Bench Testing: Rotor
- Check rotor for open field windings by using an ohmmeter across slip rings. See Fig 1. Resistance should be 2.8-3.0 ohms.
- Check rotor for shorts to ground by connecting ohmmeter between slip ring and rotor shaft. Ohmmeter should show no continuity. Check slip rings for wear or pitting. Turn rotor on lathe (if necessary). Check bearing and replace (if necessary).