This 250 HP, 1,800 RPM AC electric motor failed as a result of inefficient cooling due to corn product buildup. The excessive thermal conditions resulted in insulation degradation and a grounded winding. Our observations of the damage included:
The windings were burnt
The lubrication in both bearings was degraded thermally
The grease was darkened in color and had oil separation causing dryout
The drive end bearing housing and shaft were found to be out of tolerance
To return the motor to working order, Bodine sleeved the housing, and fabricated and installed a new shaft. Bearing isolators were installed, the stator was rewound, the bearings were replaced and the rotor assembly was balanced before reassembling the motor.