04/28/2001
Circuit Protection
One of the weak areas of the Cessna aircraft, especially prior to the
late 1990 models is lack of circuit protection. 
Often Cessna aircraft do not have enough circuit breakers for the equipment
installed during the original installation, much less with a modern avionics
stack such as Dean's. We found Cessna often used circuit breakers that
were too small current wise for the application and at times powered more than
one piece of equipment that was not marked. How did they get away with
it? I don't know but if I under protected a piece of avionics equipment
the feds would hang me. Cessna also used the cheapest circuit breakers
known to man. There is no way to pull the circuit breaker should you
desire or need to. Just because a radio is turned off doesn't mean it's
not still active. Take the ARC RT-385A radio for example. Even if
the on/off switch is placed in the "off" position, the audio amp is
always on anytime the master switch is on, yes, even with the avionics master
switch turn off in some cases. 
Cessna
radios and their strange ways of wiring the avionics system leaved a lot to be
desired but I'll get on that soap box some other time.
Dean asked us to install the proper circuit protection and install
pull-type breakers just in case he wants to such off a peculiar radio should the
cockpit environment get a little Smokey. Notice in these photos Tom Knoll
is fabricating a circuit breaker buss using some of the best breakers on the
market. Each circuit breaker is the proper amperage as determined by the
manufacture. These breakers and buss will be placed in the custom panels
where they are easy to inspect during the pre-flight.
Another thing I like about the pull type breakers is you can easily see when one
has popped because of the distance they come out. All circuit breakers we use
are Mil-spec quality. We also are starting the lower switch panel on the
co-pilots side of the aircraft. We've got a ways to go on the lower panels but
they will look great once completed.
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