>Bob,
>
>Just looking at your drawing for putting OV protection into a charging
system
>with an internally regulated alternator. Why is the feed from the bus to
the
>crowbar module on a breaker instead of a fuse? Is there any particular
>reason to put the battery master and alternator field on one switch?
The crowbar circuit is the only one that I recomend
using a breaker on. Two reasons. You may find yourself
with a quirky regulator that overshoots on some loading
conditions and resetting in flight is okay if you have
a voltmeter on board and can verify that steady state
output from your regulator/alternator is in limits.
Second, you may want to conduct ground operations battery
only where it's desireable to pull the alternator breaker
to keep the alternator off line and loading the battery
with it's field current (up to 4 amps!).
Putting the battery and alternator together on a DC power
master siwtch makes it impossible to leave the alternator
ON line with the battery OFF line . . . most alternators
are flakey without a battery on line. Further, there's
no good reason to have the alternator OFF line while
cranking the engine during pre-flight. Hence the move
to a DC Power Master switch shown in all of our drawings.
Please, don't use the classic split-rocker master switch
unless it's your desire to use the matching rockers for
all of your switching needs. Rockers are difficult to
mount an they lock you into a single supplier for spares.
Further, there is no MAGIC in the split rocker that was
pioneered into TC aircraft back in the 60's for reasons
that nobody really understood at that time.
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