Cessna 177 SERIES Service Manual

16-33.
TROUBLE
SHOOTING.
(Cont).
TROUBLE
PROBABLE
CAUSE
REMEDY
GROUND
POWER
WILL
NOT
Open
or
mis-wired
diode
on
3.
Check
polarity
and
continuity
CRANK
ENGINE.
(Cont).
ground
service
diode
board
of
diode
on
diode
board
at
rear
assembly.
of
ground
service
receptacle.
If
diode
is
open
or
improperly
wired,
replace
diode
board
assembly.
4.
Check
resistance
from
small
Faulty
external
power
con-
(coil)
terminal
of
external
power
tactor.
contactor
to
ground
(master
switch
off
and
ground
power
unplugged
Normal
indication
is
16-24
ohms
on
the
12
volt
and
50-70
on
the
24
volt.
If
resistance
indicates
an
open
coil.
replace
contactor.
If
resistance
is
normal,
proceed
to
step
5.
Faulty
contacts
in
external
5.
With
master
switch
off
and
power
contactor.
ground
power
applied.
check
for
voltage
drop
between
two
large
terminals
of
external
power
(turn
on
taxi
light
for
a
load).
Normal
indication
is
zero
volts.
If
voltage
is
intermittently
pres-
ent
or
present
all
the
time,
replace
contactor.
..
16-34.
REMOVAL
AND
INSTALLATION.
16-37.
ALTERNATOR.
(Refer
to
figure
16-3.)
a.
Open
the
battery
box
and
diconnect
the
ground
16-38.
DESCRIPTION.
Thru
1977
Models
the
alter-
cable
from
the
negative
terminal
of
the
battery
and
nator
used
on
the
aircraft
is
rated
at
14-volts
at
60-
pull
the
cable
from
the
battery
box.
amperes
continuous
output.
Beginning
with
1978
Mod-
b.
Remove
the
nuts,
washers,
ground
strap
and
els
the
alternator
used
is
rated
at
28-volts
at
60-
diode
board
from
the
studs
of
the
receptacle
and
re-
amperes.
The
alternator
is
three-phase,
delta
con-
move
the
battery
cable.
nected
with
integeral
silicon
diode
rectifiers.
The
c.
Remove
the
screws
and
nuts
holding
the
recep-
moving
center
part
of
the
alternator
(rotor)
consists
tacle.
The
receptacle
will
then
be
free
from
the
of
an
axial
winding
with
radial
interlocking
poles
bracket.
which
surround
the
winding.
With
excitation
applied
d.
To
install
a
ground
service
receptacle,
reverse
to
the
winding
through
slip
rings,
the
pole
pieces
this
procedure.
Be
sure
to
place
the
ground
strap
assume
magnetic
polarity.
The
rotor
is
mounted
in
on
the
negative
stud
of
the
receptacle.
bearings
and
rotates
inside
the
stator
which
contains
the
windings
in
which
the
ac
is
generated.
The
stator
16-35.
ALTERNATOR
POWER
SYSTEM.
windings
are
three-phase,
delta
connected,
and
are
attached
to two
diode
plates,
each
of
which
contains
16-36.
DESCRIPTION.
The
alternator
system
con-
three
silicon
diodes.
sists
of
an
engine
driven
alternator,
a
voltage
regu-
lator
mounted
on
the
left
hand
side
of
the
firewall
and
The
diode
plates
are
connected
to
accomplish
full-
a circuit
breaker
located
on
the
instrument
panel.
wave,
rectification
of
the
ac.
The
resulting
dc
out-
The
system
is
controlled
by
the
left
hand
portion
of
put
is
applied
to
the
aircraft
bus
and
sensed
by
the
the
split
rocker,
master
switch
labeled
ALT.
An
voltage
regulator.
The
regulator
contorls
the
exci-
over-voltage
sensor
switch
and
red
warning
light
tation
applied
to
the
alternator
field,
thus
controlling
labeled
HIGH
VOLTAGE
are
incorporated
to
protect
the
output
voltage
of
the
alternator.
the
system.
(refer
to
paragraph
16-46).
The
air-
craft
battery
supplies
the
source
of
power
for
ex-
citation
of
the
alternator.
Change
7
16-9

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)