Westerbeke 9.0 BCG Technical Manual page 135

3. Brushes and Brush Holders
A.
Check brushes. If the brushes are worn over
the service limit, replace them. _
B. With the brush holders assembled to the com-
mutator, check the brush spring tension. If the
spring tension has decreased over the service
limit, replace it.
C. Check continuity between the positive brush
holder and the brush holder base. In case of
continuity, replace the holder assembly.
D. Check the brush holder caulk.
4. Armature
A.
Check the armature coil using a growler tester.
If the armature is shorted, replace it.
Also check for continuity between the armature
and the commutator shaft. Replace if defec-
tive.
B. Measure the commutator
0.0.
and the depth
of undercut. Correct or replace the com-
mutator if defective. Also check the com-
mutator outside surface for dirtiness and
roughness. Polish the commutator, if rough,
with sand paper No. 300 to 400.
5. Field Coil
A. Check for continuity at both ends of the coil (be-
tween brushes). If no current is flowing, the coil
is broken. Replace the yoke assembly.
B. Check for continuity between the connector
and the yoke. If current is flowing, the coil is
grounded. In this case, check the insulated
condition and correct it. Replace the yoke as-
sembly if not repairable.
C. Check the staked condition of poles and check
the coil and other parts for looseness.
129
Description Standard Value Service Limit
Bush spring
tension 1.6 KW 1.5 kg (3.31 Ibs.) 0.7 kg (1.54Ibs.)
Bush length
1.7 mm (0.67 in.) 11.5 mm (0.45 in.)
Westerbeke Generators