Bench Testing: Rotor

Check rotor for open field windings by measuring resistance across slip rings. Rotor resistance should be within rotor specifications. See ROTOR RESISTANCE SPECIFICATIONS table. Check rotor for short circuit to ground by connecting ohmmeter between one slip ring and rotor shaft. Continuity should not exist.
Check slip rings for wear or damage. Turn rotor/slip rings on lathe if necessary. Ensure slip ring diameter is not less than .504" (12.8 mm). Check bearing and replace if necessary.

ROTOR RESISTANCE SPECIFICATIONS