Alternator Test And Maintenance - Piper PA-24 Comanche Service Manual

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PiPeR COMANCHE SERVICE MANUAL
a. When installinl a battery. always make absolutely sure the
around polarity of the battery aDd the around polarity of the alter-
nator are the same.
b. \\'ben connectinl a booster battery. lIIake certaiD
to
CQftftect the
neeltive battery teratilla" toeether .d the poaitive battery ter·
minals toaether.
c. When connectifte a charter to the battery. cOlUleet the charaer
positive lead to the battery poeitive tenniDal and tbe charaer ftela-
tive lead to the battery nelative tenninal.
d. Never operate the eltenaator on open circuit.
Make
a.olutely
certain all connections in the circuit are secure.
e. 00 not short acroas
or
arouad ally of the terminals
OD
the alter-
nator or Naulator.
f. 00 ftot attempt to poluUe the alteIDator.
9-46. T•• t And Maintenance Of Alte",at.,. (Delc .. R...
y)
9-47. Inlpection. Even thouch the Iltemator is constructed to live 10nl periods of troubl..free
service, a reaular inspection procedure should be followed to obtain the maximWll life from the
alternator.
The frequency of inspection is detenained 1arply by the type of operatine coaditions.
Hiah speed operation. hiah temperatures, .d dust .d dirt all
Utae..
e the ..ear of brushes. slip
rinas and bearinas.
At regular intervals. inspect the tenninals for corro.ioft and
IODle
connections, and the
wirina for frayed insulation. Check the mOWlWlI bolta for
tiPtn.u, and
the belt for alilftment.
proper tension and wear. Belt tension should
be
adjus* in
accotduce
with enaine manufacturer's
recommendations. When tiahtenina belt tension. apply pr.ssure alainst the stator laminations h&-
tween the end frames. and not aaainst either end frame.
Nois. from an altemator may
be
callsed by wom or dirty bearinls, loose 1'IlounUna bolts, a
loose drive pulley, a defective diode. or a defective stator.
9-48. Disou.",bly. After extll1ded periods of operation. or at time of ealine overhaul, the alter-
nator IDay be removed from the aircraft for a thoroulh inapection
and
cleanina of all parts_ The
ahemator consists of four main components - tha two end frames, the stator and the rotor.
To disassemble the altamator, take out the
(Gilt
thru·bolts, aDd separate the drive end
frame and rotor assembly from the stator assembly
by
Pryinl apart with
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screwdriver at the stator
slot. A mark will help locate the parts in the same position durin . . .sembly. The fit betweea
stator and frame is not tight. and the two
can
be saparated e..ily. Note that the separation
is
to
!)e
:nade bet....n the stator frama and drive eed &ame. After dis_sembly. placa a piece of tape
over the slip rina end frame bearing to prevent entry of dirt and other foreip material. and also
place a piece of tape over the sbaft on the slip tinC end. U brush.s are to
be
re--used. clean with
a soit dry cloth.
CAUTION
Use pressure sensitive tape and not friction tape which would leave
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gummy deposit on the shaft.
ELECTRICAL SYSTEM
ISSUED: 8111/72
3
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