X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 07 Nov 2007 09:46:33 -0500 Message-ID: X-Original-Return-Path: Received: from [206.246.194.60] (HELO visi.net) by logan.com (CommuniGate Pro SMTP 5.2c1) with ESMTP id 2459323 for lml@lancaironline.net; Tue, 06 Nov 2007 23:19:25 -0500 Received-SPF: none receiver=logan.com; client-ip=206.246.194.60; envelope-from=rpastusek@htii.com Received: from [69.143.130.212] (account rpastusek@htii.com HELO dlhtpax009) by visi.net (CommuniGate Pro SMTP 4.2) with ESMTP id 241546496 for lml@lancaironline.net; Tue, 06 Nov 2007 23:18:18 -0500 From: "Robert Pastusek" X-Original-To: "'Lancair Mailing List'" References: In-Reply-To: Subject: RE: [LML] Re: Design for Circuit Breakers & Fuses? X-Original-Date: Tue, 6 Nov 2007 23:18:32 -0500 X-Original-Message-ID: <009b01c820f5$46325840$d29708c0$@com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_009C_01C820CB.5D5C5040" X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: Acgg6ERGmgijuDqmT9SDjUU1+9jrNAACqJOw Content-Language: en-us This is a multipart message in MIME format. ------=_NextPart_000_009C_01C820CB.5D5C5040 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Colyn Case said: The pro-fuse argument makes sense to me except for one thing: A breaker gives you a positive indication that it interrupted the circuit. A fuse, particularly a hidden fuse, gives you no indication. I thought that would be bad because I'm left to diagnose a problem with incomplete information. e.g. my trim isn't working - is it something I can do something about or is the trim servo toasted? You fuse guys must have thought about this. What's the counter-argument? Colyn, You have a good point if you intend/need to troubleshoot while still in the air. As I noted in my original post, many years of doing this in military fighters (as a weapon systems operator-with a well qualified pilot still flying the jet and typically swearing because his xyz was not working) convinced me that this was (in my experience) a totally pointless exercise. I'm pretty sure I never recovered a system by resetting a CB, and I once caused a fire in the cockpit, and killed a generator another time. Still, I've heard that others have successfully recovered systems by resetting CB's. So in the end, you make your own tradeoffs/decisions. Everything is a compromise at some level. Bob ------=_NextPart_000_009C_01C820CB.5D5C5040 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Colyn Case = said:

 

The pro-fuse argument makes sense to me except for one thing:   A breaker gives you a positive indication that it interrupted the circuit.  A fuse, particularly a hidden fuse, gives = you no indication. 

 

I thought that would be bad because I'm left to diagnose = a problem with incomplete information.   e.g. my trim isn't = working - is it something I can do something about or is the trim servo = toasted?

 

You fuse guys must have thought about this.  What's = the counter-argument?

 

Colyn,

You have a good point if you intend/need to troubleshoot = while still in the air. As I noted in my original post, many years of doing = this in military fighters (as a weapon systems operator—with a well = qualified pilot still flying the jet and typically swearing because his xyz was = not working) convinced me that this was (in my experience) a totally = pointless exercise. I’m pretty sure I never recovered a system by resetting = a CB, and I once caused a fire in the cockpit, and killed a generator another = time. Still, I’ve heard that others have successfully recovered systems = by resetting CB’s. So in the end, you make your own = tradeoffs/decisions. Everything is a compromise at some level…

 

Bob

 

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