REFLECTOR: Bus, Battery & Back Order

Keith Hallsten KeithHallsten at quiknet.com
Wed Jun 15 21:35:43 CDT 2005


Terry,

Waiting for exhaust?  As I recall, Clint Anderson had mine in my hands the
same week I ordered it, even though I told him there was no rush.  They were
custom made with a 45-degree bend aft where the stacks come through the
cowl, but otherwise like the "straight down" Velocity IO-540 stacks in the
photo on the Custom Aircraft Parts website.  Beautiful work, too.

Your scheme for electrical seems pretty reasonable to me.  As long as you
have active notification of a low-voltage condition, it's not that hard to
shed load manually, and it's not an emergency.

I have also been meditating on backup for the single-AHRS, two-display GRT
EFIS.  Although I may change my mind again, I am also settling on mechanical
airspeed and altimeter.  Therefore, I'll probably leave out the backup
airspeed and altimeter in the EIS - I'll talk to them at OSH next month
about the value of cross-check info to the EFIS.  The GRT EIS 6000 will be
the only source of engine instrumentation (loss of engine instruments is a
nuisance, not an emergency).  I plan to use either a TruTrak Pictorial Pilot
or their upcoming ADI Pilot as the
autopilot-and-combination-backup-attitude-indicator.  After that, the
backups come out of the flight bag!

I'm going with the internal GPS in the EFIS as the only panel-mount GPS for
the first couple of "VFR only" years.  I plan to leave a space for a GNS
430, but not install it until and unless I establish that I need the
additional capability the way I fly.  I'll have a handheld GPS with fresh
batteries up and running on cross-country flights.

I'm putting in a single SL-30 Nav/Com, and carrying a handheld comm radio as
backup.  I'm going to talk to the vendors at OSH about satellite weather
options - that seems like a pretty valuable capability in a cross-country
airplane.

Keith Hallsten
(I mounted my straight heated pitot out the nose of the XLFG this week.
Looks cool!) 



-----Original Message-----
From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On
Behalf Of Terrence Miles
Sent: Wednesday, June 15, 2005 12:27 PM
To: reflector at tvbf.org
Subject: REFLECTOR: Bus, Battery & Back Order


Hi to everyone but in particular to Brian, Keith, Al G, and Kurt who I think

are deep into wire issues.

Here's what I got.

For Electrics:  Here's my current plan and why.  Two big batts in the nose.

One stacked on top of the other.  For now I am going to slap the ground 
leads together and run them in parallel with B&C L60 alternator (60 amps) 
and the B&C external voltage regulator and the o'volt protection.

I may one day with not a lot of effort, put in a 2nd aux battery contactor, 
but I see its practical value as limited due to what follows next.

I have decided in favor of a single power bus.  I can't see a strong enuf 
reason to break things into separate buses to power up or shed in event of 
alternator problems.  I will instead pull out a checklist and do a load shed

procedure at each components control head/ panel switch/CB/whatever.  (Two 
mags, by the way until I have her in the air and de-bugged)

When I re-read the Nuckols stuff  on dual batt & single alt, I decided it 
wasn't for guys like me.  I can put two equal amphr batts right side by 
side...read no #2awg wires running all over hell.  I don't have dual EI's.  
Sure as sh--t the day I loss a alternator would be the day the #1 comm would

be TU and I have to repower the main load buss to access #2 comm and get 
myself confused say 2 years down the road by which time all the electron 
theory will be faded into dim memory.

GRT stuff:  Single AHRS system, 2 screens, EIS in the radio stack, no 
airspeed&Alt add-on to the EIS in favor of round dials below the GRT 
screeens.  Decided basically to abandon the two spare power leads.  I am 
told a solenoid controlled contact can draw an amp to 1.5 amps just to hold 
closed, and the diodes will cost you a volt in pressure.

Some of the above was driven by electrical abnormal checklist drafting.  
Some from the local tower operator/Cozy guy/ex USAF avionics tech.  For 
backup, his personal philos is a bag of external hand helds.

What do you four think of this?  Anybody else want to chime in?

I called Affordable panels this week.  He is an RV vendor...uses the 
Approach Hub stuff.  He is very backed up.  I am looking to make the major 
buy with Stein Air.  Anybody have any comments on him?

Where's everybody else on this topic.  Are you guys going to wire up your 
own intercomponents in the avionics rack?

Last but not least...anybody else waiting for engine mounts and exhaust 
systems besides me??

Regards,
Terry





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