Hi Kelly,
Thanks for the link. Some interesting
info, but... What is lacking is any sort of statistical info to indicate
that this is a real problem. I'm not convinced that using a Cherokee as an
example system is all that applicable. And I dont know how old this article
is, but gather it is pretty old given the reference to problems with
alternator failures in cars resulting in nothing more than burning out
lights. I'd venture to say that for virtually any car built since the mid
80s, a runaway alternator output would result in far more than a few burnt
out lights.
Since virtually all cars these days use
internal solid state regulators, if these things were prone to failure,
and since a runway over volt failure on any modern car would likely toast
some pretty expensive electronics, I'd expect a fair number of really
expensive repairs, warranty issues, etc.... My conclusion is that this type
of failure is actually quite rare, but if you can point to
relevant statistical data that says otherwise, I'm all
ears.
Some folks are more risk averse than
others and a 1 in a million possibility is enough to justify making a
change. But sooner or later you have to stop engineering for every possible
risk no matter how remote the failure mode and just get on with
it.
Meanwhile, the important points I take
from this reference are, dont overload your alternator, ensure that the
field is de-energized while cranking the engine, and keep it
cool.
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. Oh, and I have a DNA muffler on
order. Should have it by next weekend but may put off installing it so I can
fly some more.
Mike Wills
RV-4 N144MW
----- Original Message -----
Sent: Sunday, August 30, 2009 1:21
PM
Subject: [FlyRotary] FW: More
Charging Circuit Info
Group,
I am still on the bandwagon
about modifying our flying alternators for an external
regulator as noted in my past posts...........After supplying group
member Tim Holt &
also the group with info how to modify the Mazda alternator I
remembered the link
below which explains in language even the electrically challenged
among us will be
able to understand...............This info may have been already seen
by some of you
but I believe all of us should file it and also copy it to have
available when wiring
our aircraft electrical systems.............IMHO!!..........
--
Kelly Troyer
"Dyke Delta"_13B
ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
--------------
Forwarded Message: --------------
From: "Kelly Troyer"
<keltro@att.net>
To: tntholt23@bellsouth.net (Timothy Holt)
Subject: More Charging Circuit Info
Date: Sun, 30 Aug 2009
20:06:30 +0000
Tim,
For your informaton here is additional justification in my
opinion for going to an external
regulator in our aircraft and having the ability to either
automaticly or manualy cut power
to the field windings in case of a shorted
regulator............Note that solid state regulators
tend to fail "Shorted" about 50% of the time and all current
internal regulators are solid
state.............Link Below..................."Nuff Said"
!!...............IMHO
--
Kelly
Troyer