Electric Motor Maintenance & Repair for Long Term Efficiency

Abstract

Energy costs to operate electric motors can be a significant part of an operating budget. For example, a recent survey of California water departments reveals energy costs for pumping and treating water may be 25% of operating costs. Strategies to reduce these costs include reducing the operating time (turning off unnecessary equipment), using controls to match pump output with demand, optimizing motor systems, and installing energy-efficient motors. To effect these measures, the end-user (a water department, for example) may use microprocessor-based devices (for logic control); power electronics (for motor speed control); and specially-built electric motors. These devices may require different maintenance procedures than the equipment used in the past, and repair practices on electric motors may require special care in order to maintain the efficiency value to which they were originally manufactured. This paper will focus on the three-phase electric motor maintenance and repair issues, with comments on the interaction with electronic drives.