REFLECTOR: Bus, Battery & Back Order

Fri Jun 17 06:31:35 CDT 2005

Al,
Thanks for the panel pic.  Can I ask you if you have a hot batt bus as well 
as an essential bus and a main bus?  Could you tell me your decisions on 
what went to hot and ess bus'es?  In the event of alternator failure will 
you be doing manual depowering (at the unit) anywhere?  I get the theory 
fine.  Seems for me the devil is in the details.

If you have time, I'd be happy to hear you explain that panel layout.  Looks 
real nice.
Terry

>From: "Al Gietzen" <ALVentures at cox.net>
>Reply-To: Velocity Aircraft Owners and Builders list <reflector at tvbf.org>
>To: "'Velocity Aircraft Owners and Builders list'" <reflector at tvbf.org>
>Subject: RE: REFLECTOR: Bus, Battery &  Back Order
>Date: Wed, 15 Jun 2005 22:10:41 -0700
>
>Hi; Terry;
>
>
>
>My electrical design was driven by a different set of needs - like having
>all electronically controlled ignition and fuel injection - so the design 
>is
>quite different.  I needed redundancy in the electrical, including allowing
>separation of the batteries to independently power flight critical loads.  
>I
>have two contactors, but normal operation will be with only one on.  And 
>the
>plane will continue to fly with both contactors off.
>
>
>
>I would only question the need for two big batteries tied together, unless
>you know you need extra weight in the nose anyway.  A single battery of 30
>amp hrs, or so, will give you plenty of time to decide where to go and time
>to get there in the event of alternator failure.
>
>
>
>I also have the GRT with single AHRS and two displays.  I have backup, but
>no gauges.  Airspeed, altitude, and vertical speed are included on my 
>engine
>monitor display, I have a digital compass, and roll attitude on the TruTrak
>Pictorial pilot.
>
>
>
>Not that it is 'essential', but I don't think you would find it very
>complicated to split buses between essential and non-essential loads, with
>the ability to dump all non-essentials with a single switch.  Then you have
>time to decide which essentials really are critical to your situation.
>
>
>
>Al
>
>
>
>
>
>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
>
>
>
>Regards,
>
>Terry
>
>
>
>
>
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