Today's Message Index:
----------------------
0. 12:23 AM - Just A Few More Days To Make Your List Contribution... (Matt Dralle)
1. 05:19 AM - Re: Checklist for abnormal ops using Z-13/8 (Jared Yates)
2. 07:14 AM - Re: Z13/8 Rev Q comments (Jeff Page)
3. 07:34 AM - Re: peak loads for motors/pumps (Robert L. Nuckolls, III)
4. 09:27 AM - Re: Re: Z13/8 Rev Q comments (Robert L. Nuckolls, III)
5. 04:44 PM - Re: OV protection for Alt energized contactor (Noel Loveys)
6. 04:44 PM - Re: Noises in transmitted signals (Noel Loveys)
7. 08:08 PM - Re: OV protection for Alt energized contactor (Robert L. Nuckolls, III)
Message 0
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| Subject: | Just A Few More Days To Make Your List Contribution... |
There is less than a week left in this year's List Fund Raiser and only a few short
days to grab one of the great Contribution Gifts available this year. Support
is still significantly lagging behind last year at this point but hopefully
it will pick up here towards the end. Please remember that it is solely the
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I want to thank everyone that has already made a generous contribution to support
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Thank you!
Matt Dralle
Matronics EMail List and Forum Administrator
Message 1
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| Subject: | Re: Checklist for abnormal ops using Z-13/8 |
Have you considered turning everything off in the event of electrical smoke
instead of switching to ebus mode? My inclination would be something more
like this:
1: all electrical switches off
2: if smoke persists, open windows and vents and land as soon as possible,
off airport if necessary.
3: if smoke ceases, consider landing as soon as possible on an airport, or
if operationally necessary (IMC etc), energize ebus to see if smoke returns
4: if smoke returns, complete steps one and two above and stop checklist
5: if smoke does not return, continue to nearest airport.
6: if workload permits, declare an emergency and use hand-held backup radio
to alert SAR resources
On Tue, Nov 23, 2010 at 8:04 PM, Lincoln Keill <airlincoln@sbcglobal.net>wr
ote:
> I'm roughing out a draft for two abnormal electrical systems checklists f
or
> Z-13/8 using B&C's LR-3C regulator and a PC-680 battery. I'm sure someon
e
> has trod this ground already -- here's my first draft -- any comments or
> suggestions?
>
> LOW VOLTAGE LIGHT FLASHING
>
> 1. E-BUS ALT FEED switch ' ON
>
> 2. AUX ALT switch ' ON
>
> 3. If LOW VOLT light extinguishes / not flashing:
>
> 3A. DC POWER MASTER switch=97OFF
>
> 3B. Verify ENDURANCE BUS voltage > 13.0
>
> 3C. Continue to destination -- monitor E-BUS voltage
>
> 3D. On final approach ' DC POWER MASTER switch=97ON
>
> 4. If LOW VOLT light continues flashing:
>
> 4A. Hack clock / note time
>
> 4B. DC POWER MASTER switch ' OFF
>
> 4C. Transponder -- 7700
>
> 4D. Land at nearest suitable airport (within 60 minutes)
>
> 4E. On final approach ' DC POWER MASTER switch=97ON
>
>
> -------------------------------------------------------------------------
------------
>
> 5. Once on the ground & parked, begin troubleshooting
>
> 6. If ALT FLD circuit breaker is open/tripped (overvoltage):
>
> 6A. Reset CB and run engine -- note primary alternator field voltage
> using test probe
>
> 6B. Refer to AEC Page Z-8 for troubleshooting guidance
>
>
> *ELECTRICAL SMOKE / FIRE*
>
> *
> *
>
> 1. E-BUS ALT FEED switch ' ON
>
> 2. DC POWER MASTER switch ' OFF
>
> 3. Cabin heat ' OFF
>
> 4. Eyeball vents (both) ' FULL OPEN
>
> 5. Transponder -- 7700
>
> 6. Hack clock / note time
>
> 7. If smoke/fire diminishes/extinguishes:
>
> 7A. Land at nearest suitable airport (within 60 minutes)
>
> 8. If smoke/fire continues:
>
> 8A. Obtain VMC
>
> 8B. E-BUS ALT FEED switch ' OFF
> 8C. Land immediately
>
> *
>
===========
===========
===========
============*
>
>
Message 2
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| Subject: | Re: Z13/8 Rev Q comments |
> My battery will be on the front of the firewall. I planned the
> connections between busses, contactors and relays all to be less than
> 6", so I originally omitted fuses. I am minimizing my inventory by
> purchasing only 14, 18 and 22 gauge wire, since the numbers worked out
> that I would rarely need 16 and 20 gauge wire. So the 16 awg feeders
> changed to 14 awg.
>
> I can send you a chunk of any other size . . . but
> it would be better to go down as opposed to up
> in size for the un-fused, short wires. 20AWG would
> be fine. Use REAL PIDG terminals on these wires.
>
> Since my busses will be fuse blocks, it is quite easy to use one of
> the fuse positions to feed the bus. However, I would prefer fewer
> connections if you think the additional fuses are not needed.
>
> Okay, 20AWG and no fuses it is.
So assuming all these wires are 6" or less, should I use 20awg and no
fuses on both the diode and the relay path to the Endurance bus ?
> My "Endurance" bus grew. I will be flying IFR. My Plan B for a main
> alternator failure is to have a sufficient secondary alternator to
> continue to power one Dynon Skyview screen, a Garmin 430W, audio panel
> and instrument lights and some indicators. This could be 10A, peaking
> to 16A during transmissions. Rather than a load meter, the low
> voltage indicator will confirm that the secondary alternator is
> carrying the load. The dark and stormy night equipment is my Plan C.
>
> Okay, does your SD-8 drive pad give you 4000 rpm
> at engine red-line? Even then, you won't keep a low
> voltage warning light OFF during endurance operations.
> The SD-8 may be too small for your plan-b loads in
> an un-limited endurance mode. You may have to up-size
> the alternator or plan for using significant battery
> energy to support the e-bus. This is STILL much better
> than a battery-only scenario but might call for a
> comfortable plan-b endurance of 1 hour or so. You'll
> want to measure your REAL plan-b loads as soon as
> all the goodies can be fired up.
For a while, I was planning on a larger secondary alternator, but the
plan was getting out of control for an unlikely situation. Glenn's
comments make sense. I think I am better off minimizing the
electrical usage. Some of the items, like the Skyview will probably
take less in actual use than the rated maximum.
I can use a low voltage warning for the SD-8 with a lower voltage trip
point, so I know when the battery is actually carrying part of the load.
At 2700 rpm, the SD-8 will be turning 3500 rpm, with higher fuel
consumption. I can make that tradeoff in flight, depending on the
distance of the destination.
Jeff Page
Dream Aircraft Tundra #10
Message 3
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| Subject: | Re: peak loads for motors/pumps |
At 06:49 PM 11/23/2010, you wrote:
>Say you're doing your load analysis and you have a flap motor
>(running all of 30 seconds during a flight) that when turned on
>briefly draws 14 amps and then quickly settles down to 3.5 amps
>while running -- do you consider the "peak load" 14 amps or 3.5 amps
>as far as determining wire size and fuse size? Same question with a
>high pressure electric fuel pump for fuel injected engines.
Transient peak current demands are generally not part of
a load analysis because they are not high energy events.
By high energy, we're considering watt-seconds of demand
during a transient event is tiny when compared with the
sum total of all other loads.
Another example: The cold resistance of an 28v incandescent
landing light bulb can easily be under 1/2 ohm. 1/2 ohm
across 28v is 56 amps . . . except that this current is so
large compared to normal running current of say 4 amps,
the resistance of wring sized to OPERATED the lamp contributes
greatly to the mitigation of inrush current.
The energy demands of a start up transient (say 10A average
at 28v for .2 seconds) would be 56 watt-seconds. The energy
demands for the next ten minutes for approach to landing and
taxi in is (4A at 28v for 600 seconds) or 67200 watt-seconds.
A load analysis focuses on a flight-cycle. From master
switch ON to master switch OFF with one question in mind.
Does the power generation system produce enough energy to
recharge a battery used for cranking and to run all necessary
accessories for all phases of flight.
See the exemplar load analysis aids and samples at:
http://www.aeroelectric.com/PPS/Load_Analysis/
This does not mean that inrush currents are not an important
part of the system's performance analysis. Inrush currents
represent a potential for antagonizing other systems. I.e.,
as far as your GPS, EFIS, radio, or MP3 player is concerned,
turning on that landing light or pump motor is an influence
upon the quality of incoming power. A noise.
A low internal impedance of the battery goes to mitigation
of bus voltage excursions during the inrush event. Sizes of bus
feeders has a smaller but significant influence too. But as
a general rule, the only design consideration for wiring up
devices that produce large transient events is to make sure their
circuit protection doesn't nuisance trip.
Bob . . .
Message 4
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| Subject: | Re: Z13/8 Rev Q comments |
At 09:03 AM 11/24/2010, you wrote:
For a while, I was planning on a larger secondary alternator, but the
plan was getting out of control for an unlikely situation. Glenn's
comments make sense. I think I am better off minimizing the
electrical usage. Some of the items, like the Skyview will probably
take less in actual use than the rated maximum.
Exactly! I can't tell you how many exercises in load
analysis ended with considerable error in the final
totals. Not so much from a variance in the published
values for any one accessory . . . but when you have
dozens of accessories . . .
You know the ol' saw: "A million here, a billion there
and pretty soon, we're talking about real money!"
The neat thing about the e-bus architecture is the
ease with which an experimental direct measurement
of endurance loads can be accomplished. I've oft
pondered the notion of adding a shunt in series
with the e-bus alternate feed path. Silly of course,
this is a one-time exercise that does not justify
permanent installation of instrumentation.
I can use a low voltage warning for the SD-8 with a lower voltage trip
point, so I know when the battery is actually carrying part of the load.
At 2700 rpm, the SD-8 will be turning 3500 rpm, with higher fuel
consumption. I can make that tradeoff in flight, depending on the
distance of the destination.
Now you're THINKING about it. Today's bright stars
for plan-b may differ from what you ultimately
fly with. But every modification will go toward
establishing and meeting design goals for NEVER
experiencing an electrical emergency.
Bob . . .
Message 5
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| Subject: | OV protection for Alt energized contactor |
What causes the light to flash? I don't even see an enunciator light in the
schematic.
Noel
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: November 23, 2010 7:20 PM
Subject: RE: AeroElectric-List: OV protection for Alt energized contactor
<nuckolls.bob@aeroelectric.com>
At 01:49 PM 11/23/2010, you wrote:
<noelloveys@yahoo.ca>
>
>Looks to me if the S terminal of your Ford regulator senses too high a
>voltage for any reason then it will cut all power to the F terminal of your
>alternator. Problem with this set up is that it doesn't give you an
>indication that you have gone into an OV situation.
OV is a transient event . . . perhaps 100 mS long followed
by a very long LV condition which flashes a light.
Bob . . .
Message 6
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| Subject: | Noises in transmitted signals |
Hams ( amateur operators ) still do!
Noel
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
RGent1224@aol.com
Sent: November 23, 2010 8:45 PM
Subject: Re: AeroElectric-List: Noises in transmitted signals
Back in the '50's we called that a dummy load for testing the rig
D
In a message dated 11/23/2010 3:48:46 P.M. Central Standard Time,
noelloveys@yahoo.ca writes:
If you want to try this you can wire a light bulb of sufficient wattage
across the antenna terminals. Don=995t be surprised if the light
bulb glows when the PTT is keyed.
Message 7
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| Subject: | OV protection for Alt energized contactor |
At 06:24 PM 11/24/2010, you wrote:
>
>What causes the light to flash? I don't even see an enunciator light in the
>schematic.
Depends on who's LV warning device one chooses to install . . .
but all those offered in the past and future from AEC have
flashers built in. For an exemplar schematic of a discontinued
product, see:
http://www.aeroelectric.com/Catalog/AEC/9005/LV_Warn_Fab_and_Install.pdf
This and similar LV warning devices are shown on every
one of the Z-figures. It drives an LED lamp fixture
placarded LV WARN.
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
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