X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [216.52.245.18] (HELO ispwestemail2.mdeinc.com) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 934152 for flyrotary@lancaironline.net; Thu, 05 May 2005 20:42:30 -0400 Received-SPF: none receiver=logan.com; client-ip=216.52.245.18; envelope-from=wschertz@ispwest.com Received: from 7n7z201 (unverified [63.13.186.38]) by ispwestemail2.mdeinc.com (Vircom SMTPRS 4.1.361.0) with SMTP id for ; Thu, 5 May 2005 17:41:42 -0700 Message-ID: <015e01c551d4$5ff2c730$6401a8c0@7n7z201> From: "William" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Mismarked Fuse?? Date: Thu, 5 May 2005 19:41:42 -0500 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 Ed, your hypothetical scenario has a problem. Although power is current*voltage, it is really current time *voltage_drop* across the fuse. The voltage drop will not go up unless the current goes up. Bill Schertz KIS Cruiser # 4045 ----- Original Message ----- From: "Ed Anderson" > Here is a hypothetical scenario - lets say your alternator decides to go > west in a failure mode that produces 40 volts (yes, there is an > overvoltage failure that can produce voltages approach 60 -100 volts). > Since you fuel pump will draw the basically the same current (perhaps a > bit more with the higher voltage) the power across the fuse (Power = > current * Voltage) will jump approx 4-5 fold. (It is the power rating > rather than current that causes a fuse to blow by the way). You have just > blown several fuses - could be critical ones. Your alternator has died or > you have disabled it and you could make it on the battery - but, fuse is > blown. Circuit breaker reset and one of your two redundant circuits > (perhaps both) may work again. Just a hypothetical scenario. .net/lists/flyrotary/List.html