Revisit EASA's 2024 Convention & Solutions Expo by buying access to recordings of the general sessions and education events streamed from EASA's website! These recordings provide just over 32 hours of training. Downloadable PDFs of slides and technical papers are included!

This book was developed to help electric motor technicians and engineers prevent repeated failures because the root cause of failure was never determined. By using a proven methodology combined with extensive lists of known causes of failures, one can identify the actual cause of failure without being an “industry expert.” In fact, when properly used, this material will polish one’s diagnostic skills that would qualify one as an industry expert.

The paper "Case Studies in Failure Analysis" by Chuck Yung, presented at the EASA Convention 2019, delves into the methodologies and practical examples of root cause failure analysis (RCFA) for electric motors. Yung emphasizes the importance of understanding motor design, application, appearance of failure, and operating environment to accurately diagnose motor failures. While extensive investigations are necessary for critical motors, less critical motors can often be assessed using experience and common sense.

I suspect that just about everyone in our industry at one time or another has had the joy of repairing a “purpose-built” motor. This kind of motor is built for a specific purpose and has characteristics that may allow it to operate under non-standard conditions. Due to the limited information that some of them display on the nameplate, the repair of these motors can be somewhat of a challenge. Sometimes these motors possess differences such as the color of paint, the shaft size, the bearing size, or type. It can be the operating temperature and at times it can be the motor in its entirety. Following are a few useful tips we use when repairing a motor with so many question marks.

Sospecho que casi todos en nuestra industria alguna vez han tenido el placer de reparar un motor “fabricado con requisitos especiales”. Este tipo de motor está construido para un propósito específico y tiene características que le pueden permitir funcionar bajo condiciones no habituales. Debido a la información limitada que algunos de ellos muestran en su placa de datos, la reparación de estos motores puede resultar un reto.

Learn how a fellow EASA service center interpreted different maintenance philosophies and put their own development in that curve. Their evolution has gone from workshop to predictive maintenance and beyond–to proactive maintenance, including 3D scan/print and the Internet of Things (IoT). 

This article demonstrates the suitability of resin rich insulation systems for hydro generator service and highlights the advantages of being able to introduce remedial measures during the life of the winding to address issues and ensure that acceptable winding life is achieved 

This article describes the technical issues in online partial discharge (PD) detection on motors fed by VS-PWM drives, and gives an example of one system that detected the PD successfully.

By this time we should all know that stator core loss testing is a required part of a quality rewind. A core loss test before and after burn-off is specified in the EASA Recommended Practice for the Repair of Rotating Electrical Apparatus (ANSI/EASA AR100) and The Effect of Repair/Rewinding on Motor Efficiency; EASA/AEMT Rewind Study and Good Practice Guide to Maintain Motor Efficiency.

Topics covered in this article include:

• Lessons learned
• Rebates add incentive
• Learning from other members
• Determining if the core is usable
• Accurate iron measurements