Bench Testing: Rotor

Check rotor for open field windings by measuring resistance across slip rings. Resistance should be within specifications. See ROTOR RESISTANCE SPECIFICATIONS table. Check rotor for short circuit to ground by connecting ohmmeter between one slip ring and rotor. Continuity should not exist. If resistance and continuity are not as specified, replace rotor.
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

Application

⁽¹⁾ Ohms

ES300, LS400, RX300 & SC300

2.1-2.5

GS300 & GS400

2.2-2.4

SC400

2.7-3.1

⁽¹⁾	Measured at 68°F (20°C).