Return-Path: Received: from relay03.roc.ny.frontiernet.net ([66.133.131.36] verified) by logan.com (CommuniGate Pro SMTP 4.1.6) with ESMTP id 2716693 for flyrotary@lancaironline.net; Sun, 09 Nov 2003 21:30:01 -0500 Received: (qmail 9135 invoked from network); 10 Nov 2003 02:30:00 -0000 Received: from unknown (HELO frontiernet.net) ([170.215.97.8]) (envelope-sender ) by relay03.roc.ny.frontiernet.net (FrontierMTA 2.3.6) with SMTP for ; 10 Nov 2003 02:30:00 -0000 Message-ID: <3FAEF85F.A3198D10@frontiernet.net> Date: Sun, 09 Nov 2003 20:30:55 -0600 From: Jim Sower X-Mailer: Mozilla 4.77 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Murphy's law of precautionary landings References: Content-Type: multipart/alternative; boundary="------------9ACCDDA8CDBFA220E4CB4689" --------------9ACCDDA8CDBFA220E4CB4689 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit What's the point of having a 75 amp alternator if it's going to blow it's fuze at 80% capacity? The fuze is not for any alternator failure that I'm aware of. It's to prevent an electrical fire if the alternator output shorts to ground or something. OV protection is for alternator failures. Anyway, it can't hurt to ask Nuckolls. I'm anxious to hear what he says. John Slade wrote: > A 100 A fuze is pretty stout. There was a recent bit on the > Velocity forum to the effect that a 60 amp alternator needs an > 80 amp fuze at a minimum. If your alternator is over 75 A, > you might want to go to a 120 A fuze. Hmmm. There was > discussion on the aero-electric list recently which said the > opposite. i.e. a 60A fuse is good for a 75A alternator. I tend > to go with Nuckolls when there's conflicting info in > electrical stuff. Rusty, it might be a good idea to get his > opinion before installing a nail for a fuse. I'll be > interested to read his thoughts on this.John Slade -- Jim Sower Crossville, TN; Chapter 5 Long-EZ N83RT, Velocity N4095T --------------9ACCDDA8CDBFA220E4CB4689 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit What's the point of having a 75 amp alternator if it's going to blow it's fuze at 80% capacity?  The fuze is not for any alternator failure that I'm aware of.  It's to prevent an electrical fire if the alternator output shorts to ground or something.  OV protection is for alternator failures.  Anyway, it can't hurt to ask Nuckolls.  I'm anxious to hear what he says.

John Slade wrote:

 A 100 A fuze is pretty stout.  There was a recent bit on the Velocity forum to the effect that a 60 amp alternator needs an 80 amp fuze at a minimum.  If your alternator is over 75 A, you might want to go to a 120 A fuze. Hmmm. There was discussion on the aero-electric list recently which said the opposite. i.e. a 60A fuse is good for a 75A alternator. I tend to go with Nuckolls when there's conflicting info in electrical stuff. Rusty, it might be a good idea to get his opinion before installing a nail for a fuse. I'll be interested to read his thoughts on this.John Slade 

--
Jim Sower
Crossville, TN; Chapter 5
Long-EZ N83RT, Velocity N4095T
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