REFLECTOR: Load distrib

[Al Gietzen]

Y'all,

 

Great posts!!   Geez I am going to have to get and get trained in speed
reading!  Several have mentioned dual screen GRT's, but I didn't see mention
of dual AHRS.  So here's my two part question:

 

Q #1.  What are you guys doing for attitude/airspeed indicator back up when
AHRS goes bad?  

Terry;

 

My engine monitor includes readout of true air speed, vertical speed, and
density altitude, along with RPM and all the engine stuff; so in the event
of AHRS or screen failure, I have those as backup.  The TruTrak Pictorial
Pilot AP has attitude indication in the roll axis.

   

Where's everybody mounting their EIS 6000's.  In pilot's eye view or
elsewhere?

 

My dual screens are side by side, and since my EM does not feed the EFIS
screen; the engine monitor screen is centered directly underneath.  It's a 3
screen setup. The controls for the engine control computer is right under
that.

 

In addition to what I call 'engine critical' bus fed directly from both
batteries (with isolation diodes), I have the breaker buses separated into
essential and distribution, connected through a breaker switch.  If I need
to cut load I can hit that switch and cut non-essential.  If I need to go
further it is switching off individual items.

 

 

 

 

 

 

 : reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf
Of Craig and/or Denise Woolston
Sent: Friday, February 25, 2005 10:30 AM
To: 'Velocity Aircraft Owners and Builders list'
Subject: RE: REFLECTOR: electrical sys design

John and I are going with a dual alternator/dual battery system also.  We
are going the dual screen GRT also.  Add to that the Blue Mountain G3 with
autopilot and we basically have dual everything except the engine.  My plan
is the 70amp alternator that came with our IO-550 and either the 7 or 20 amp
vacuum pump pad B&C.  The essential bus will have the radio, transponder, BM
EFIS, EIS.  The main bus everything else.  I want to know that both my
alternators are working before launching into the soup so both will be
"active" all the time.  We plan to use Bob's Low Voltage Module to auto
connect the Essential to the Main if the Essential alternator goes down.  We
will have a crossfeed switch OFF/AUTO/ON.  The AUTO will be Normal Ops so
there is no pilot work load during a failure.  If the ESSENTIAL does down,
then it will auto switch to the MAIN.  If the MAIN alternator goes down then
we get the Low Volt on MAIN and can when pilot work load dictates go to
forced XFEED.  The Low Volt Module will then flash if the load is too great,
so we can shed what we need to as appropriate.

 

Currently I'm thinking a 24ah for starting and the main bus and a 17ah or
smaller for the essential bus.  My thought is to always start on the 24 and
then 17 is only seeing starting operations on those cold mornings or hot
starts that go bad???  Plus there will be no voltage sag on the 17 under
normal start so the EIS will be available immediately.

 

My solution for the below is three annunciator, a LOW VOLT and then under it
a MAIN and ESTL, which will light as described above.  Plus the EIS is on
the ESSENTIAL bus so it will read that voltage and the GRT EFIS is on the
MAIN bus so it will read that one.  Which should trigger my other
annunciators a ENGINE and a EFIS.  I'll be looking at a fricking XMAS tree
which will be hard to miss.

 

 

Craig

XL-5FG in Palmdale,CA

 


  _____  


From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Terrence Miles
Sent: Thursday, February 24, 2005 6:14 PM
To: 'Velocity Aircraft Owners and Builders list'
Subject: RE: REFLECTOR: electrical sys design

 

If it works out that way then I'll drop to a motorcycle batt with an ammeter
and voltmeter on the primary system  Then I understand that there is an aux
plug on the GRT EIS audio warning I could steal and/or maybe set abnormal
range gauge readings  to a master caution.   One problem w/ electrical
abnormals is you don't see 'em until the lights go out.

 

 

 

 

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