INSPECTION

PROCEDURE

1. INSPECT GENERATOR BRUSH HOLDER ASSEMBLY

(a) Using a vernier caliper, measure the brush length.

Text in Illustration

*a

Length

Standard exposed length:

9.5 to 11.5 mm (0.374 to 0.453 in.)

Minimum exposed length:

4.5 mm (0.177 in.)

If the brush length is less than the minimum, replace the generator brush holder assembly.

2. INSPECT GENERATOR ROTOR ASSEMBLY

(a) Check that the generator rotor bearing is not rough or worn.

If necessary, replace the generator rotor assembly.

(b) Check the generator rotor assembly for an open circuit.

(1) Measure the resistance according to the value(s) in the table below.

Text in Illustration

*a

Slip Ring

Standard Resistance:

Generator Assembly Type

Tester Connection

Condition

Specified Condition

for 100A

Slip ring - Slip ring

20°C (68°F)

1.8 to 2.2 Ω

for 130A

1.55 to 1.95 Ω

If the result is not as specified, replace the generator rotor assembly.

(c) Check the generator rotor assembly for an open circuit.

(1) Measure the resistance according to the value(s) in the table below.

Text in Illustration

*a

Slip Ring

*b

Rotor Core

Standard Resistance:

Tester Connection

Condition

Specified Condition

Slip ring - Rotor core

Always

10 MΩ or higher

If the result is not as specified, replace the generator rotor assembly.

(d) Using a vernier caliper, measure the slip ring diameter.

Text in Illustration

*a

Diameter

Standard diameter:

14.2 to 14.8 mm (0.559 to 0.583 in.)

Minimum diameter:

14.0 mm (0.551 in.)

If the diameter is less than the minimum, replace the generator rotor assembly.