27370
1.INSPECT GENERATOR BRUSH HOLDER ASSEMBLY
| *a | Length |
Using a vernier caliper, measure the brush length.
9.5 to 11.5 mm (0.374 to 0.453 in.)
4.5 mm (0.177 in.)
If the brush length is less than the minimum, replace the generator brush holder assembly.
27330
2.INSPECT GENERATOR ROTOR ASSEMBLY
Check that the generator rotor bearing is not rough or worn.
If necessary, replace the generator rotor assembly.
| *a | Slip Ring |
Check the generator rotor assembly for an open circuit.
Measure the resistance according to the value(s) in the table below.
| Generator Assembly Type | Tester Connection | Condition | Specified Condition |
|---|---|---|---|
| for 100 A | Slip ring - Slip ring | 20°C (68°F) | 1.8 to 2.2 Ω |
| for 130 A | 1.55 to 1.95 Ω |
If the result is not as specified, replace the generator rotor assembly.
| *a | Slip Ring |
| *b | Rotor core |
Check the generator rotor assembly for an open circuit.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
|---|---|---|
| Slip ring - Rotor core | Always | 1 MΩ or higher |
If the result is not as specified, replace the generator rotor assembly.
| *a | Diameter |
Using a vernier caliper, measure the slip ring diameter.
14.2 to 14.8 mm (0.559 to 0.583 in.)
14.0 mm (0.551 in.)
If the diameter is less than the minimum, replace the generator rotor assembly.