Cessna T188C - Page 325

MODEL 188 & T188 SERIES SERVICE MANUAL
16-30. REMOVAL AND INSTALLATION. (See tion. For maintenance of the alternator, refer to the
figure 16-2.)
Cessna Alternator Charging
Systems Service/Parts
a.
Open battery box
and disconnect the
ground
Manual.
cable from
the negative
terminal of
the battery
and
CAUTION
pull the cable from the battery box.
b. Remove the rubber nipples, nuts, washers and Due to the high torque requirements of the
ground strap from the studs of the receptacle. Then 100 ampere alternator, at low rpm, night
remove the cable/cables and the battery contactor lighting such as spray lights, should not
closing circuit wire. be turned on with the engine operating be-
c. Remove
the screws
and nuts holding
the recep-
low
1000 rpm as
alternator drive
belt
tacle. The receptacle will then be free from the slippage may occur causing short belt life
bracket. or breakage.
d. To install a ground service receptacle, reverse
this
procedure.
Be sure to
place the ground
strap
CAUTION
on the negative stud of the receptacle.
The alternator is very susceptible to reverse
16-31. ALTERNATOR.
polarity current because
of the silicon diodes.
The diodes,
having a very
high resistance
to
16-32. DESCRIPTION.
The
alternators used
on the
reverse current
flow, are
used without
any
aircraft are belt driven, three phase with integral cutout relay such as used on a generator sys-
silicon diode rectifiers. Thru 18803046 the alternator- tem. The alternator diodes are arranged with
s are rated at
14 volts at 60 amperes, 28 volts
at 60 their cathodes
connected to the aircraft bus
amperes or 28 volts
at 100 amperes continuous output,
bar which is positive
and no back current will
depending on 12
or 24 volt system. Beginning
with 188- flow. If the polarity
of the battery is reversed
03047 the
alternators are 28 volts at 60
amperes or 28 the diodes
will offer no resistance to
the cur-
volts at
95 amperes continuous
output.
The alternator
rent flow.
The current
rating of the
diodes is
is mounted on the left side of the engine accessory sec- exceeded and diode failure may result.
SHOP NOTES:
16-21