Mitsubishi diesel engines Service Manual page 172

ELECTRICAL SYSTEM - DISASSEMBLY, INSPECTION AND REASSEMBLY
Inspecting the armature
(2)
Using a dial gauge, measure the commutator
(a)
for radial runout. If the measure value is equal
to or exceeds the limit, correct (within the
diameter limit) or replace.
M001T68281
Commutator
radial runout M008T70471A
M008T81071A
Measure the commutator diameter.
(b)
If the measured value is equal to or less than
the limit, replace.
M001T68281
Commutator
diameter
M008T70471A
M008T81071A
Measure the depth of undercutting between the
(c)
commutator segments.
If the measured value is equal to or less than
the limit, correct or replace.
Mica M001T68281
undercutting M008T70471A
depth M008T81071A
Armature coil short circuit
(d)
Using a growler, test the armature coil for
short circuit.
indicated.
How to inspect: (Before inspection, remove any
debris from the armature coil.) With
a thin iron plate positioned parallel
with the armature coil, slowly rotate
the armature coil. While the coil is
running, the iron plate should not be
pulled onto the coil or vibrate.
Unit: mm (in.)
Standard
Limit
value
0.05
(0.002) 0.10
0.03
(0.004)
(0.001)
Unit: mm (in.)
Standard
Limit
value
29.4 28.8
(1.16) (1.13)
32.0 31.4
(1.26) (1.24)
Unit: mm (in.)
Standard
Limit
value
0.5 0.2
(0.02) (0.01)
Replace if short circuit is
Commutator
Measuring the commutator radial runout
Measuring the commutator diameter
Undercutting
Segment
Measuring the mica undercutting depth
Growler
Testing the armature coil for short circuit
Mica
Iron plate
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