Improved motors for utility applications. Volume 2: Industry assessment study

Auxiliary drive motor failures in electric utility applications result in large repair costs and energy replacement costs. In order to assess the motor reliability experience of the utility industry and identify specific problem areas, computerized databases were established for all fuel sources, geographic factors and motor manufacturers. Failures of specific components in certain specific applications appear to be associated with specific manufacturers. However, overall, 22% of all reported failures were attributed to winding failure and 13% to sleeve bearings. Numerous examples of misapplication were discovered such as the horizontal motor which was vertically mounted by an OEM, inadequately balanced hydraulic thrust loads in a packaged motor/pump system and inappropriate enclosure specified for a motor located outdoors. The internal procedures and practices of those utilities which had particularly low failure rate experience included such factors as stringent specifications, objective purchasing policies, adequate record keeping and preventative maintenance programs.