Rotor: Testing and Inspection

Fig. 2 Testing Rotor Assembly:

1. Using a suitable ohmmeter check resistance between the two sections of the rotor slip rings. Take resistance readings at a minimum of four points around slip rings.
2. Resistance should be 2.9-3.5 ohms on 60 amp rotor or 3.0-3.6 ohms on 75 amp rotor. If resistance is not as specified, replace rotor.