----- Original Message -----

Sent: Sunday, May 01, 2005 8:25 = PM

Subject: [FlyRotary] Re: Ed's = new rotor=20 housings

John=20 Slade wrote:

My=20 understanding is that the pumps, at least the ones I'm using (or at = least WAS=20 using when I used to be able to fly this #@#$ing=20 thing, long ago), are designed to run continuously. = I have one=20 Walbro Inline fuel pump-GSL393 (from Tracy) and one Walbro Inline fuel = pump-GSL394 from Lightning Motorsports. Both have metal screw in=20 connectors which fit AN adapters. They're fused at 20=20 amps.

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OK,=20 I'll stir the pot some more. I am not an electrical engineer, but I do = understand the power of redunancy!

I=20 will take two separately fused circuits over 1 circuit breaker every = day of=20 the week. If there is a short in my one device or in the power supply = lines, I=20 do not wish to be starting a fire by resetting circuit breakers while = looking=20 for a glider port. I know there are rotary powered airplanes out there = that=20 depend on one circuit breaker for the entire electrical engine power = source=20 that have many, many more hours of rotary time than me, but I sleep = better=20 have two parallel circuits bringing electrical power to my fused = engine buss=20 and then reduntant pumps on entirely separate fused circuits. My pumps = are=20 both checked during run up and both on during T/O and=20 landing.

Bernie

I've got=20 to up the anti myself. I agree with Bernie, I prefer two = separate=20 circuits, one for each pump both of which are however, protected = by=20 separate circuit breakers vice fuses. Having flown over 2000 = hours in=20 military aircraft as an Electronic Warfare type, there has been = numerous=20 times, I was able to get a system that was temporarily kicked off-line = by a=20 power surge, intermittent cable /connector problem, etc. Working = again. =20 Resetting the circuit breaker would "SOMETIMES" bring them back on = line=20 functioning. You do not have that possibility with a blown=20 fuse.

Yes, most=20 of the time whatever would pop a fuse will keep a circuit breaker = popping as=20 well - BUT, there are intermittent problems where the ability to push = a=20 circuit breaker back in can save the day. Nothing against fuses, = I do=20 use them in non-flight critical = areas.

Personal=20 opinion, of course

Ed=20