X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from imf17aec.mail.bellsouth.net ([205.152.59.65] verified) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 933133 for flyrotary@lancaironline.net; Thu, 05 May 2005 00:30:53 -0400 Received-SPF: pass receiver=logan.com; client-ip=205.152.59.65; envelope-from=sqpilot@bellsouth.net Received: from paul52u7f5qyav ([209.214.45.48]) by imf17aec.mail.bellsouth.net (InterMail vM.5.01.06.11 201-253-122-130-111-20040605) with SMTP id <20050505043004.UCQG2434.imf17aec.mail.bellsouth.net@paul52u7f5qyav> for ; Thu, 5 May 2005 00:30:04 -0400 Message-ID: <018c01c5512b$194ce300$302dd6d1@paul52u7f5qyav> From: "Paul" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] To Fuse or not to Fuse Date: Wed, 4 May 2005 23:29:58 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0189_01C55101.2F946A40" 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 This is a multi-part message in MIME format. ------=_NextPart_000_0189_01C55101.2F946A40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi, Ed....thanks for the links. After successfully resetting fuses in = military aircraft, I feel more comfort in knowing that I at least have = the option to reset or not to reset. In one case, it was the landing = gear motor on a King Air that got pretty hot during touch-and-go's = during a checkride. Once the motor cooled, the circuit breaker was = successfully reset, and we were able to lower the gear. I am replacing = my fuel pump fuses with CB's. Anyway, the purpose of this email is to comment on the fuse that = blew on my fuel pump circuit. We looked at it with a maginfying glass, = and there was no dark or black area around the break, as there often = appears after a fuse blows. What we did notice, however is that the gage = of the wire inside the fuse looked suspiciously small. We compared it to = 5 or 6 other 20 amp fuses we had, and the wire was definately smaller in = gage. It looked to be the same size as a 7 1/2 amp fuse we compared it = to. It did, however have the standard yellow plastic cap and marking of = 20 on it. It definately was a lighter gage wire used for the fuse = portion than the other 20 amp fuses we had. Possibly a manufacturing = defect, or maybe it was a 7 1/2 amp fuse and it received a yellow cap = marked 20 amps somewhere along the assembly line or ??? Don't know the = answer to this one, but there is no doubt at all that the wire was = similar in size to a 7 1/2 amp fuse. Maybe something to look at when = installing them. Might have been made on a Monday or a Friday. FWIW. = Paul Conner ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Monday, May 02, 2005 8:16 AM Subject: [FlyRotary] To Fuse or not to Fuse=20 Since this is the umpteenth time that the fuse vs CB topic has come up = (not just on the rotary lists but aircraft list in general), and = certainly won't e the last, I decided to do something different than = just spout my views on the topic. I surfed the net and see if I could = find anything on it. Here are some of the URLs I found of interest. This guy actually did some tests and found among other things that a = fuse rated capacity can slowly degrade with repeated high current flows = even if below its burst point. But, read it and draw your own = conclusions. http://www.campbells.org/Airplanes/AirplaneCircuitBreakersVsFuses.html This one has an interesting summary, but since they are presented by = the makers of CB can be considered Biased http://www.adverc.co.uk/technical/technical-fuses.asp Another maker of CB propaganda, however they do point out that you can = not test a fuse since it is destroyed if it proves it works at the = specified rating where as you can a CB = http://www.ammagazine.com/CDA/ArticleInformation/features/BNP__Features__= Item/0,2606,111238,00.html Here is Bob K's and his well reasoned argument FOR fuses http://www.aeroelectric.com/articles/Rev9/ch10-9.pdf It appears that there is as much debate outside the aviation community = (or more) about fuses Vs CB. It appears to me the CB is winning there = simply because of convince rather than any technical advantage - That = is once the problem causing the short is fixed, you simply reset the CB = rather than trying to find a fuse of the right rating and shape to = replace the blown one and possibly sticking in the wrong fuse. And you = know Americans - convince before all else {:>) - At least that's the = way it appears to me. Ed Ed Anderson Rv-6A N494BW Rotary Powered Matthews, NC eanderson@carolina.rr.com -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.11.1 - Release Date: 5/2/2005 ------=_NextPart_000_0189_01C55101.2F946A40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi, Ed....thanks for the links.  = After=20 successfully resetting fuses in military aircraft, I feel more comfort = in=20 knowing that I at least have the option to reset or not to reset.  = In one=20 case, it was the landing gear motor on a King Air that got pretty hot = during=20 touch-and-go's during a checkride. Once the motor cooled, the circuit = breaker=20 was successfully reset, and we were able to lower the gear. I am = replacing my=20 fuel pump fuses with CB's.
     Anyway, the = purpose of=20 this email is to comment on the fuse that blew on my fuel pump circuit. = We=20 looked at it with a maginfying glass, and there was no dark or black = area around=20 the break, as there often appears after a fuse blows. What we did = notice,=20 however is that the gage of the wire inside the fuse looked suspiciously = small.=20 We compared it to 5 or 6 other 20 amp fuses we had, and the wire was = definately=20 smaller in gage. It looked to be the same size as a 7 1/2 amp fuse we = compared=20 it to. It did, however have the standard yellow plastic cap and marking = of 20 on=20 it.  It definately was a lighter gage wire used for the fuse = portion than=20 the other 20 amp fuses we had. Possibly a manufacturing defect, or maybe = it was=20 a 7 1/2 amp fuse and it received a yellow cap marked 20 amps somewhere = along the=20 assembly line or ???  Don't know the answer to this one, but there = is no=20 doubt at all that the wire was similar in size to a 7 1/2 amp fuse. = Maybe=20 something to look at when installing them. Might have been made on a = Monday or a=20 Friday.   FWIW.   Paul Conner
 
----- Original Message -----
From:=20 Ed=20 Anderson
Sent: Monday, May 02, 2005 8:16 = AM
Subject: [FlyRotary] To Fuse or = not to=20 Fuse

 
Since this is the umpteenth time that = the fuse vs=20 CB topic has come up (not just on the rotary lists but aircraft list = in=20 general), and certainly won't e the last, I decided to do something = different=20 than just spout my views on the topic.  I surfed the net and see = if I=20 could find anything on it.
 
Here are some of the URLs I found of=20 interest.
 
This guy actually did some tests and = found among=20 other things that a fuse rated capacity can slowly degrade with = repeated high=20 current flows even if below its burst point.  But, read it and = draw your=20 own conclusions.
 
http://www.campbells.org/Airplanes/AirplaneCircuitBreakersVsFuses.= html
 
This one has an interesting summary, = but since=20 they are presented by the makers of CB can be considered = Biased
 
http://www= .adverc.co.uk/technical/technical-fuses.asp
 
 
Another maker of CB propaganda, = however they do=20 point out that you can not test a fuse since it is destroyed if it = proves it=20 works at the specified rating where as you can a CB
 
http://www.ammagazine.com/CDA/Article= Information/features/BNP__Features__Item/0,2606,111238,00.html=
 
Here is Bob K's and his well = reasoned =20 argument  FOR fuses
 
http://www.= aeroelectric.com/articles/Rev9/ch10-9.pdf
 
 
It appears that there is as much = debate outside=20 the aviation community (or more) about fuses Vs CB.  It appears = to me the=20 CB is winning there simply because of convince rather than any = technical=20 advantage -  That is once the problem causing the short is fixed, = you=20 simply reset the CB rather than trying to find a fuse of the right = rating and=20 shape to replace the blown one and possibly sticking in the wrong=20 fuse. And you know Americans - convince before all else {:>) - =  At least that's the way it appears to me.
 
Ed
 
Ed Anderson
Rv-6A N494BW Rotary=20 Powered
Matthews, NC
eanderson@carolina.rr.com

No virus found in this incoming message.
Checked by AVG=20 Anti-Virus.
Version: 7.0.308 / Virus Database: 266.11.1 - Release = Date:=20 5/2/2005
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