Cessna 177 SERIES Service Manual

16-39A.
TROUBLE
SHOOTING
THE
ALTERNATOR
SYSTEM
(BEGINNING
WITH
1978
MODELS)
(CONT.)
b. ENGINE
RUNNING
(Cont.)
TROUBLE
PROBABLE
CAUSE
REMEDY
ALTERNATOR
SYSTEM
WILL
Alternator
output
voltage
2.
Check
resistance
from
case
NOT
KEEP
BATTERY
insufficient
(cont.)
of
alternator
to
airframe
ground.
CHARGED.
(Cont.)
Normal
indication
is
very
low
resistance.
If
reading
indicates
no.
or
poor
continuity,
repair
or
replace
alternator
ground
wiring.
16-40.
REMOVAL
AND
INSTALLATION.
16-43.
DESCRIPTION.
The
alternator
voltage
regu-
(Refer
to
figure
16-4.
)
lator
contains
two
relays.
One
relay
is actuated
by
a.
Ensure
that
master
switch
is
off
and
the
negative
the
aircraft
master
switch
and
connects
the
regulator
lead
is
disconnected
from
the
battery.
to
the
battery.
The
second
relay
is
a
two-stage,
vol-
b.
Remove
wiring
from
the
alternator
and
label.
tage
sensitive
device,
which
is
used
to
control
the
c.
Remove
safety
wire
from
the
upper
adjusting
current
applied
to the
field
winding
of
the
alternator.
bolt
and
loosen
bolt.
When
the
upper
set
of
contacts
on
the
voltage
regula-
d.
Remove
safety
wire
from
lower
adjusting
bolt
tor
relay
are
closed,
full
bus
voltage
is applied
to
the
and
remove
bolt.
field.
This
condition
will
exist
when
the
battery
is
e.
Remove
the
locknut
from
the
alternator
mounting
being
heavily
charged
or
when
a very
heavy
load
is
bolt.
applied
to
the
system.
When
the
upper
contacts
open.
f.
Remove
the
alternator
drive
belt
and
the
alterna-
as
the
voltage
begins
to rise
toward
normal
bus
volt-
tor
mounting
bolt,
the
alternator
will
then
be
free
for
age
to
the
alternator
field
is
reduced
through
a resis-
removal.
tor
network
in
the
base
of
the regulator,
thus
reducing
g.
To
replace
the
alternator,
reverse
this
proce-
the
output
from
the
alternator.
As
the
voltage
con-
dure.
tinues
to
rise.
assuming
a very
light
load
on
the sys-
h. Apply
a torque
wrench
to
the nut
on
alternator
tem,
the
lower
contacts
will
close
and
ground
the
al-
pulley
and
adjust
the belt
tension
so the
belt
slips
ternator
field
and
shut
the
alternator
completely
off.
when
the
following
torque
value
is
applied.
Under
lightly
loaded
conditions
the
voltage
relay
will
vibrate
between
the
intermediate
charge
rate
and
the
TORQUE
VALUES
lower
(completely
off) contacts.
Under
a
moderate
FOR
load,
the
relay
will
vibrate
between
the
intermediate
CHECKING
ALTERNATOR
BELT
TENSION
charge
rate
and
the
upper
(full
output)
contacts.
Used
Belt
New
Belt
The
voltage
relay
is temperature
compensated
so
that
the
battery
is
supplied
with
the
proper
charging
volt-
Slips
At
Slips
At
age
for
all
operating
temperatures.
With
the
battery
7
to
9
Ft.
Lbs.
11
to
13
Ft.
Lbs
fully
charged
(ship's
ammeter
indicating
at
or
near
-_NOTE-
zero)
and a moderate
load applied
to
the system
(a
taxi
light
turned
on),
the
voltage
at
the
bus
bar
should
Whenever
a new
belt
is
installed,
belt
tension
be
within
the
range
shown
according
to the
volt-
should
be
checked
within
10
to 25
hours
of
age
vs temperature
chart
in the
Cessna
Alternator
operation.
Charging
Systems
Service/Parts
Manual.
The
voltage
regulator
is adjustable,
but
adjustment
on
the
aircraft
is
not
recommended.
A
bench
adjustment
i.
Tighten
and
safety
wire
upper
and
lower
adjust-
procedure
is
outlined
in the
Cessna
Alternator
Charg-
ing
bolts.
ing
Systems
Service/Parts
Manual.
j.
Tighten
alternator
mounting
bolt.
16-43A.
ALTERNATOR
VOLTAGE
REGULATOR.
16-41.
ALTERNATOR
FIELD
CIRCUIT
PROTEC-
AIRCRAFT
SERLAL
17702314
THRU
17702672.
TION.
On models
prior
to
1970.
a 2-amp
automatic
resetting
circuit
breaker
located
on
the
back
of the
16-43B.
DESCRIPTION.
The
voltage
regulator
is
instrument
panel
is
provided
to protect
the
alternator
semi-solid
state.
The
mechanical
relay
in the
regu-
field
circuit.
On
1970
models
and
on.
a
manually-
lator
is
actuated
by
the
aircraft
master
switch
and
resettable
circuit
breaker
located
on
the
switch
panel
connects
the
regulator
to
the
battery.
The
solid-state
is provided
to
protect
the
alternator
field
circuit.
portion
is
voltage
sensitive
and
controls
the
current
applied
to
the field
windings
of
the alternator.
The
16-42.
ALTERNATOR
VOLTAGE
REGULATOR.
regulator
is a
remove
and
replace
item
and
not
re-
THRU
AIRCRAFT
SERIAL
17702313.
pairable.
The
regulator
is adjustable.
but
adjustment
on
the
aircraft
is
not
recommended.
A
bench
adjust-
ment
procedure
is
outlined
in
the Cessna
Alternator
Change
7
16-12C

Cessna 177 SERIES Specifications

General

Manufacturer	Cessna
Engine Type	Piston
Wingspan	35 ft 6 in (10.82 m)
Seating Capacity	4
Number Built	4, 295
Engine	Lycoming O-360
Horsepower	180 hp
Maximum Takeoff Weight	2, 500 lb (1, 134 kg)