Return-Path: Sender: (Marvin Kaye) To: lml Date: Wed, 09 Jul 2003 14:51:26 -0400 Message-ID: X-Original-Return-Path: Received: from siaag1ab.compuserve.com ([149.174.40.4] verified) by logan.com (CommuniGate Pro SMTP 4.1b8) with ESMTP id 2460466 for lml@lancaironline.net; Wed, 09 Jul 2003 14:47:26 -0400 Received: (from mailgate@localhost) by siaag1ab.compuserve.com (8.12.9/8.12.7/SUN-2.7) id h69IlP2C005446 for lml@lancaironline.net; Wed, 9 Jul 2003 14:47:25 -0400 (EDT) X-Original-Date: Wed, 9 Jul 2003 14:44:44 -0400 From: James Frantz Subject: [LML] Alternator Sizing X-Original-Sender: James Frantz X-Original-To: "Lancair Mailing List" X-Original-Message-ID: <200307091445_MC3-1-414D-3672@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline Message text written by "Lancair Mailing List" >Thanks for all the good advice on my power budget and alternator sizing.= = It = will take a little while to digest it all, but I still have a few weeks before = I need to walk over to Bill Bainbridge's booth at Oshkosh and buy an = alternator.< One of the common errors I see is under sizing the alternator. On my 360= with a vacuum system, a 65amp alternator was just barely big enough using= the 80% rule for continuous loads. LNN issue 16 August/September 1995 goe= s into great detail on how to size the alternator and gives several load analysis examples which would be a great help. = The last thing you want is while flying into IFR and rain, having the pit= ot tube draw more amps as it tries to keep the pitot tube up to temp and overloading the alternator tripping it off line. At this point only essential bus items are powered, and that is an emergency in my book (no auto pilot, and other nice to have instruments all gone). If you are all electric, I doubt a 65 amp alternator would do the trick f= or an IFR airplane. BTW, the battery should be able to power the essential instruments for 30 minutes. James B. Frantz Proprietary Software Systems, Inc. = www.angle-of-attack.com LFrantz@compuserve.com (952) 474-4154