Iseki SCM49, Руководство по обслуживанию, Страница: 105 / 128

105
CHAPTER 9. ELECTRICAL ACCESSORIES
armature coil core. If there is no continuity, the
armature coil is normal.
Fig. 9-11
2) Inspection of armature coil for short circuit
• Turn the armature coil on a armature coil tester
while holing a piece of iron closely above the
armature. If the iron piece does not vibrate nor
is attracted to the armature, the armature is nor-
mal.
Note: The armature coil surfaces should be
cleaned ahead of time.
Fig. 9-12
3) Inspection of the commutator
• Inspect the commutator surfaces for dirt, burn-
ing, damage, etc. Minor damage can be corrected
with sandpaper of #400 or higher no.
• Inspect the commutator for run-out with a dial
gauge on a V-block.
Standard value Usable limit
0.02 mm 0.05 mm
• Measure the commutator diameter with vernier
calipers.
Standard value Usable limit
30 mm 29 mm
Fig. 9-14
• Measure mica depth against segment top.
Standard value Usable limit
0.5 - 0.8 mm 0.2 mm
Fig. 9-15
4) Inspection of field coils for short circuit
• Inspect for continuity across the lead from termi-
nal C and field coil brush. If there is continuity,
the coils are normal.
Fig. 9-16
5) Inspection of field coils for grounding
• Inspect continuity across the field coil brush and
field coil. If there is no continuity, the coils are
normal.
Fig. 9-13