Inspection and Repair

1. ROTOR




1. Slip ring surface
Inspect slip rings for contamination or any roughness of the sliding surface.
Clean or polish with #500 to #600 emery paper if defective.




2. Slip ring outside diameter
Measure slip ring outside diameter. If slip ring is worn, replace rotor.

Slip ring outside diameter:
Standard
27 mm (1.06 in)
Limit
26 mm (1.02 in)




3. Continuity test
Check continuity between slip rings. If continuity does not exist, replace rotor.




4. Insulation test
Check continuity between slip ring and rotor core or shaft. If continuity exists, replace rotor.




5. Ball bearing
Check rear ball bearing. Replace it if it is noisy or if rotor does not turn smoothly.
2. STATOR




1. Continuity test
Inspect stator coil for continuity between its terminals. When there is no continuity between individual terminals, cable is broken. Replace stator coil.




2. Insulation test
Inspect stator coil for continuity between stator core and each terminal. If there is continuity, replace stator coil.




3. BRUSH
Measure brush length. If brush is worn, replace brush holder assembly.

Brush length (l):
Standard
20.5 mm (0.807 in)
Limit
1.5 mm (0.059 in)




4. DIODE ASSEMBLY

CAUTION: Never use a high tension insulation tester, such as a megger as it will damage diodes with its high tension.

The diode consists of eight diodes, four each being located on the positive and negative sides. The diode is necessary to restrict current flow to one direction.
Check all diodes, for continuity. If any diode is faulty, replace diode assembly.




1. Diodes on "+" side Continuity of proper diodes on "+" side




2. Diodes on "-" side Continuity of proper diodes on side
5. IC REGULATOR




1. Compose a circuit diagram as shown in figure.




2. Check operation as shown in chart below.