Yanmar 3JH3E Service Manual page 212

Chapter 9 Electrical System
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3.4JH3(B)(C)E
3) Rotor coil insulation test
Check the continuity between the slip ring and the
rotor core, or the shaft. If there is continuity, insulation
inside the rotor is defective, causing a short with the
earth circuit. Replace the rotor coil,
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4) Check the rear side ball bearing.
If
the rotation
of
the
bearing is heavy, or produces abnormal sounds,
replace the ball bearing.
(3} Stator
1) Stator coil continuity test
Check the continuity between each terminal of the sta-
tor
coil.
If
there is no continuity, there is a wire
break
in
the stator coil. Replace the stator coil.
Resistance value
Pn·nred
in Japan
HI!\SHJ.ll8009
Approx. 0.0770 at 20'C
1-phase resistance
9-27
2} Stator coil insulation test
Check the continuity between the terminais and the
stator core.
II
there is continuity, insulation of the sta-
tor coil is defective. This
wm
cause a short-circuit with
the earth core. Replace the stator coil.
(4) Brush
The brush
is hard
and wears
slowly,
but
when it is
worn beyond the allowable limit, replace ft. When
replacing the brush, also check the strength of the
brush spring.
To check, push the spring down to 2mm (0.0787in.}
from the end surface of the brush holder, and read the
gauge.
Brush spring stre rath
255-3459
{5) Brush wear
Check the brush length.
The brush wears very little, but replace the brush lf
worn over the wear limit line printed on the brush.
/
Wear limit line (brush)
mm
Maintenance standard Wear limit
Brush length 16 9