Starting Motor Bench Tests - Piper PA-24 Comanche Service Manual

PIPER COMANCHE SERVICE MANUAL
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GROUND
-STARTING MOTOR
BATTERY
BATTERY
~~!~I
i'NI~WiIami
SWITCH CARlON PILE
I'-
-M;jRiOouU1N=D)-~==!l_~
FIGURE 9-29..
Mo-LOAD TIST
HOOKUP FIGURI9-29f. STALL-TORQUE
HOOKUP
play should be .005 to .050 of en iDch.
b. New bn.Jahes should
be
properly ..ated whe"
~:IIta11iDlby
wrappiDl a .trip of 00 sandpaper
arcuttd
the commutator (With
the
.8Ildinc sid. out) 1.25 to 1.50 tilDe.
auimum.
Drop brushes on
sandpaper covered CClllllDutatcr .nd
tum
the
umaNre
.lowly ill the diNCtion
of
rotatien.
Dust
should be blown out of the 1lI0tor after sandine.
MOTE
•
The .priDe
tensien is 32 to 40 ounc .. with new brushes. Thi. ten-
sion
is lIIe••
ured
with the
selle hooked WIder the brush sprine near
the
brush and
the
:eadinl i. taken
at
rient lillie. to the line of
force exerted by th_ brush spril'll.
c.
Check the
po.ition of the pinion to be sur. the unit wil1.mah properly with the flywheel
rinl lear. See specifications for unit
fot
COrNet
dimensions. Refer to P.ralta"h 9-90.
9-38.
B.nch
T.,tl.
a. After the ItartinlllIotor is r....embl.d, it should
be
t..ted to
He
that the ng.load current
at
a
certain volta. ia within specification. _ liven
i.D
par_paph 9-90.
To mat.
this test.
eea-
nect as shown in
FiCUnt 9-291.
If
curtent
is
too bilh. eh-ek the besriDl aUlnment and end
play
to make sure there is no bindinc or interfetencer. T.. o or three sharp ras- on the fr ame with a raw-
hide hamlller will oftell help to alien the bearinp
and
f~ the armature.
b.
If no difficulty is indicated in the above telt, a ItaU torque test may
be
made to see if
the starting motor is producillg its rated crankinl po.... M.ke test connections as shown in
F i
g\lfe
9-29f.
c. If torque and current
.e
net wit:bin specificatioM, cbeck the seatinl ol the brushes and
!ntemal connectiOllS for hip resistance. If the.e checkll are made and found to
be
in
IOod
order.
replace frame and field assembly end retest starter.
EL.ECTRICAL SYSTEM
ISSUED: 8/18/72
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C1S