Mailing List flyrotary@lancaironline.net Message #21223
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: Re: [FlyRotary] Re: Ed's new rotor housings
Date: Sun, 1 May 2005 20:36:10 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
 
----- Original Message -----
Sent: Sunday, May 01, 2005 8:25 PM
Subject: [FlyRotary] Re: Ed's new rotor housings

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 Motorsports. Both have metal screw in connectors which fit AN adapters. They're fused at 20 amps.
 
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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 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 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 electrical power to 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.
 
Bernie
 
 
I've got to up the anti myself.  I agree with Bernie, I prefer two separate circuits, one for each pump both of which are however, protected by separate circuit breakers vice fuses.  Having flown over 2000 hours in military aircraft as an Electronic Warfare type, there has been numerous times, I was able to get a system that was temporarily kicked off-line by a power surge, intermittent cable /connector problem, etc. Working again.  Resetting the circuit breaker would "SOMETIMES" bring them back on line functioning.  You do not have that possibility with a blown fuse.
 
Yes, most of the time whatever would pop a fuse will keep a circuit breaker popping as well - BUT, there are intermittent problems where the ability to push a circuit breaker back in can save the day.  Nothing against fuses, I do use them in non-flight critical areas. 
 
Personal opinion, of course
 
Ed
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