X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-01.southeast.rr.com ([24.25.9.100] verified) by logan.com (CommuniGate Pro SMTP 5.1.0) with ESMTP id 1491561 for flyrotary@lancaironline.net; Sat, 21 Oct 2006 16:54:16 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.100; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-098-062.carolina.res.rr.com [24.74.98.62]) by ms-smtp-01.southeast.rr.com (8.13.6/8.13.6) with SMTP id k9LKrid7016507 for ; Sat, 21 Oct 2006 16:53:47 -0400 (EDT) Message-ID: <000d01c6f553$030a86b0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Fuse Ratings for Wiring?? Date: Sat, 21 Oct 2006 16:53:50 -0400 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 X-Virus-Scanned: Symantec AntiVirus Scan Engine Hi Larry, thanks for another perspective on the rating problem. I certainly agree that we only want to allow the amount of current to flow through the wires that the equipment load (with some margin) requires. That is exactly why I say rate for the load and not the wire - this of course assumes your wiring design selected an appropriate size/rating wire for the equipment in the first place. If my wiring selection will support my normal equipment load and I fuse/CB that line for the equipment load (which is less than the wire capability), I automatically protect the wire. However, I've learned (well mostly) that convention,custom and natural laws are not violated without cost. Now I do like the quantum mechanics idea - just teleport to a distant location - Nahh, not as much fun - I mean how much discussion can we get into about quantum mechanics and rotary engines {:>). Ed SNIP..... In summation we want to allow only the amount of > current to flow thru those little wires as we need, and no more > than that. That is what these two rules accomplish. They were > written in the National electrical code and based on physics. > And as we know the laws of physics will not be denied, > except by quantum mechanics. But we are not building > obam aircraft that require quantum mechanics,yet. HTH > Larry Mac Donald > lm4@juno.com > Rochester N.Y. > Do not achcive > > Max. current for 14 Ga. wire is 20 amps and > On Fri, 20 Oct 2006 18:12:11 -0400 "Ed Anderson" > writes: >> One thing I have never really understood regarding fuses (or CB >> for that >> matter) is - why you would use a fuse/CB with the rating set to >> protect the >> wire!!! If you have a system operating off a power wire, it is >> highly >> likely that the wire will flow much more current than the system >> requires by >> quite a bit. So if you select a fuse or CB rating that protects the > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net/lists/flyrotary/ >