Cessna 182 1973 - Electrical System Overview

the
opposite
tank,
expect an equal
duration
from
the
remaining
fuel.
The
airspace
in
both
fuel
tanks
is
inter-
connected
by a
vent
line
(see
figure
2-2)
and,
therefore,
some
sloshing
of
fuel
between
tanks
can
be
expected
when
the tanks
are
nearly
full
and the
wings
are
not
level.
For
fuel
system
servicing
information,
refer
to
Lubrication
and
Ser-
vicing
Procedures
in
Section
V.
ELECTRICAL
SYSTEM.
Electrical
energy
is
supplied
by
a 14-volt,
direct-current
system
powered
by
an
engine-driven
alternator
(see
figure
2-3).
The
12-volt
battery-is
located
aft
of
the
rear
baggage
compartment
wall.
Power
is
supplied
to
all
electrical
circuits
through a
split
bus
bar,
one
side
con-
taining
electronic
system
circuits
and
the
other
side
having
general
elec-
trical
system
circuits.
Both
sides
of
the bus
are
on
at
all
times
except
when
either
an
external
power
source
is
connected
or
the
starter
switch
is
turned
on;
then
a
power
contactor is
automatically
activated
to
open
the
circuit
to the
electronics
bus.
Isolating
the
electronic circuits
in
this
manner
prevents
harmful
transient
voltages
from
damaging
the
transistors
in
the
electronics
equipment.
MASTER
SWITCH.
The
master
switch
is
a
split-rocker
type
switch labeled
"MASTER,"
and
is
"ON" in
the
up
position
and
"OFF"
in
the
down
position.
The
right
half
of
the
switch,
labeled
"BAT,"
controls
all
electrical
power
to the
airplane.
The
left
half,
labeled
"ALT,"
controls
the
alternator.
Normally,
both
sides
of
the
master
switch
should be
used
simulta-
neously;
however,
the
"BAT" side
of
the
switch
could
be
turned
"ON"
separately
to
check
equipment
while
on
the
ground.
The
"ALT" side
of
the
switch,
when
placed
in the
"OFF"
position,
removes
the
alternator
from
the
electrical
system.
With
this
switch
in the "OFF"
position,
the
entire
electrical
load
is
placed
on
the
battery.
Continued
operation
with
the
alternator
switch
"OFF"
will
reduce
battery
power
low
enough
to
open
the
battery
contactor,
remove
power
from
the
alternator
field,
and
pre-
vent
alternator
restart.
AMMETER.
The
ammeter
indicates
the flow
of
current,
in
amperes,
from
the
al-
2-3