certainly help me simplify my system.
>>
>>
>>
>>I'd appreciate if you good folks would give my drawing a good review.
>>Questions, comments and critiques are all welcome.
>>
>>
>>
>>Thanks again
>>
>>Gerry van Dyk
>>
>>Tailwind C-GVDZ
>>
Message 9
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| Subject: | Re: Plane Power alternator $$$$ |
On Fri, Dec 29, 2023 at 11:47=AFAM Coastflyer <jessejenks72@gmail.com
> wrote:
> jessejenks72@gmail.com>
>
> That=99s ok Bob, I wanted to replace the battery anyway. I do appre
ciate
> your analysis.
> I took some video yesterday, still with the old battery.
>
> https://youtu.be/1TluvrVBLJo?si=IkUwgLP910Cht7Kt
>
> I'd suggest taking a long hard look at the circuit between your current
shunt and the engine monitor. If it's a resistance type shunt and you have
the recommended protective fuses in the sense lines (or a flaky connection
anywhere in either line), then you will see wildly varying current
displayed with no actual changes in current. My Dynon monitor was installed
with glass fuses in those lines, and it does exactly what yours is doing.
Reaching under the panel and wiggling inline fuse holders will
(temporarily) make the symptom go away.
Charlie
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Message 10
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| Subject: | Re: Tailwind Electrical System Drawing and |
Power Analysis
Gerry, before looking at the details what are you planning to use the
airplane for? What do you want the system to do?
Long range IFR touring, medium range VFR/occasional IFR touring and VFR
hamburger runs, something else? Peter
On Fri, 29 Dec 2023, 19:27 Gerry van Dyk, <gerry.vandyk@eastlink.ca> wrote:
> Hello again all
> Peter I'll follow-up here on those couple of points...
>
> I've attached the latest revision to my architecture. Thinking about wha
t
> you've suggested, separating the main alternator to it's own switch, I've
> done so, and it cleans up both the drawing and the electrical system quit
e
> a bit. Effectively what we've done is separate the "battery / alt / DC
> power" switch shown on the Z13/8 drawing into two. I've got a keyed swit
ch
> which I want for some basic theft deterrence, and then the main alt switc
h.
>
> In operation we'll turn on the main bus, which will mean the entire panel
> will be up. The big consumers will of course be off, pitot heat, exterio
r
> lighting, AP servos, boost fuel pump, and the radios will be in passive
> receive mode. At this point we'd close the ebus / aux alt switch and sta
rt
> the engine. Dynon says this will not bring down the EFIS's so with the EM
S
> operating we should see the aux alternator bump the voltage, I'd flip the
> switch on and off if need be to see this change. Satisfied that the aux
> alternator is operating we'll then bring the main alternator online and
> turn the e-bus / aux alt switch off. Or I may come around on leaving it
on
> for normal operations.
>
> For alternator-out condition: turn the e-bus / aux alt switch on, open th
e
> main battery switch, dropping out the battery contactor and therefor the
> main bus. If the main alt has failed or thrown the belt, it won't matter
> much if we turn off the main alt switch or not.
>
> What are your thoughts on this layout? I known I haven't used all your
> suggestions, I hope you take no offense to it, I think some were moving
> away from the original Z13/8 philosophy which I do rather agree with.
>
> Best regards
> Gerry
>
>
> ------ Original Message ------
> From "Gerry van Dyk" <gerry.vandyk@eastlink.ca>
> To aeroelectric-list@matronics.com
> Date 2023-12-29 8:12:00 AM
> Subject Re[2]: AeroElectric-List: Tailwind Electrical System Drawing and
> Power Analysis
>
> Hi Peter, thanks for your thoughts.
> Why do you want to switch the SD-8 alternator?
> because it is shown on the original Z-13/8 drawing. I'm working from rev
> T 1/07/14. Is there a later revision with this switch removed?
> Why switch battery power to the bus twice?
> As I mentioned, I want to start the engine on the E-bus. I need to suppl
y
> power to the starter, but leave the main bus un-powered, in order to chec
k
> the function of SD-8. Supplying starting power through the E-bus seems
> impractical.
> Use an externally regulated main alternator to avoid having to switch the
> alternator output.
> Yeah, I'm hamstringing myself a little bit here. I bought the AL 12-E160
> alt several years ago, I don't have a spare couple thousand dollars to bu
y
> another. I'll have to think about it better, but on the face of it, havi
ng
> a separate regulator doesn't seem to change how the alternator is
> controlled. Mr. Nuckolls has mentioned on many occasions that we want to
> have definite control of the alternator output with a switch in the
> cockpit. Z12/8 shows this switch in the center of the drawing.
> Provide a method to connect the battery directly to the bus. (I presume
> your're talking about the main bus here.)
> Perhaps I'm being foolish here. I'm placing an absolute requirement to
> check the operation of the backup alternator at the beginning of every
> flight. My life will depend on it should the main alternator fail. With
> the main bus and main alternator connected directly to the battery
> contactor they will be running at startup. As yet I don't see a way to
> check the backup alternator operation with the main's running. I'd like
to
> do so without turning half the panel on-off-on during startup.
> Do not use a diode in the feed to the essential bus.
> This diode is called for by B&C on their installation drawing 504-500, an
d
> they provide it in the kit. What would be the reason to remove it?
> There are a number of services connected directly to the battery just
> waiting to flatten it
> Quite right, and this duplicates what's shown on Z13-8. They are a coupl
e
> of conveniences, loading the baggage compartment, charging a phone etc,
> without having to turn on the battery master and it's relatively large
> current draw. In building my panel, all switches will be down=off, and
> they're all in two rows so visually obvious when left on. I'll have to
> have a quick scan of the panel when leaving the airplane, and if I flatte
n
> the battery by mistake, my fault.
> If the voltage of the SD8 is set (say) 0.2v lower than the main alternato
r
> it will not produce power if the main is on line. If the main fails it
> takes up the load.
> I presume you are making another case for removing the backup alt switch.
> Again, it is called for on Z13/8, but your point is well taken.
> For my liking you have too many relays between the battery and the bus ba
r.
> I absolutely agree, I haven't yet come up with an elegant solution to
> check the backup alternator without cycling the avionics.
> If you use an externally regulated main alternator then initially only
> switch on the SD8 on start up. Then power up the main alternator regulato
r
> and bring that on line.
> I think we've covered this already. In order to start the engine I need
> to switch on the battery contactor, which would also bring the main bus a
nd
> main alt online. I could move the starter wire to the always-hot side of
> the battery contactor, so the mains are still inop, but with that wire
> permanently hot, and 2 gauge wire at that, it violates the idea of making
> the electrical system as inert as possible in a forced landing. Again, I
> don't see the difference between an externally or internally regulated
> alternator. The red wire to lead 1 on the alt connector is the equivalen
t
> of the A wire on an external regulator, the jumper is the same as one to
> the S wire, and the F wire is internal.
> Peter, writing this is making me think about separating the main alt
> control to a separate switch. Let me think that through a bit and I'll
> report back later.
> Install a switch that powers up the essential (or main) bus directly from
> the battery, if the switch is a double pole use the second pole to disabl
e
> the starter.
> Interesting, I'll think that out as well.
> The large diode in the feed line to the essential bus will always drop th
e
> voltage by an amount. The benefit is auto load shedding but do you need
> that with 2 alternators? If you really want to shed the main bus use a
> large switch and ensure there is a path to the essential bus directly fro
m
> the battery. I used to have a feed diode and would not use one again.
> Yes, I believe it is necessary. 8 amps will not power the entire panel,
> so the load shedding is still valid. Incidentally, I discovered on the
> SD-8 literature that a Lycoming will need to run at 2500 rpm to get the
> full 8 amps out of the SD-8. it's looking like about 6.8 amps at 2300
> rpm. Your suggestion will mean both main and E-bus need to be switched o
n
> for normal operations. Bob has made note on many of his drawings that "a
ll
> buses are on when the main is on". I've had that in mind when drawing th
is
> up. Having the E-bus switched on for normal ops means the backup
> alternator is always running, though as you've suggested it can be set
> lower than the main, and loaf along in the background. I need to get my
> head around this idea.
> A diode is very beneficial on the starter contactor.
> That's a whoops, should have added it to the drawing, I'll get it on ther
e.
> Having a low voltage waring that is independent of the EFIS is useful. It
> is possible you will get immune to EFIS warnings
> Yes, I do agree here. I was hoping the 'alt out light' function of the
> main alternator would be a 'low voltage monitor' as B&C does on their new
er
> AVC regulator. After exchanging a couple of emails with Tim at Plane
> Power, it indeed only sees the output within the alternator, nothing
> outside. I've already got the Dynon EMS with all the engine sensors, so
it
> makes some sense to use what I've got. My thinking is if it becomes
> annoying I can add the separate voltage monitoring system after the fact.
> Tim at PP did mention that he regularly sees OBAM guys using the EFIS for
> voltage monitoring, and all too often they've got parameters set way too
> stringent, and get many nuisance warnings. As yet I haven't investigated
> what parameters and settings I can work with, so the external LV warning
is
> always on the table.
>
> Thanks very much for the thoughts Peter. It's very useful to think
> through the questions and comments.
>
> Cheers
> Gerry
>
>
> ------ Original Message ------
> From "Peter Pengilly" <peter@sportingaero.com>
> To aeroelectric-list@matronics.com
> Date 2023-12-29 2:11:12 AM
> Subject RE: AeroElectric-List: Tailwind Electrical System Drawing and
> Power Analysis
>
> Why do you want to switch the SD-8 alternator?
>
> Why switch battery power to the bus twice?
>
> Use an externally regulated main alternator to avoid having to switch the
> alternator output.
>
> Provide a method to connect the battery directly to the bus.
>
> Do not use a diode in the feed to the essential bus.
>
> There are a number of services connected directly to the battery just
> waiting to flatten it
>
>
> If the voltage of the SD8 is set (say) 0.2v lower than the main alternato
r
> it will not produce power if the main is on line. If the main fails it
> takes up the load.
>
> For my liking you have too many relays between the battery and the bus ba
r.
>
> If you use an externally regulated main alternator then initially only
> switch on the SD8 on start up. Then power up the main alternator regulato
r
> and bring that on line.
>
> Install a switch that powers up the essential (or main) bus directly from
> the battery, if the switch is a double pole use the second pole to disabl
e
> the starter.
>
> The large diode in the feed line to the essential bus will always drop th
e
> voltage by an amount. The benefit is auto load shedding but do you need
> that with 2 alternators? If you really want to shed the main bus use a
> large switch and ensure there is a path to the essential bus directly fro
m
> the battery. I used to have a feed diode and would not use one again.
>
> A diode is very beneficial on the starter contactor.
>
> Having a low voltage waring that is independent of the EFIS is useful. It
> is possible you will get immune to EFIS warnings
>
>
> Peter
>
>
> *From:* owner-aeroelectric-list-server@matronics.com <
> owner-aeroelectric-list-server@matronics.com> *On Behalf Of *Gerry van Dy
k
> *Sent:* Thursday, December 28, 2023 11:32 PM
> *To:* aeroelectric-list@matronics.com
> *Subject:* AeroElectric-List: Tailwind Electrical System Drawing and
> Power Analysis
>
>
> Hello again all
>
> Well, I think I'm ready for a good critique on my proposed electrical
> system for my Tailwind project. For the most part it's based on Z13/8,
> we're using a Plane Power AL12-E160 primary alternator, and of course the
> B&C SD-8 backup alternator. The E160 is internally regulated, and also h
as
> an internal crowbar system and alt-out panel light output, which I intend
> to use. The SD-8 has their older PMR1 regulator, so we've got the extern
al
> crowbar module and no voltage sensing. I've drawn these items as shown o
n
> their respective install instructions call for.
>
>
> As I mentioned earlier, I intended to start the engine on the endurance
> bus, and check the SD-8 operation during the startup procedure. I had
> neglected to think about where the starter was going to get power from, s
o
> the idea has forced an additional switch and relay (a rather robust one a
t
> that) to run the main bus. The battery contactor would be closed for
> startup, then the SD-8 operation checked and finally the main bus would b
e
> brought up to begin normal operation.
>
>
> I'm a little uneasy about this extra switching, as I know this group is
> inclined toward fewer failure points, and with good reason. As I look at
> the 'textbook' Z13/8 drawing, with my dual EFIS, IFR capable panel in min
d,
> it seems to me that a startup would bring the entire panel up with the ma
in
> bus, then with the engine running I'd have to close the E-bus switch, ope
n
> the battery contactor, dropping out half the instrument panel. Then chec
k
> the backup alternator operation, and finally reboot the rest of the panel
> again. It just really feels rather clunky to me.
>
>
> Bob, have I missed something with the original architecture concept? Is
> there a way to check the backup alternator function while the main bus is
> up and running? It would certainly help me simplify my system.
>
>
> I'd appreciate if you good folks would give my drawing a good review.
> Questions, comments and critiques are all welcome.
>
>
> Thanks again
>
> Gerry van Dyk
>
> Tailwind C-GVDZ
>
>
Message 11
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|
| Subject: | Tailwind Electrical System Drawing and Power |
Analysis
It will be for mainly VFR touring and vacation, IFR Training and
eventually IFR travel though VFR will be preferred over IFR. The VFR
weekend breakfast flyins and hambergers will likely be the bulk of
service. I want the personal rating and currency and the airplane's IFR
capability to be there the 2 or 3 time per year when it's likely to be
required. Like an annual pilgrimage to Osh. I don't want to be
stranded for weather that's overcast but otherwise fairly benign.
Does that answer the question?
Gerry
------ Original Message ------
>From "Peter Pengilly" <peter@sportingaero.com>
To "Aeroelectric List (aeroelectric-list@matronics.com)"
<aeroelectric-list@matronics.com>
Date 2023-12-29 12:44:19 PM
Subject Re: Re[3]: AeroElectric-List: Tailwind Electrical System Drawing
and Power Analysis
>Gerry, before looking at the details what are you planning to use the
>airplane for? What do you want the system to do?
>Long range IFR touring, medium range VFR/occasional IFR touring and VFR
>hamburger runs, something else? Peter
>
>On Fri, 29 Dec 2023, 19:27 Gerry van Dyk, <gerry.vandyk@eastlink.ca>
>wrote:
>>Hello again all
>>Peter I'll follow-up here on those couple of points...
>>
>>I've attached the latest revision to my architecture. Thinking about
>>what you've suggested, separating the main alternator to it's own
>>switch, I've done so, and it cleans up both the drawing and the
>>electrical system quite a bit. Effectively what we've done is
>>separate the "battery / alt / DC power" switch shown on the Z13/8
>>drawing into two. I've got a keyed switch which I want for some basic
>>theft deterrence, and then the main alt switch.
>>
>>In operation we'll turn on the main bus, which will mean the entire
>>panel will be up. The big consumers will of course be off, pitot
>>heat, exterior lighting, AP servos, boost fuel pump, and the radios
>>will be in passive receive mode. At this point we'd close the ebus /
>>aux alt switch and start the engine. Dynon says this will not bring
>>down the EFIS's so with the EMS operating we should see the aux
>>alternator bump the voltage, I'd flip the switch on and off if need be
>>to see this change. Satisfied that the aux alternator is operating
>>we'll then bring the main alternator online and turn the e-bus / aux
>>alt switch off. Or I may come around on leaving it on for normal
>>operations.
>>
>>For alternator-out condition: turn the e-bus / aux alt switch on, open
>>the main battery switch, dropping out the battery contactor and
>>therefor the main bus. If the main alt has failed or thrown the belt,
>>it won't matter much if we turn off the main alt switch or not.
>>
>>What are your thoughts on this layout? I known I haven't used all
>>your suggestions, I hope you take no offense to it, I think some were
>>moving away from the original Z13/8 philosophy which I do rather agree
>>with.
>>
>>Best regards
>>Gerry
>>
>>
>>------ Original Message ------
>>From "Gerry van Dyk" <gerry.vandyk@eastlink.ca>
>>To aeroelectric-list@matronics.com
>>Date 2023-12-29 8:12:00 AM
>>Subject Re[2]: AeroElectric-List: Tailwind Electrical System Drawing
>>and Power Analysis
>>
>>>Hi Peter, thanks for your thoughts.
>>>Why do you want to switch the SD-8 alternator?
>>>because it is shown on the original Z-13/8 drawing. I'm working from
>>>rev T 1/07/14. Is there a later revision with this switch removed?
>>>Why switch battery power to the bus twice?
>>>As I mentioned, I want to start the engine on the E-bus. I need to
>>>supply power to the starter, but leave the main bus un-powered, in
>>>order to check the function of SD-8. Supplying starting power
>>>through the E-bus seems impractical.
>>>Use an externally regulated main alternator to avoid having to switch
>>>the alternator output.
>>>Yeah, I'm hamstringing myself a little bit here. I bought the AL
>>>12-E160 alt several years ago, I don't have a spare couple thousand
>>>dollars to buy another. I'll have to think about it better, but on
>>>the face of it, having a separate regulator doesn't seem to change
>>>how the alternator is controlled. Mr. Nuckolls has mentioned on many
>>>occasions that we want to have definite control of the alternator
>>>output with a switch in the cockpit. Z12/8 shows this switch in the
>>>center of the drawing.
>>>Provide a method to connect the battery directly to the bus. (I
>>>presume your're talking about the main bus here.)
>>>Perhaps I'm being foolish here. I'm placing an absolute requirement
>>>to check the operation of the backup alternator at the beginning of
>>>every flight. My life will depend on it should the main alternator
>>>fail. With the main bus and main alternator connected directly to
>>>the battery contactor they will be running at startup. As yet I
>>>don't see a way to check the backup alternator operation with the
>>>main's running. I'd like to do so without turning half the panel
>>>on-off-on during startup.
>>>Do not use a diode in the feed to the essential bus.
>>>This diode is called for by B&C on their installation drawing
>>>504-500, and they provide it in the kit. What would be the reason to
>>>remove it?
>>>There are a number of services connected directly to the battery just
>>>waiting to flatten it
>>>Quite right, and this duplicates what's shown on Z13-8. They are a
>>>couple of conveniences, loading the baggage compartment, charging a
>>>phone etc, without having to turn on the battery master and it's
>>>relatively large current draw. In building my panel, all switches
>>>will be down=off, and they're all in two rows so visually obvious
>>>when left on. I'll have to have a quick scan of the panel when
>>>leaving the airplane, and if I flatten the battery by mistake, my
>>>fault.
>>>If the voltage of the SD8 is set (say) 0.2v lower than the main
>>>alternator it will not produce power if the main is on line. If the
>>>main fails it takes up the load.
>>>I presume you are making another case for removing the backup alt
>>>switch. Again, it is called for on Z13/8, but your point is well
>>>taken.
>>>For my liking you have too many relays between the battery and the
>>>bus bar.
>>>I absolutely agree, I haven't yet come up with an elegant solution to
>>>check the backup alternator without cycling the avionics.
>>>If you use an externally regulated main alternator then initially
>>>only switch on the SD8 on start up. Then power up the main alternator
>>>regulator and bring that on line.
>>>I think we've covered this already. In order to start the engine I
>>>need to switch on the battery contactor, which would also bring the
>>>main bus and main alt online. I could move the starter wire to the
>>>always-hot side of the battery contactor, so the mains are still
>>>inop, but with that wire permanently hot, and 2 gauge wire at that,
>>>it violates the idea of making the electrical system as inert as
>>>possible in a forced landing. Again, I don't see the difference
>>>between an externally or internally regulated alternator. The red
>>>wire to lead 1 on the alt connector is the equivalent of the A wire
>>>on an external regulator, the jumper is the same as one to the S
>>>wire, and the F wire is internal.
>>>Peter, writing this is making me think about separating the main alt
>>>control to a separate switch. Let me think that through a bit and
>>>I'll report back later.
>>>Install a switch that powers up the essential (or main) bus directly
>>>from the battery, if the switch is a double pole use the second pole
>>>to disable the starter.
>>>Interesting, I'll think that out as well.
>>>The large diode in the feed line to the essential bus will always
>>>drop the voltage by an amount. The benefit is auto load shedding but
>>>do you need that with 2 alternators? If you really want to shed the
>>>main bus use a large switch and ensure there is a path to the
>>>essential bus directly from the battery. I used to have a feed diode
>>>and would not use one again.
>>>Yes, I believe it is necessary. 8 amps will not power the entire
>>>panel, so the load shedding is still valid. Incidentally, I
>>>discovered on the SD-8 literature that a Lycoming will need to run at
>>>2500 rpm to get the full 8 amps out of the SD-8. it's looking like
>>>about 6.8 amps at 2300 rpm. Your suggestion will mean both main and
>>>E-bus need to be switched on for normal operations. Bob has made
>>>note on many of his drawings that "all buses are on when the main is
>>>on". I've had that in mind when drawing this up. Having the E-bus
>>>switched on for normal ops means the backup alternator is always
>>>running, though as you've suggested it can be set lower than the
>>>main, and loaf along in the background. I need to get my head around
>>>this idea.
>>>A diode is very beneficial on the starter contactor.
>>>That's a whoops, should have added it to the drawing, I'll get it on
>>>there.
>>>Having a low voltage waring that is independent of the EFIS is
>>>useful. It is possible you will get immune to EFIS warnings
>>>Yes, I do agree here. I was hoping the 'alt out light' function of
>>>the main alternator would be a 'low voltage monitor' as B&C does on
>>>their newer AVC regulator. After exchanging a couple of emails with
>>>Tim at Plane Power, it indeed only sees the output within the
>>>alternator, nothing outside. I've already got the Dynon EMS with all
>>>the engine sensors, so it makes some sense to use what I've got. My
>>>thinking is if it becomes annoying I can add the separate voltage
>>>monitoring system after the fact. Tim at PP did mention that he
>>>regularly sees OBAM guys using the EFIS for voltage monitoring, and
>>>all too often they've got parameters set way too stringent, and get
>>>many nuisance warnings. As yet I haven't investigated what
>>>parameters and settings I can work with, so the external LV warning
>>>is always on the table.
>>>
>>>Thanks very much for the thoughts Peter. It's very useful to think
>>>through the questions and comments.
>>>
>>>Cheers
>>>Gerry
>>>
>>>
>>>------ Original Message ------
>>>From "Peter Pengilly" <peter@sportingaero.com>
>>>To aeroelectric-list@matronics.com
>>>Date 2023-12-29 2:11:12 AM
>>>Subject RE: AeroElectric-List: Tailwind Electrical System Drawing and
>>>Power Analysis
>>>
>>>>Why do you want to switch the SD-8 alternator?
>>>>
>>>>Why switch battery power to the bus twice?
>>>>
>>>>Use an externally regulated main alternator to avoid having to
>>>>switch the alternator output.
>>>>
>>>>Provide a method to connect the battery directly to the bus.
>>>>
>>>>Do not use a diode in the feed to the essential bus.
>>>>
>>>>There are a number of services connected directly to the battery
>>>>just waiting to flatten it
>>>>
>>>>
>>>>
>>>>If the voltage of the SD8 is set (say) 0.2v lower than the main
>>>>alternator it will not produce power if the main is on line. If the
>>>>main fails it takes up the load.
>>>>
>>>>For my liking you have too many relays between the battery and the
>>>>bus bar.
>>>>
>>>>If you use an externally regulated main alternator then initially
>>>>only switch on the SD8 on start up. Then power up the main
>>>>alternator regulator and bring that on line.
>>>>
>>>>Install a switch that powers up the essential (or main) bus directly
>>>>from the battery, if the switch is a double pole use the second pole
>>>>to disable the starter.
>>>>
>>>>The large diode in the feed line to the essential bus will always
>>>>drop the voltage by an amount. The benefit is auto load shedding but
>>>>do you need that with 2 alternators? If you really want to shed the
>>>>main bus use a large switch and ensure there is a path to the
>>>>essential bus directly from the battery. I used to have a feed diode
>>>>and would not use one again.
>>>>
>>>>A diode is very beneficial on the starter contactor.
>>>>
>>>>Having a low voltage waring that is independent of the EFIS is
>>>>useful. It is possible you will get immune to EFIS warnings
>>>>
>>>>
>>>>
>>>>Peter
>>>>
>>>>
>>>>
>>>>From:owner-aeroelectric-list-server@matronics.com
>>>><owner-aeroelectric-list-server@matronics.com> On Behalf Of Gerry
>>>>van Dyk
>>>>Sent: Thursday, December 28, 2023 11:32 PM
>>>>To:aeroelectric-list@matronics.com
>>>>Subject: AeroElectric-List: Tailwind Electrical System Drawing and
>>>>Power Analysis
>>>>
>>>>
>>>>
>>>>Hello again all
>>>>
>>>>Well, I think I'm ready for a good critique on my proposed
>>>>electrical system for my Tailwind project. For the most part it's
>>>>based on Z13/8, we're using a Plane Power AL12-E160 primary
>>>>alternator, and of course the B&C SD-8 backup alternator. The E160
>>>>is internally regulated, and also has an internal crowbar system and
>>>>alt-out panel light output, which I intend to use. The SD-8 has
>>>>their older PMR1 regulator, so we've got the external crowbar module
>>>>and no voltage sensing. I've drawn these items as shown on their
>>>>respective install instructions call for.
>>>>
>>>>
>>>>
>>>>As I mentioned earlier, I intended to start the engine on the
>>>>endurance bus, and check the SD-8 operation during the startup
>>>>procedure. I had neglected to think about where the starter was
>>>>going to get power from, so the idea has forced an additional switch
>>>>and relay (a rather robust one at that) to run the main bus. The
>>>>battery contactor would be closed for startup, then the SD-8
>>>>operation checked and finally the main bus would be brought up to
>>>>begin normal operation.
>>>>
>>>>
>>>>
>>>>I'm a little uneasy about this extra switching, as I know this group
>>>>is inclined toward fewer failure points, and with good reason. As I
>>>>look at the 'textbook' Z13/8 drawing, with my dual EFIS, IFR capable
>>>>panel in mind, it seems to me that a startup would bring the entire
>>>>panel up with the main bus, then with the engine running I'd have to
>>>>close the E-bus switch, open the battery contactor, dropping out
>>>>half the instrument panel. Then check the backup alternator
>>>>operation, and finally reboot the rest of the panel again. It just
>>>>really feels rather clunky to me.
>>>>
>>>>
>>>>
>>>>Bob, have I missed something with the original architecture concept?
>>>> Is there a way to check the backup alternator function while the
>>>>main bus is up and running? It would certainly help me simplify my
>>>>system.
>>>>
>>>>
>>>>
>>>>I'd appreciate if you good folks would give my drawing a good
>>>>review. Questions, comments and critiques are all welcome.
>>>>
>>>>
>>>>
>>>>Thanks again
>>>>
>>>>Gerry van Dyk
>>>>
>>>>Tailwind C-GVDZ
>>>>
Message 12
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| Subject: | Re: Plane Power alternator $$$$ |
Thanks Charlie, I will check out those wires. I dont think I have fuses in them
but will check all the connections. Its possible I could have damaged one of
the connections at the shunt when I was hurriedly removing the cover on the current
limiter (which is right above the shunt) after the original alternator failure.
Bob, I will try isolating all the loads. I think I already tried turning the avionics
master off, and I have turned off all the exterior lighting, but I will
try everything again. It could be the Dynon I could pull the fuse and run it
on its backup battery. Otherwise, there is only the alternator field, battery
solenoid, and elevator trim, and a USB charge outlet. I did unplug my phone,
but will try pulling the fuse.
Yes, the oscillation started when I installed the new alternator. The battery is
5 years old and I havent done a capacity test, and it did get deeply discharged
during the alternator failure flight.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=512982#512982
Message 13
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| Subject: | Re: Tailwind Electrical System Drawing and |
Power Analysis
I don't like the key switch.=C2- If you turn it off with the engine runn
ing it could cause a load dump by disconnecting the alternator from the bat
tery.=C2- Use a DPDT key switch to turn off the alternator as well, or I
used a momentary key switch in place of a pushbutton for the starter.=C2-
Not so much for theft protection, but to protect from having some kid (or
adult) accidentally engage the starter at Oshkosh.
On Friday, December 29, 2023 at 01:30:30 PM CST, Gerry van Dyk <gerry.v
andyk@eastlink.ca> wrote:
Hello again allPeter I'll follow-up here on those couple of points...
I've attached the latest revision to my architecture.=C2- Thinking about
what you've suggested, separating the main alternator to it's own switch, I
've done so, and it cleans up both the drawing and the electrical system qu
ite a bit.=C2- Effectively what we've done is separate the "battery / alt
/ DC power" switch shown on the Z13/8 drawing into two.=C2- I've got a k
eyed switch which I want for some basic theft deterrence, and then the main
alt switch.
In operation we'll turn on the main bus, which will mean the entire panel w
ill be up.=C2- The big consumers will of course be off, pitot heat, exter
ior lighting, AP servos, boost fuel pump, and the radios will be in passive
receive mode.=C2- At this point we'd close the ebus / aux alt switch and
start the engine. Dynon says this will not bring down the EFIS's so with t
he EMS operating we should see the aux alternator bump the voltage, I'd fli
p the switch on and off if need be to see this change.=C2- Satisfied that
the aux alternator is operating we'll then bring the main alternator onlin
e and turn the e-bus / aux alt switch off.=C2- Or I may come around on le
aving it on for normal operations.
For alternator-out condition: turn the e-bus / aux alt switch on, open the
main battery switch, dropping out the battery contactor and therefor the ma
in bus.=C2- If the main alt has failed or thrown the belt, it won't matte
r much if we turn off the main alt switch or not.
What are your thoughts on this layout?=C2- I known I haven't used all you
r suggestions, I hope you take no offense to it, I think some were moving a
way from the original Z13/8 philosophy which I do rather agree with.
Best regardsGerry
------ Original Message ------From "Gerry van Dyk" <gerry.vandyk@eastlink.c
a>To aeroelectric-list@matronics.comDate 2023-12-29 8:12:00 AMSubject Re[2]
: AeroElectric-List: Tailwind Electrical System Drawing and Power Analysis
Hi Peter, thanks for your thoughts.Why do you want to switch the SD-8 alter
nator?because it is shown on the original Z-13/8 drawing.=C2- I'm working
from rev T 1/07/14.=C2- Is there a later revision with this switch remov
ed?Why switch battery power to the bus twice?As I mentioned, I want to star
t the engine on the E-bus.=C2- I need to supply power to the starter, but
leave the main bus un-powered, in order to check the function of SD-8.=C2
- Supplying starting power through the E-bus seems impractical.Use an ext
ernally regulated main alternator to avoid having to switch the alternator
output.Yeah, I'm hamstringing myself a little bit here.=C2- I bought the
AL 12-E160 alt several years ago, I don't have a spare couple thousand doll
ars to buy another.=C2- I'll have to think about it better, but on the fa
ce of it, having a separate regulator doesn't seem to change how the altern
ator is controlled.=C2- Mr. Nuckolls has mentioned on many occasions that
we want to have definite control of the alternator output with a switch in
the cockpit.=C2- Z12/8 shows this switch in the center of the drawing.Pr
ovide a method to connect the battery directly to the bus.=C2- (I presume
your're talking about the main bus here.)Perhaps I'm being foolish here.
=C2- I'm placing an absolute requirement to check the operation of the ba
ckup alternator at the beginning of every flight.=C2- My life will depend
on it should the main alternator fail.=C2- With the main bus and main al
ternator connected directly to the battery contactor they will be running a
t startup.=C2- As yet I don't see a way to check the backup alternator op
eration with the main's running.=C2- I'd like to do so without turning ha
lf the panel on-off-on during startup.Do not use a diode in the feed to the
essential bus.This diode is called for by B&C on their installation drawin
g 504-500, and they provide it in the kit.=C2- What would be the reason t
o remove it?There are a number of services connected directly to the batter
y just waiting to flatten itQuite right, and this duplicates what'
s shown on Z13-8.=C2- They are a couple of conveniences, loading the bagg
age compartment, charging a phone etc, without having to turn on the batter
y master and it's relatively large current draw.=C2- In building my panel
, all switches will be down=off, and they're all in two rows so visually
obvious when left on.=C2- I'll have to have a quick scan of the panel whe
n leaving the airplane, and if I flatten the battery by mistake, my fault.I
f the voltage of the SD8 is set (say) 0.2v lower than the main alternator i
t will not produce power if the main is on line. If the main fails it takes
up the load.I presume you are making another case for removing the backup
alt switch.=C2- Again, it is called for on Z13/8, but your point is well
taken.For my liking you have too many relays between the battery and the bu
s bar.I absolutely agree, I haven't yet come up with an elegant solution to
check the backup alternator without cycling the avionics.If you use an ext
ernally regulated main alternator then initially only switch on the SD8 on
start up. Then power up the main alternator regulator and bring that on lin
e.I think we've covered this already.=C2- In order to start the engine I
need to switch on the battery contactor, which would also bring the main bu
s and main alt online.=C2- I could move the starter wire to the always-ho
t side of the battery contactor, so the mains are still inop, but with that
wire permanently hot, and 2 gauge wire at that, it violates the idea of ma
king the electrical system as inert as possible in a forced landing.=C2-
Again, I don't see the difference between an externally or internally regul
ated alternator.=C2- The red wire to lead 1 on the alt connector is the e
quivalent of the A wire on an external regulator, the jumper is the same as
one to the S wire, and the F wire is internal.Peter, writing this is makin
g me think about separating the main alt control to a separate switch.=C2
- Let me think that through a bit and I'll report back later.Install a sw
itch that powers up the essential (or main) bus directly from the battery,
if the switch is a double pole use the second pole to disable the starter.I
nteresting, I'll think that out as well.The large diode in the feed line to
the essential bus will always drop the voltage by an amount. The benefit i
s auto load shedding but do you need that with 2 alternators?=C2-=C2-If
you really want to shed the main bus use a large switch and ensure there i
s a path to the essential bus directly from the battery. I used to have a f
eed diode and would not use one again.Yes, I believe it is necessary.=C2-
8 amps will not power the entire panel, so the load shedding is still vali
d.=C2- Incidentally, I discovered on the SD-8 literature that a Lycoming
will need to run at 2500 rpm to get the full 8 amps out of the SD-8.=C2-
it's looking like about 6.8 amps at 2300 rpm.=C2- Your suggestion will me
an both main and E-bus need to be switched on for normal operations.=C2-
Bob has made note on many of his drawings that "all buses are on when the m
ain is on".=C2- I've had that in mind when drawing this up.=C2- Having
the E-bus switched on for normal ops means the backup alternator is always
running, though as you've suggested it can be set lower than the main, and
loaf along in the background.=C2- I need to get my head around this idea.
A diode is very beneficial on the starter contactor.That's a whoops, should
have added it to the drawing, I'll get it on there.Having a low voltage wa
ring that is independent of the EFIS is useful. It is possible you will get
immune to EFIS warningsYes, I do agree here.=C2- I was hoping t
he 'alt out light' function of the main alternator would be a 'low voltage
monitor' as B&C does on their newer AVC regulator.=C2- After exchanging a
couple of emails with Tim at Plane Power, it indeed only sees the output w
ithin the alternator, nothing outside.=C2- I've already got the Dynon EMS
with all the engine sensors, so it makes some sense to use what I've got.
=C2- My thinking is if it becomes annoying I can add the separate voltage
monitoring system after the fact.=C2- Tim at PP did mention that he regu
larly sees OBAM guys using the EFIS for voltage monitoring, and all too oft
en they've got parameters set way too stringent, and get many nuisance warn
ings.=C2- As yet I haven't investigated what parameters and settings I ca
n work with, so the external LV warning is always on the table.
Thanks very much for the thoughts Peter.=C2- It's very useful to think th
rough the questions and comments.
CheersGerry
------ Original Message ------From "Peter Pengilly" <peter@sportingaero.com
>To aeroelectric-list@matronics.comDate 2023-12-29 2:11:12 AMSubject RE: Ae
roElectric-List: Tailwind Electrical System Drawing and Power Analysis
Why do you want to switch the SD-8 alternator?
Why switch battery power to the bus twice?
Use an externally regulated main alternator to avoid having to switch the a
lternator output.
Provide a method to connect the battery directly to the bus.
Do not use a diode in the feed to the essential bus.
There are a number of services connected directly to the battery just waiti
ng to flatten it
=C2-
If the voltage of the SD8 is set (say) 0.2v lower than the main alternator
it will not produce power if the main is on line. If the main fails it take
s up the load.
For my liking you have too many relays between the battery and the bus bar.
If you use an externally regulated main alternator then initially only swit
ch on the SD8 on start up. Then power up the main alternator regulator and
bring that on line.
Install a switch that powers up the essential (or main) bus directly from t
he battery, if the switch is a double pole use the second pole to disable t
he starter.
The large diode in the feed line to the essential bus will always drop the
voltage by an amount. The benefit is auto load shedding but do you need tha
t with 2 alternators? If you really want to shed the main bus use a large s
witch and ensure there is a path to the essential bus directly from the bat
tery. I used to have a feed diode and would not use one again.
A diode is very beneficial on the starter contactor.
Having a low voltage waring that is independent of the EFIS is useful. It i
s possible you will get immune to EFIS warnings
=C2-
Peter
=C2-
From: owner-aeroelectric-list-server@matronics.com <owner-aeroelectric-list
-server@matronics.com> On Behalf Of Gerry van Dyk
Sent: Thursday, December 28, 2023 11:32 PM
Subject: AeroElectric-List: Tailwind Electrical System Drawing and Power An
alysis
=C2-
Hello again all
Well, I think I'm ready for a good critique on my proposed electrical syste
m for my Tailwind project.=C2- For the most part it's based on Z13/8, we'
re using a Plane Power AL12-E160 primary alternator, and of course the B&C
SD-8 backup alternator.=C2- The E160 is internally regulated, and also ha
s an internal crowbar system and alt-out panel light output, which I intend
to use.=C2- The SD-8 has their older PMR1 regulator, so we've got the ex
ternal crowbar module and no voltage sensing.=C2- I've drawn these items
as shown on their respective install instructions call for.
=C2-
As I mentioned earlier, I intended to start the engine on the endurance bus
, and check the SD-8 operation during the startup procedure.=C2- I had ne
glected to think about where the starter was going to get power from, so th
e idea has forced an additional switch and relay (a rather robust one at th
at) to run the main bus.=C2- The battery contactor would be closed for st
artup, then the SD-8 operation checked and finally the main bus would be br
ought up to begin normal operation.
=C2-
I'm a little uneasy about this extra switching, as I know this group is inc
lined toward fewer failure points, and with good reason.=C2- As I look at
the 'textbook' Z13/8 drawing, with my dual EFIS, IFR capable panel in mind
, it seems to me that a startup would bring the entire panel up with the ma
in bus, then with the engine running I'd have to close the E-bus switch, op
en the battery contactor, dropping out half the instrument panel.=C2- The
n check the backup alternator operation, and finally reboot the rest of the
panel again.=C2- It just really feels rather clunky to me.
=C2-
Bob, have I missed something with the original architecture concept?=C2-
Is there a way to check the backup alternator function while the main bus i
s up and running?=C2- It would certainly help me simplify my system.
=C2-
I'd appreciate if you good folks would give my drawing a good review.=C2-
Questions, comments and critiques are all welcome.
=C2-
Thanks again
Gerry van Dyk
Tailwind C-GVDZ
Message 14
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| Subject: | Re: Fusible links |
At 10:12 AM 12/29/2023, you wrote:
>Hi Chris;
>Hi All;
>That's a great demonstration Chris.
>And it evidences exactly why I would not use fusible links in an
>aircraft, or automobile for that matter.
>There's smoke, there's fire, and there's molten metal!
>With most fuses the burned wire, smoke, and fire are contained.
>Cheers! Stu.
Chris' demonstrations are essentially the
same as those I conducted 23 years ago
when this article was published on
the website.
https://tinyurl.com/msx5ofe
The original impetus for
the article was to craft a robust,
minimum labor, alternative to the
signal leads from a firewall mounted
shunt extending to the instrument on
the panel.
In this special case, the links
were out on the firewall . . .
having the links 'fuse' under
fiberglas sleeving presented
no special hazard.
AeroElectric -and- B&C sold
a goodly number of kits that
included the somewhat hard-to-
find silicon impregnated fiberglas
sleeve.
This was before I became aware
of sources for bulk, cut-n-terminate
fuse link wire which is now readily
available from a constellation
of sources.
This stuff is ordinary, stranded
copper wire insulated in 'magic
plastic'. One of the first materials
to be qualified was 'Hypalon' by
DuPont. It was favored for use in
all manner of industrial grade
electric vehicles including over
the rails engines, mining engines,
cranes, etc. Any situation where
people shared close spaces with
really fat wires.
The smoke emitted by a faulted
cable was very low toxicity and
irritation. Hence it became a go-to
choice for fusible links as well.
The stuff is TOUGH! It's used to
fabricate all manner of inflatable
rubber flotation. This toughness
goes to it's ability to contain
byproducts of the melted wire
within.
Hypalon is no longer made, newer
competitive products have forced it
out of the market place.
Due to the general ruggedness of
fusible link insulation, smaller
wire down to 22AWG is available for
nasty environment applications as
well as fusible links.
By the way, there's a rather extensive
SAE specification describing requirements
for fusible link fabrication and
peformance. Fusible links should qualify
to SAE J-1128 Type HTS. Fusible links
should not be used in systems
that exceed 50V.
At 60+ years, this is almost vintage
technology with well proven track
records.
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
In the interest of creative evolution
of the-best-we-know-how-to-do based
on physics and good practice.
Message 15
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| Subject: | Re: Re[3]: Tailwind Electrical System Drawing and Power |
Analysi
Suggestions:
Replace the 15A E-Bus fuse with a fusible link. It is not good practice to have
fuses in series.
Locate the E-Bus relay near the battery bus.
In the event of over voltage, the crowbar module will smoke.
Protect it with a 3 amp fuse or circuit breaker.
The 2A fuse in the battery contactor coil circuit is a good idea.
It will protect against reversed battery polarity. (It happens)
Consider using a Hall Effect sensor instead of a shunt, if compatible with your
Dynon.
The starter contactor diode is wired wrong. Connect the banded end to the "S"
terminal.
Connect the other end of the diode to the other end of the contactor coil (ground).
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=512985#512985
Message 16
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| Subject: | Re: Fusible links |
What I found very interesting is how often the melt/disconnect occurred
near the butt splices.
Seems to negate the theory of the splices and bigger wire leading away
the heat needing to melt the wire.
Any chance that you "nicked" one or more of the strands when stripping
the insulation?
Would be interesting to see the same experiment with soldered connections.
Finn
On 12/29/2023 10:30 AM, Christopher Cee Stone wrote:
> My very basic test rig with somewhat empirical results- no measured data.
>
> Objective: observe failure of fusible links of various lengths when
> subjected to a high current short circuit event.
>
> 12V wet cell, new, fully charged battery
> Knife switch
> 18 ga tefzel feeder, 20" length x2
> PIDG style butt splices (red)
> Camera
>
> DUT: 2", 6", 13" lengths 24 ga tefzel FL (M22759/16)
>
> Procedure:
> Fabricate fusiblelinks of 2, 6 an 13 inch lengths
> Crimp w/ AMP PIDG crimper to
> Feeder 20" 18 ga tefzel
> Clamp feeders to B+ Knife switch and B- battery terminal
> Start camera video
> Rabidly close switch
>
> Two inch FL setup
> 2InchSetup.jpg
> Crimp tool and butt splice
> AmpCrimpTool.jpg
> results:
>
> http://tinyurl.com/mryadbfx
>
> No fiberglas sleeve was used so that failure could be observed.
>
> Comments, questions, critique!
>
> ...chris
>
> On Sat, Dec 23, 2023 at 8:02AM Robert L. Nuckolls, III
> <nuckolls.bob@aeroelectric.com> wrote:
>
> At 09:31 AM 12/23/2023, you wrote:
>> Back to the original question of the length of a fusible link.
>> That is the length of smaller gauge wire comprising the 'link'.
>
>
> Had to do some 'digging' to see if I could
> find where that 3-6 inch citation came from.
> No joy.
>
> Actually, 6" is the minimum. 9" is more typical,
> 10" not unheard of. 3" is too short . . .
>
> . . . and INSULATED with material resistant to
> energy released by clearing the fault.
>
> See: http://tinyurl.com/4vnzdjpc
>
>
> <http://tinyurl.com/4vnzdjpc>
>
> Bob . . .
>
> ////
> (o o)
> ===========o00o=(_)=o00o========
> < Go ahead, make my day . . . >
> < show me where I'm wrong. >
> ================================
>
> In the interest of creative evolution
> of the-best-we-know-how-to-do based
> on physics and good practice.
>
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