X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.122] verified) by logan.com (CommuniGate Pro SMTP 5.2.15) with ESMTP id 3781665 for flyrotary@lancaironline.net; Sun, 26 Jul 2009 15:43:08 -0400 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.122; envelope-from=eanderson@carolina.rr.com Received: from computername ([75.191.186.236]) by cdptpa-omta01.mail.rr.com with ESMTP id <20090726194229450.LNJV26619@cdptpa-omta01.mail.rr.com> for ; Sun, 26 Jul 2009 19:42:29 +0000 From: "Ed Anderson" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Charging Systems and Troubleshooting Date: Sun, 26 Jul 2009 15:42:31 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Office Outlook, Build 11.0.5510 thread-index: AcoOJEOlXLZkGdzqQeeiyg26bNSeZwABMmSg X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 In-Reply-To: Message-Id: <20090726194229450.LNJV26619@cdptpa-omta01.mail.rr.com> That is interesting, always wondered why I put the split switch (Alt/Bat) in as I never turn one on/off without turning the both on/off. Now I can see some merit to not turning on the alternator switch until the engine has started. Good find Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com http://www.andersonee.com http://www.dmack.net/mazda/index.html http://www.flyrotary.com/ http://members.cox.net/rogersda/rotary/configs.htm#N494BW http://www.rotaryaviation.com/Rotorhead%20Truth.htm -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bill Bradburry Sent: Sunday, July 26, 2009 3:06 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Charging Systems and Troubleshooting Al, I think his point is that the alternator is damaged by turning it on during cranking and that the automobile systems eliminate that problem by not turning the alternator on till after the start key is released. Bill B -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Al Gietzen Sent: Sunday, July 26, 2009 12:28 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Charging Systems and Troubleshooting 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 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 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html __________ Information from ESET NOD32 Antivirus, version of virus signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com __________ Information from ESET NOD32 Antivirus, version of virus signature database 3267 (20080714) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com