X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao104.cox.net ([68.230.241.42] verified) by logan.com (CommuniGate Pro SMTP 5.2.15) with ESMTP id 3781442 for flyrotary@lancaironline.net; Sun, 26 Jul 2009 11:27:30 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.42; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao104.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090726152653.OUMP17135.fed1rmmtao104.cox.net@fed1rmimpo02.cox.net> for ; Sun, 26 Jul 2009 11:26:53 -0400 Received: from BigAl ([72.192.133.78]) by fed1rmimpo02.cox.net with bizsmtp id LfSt1c0041hf1Cg04fStnG; Sun, 26 Jul 2009 11:26:53 -0400 X-VR-Score: 0.00 X-Authority-Analysis: v=1.0 c=1 a=ZiyHSl6GE8gA:10 a=Ia-xEzejAAAA:8 a=JXj8tel4AAAA:8 a=7g1VtSJxAAAA:8 a=C9leAQkzxLbAgt1eipgA:9 a=Xx7sB3BNcIu51rK8HUwA:7 a=5n2PTxA54nYm1f_h7OAlBXfhIjgA:4 a=DHgN2xDCXMcA:10 a=EzXvWhQp4_cA:10 X-CM-Score: 0.00 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Charging Systems and Troubleshooting Date: Sun, 26 Jul 2009 08:28:14 -0800 Message-ID: <8DD1FD0FB9F542B3A26D741E739F1732@BigAl> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6838 Importance: Normal Thread-Index: AcoN/cb/upMW+olfR/yxBtj9J2KHNAADjNcg In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 Bill; That is a very interesting read. Would have been good to know before = wiring my airplane. I didn't put in a separate switch for alternator field = because 'Why should I - cars don't have one'. I have a pullable breaker which I occasionally pull when I expect to have the power on with the engine off = for extended periods - like entering flight plans, doing EFIS upgrades, or = back when I did a lot of programming of the EC2. It hadn't occurred to me = that there could be increased contact resistance in the breaker causing = higher output voltage. Nor had I considered that there would be high output current from the alternator during start. However; I question his argument on this = point. How much current will the alternator put out a cranking speed? And even = if it is off during cranking; the moment you turn it on once the engine is running, it senses low voltage (from the drawdown during cranking) and = puts out maximum current for a short time. Anybody have any real numbers on this? Al G -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry Sent: Sunday, July 26, 2009 6:31 AM To: Rotary motors in aircraft Subject: [FlyRotary] Charging Systems and Troubleshooting =20 This has some pretty good "how to" on troubleshooting your charging = system. It is based on a Piper system, but is pretty close to the Nuckolls way. Also there was a discussion a while back about whether you should turn = the alternator on before starting the engine. This has a different take on = that subject. http://www.nflite.com/ChargingSystem.html Bill B -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html