Today's Message Index:
----------------------
1. 05:29 AM - Re: Z101 with Rotax 915iS (Matthew S. Whiting)
2. 06:31 AM - Re: Re: Z101 with Rotax 915iS (Matthew S. Whiting)
3. 09:18 AM - Re: What is an RG battery? (BonniCase)
4. 09:36 AM - Re: Z101 with Rotax 915iS (Ernest Christley)
5. 10:44 AM - Re: digest distribution stopped? (farmrjohn)
6. 11:27 AM - Re: With Flooded cells, at what discharge does damage start? (skywagon185guy .)
7. 11:45 AM - Re: SDS CPI-2 internal crowbar (Robert L. Nuckolls, III)
8. 01:30 PM - Re: Re: Z101 with Rotax 915iS (Ken Ryan)
9. 01:31 PM - Re: Z101 with Rotax 915iS (Ernest Christley)
10. 02:16 PM - Re: Surplus Wire (BMC_Dave)
11. 02:50 PM - Re: Re: Surplus Wire (Charlie England)
12. 03:26 PM - Re: With Flooded cells, at what discharge does damage start? (Ernest Christley)
13. 03:32 PM - Re: Re: Z101 with Rotax 915iS (Ernest Christley)
14. 03:52 PM - Re: Re: Z101 with Rotax 915iS (C&K)
15. 05:00 PM - Z-11 ground avionics bus question (Ben Beaird)
16. 05:07 PM - Re: Re: Surplus Wire (Robert L. Nuckolls, III)
17. 05:08 PM - Re: Z-11 ground avionics bus question (Robert L. Nuckolls, III)
18. 08:00 PM - Re: Surplus Wire (BMC_Dave)
Message 1
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| Subject: | Re: Z101 with Rotax 915iS |
Yes, exactly what I was looking at. I would probably spring a few hundred m
ore for a B&C unit, but I suspect a car one would do the job as a second alt
ernator. I am attending the Lockwood installation course in August, assumin
g covid doesn=99t return and kill it, so I will know more then and be a
ble to ask some questions, but it looks very doable with the Rotax pulley an
d mounting rings. Although those pieces alone are about $1,000 as I recall.
Crazy expensive, but then I own a BMW motorcycle so I am used to parts tha
t cost 3X what they should.
Matt
> On Jun 17, 2020, at 5:13 AM, Charlie England <ceengland7@gmail.com> wrote:
>>
> Followup; if this is the right option, looks like you could buy all the Ro
tax drive & mounting bits, and still save about $1000 on the alternator itse
lf, by using an off the shelf automotive model. The image in that parts brea
kout looks like a very common Nippon Denso internally regulated alternator t
hat's available in output levels from around 35A to over 55A. They're all ba
sically the same external dimensions.
>
> Charlie
Message 2
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| Subject: | Re: Z101 with Rotax 915iS |
I believe Joe is correct and this is the reason I desire an external alternator.
Even though the 915 has two alternators, it effectively only has one from the
perspective of ships power. From page 3 of the Appendix to the Rotax 915iS
installation manual.
Engagement of the backup power supply system Generator B is done by the Engine
Control Unit (ECU) in the case of over voltage and under voltage. If the voltage
of power supply system Generator A decreases signifi- cantly or at all, the
control transition of the power supplies is additionally done per mechanical
means (relays drop out). These mechanism allow engagement of backup power supply
under every probable circumstance.
If power supply system Generator B is used to supply the aircraft electrical system
(possible in common opera- tion mode) it must be noted that in case of failure
this power supply system B is disconnected from the aircraft to serve as
the backup to the EMS.
> On Jun 17, 2020, at 5:15 AM, Ken Ryan <keninalaska@gmail.com> wrote:
>
>
> All accurate Joe. But I think there is a wrinkle. It is my understanding that
if Gen A fails, AND the Emergency Power Switch is closed, THEN Gen B will operate
both Engine and power the Bus. At least that's my understanding.
Message 3
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| Subject: | Re: What is an RG battery? |
Hello....i didn't have good experience with RG battery. If you are having with
your battery backup. If possible, try connecting it to a different outlet. If
it is in a surge protector, remove it off the surge protector and connect it directly
to the outlet. If there are still issues, it may be an issue with the
unit itself.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=496883#496883
Message 4
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| Subject: | Re: Z101 with Rotax 915iS |
$1,000?!=C2- For a pulley and some brackets?For those prices, you could
have a machine shop design and custom build the pieces.=C2- Does no on in
your EAA chapter own a lathe?=C2- No one around you does aluminum castin
g?
I mean, c'mon Rotax.=C2- I understand you've got to make a profit.=C2-
But, you don't have to make it all off of one sale.
On Wednesday, June 17, 2020, 8:30:21 AM EDT, Matthew S. Whiting <m.whit
ing@frontier.com> wrote:
Yes, exactly what I was looking at. =C2-I would probably spring a few hu
ndred more for a B&C unit, but I suspect a car one would do the job as a se
cond alternator. =C2-I am attending the Lockwood installation course in A
ugust, assuming covid doesn=99t return and kill it, so I will know mo
re then and be able to ask some questions, but it looks very doable with th
e Rotax pulley and mounting rings. =C2-Although those pieces alone are ab
out $1,000 as I recall. =C2-Crazy expensive, but then I own a BMW motorcy
cle so I am used to parts that cost 3X what they should. =C2-
Matt
On Jun 17, 2020, at 5:13 AM, Charlie England <ceengland7@gmail.com> wrote:
Followup; if this is the right option, looks like you could buy all the Rot
ax drive & mounting bits, and still save about $1000 on the alternator itse
lf, by using an off the shelf automotive model. The image in that parts bre
akout looks like a very common Nippon Denso internally regulated alternator
that's available in output levels from around 35A to over 55A. They're all
basically the same external dimensions.
Charlie
Message 5
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| Subject: | Re: digest distribution stopped? |
Well, still no digest even after supposedly re-subscribing with the Matronics Email
Distribution Tool and completing the email confirmation link. The tool shows
subscribed to the AeroElectric list but I haven't received any digests like
I had been. Is anyone else experiencing this?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=496886#496886
Message 6
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| Subject: | Re: With Flooded cells, at what discharge does damage |
start?
Solar charger.....
These are wonderful for certain applications, but, not for flooded 12v
common batteries. A "12v panel", can raise to 18v on a sunny day.
Even if it is only pumping out 0.1 amp, that will overcharge most lead acid
batteries eventually, leading to "gassing".
A cheap fix possible for using a low current panel is to trap the voltage
output with a zener type diode or similar chosen to shunt current at some
recommended voltage.
On Sat, Jun 13, 2020 at 5:41 PM Ernest Christley <echristley@att.net> wrote:
> Would a solar trickle charger help? I got one off Amazon for less than
> $15 that is flexible and tops out at 14.4V.
>
> On Saturday, June 13, 2020, 10:25:34 AM EDT, Steve Stearns <
> steve@tomasara.com> wrote:
>
>
> Greetings,
>
> This isn't a relevant question for modern aircraft but I think the
> membership of this list will likely know so I hope I don't bother anyone by
> posting here.
>
> If you have a rarely used car with a traditional flooded cell lead-acid
> battery and keep an eye on the battery voltage, at what voltage should it
> be recharged to maintain a normal life? My old jeep has a small load while
> parked so the battery slowly drains and it is neither convenient for me to
> disconnect the battery nor keep a maintainer connected. If I charge it
> back up with my smart charger before the (nominally 70deg f) battery
> voltage drops to say, 12V will I still get full life out of the battery?
>
> Thanks in advance,
> Steve Stearns
> O235 Longeze
> Boulder/Longmont CO
>
Message 7
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| Subject: | Re: SDS CPI-2 internal crowbar |
At 04:44 PM 6/16/2020, you wrote:
>This thread over on VAF is interesting. I have
>the CPI-2 with their recommended small backup
>battery in my single-alternator, single-battery
>(for the main electrical system) VFR-only airplane.=C2
>
>I'm planning an IFR upgrade with a full suite of
>Garmin G3X goodies, and want to follow the Z101 architecture. =C2
>
>It seems that their internal crowbar & fuse
>leave me stuck with their backup battery. =C2
>
><http://www.vansairforce.com/community/showthread.php?t=154648&page=34>
http://www.vansairforce.com/community/showthread.php?t=154648&page=34
This thread is a bit mystifying. OV conditions come from
one and only one source(s) . . . alternators with failed
regulators.
An OV condition is not a transient event . . . it's
a consistently rising voltage that will generally
be limited by the battery(ies) as their chemistry
gamely absorbs the excess energy condition. Hence
the voltage does not rise quickly (i.e. volts per
second) but rather sedately in electronic terms.
For decades we have been designing, qualifying and
integrating aviation electro-whizzies that are
capable players in the wild and wooley world
of vehicular DC power systems . . . matters not
whether cars, trucks, earth movers . . . or
airplanes.
In 1935 some pretty smart cookies in
the aviation industry got together in Washington
DC and founded the Radio Technical Commission
for Aeronautics (known today as RTCA).
https://tinyurl.com/y78zvrt8
For 85 years these folk have been sifting the
sands of physics in performance of electrical
and electronics systems for aircraft. Their
goal was to craft guidelines for the design
and qualification of all manner of electrical
accessory to (1) insure design performance
under all anticipated conditions and (2)
make sure that all accessories 'play nice'
in the same sandbox such that arguments
and spats do not put airframe or crew
at risk.
When it comes to ov definition, detection
and response, the attached figures speak
to 70+ years of design philosophy in
aviation electrical systems. 14V devices
are TESTED to withstand 20V perturbations
for 1S and 30 (or 40) Volt perturbations
for 100mS.
Every device bolted to an airplane is
expected to shrug off bus voltage
perturbations between the high and
low voltage plots for intervals of
time laid out on the x-axis. When
tasked with my first ov relay design
about 1975, the rule of thumb was to
design for a 50mS response to a step
increase in bus voltage from 14.2
to 20 volts.
While the electronics were solid-state,
the 'timers' were pretty crude by contemporary
standards. Today, micro-controllers
allow us to start a timer when the
voltage exceeds some lower discriminator,
say 15 volts. If the voltage stays above
that value for 500 milliseconds, we
trip the ov protection system. If the
voltage falls below 15v before
time-out, the timer resets and the process
starts over.
This all but eliminates nuisance tripping
of an ov protection system while offering
robust but timely management of a recalcitrant
regulator/alternator.
Contemporary design recommendations are
not difficult to accommodate . . . been
doing it for decades. I've designed
many products, some incorporating delicate
silicon, wherein power was supplied
directly from ship's bus . . .
Often we were requested to qualify for
indirect effects of lightning strike. Again,
not difficult.
I hope this lays foundation for consternation
felt when I read about difficulties builders are
having with the built-in ov protection on
some product. It's even more difficult
to understand how suppliers can offer
what appears to be capable of producing
really gee-whiz performance in some device
but are unable to tailor electrical input-output
ports to comfortably thrive in the aircraft
environment. Adding any form of OV 'protection'
to an accessory is completely redundant; i.e.
unnecessary.
Bob . . .
Message 8
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| Subject: | Re: Z101 with Rotax 915iS |
If Gen A fails, the ECU will disconnect Gen B from the charging system
(battery) and connect it to essential engine loads. Rotax does not want you
to do it, but if you then close the Emergency Power switch, Gen B will also
be re-connected to the charging system. In this condition, it would be
possible to load the generator to the point where voltage drops to a level
where the essential engine equipment fails. Because Rotax does not publish
how much current the engine requires, it is difficult to determine what is
safely available for running non-engine equipment.
On Wed, Jun 17, 2020 at 5:37 AM Matthew S. Whiting <m.whiting@frontier.com>
wrote:
> m.whiting@frontier.com>
>
> I believe Joe is correct and this is the reason I desire an external
> alternator. Even though the 915 has two alternators, it effectively only
> has one from the perspective of ship=99s power. From page 3 of the
Appendix
> to the Rotax 915iS installation manual.
>
> =9CEngagement of the backup power supply system Generator B is done
by the
> Engine Control Unit (ECU) in the case of over voltage and under voltage.
If
> the voltage of power supply system Generator A decreases signifi- cantly
or
> at all, the control transition of the power supplies is additionally done
> per mechanical means (relays drop out). These mechanism allow engagement
of
> backup power supply under every probable circumstance.
>
> If power supply system Generator B is used to supply the aircraft
> electrical system (possible in common opera- tion mode) it must be noted
> that in case of failure this power supply system B is disconnected from t
he
> aircraft to serve as the backup to the EMS.=9C
>
>
> > On Jun 17, 2020, at 5:15 AM, Ken Ryan <keninalaska@gmail.com> wrote:
> >
> > =EF=BB
> > All accurate Joe. But I think there is a wrinkle. It is my understandin
g
> that if Gen A fails, AND the Emergency Power Switch is closed, THEN Gen B
> will operate both Engine and power the Bus. At least that's my
> understanding.
>
>
===========
===========
===========
===========
===========
>
>
Message 9
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| Subject: | Re: Z101 with Rotax 915iS |
$1,000?!=C2- For a pulley and some brackets?For those prices, you could
have a machine shop design and custom build the pieces.=C2- Does no on in
your EAA chapter own a lathe?=C2- No one around you does aluminum castin
g?
I mean, c'mon Rotax.=C2- I understand you've got to make a profit.=C2-
But, you don't have to make it all off of one sale.
On Wednesday, June 17, 2020, 8:30:21 AM EDT, Matthew S. Whiting <m.whit
ing@frontier.com> wrote:
Yes, exactly what I was looking at. =C2-I would probably spring a few hu
ndred more for a B&C unit, but I suspect a car one would do the job as a se
cond alternator. =C2-I am attending the Lockwood installation course in A
ugust, assuming covid doesn=99t return and kill it, so I will know mo
re then and be able to ask some questions, but it looks very doable with th
e Rotax pulley and mounting rings. =C2-Although those pieces alone are ab
out $1,000 as I recall. =C2-Crazy expensive, but then I own a BMW motorcy
cle so I am used to parts that cost 3X what they should. =C2-
Matt
On Jun 17, 2020, at 5:13 AM, Charlie England <ceengland7@gmail.com> wrote:
Followup; if this is the right option, looks like you could buy all the Rot
ax drive & mounting bits, and still save about $1000 on the alternator itse
lf, by using an off the shelf automotive model. The image in that parts bre
akout looks like a very common Nippon Denso internally regulated alternator
that's available in output levels from around 35A to over 55A. They're all
basically the same external dimensions.
Charlie
Message 10
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| Subject: | Re: Surplus Wire |
The shield is sized for the combined current of the wires right? I'd like to use
it for the other current conductor if I can.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=496895#496895
Message 11
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| Subject: | Re: Surplus Wire |
On Wed, Jun 17, 2020 at 4:23 PM BMC_Dave <bmcdave85@gmail.com> wrote:
>
> The shield is sized for the combined current of the wires right? I'd like
> to use it for the other current conductor if I can.
>
>
> *In general*, that's not a bet I'd make, because shields are, well,
shields. You don't normally see them carrying serious current, in the sense
of actual power (RF transmission lines obviously excepted). Having said
that, if we're still talking about 24 awg wire, it's extremely unlikely
that the shield would be any smaller than that. If you're talking about
using the shield for a single circuit's ground return, it sounds
reasonable, but check for yourself by stripping a conductor, measuring
approx. dia. with calipers, and then do the same with the shield 'drain'
wire, assuming that it's a foil style shield. If it's braided copper
strands, then the effective gauge might well be much larger than the
combination of all 5 conductors combined. Just check it. Compute cross
sectional area for a bare 24 awg wire, and do the same for the shield
drain, using the basic pi * r^2 formula for the area of a circle.
Message 12
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| Subject: | Re: With Flooded cells, at what discharge does damage |
start?
I recently bought a solar panel that maxes out at 14.4V.=C2- It was adve
rtised for that, but I tested it anyway.=C2- Given that it will output 0.
0V half the time, it's max output of 0.38A should be just right.
It's flexible, and I attached to my canopy cover with velcro.
On Wednesday, June 17, 2020, 2:28:06 PM EDT, skywagon185guy . <skywagon
185@gmail.com> wrote:
Solar charger.....These are wonderful for certain applications, but, not f
or flooded 12v common batteries.=C2- A "12v panel", can raise to 18v on a
sunny day.Even if it is only pumping out 0.1 amp, that will overcharge mos
t lead acid batteries eventually, leading to "gassing".A cheap fix possible
for using=C2-a low current panel is to trap the voltage output with a ze
ner type diode or similar chosen to shunt current at some recommended volta
ge.
On Sat, Jun 13, 2020 at 5:41 PM Ernest Christley <echristley@att.net> wrote
:
Would a solar trickle charger help?=C2- I got one off Amazon for less th
an $15 that is flexible and tops out at 14.4V.
On Saturday, June 13, 2020, 10:25:34 AM EDT, Steve Stearns <steve@tomas
ara.com> wrote:
Greetings,
This isn't a relevant question for modern aircraft but I think the membersh
ip of this list will likely know so I hope I don't bother anyone by posting
here.
If you have a rarely used car with a traditional flooded cell lead-acid bat
tery and keep an eye on the battery voltage, at what voltage should it be r
echarged to maintain a normal life?=C2- My old jeep has a small load whil
e parked so the battery slowly drains and it is neither convenient for me t
o disconnect the battery nor keep a maintainer connected.=C2- If I charge
it back up with my smart charger=C2-before the (nominally 70deg f) batte
ry voltage drops to say, 12V will I still get full life out of the battery?
Thanks in advance,Steve StearnsO235=C2-LongezeBoulder/Longmont CO
Message 13
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| Subject: | Re: Z101 with Rotax 915iS |
They don't publish how much the engine requires, but would it be difficult
to insert a meter between the generator and the engine bus?
On Wednesday, June 17, 2020, 4:31:44 PM EDT, Ken Ryan <keninalaska@gmai
l.com> wrote:
If Gen A fails, the ECU will disconnect Gen B from the charging system (ba
ttery) and connect it to essential engine loads. Rotax does not want you to
do it, but if you then close the Emergency Power switch, Gen B will also b
e re-connected to the charging system. In this condition, it would be possi
ble to load the generator to the point where voltage drops to a level where
the essential engine equipment fails. Because Rotax does not publish how m
uch current the engine requires, it is difficult to determine what is safel
y available for running non-engine equipment.
On Wed, Jun 17, 2020 at 5:37 AM Matthew S. Whiting <m.whiting@frontier.com>
wrote:
ontier.com>
I believe Joe is correct and this is the reason I desire an external altern
ator.=C2- Even though the 915 has two alternators, it effectively only ha
s one from the perspective of ship=99s power.=C2- From page 3 of th
e Appendix to the Rotax 915iS installation manual.
=9CEngagement of the backup power supply system Generator B is done b
y the Engine Control Unit (ECU) in the case of over voltage and under volta
ge. If the voltage of power supply system Generator A decreases signifi- ca
ntly or at all, the control transition of the power supplies is additionall
y done per mechanical means (relays drop out). These mechanism allow engage
ment of backup power supply under every probable circumstance.
If power supply system Generator B is used to supply the aircraft electrica
l system (possible in common opera- tion mode) it must be noted that in cas
e of failure this power supply system B is disconnected from the aircraft t
o serve as the backup to the EMS.=9C
> On Jun 17, 2020, at 5:15 AM, Ken Ryan <keninalaska@gmail.com> wrote:
>
> =EF=BB
> All accurate Joe. But I think there is a wrinkle. It is my understanding
that if Gen A fails, AND the Emergency Power Switch is closed, THEN Gen B w
ill operate both Engine and power the Bus. At least that's my understanding
.
-
Electric-List" rel="noreferrer" target="_blank">http://www.matronics.co
m/Navigator?AeroElectric-List
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eferrer" target="_blank">http://forums.matronics.com
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=C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin.
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Message 14
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| Subject: | Re: Z101 with Rotax 915iS |
Well on the 912is since gen A is rated at 16 amps and gen B at 30 amps
that's a big hint.
But then I read that having both fuel pumps on might trip off gen A
which just seems like poor design if true.
Don't know if this is the same on the 915.
Ken L.
On 17/06/2020 10:07 AM, Ken Ryan wrote:
> If Gen A fails, the ECU will disconnect Gen B from the charging system
> (battery) and connect it to essential engine loads. Rotax does not
> want you to do it, but if you then close the Emergency Power switch,
> Gen B will also be re-connected to the charging system. In this
> condition, it would be possible to load the generator to the point
> where voltage drops to a level where the essential engine equipment
> fails. Because Rotax does not publish how much current the engine
> requires, it is difficult to determine what is safely available for
> running non-engine equipment.
>
> On Wed, Jun 17, 2020 at 5:37 AM Matthew S. Whiting
> <m.whiting@frontier.com <mailto:m.whiting@frontier.com>> wrote:
>
> <m.whiting@frontier.com <mailto:m.whiting@frontier.com>>
>
> I believe Joe is correct and this is the reason I desire an
> external alternator. Even though the 915 has two alternators, it
> effectively only has one from the perspective of ships power.
> From page 3 of the Appendix to the Rotax 915iS installation manual.
>
> Engagement of the backup power supply system Generator B is done
> by the Engine Control Unit (ECU) in the case of over voltage and
> under voltage. If the voltage of power supply system Generator A
> decreases signifi- cantly or at all, the control transition of the
> power supplies is additionally done per mechanical means (relays
> drop out). These mechanism allow engagement of backup power supply
> under every probable circumstance.
>
> If power supply system Generator B is used to supply the aircraft
> electrical system (possible in common opera- tion mode) it must be
> noted that in case of failure this power supply system B is
> disconnected from the aircraft to serve as the backup to the EMS.
>
>
> > On Jun 17, 2020, at 5:15 AM, Ken Ryan <keninalaska@gmail.com
> <mailto:keninalaska@gmail.com>> wrote:
> >
> >
> > All accurate Joe. But I think there is a wrinkle. It is my
> understanding that if Gen A fails, AND the Emergency Power Switch
> is closed, THEN Gen B will operate both Engine and power the Bus.
> At least that's my understanding.
>
>
> ==========
> -
> Electric-List" rel="noreferrer"
> target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
> ==========
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> eferrer" target="_blank">http://forums.matronics.com
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Message 15
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| Subject: | Z-11 ground avionics bus question |
I hope the answer to this question is not too obvious;
On Z-11 (and others), the connection between the instrument panel ground
bus and the avionics ground bus is designated 5X20AWG. What exactly does
that mean?
- Do I take up 5 tabs on my ground buses with 20 ga wires?
Thanks,
Ben
Glastar
Message 16
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| Subject: | Re: Surplus Wire |
At 04:12 PM 6/17/2020, you wrote:
>
>The shield is sized for the combined current of the wires right? I'd
>like to use it for the other current conductor if I can.
NO . . . it's for conducting the products of electro-static
coupling. Essentially zero current. Run AMPs through
a known length of shield, measure voltage drop through
that segment. Compute the AWG equivalent from the
resistance values in a wire table.
Bob . . .
Message 17
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| Subject: | Re: Z-11 ground avionics bus question |
At 06:57 PM 6/17/2020, you wrote:
>I hope the answer to this question is not too obvious;
>
>On Z-11 (and others), the connection between the
>instrument panel ground bus and the avionics
>ground bus is designated 5X20AWG. What exactly does that mean?=C2
> * Do I take up 5 tabs on my ground buses with 20 ga wires?
Yeah . . . 5 separate strands of 20AWG as long as
you have the spares . . . otherwise . . . plan-B.
The individual strands are easy.
Bob . . .
Message 18
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| Subject: | Re: Surplus Wire |
Looking at the BMS13-48 spec the flat shield is tin coated copper, 0.0015" +-.0004
thk and 0.020" wide. I counted 16 strands in the braid I disassembled.
So 0.02"x.0011"x16 is 0.000352 sqin area, which is between 13-14ga (13.6, apparently).
So that's what, 20ish Amps conservatively?
So the 5x 24ga conductors, slightly de-rated to 10A, seems the shield would be
more than up to it.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=496905#496905
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