HV motor condition monitoring-the end user´s view

High voltage electric motors commonly drive critical items of plant equipment. Failures, even when a unit spare is available, will have a significant impact on production. Running to failure can result in significant repair costs and, where a unit spare is not available, repair lead times, often measured in weeks or months, can generate major production losses. It is in the interest of any operator to monitor the online condition of such motors, not only to predict failures, allowing the impact on production to be minimised and failure damage limited, but also to gather essential data for the elimination of the defects causing failure. Many maintenance strategies are centred on time interval based offline electrical tests and vibration monitoring. Vibration monitoring is often based on the needs of the driven machine rather than the electric motor. However, there are a number of other condition monitoring technologies available that can be successfully applied to electric motors, both online and during workshop tests. In this article, the applicability of the full range of condition monitoring technologies to electric motors are reviewed and an end user´s view of their effectiveness presented