X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from [199.185.220.223] (HELO priv-edtnes27.telusplanet.net) by logan.com (CommuniGate Pro SMTP 4.3c5) with ESMTP id 921858 for flyrotary@lancaironline.net; Sun, 01 May 2005 23:56:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=199.185.220.223; envelope-from=echolakeresort@telus.net Received: from boucher-oddle24 ([207.194.26.51]) by priv-edtnes27.telusplanet.net (InterMail vM.6.01.04.04 201-2131-118-104-20050224) with ESMTP id <20050502035605.JAM137.priv-edtnes27.telusplanet.net@boucher-oddle24> for ; Sun, 1 May 2005 21:56:05 -0600 Received: from 127.0.0.1 (AVG SMTP 7.0.308 [266.11.0]); Sun, 01 May 2005 20:56:03 -0700 Message-Id: <4275A4D0.000042.02736@BOUCHER-ODDLE24> Date: Sun, 1 May 2005 20:56:00 -0700 (Pacific Standard Time) X-Mailer: IncrediMail (3001609) From: "Echo Lake Fishing Resort (Georges Boucher)" References: To: Subject: Re: [FlyRotary] Re: Ed's new rotor housings X-FID: FLAVOR00-NONE-0000-0000-000000000000 X-Priority: 3 Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="=======AVGMAIL-4275A4D35095=======" --=======AVGMAIL-4275A4D35095======= Content-Type: Multipart/Alternative; boundary="------------Boundary-00=_C9GUPQM4G6G000000000" --------------Boundary-00=_C9GUPQM4G6G000000000 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Jim=0D Then why nnot use a HEAVY CB, it would give you the option to reset?=0D Georges B.=0D =0D -------Original Message-------=0D =0D From: Rotary motors in aircraft=0D Date: 05/01/05 20:47:32=0D To: Rotary motors in aircraft=0D Subject: [FlyRotary] Re: Ed's new rotor housings=0D =0D I'm not convinced of the utility of Circuit Breakers for flight critical systems. I would put each of my fuel pumps, the EFIs and what have you o= n dedicated circuits, each protected with a HEAVY fuse. My objective is no= t to protect my fuel pump in case of a surge. It's a flight critical component, so I'm going to allow it to go while it can. The fuse is waaa= ay heavier than the pump (or whatever) draws, and is meant to protect the wi= re going to the mechanism rather than the mechanism itself. I do not regard fuel pumps as delicate items, so I don't intend to protect them from transient surges and the like. I will ride it 'till it drops, and the fu= se will blow shortly before the wire melts.=0D =0D Delicate avionics I might very well protect with CBs. These might need t= o be protected from transient surges/voltage spikes (from whence I cannot s= ay since I have OV protection on my alternator) and the like.=0D =0D Heavy duty, robust components like fuel pumps need no such coddling IMO .= =2E.. Jim S.=0D =0D =0D WALTER B KERR wrote: =0D John Slade wrote:=0D =0D My understanding is that the pumps, at least the ones I'm using (or at le= ast WAS using when I used to be able to fly this #@#$ing thing, long ago), ar= e designed to run continuously. I have one Walbro Inline fuel pump-GSL393 (from Tracy) and one Walbro Inline fuel pump-GSL394 from Lightning Motorsports. Both have metal screw in connectors which fit AN adapters. T= hey re fused at 20 amps.=0D =0D ----------------------------------------------------------------------=0D =0D OK, I'll stir the pot some more. I am not an electrical engineer, but I d= o understand the power of redunancy!=0D =0D I will take two separately fused circuits over 1 circuit breaker every da= y of the week. If there is a short in my one device or in the power supply lines, I do not wish to be starting a fire by resetting circuit breakers while looking for a glider port. I know there are rotary powered airplane= s out there that depend on one circuit breaker for the entire electrical engine power source that have many, many more hours of rotary time than m= e, but I sleep better have two parallel circuits bringing electrical power t= o my fused engine buss and then reduntant pumps on entirely separate fused circuits. My pumps are both checked during run up and both on during T/O = and landing.=0D =0D Bernie=0D =20 --------------Boundary-00=_C9GUPQM4G6G000000000 Content-Type: Text/HTML; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
 Jim
Then why nnot use a HEAVY CB, it would give you the option to reset?=
Georges B.
 
-------Original Message-------
 
Date: 05/01/05 20:= 47:32
Subject: [FlyRotar= y] Re: Ed's new rotor housings
 
I'm not convinced of the utility of Circuit Breakers for= flight critical systems.  I would put each of my fuel pumps, the EF= Is and what have you on dedicated circuits, each protected with a HEAVY f= use.  My objective is not to protect my fuel pump in case of a surge= =2E  It's a flight critical component, so I'm going to allow it to g= o while it can.  The fuse is waaaay heavier than the pump (or whatev= er) draws, and is meant to protect the wire going to the mechanism rather= than the mechanism itself.  I do not regard fuel pumps as delicate = items, so I don't intend to protect them from transient surges and the li= ke.  I will ride it 'till it drops, and the fuse will blow shortly b= efore the wire melts.

Delicate avionics I might very well protect = with CBs.  These might need to be protected from transient surges/vo= ltage spikes (from whence I cannot say since I have OV protection on my a= lternator) and the like.

Heavy duty, robust components like fuel p= umps need no such coddling IMO .... Jim S.


WALTER B KERR wrote= :=20
John Slade wrote:
 
My understanding is that the pumps, at least the ones I'm using = (or at least WAS using when I used to be able to fly this #@#$ing thing, long ago), are designed to run = continuously. I have one Walbro Inline fuel pump-GSL393 = (from Tracy) and one Walbro Inline fuel pump-GSL394 from Lightning M= otorsports. Both have metal screw in connectors which fit AN adapters. Th= ey're fused at 20 amps.
 
----------------------------------------------------------------= ------
 
OK, I'll stir the pot some more. I am not an electrical engineer= , but I do understand the power of redunancy!
 
I will take two separately fused circuits over 1 circuit breaker= every day of the week. If there is a short in my one device or in the po= wer supply lines, I do not wish to be starting a fire by resetting circui= t breakers while looking for a glider port. I know there are rotary power= ed airplanes out there that depend on one circuit breaker for the entire = electrical engine power source that have many, many more hours of rotary = time than me, but I sleep better have two parallel circuits bringing elec= trical power to my fused engine buss and then reduntant pumps on entirely= separate fused circuits. My pumps are both checked during run up and bot= h on during T/O and landing.
 
Bernie
 
--------------Boundary-00=_C9GUPQM4G6G000000000-- --=======AVGMAIL-4275A4D35095======= Content-Type: text/plain; x-avg=cert; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Content-Description: "AVG certification" No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.308 / Virus Database: 266.11.0 - Release Date: 4/29/2005 --=======AVGMAIL-4275A4D35095=======--