Application of infrared thermography to fault detection in industrial induction motors: Case stories

Infrared thermography has been extensively applied over decades to areas such as maintenance of electrical installations. Its use in electrical machines has been mainly circumscribed to the detection of faults in static machines, such as power transformers. However, with regard to the predictive maintenance of rotating electrical machines, its use has been much more limited. In spite of this fact, the potential of this tool, together with the progressive decrease in the price of infrared cameras, make this technique a very interesting option to, at least complement, the diagnosis provided by other well-known techniques, such as current or vibration data analysis. In this context, infrared thermography has recently shown potential for the detection of motor faults including misalignments, cooling problems, bearing damages or connection defects. This work presents several industrial cases that help to illustrate the effectiveness of this technique for the detection of a wide range of faults in field induction motors. The data obtained with this technique made it possible to detect the presence of faults of diverse nature (electrical, mechanical, thermal and environmental); these data were very useful to either diagnose or to complement the diagnosis provided by other tools.