Return-Path: Received: from BAY0-SMTP07.adinternal.hotmail.com ([65.54.241.114] verified) by logan.com (CommuniGate Pro SMTP 4.1b8) with ESMTP id 2431362 for flyrotary@lancaironline.net; Mon, 16 Jun 2003 14:19:04 -0400 X-Originating-IP: [68.107.116.221] X-Originating-Email: [alventures@msn.com] Received: from BigAl ([68.107.116.221]) by BAY0-SMTP07.adinternal.hotmail.com with Microsoft SMTPSVC(5.0.2195.5600); Mon, 16 Jun 2003 11:19:03 -0700 Reply-To: From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Starter Problem Date: Mon, 16 Jun 2003 11:19:07 -0700 Organization: ALVentures Message-ID: <000f01c33433$c9cfa170$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4024 Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 In-Reply-To: Return-Path: alventures@email.msn.com X-OriginalArrivalTime: 16 Jun 2003 18:19:03.0135 (UTC) FILETIME=[C3E99EF0:01C33433] >why the separate contactor? Tracy, Are you saying a contactor isnt needed for the starter? John Slade The starter solenoid is itself a large contactor. At the same time it closes the contacts for the motor current, it also engages the starter drive gear. I had concluded also that using a heavy "contactor" relay in the starter circuit was redundant; but be aware that the starter solenoid has a very large in-rush current, and a fairly high holding current - just guessing maybe 7-10 amps. I was just testing my starter engagement a couple of days ago by touching the alligator clip on a jumper lead to the battery terminal. Lots of sparks making and breaking, and the jumper (about a #20 wire) heated up pretty quickly on the holding current. If you use an intermediate relay, make it pretty heavy duty and use spike suppression; or if not - likewise on your push button switch. Al