The Diagnosis and Solution of Electrical Machine Problems - Part I: Design Influences

The minimization of problems in electrical machines requires, in the first instance, comprehensive standards of design, manufacture, and factory testing. This must be followed by correct installation and commissioning. Satisfactory service will then depend on the implementation of appropriate operational routines and maintenance procedures. Large horizontal cage induction motors are considered, and some of the design and constructional factors which can contribute to the avoidance of problems are examined. These problems may include vibration, noise, and overstressing or fatigue of the shaft, laminations, or stator frame, and premature failure of bearings, stator winding, or rotor cage. An example is given of the analysis of the ability of a rotor cage design to withstand the thermal and rotational stressing associated with a large number of starts.