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I believe that modern aircrafts should be treated
like modern cars. Turn the power ON, turn the ignition switch to start the
engine and let it warm up while you do your checkup. I do have 2
independent electrical systems, with alternator overvoltage crobars, no field
switches, these switches bring noise into the cockpit. I have 3 main
switches: Instruments, Equipment and Engine and they are turned ON in that order
before I hit the starter. No manufacturer should sell electrical and
electronic equipment that cannot withstand that much abuse if we can call this
abuse. Equipment that fail under NORMAL use is defective
equipment.
Rino Lacombe
Renesis powered Glass Goose
----- Original Message -----
Sent: Monday, August 31, 2009 4:18
PM
Subject: [FlyRotary] Re: FW: More
Charging Circuit Info
From
Mike - …..ensure that the field is de-energized
while cranking the engine.
And I will
respectfully disagree with that – at least until somebody can prove me wrong.
The output current is a function of rpm as well as what the voltage
regulator is demanding. From what I can find, I conclude that
alternators typically won’t put out their rated current until they get
spinning about 1500 – 2000 rpm, or more (which is usually about double engine
rpm). So there is no risk of damaging the rectifier diodes at cranking
speed.
I’m going to guess
that it is a worse shock to the electronics if the field is suddenly turned on
at higher rpm when the regulator is on full demand – although I don’t think
it’s an issue.
Off topic, another 1.2
hours closer to completing my Phase 1. This was the first flight that
after I landed I didnt have anything on my list to fix before the next
flight. 95 degrees OAT at takeoff today and the oil temp got to 200
at the top of the climb to 5000' but backed off to 192 after I leveled.
H2O temp never above 180. Starting to gain some confidence in it.
Contrary to our
friend George’s faint praiseJ, I’d say your
temps are excellent. If it does that well at OAT of 95 F; then
your next thing will be to think about adjustable cowl flap to reduce
cooling drag at cruise on a cooler day.
Al
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