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Bench Testing: Rotor

  1. Place ohmmeter on lowest scale. Connect ohmmeter across slip rings. Ensure resistance is within specification. See ROTOR RESISTANCE table.
  2. If resistance is too low, rotor has short circuit and must be replaced. If resistance is infinite (no continuity), rotor has open circuit and must be replaced.
  3. Place ohmmeter on X1000 scale. Connect ohmmeter between rotor core and either slip ring. Continuity should not exist. If continuity exists, rotor is grounded and must be replaced.
ROTOR RESISTANCE

Application Ohms
80-Amp Generator 2.6-3.2
140-Amp Generator 2.4-2.8