X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 27 Dec 2007 09:12:48 -0500 Message-ID: X-Original-Return-Path: Received: from mail34.syd.optusnet.com.au ([211.29.133.218] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTPS id 2621059 for lml@lancaironline.net; Thu, 27 Dec 2007 08:46:04 -0500 Received-SPF: pass receiver=logan.com; client-ip=211.29.133.218; envelope-from=fredmoreno@optusnet.com.au Received: from fred ([202.139.5.198]) (authenticated sender fredmoreno) by mail34.syd.optusnet.com.au (8.13.1/8.13.1) with ESMTP id lBRDixwv010219 for ; Fri, 28 Dec 2007 00:45:09 +1100 From: "Fred Moreno" X-Original-To: "Lancair Mail" Subject: Glass Panel Back-up X-Original-Date: Thu, 27 Dec 2007 22:45:09 +0900 X-Original-Message-ID: <01a301c8488e$ba457850$c6058bca@fred> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_01A4_01C848DA.2A2D2050" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6822 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 Thread-Index: AchIeAN2l7BWWTLGRZaIJTBVZGA1UwAFeqiA Importance: Normal This is a multi-part message in MIME format. ------=_NextPart_000_01A4_01C848DA.2A2D2050 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable =20 Fred, re: the 350 diagram, they did some interesting things. I wonder if you = have more information about: - what is in the "junction boxes" - how they wired the contactors =20 Here's a question: where should you source the power for your xfeed contactor coil, left batt coil, right batt coil? =20 e.g. if you source the right batt coil from the right batt itself, you = can't charge that battery unless it's already in pretty good shape. My conclusion was as follows: - xfeed fed from essential bus. It will be up if one of the two batt = busses is up. - right batt from right batt (directly) and left batt bus - left batt from left batt (directly) and right batt bus =20 As for your question, I have a clear and definitive answer: I don't = know. Except I think (working from memory of the figure) the relays are = powered from the essential bus. Have a close look.=20 =20 As for your conclusions, I entirely agree. I first noted some years ago when doing the preliminary design that the AeroElectric Connection = layout for dual alternator dual bus has an interesting deficiency. If you = flatten both batteries, the power from the ground power supply can only turn its respective buss, and not the other. I put in a switch and current = limiting resistor that allows the B buss on my plane, the one getting ground = power, to feed power to the A buss relay to bring the A battery on line. = Powering the relays off the essential buss achieves the result automatically. I wish I had seen the Columbia schematic much earlier.=20 =20 Fred ------=_NextPart_000_01A4_01C848DA.2A2D2050 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

 

Fred,

re: the 350 diagram, they did some interesting = things.  I wonder if you have more information about:

- what is in the "junction = boxes"

- how they wired the contactors

 

Here's a question: where should you source the power = for your xfeed contactor coil, left batt coil, right batt = coil?

 

e.g. if you source the right batt coil from the right = batt itself, you can't charge that battery unless it's already in pretty good = shape.

My conclusion was as follows:

- xfeed fed from essential bus.  It will be up = if one of the two batt busses is up.

- right batt from right batt (directly) and left batt = bus

- left batt from left batt (directly) and right batt = bus

 

As for your question, I have a = clear and definitive answer: I don’t know.  Except I think (working = from memory of the figure) the relays are powered from the essential = bus.  Have a close look.

 

As for your conclusions, I = entirely agree.  I first noted some years ago when doing the preliminary design that the AeroElectric Connection layout for dual alternator dual bus has an = interesting deficiency.  If you flatten both batteries, the power from the = ground power supply can only turn its respective buss, and not the other.  = I put in a switch and current limiting resistor that allows the B buss on my = plane, the one getting ground power, to feed power to the A buss relay to bring = the A battery on line.  Powering the relays off the essential buss = achieves the result automatically.   I wish I had seen the = Columbia schematic much earlier.

 

Fred

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