Checking the brush wear

Checking the brush wear

• Check the outside of the voltage regulator for damage.
• Change the regulator if the brushes are split or if the protrusion dimension "a" is below the specified value.

1. Minimum brush length
2. a = 7 mm

• Also check that the brushes run smoothly and that their springs are rigid enough to ensure good contact of the brushes on the collectors.

Continuity test of the rotor winding

• Check that the resistance of the rotor winding is within the specified ratings connecting the prods of the tester on the collector rings.

1. Rotor winding resistance
2. 2.6 ÷ 2.8 Ω

Rotor insulation test

• Place one tester prod on a collector ring and the other one on the rotor core, then check that the tester does not signal the passage of current.

Measuring the concentricity of the rotor and collector rings

• Set the rotor on special supports and using a dial gauge on a magnetic support base, check that the eccentricity of the rotor outside diameter does not exceed the specified value.

1. Eccentricity of rotor outside diameter
2. ≤ 0.05 mm

• In the same way, check that the difference on the collector rings does not exceed the specified value. If necessary, turn the outsides of the collector rings.

1. Eccentricity of collector rings
2. ≤ 0.03 mm

• Repeat the operation for the second collector ring.