For service professionals working with large electric motors and generators, machines with voltage ratings 5 kV and higher can be vulnerable to invisible threats of partial discharge (PD). Corona and PD activity have long been a challenge to detect before failure occurs. Traditionally, detecting these issues required indirect methods like radio interference voltage (RIV) testing, ultrasonic detection or offline insulation tests. But recent advances in partial discharge imaging—sometimes called corona cameras—are giving engineers and technicians a powerful new tool: the ability to see electrical discharge activity directly and in real time. 

Para los profesionales que trabajan con grandes motores y generadores eléctricos, las máquinas con tensiones nominales de 5 kV o superiores pueden ser vulnerables a amenazas invisibles de descargas parciales (DP). Detectar la actividad corona y las DP antes de que se produzca un fallo ha sido un desafío durante mucho tiempo. Tradicionalmente, detectar estos problemas requería métodos indirectos como pruebas de voltaje de radio interferencia (RIV), detección ultrasónica o pruebas de aislamiento a máquina parada. Sin embargo, los recientes avances en imágenes de descargas parciales, a veces llamadas cámaras corona, brindan a ingenieros y técnicos una nueva y poderosa herramienta: la capacidad de ver la actividad de descargas eléctricas directamente y en tiempo real.

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!

Are you encountering high no-load current or high current with load? This presentation will look into the causes and cures.

En el actual entorno competitivo cada vez mayor, los usuarios finales buscan centros de servicio de máquinas eléctricas rotativas que aumenten su oferta de valor agregado. Una de las formas más fáciles para que un centro de servicios logre esto es efectuando una inspección minuciosa y detallada de los equipos que reciben para reparación. Los resultados de dicha inspección permiten mejorar la confiabilidad de los equipos que se logra a través de los resultados de la evaluación y las recomendaciones que ofrece el centro de servicio para prevenir fallas recurrentes y mejorar el tiempo medio entre fallas.

The worn carbon brush face indicates the operating conditions. Therefore, it can be utilized by brush experts as a highly effective diagnostic tool for troubleshooting and determination of root causes. If these warning signs shown at the brush face can be identified and proactively addressed in a timely manner, then major unexpected expensive catastrophic failures like flashover or repair of the contact surface can be avoided.

Balancing plant maintenance costs and activities with the need to achieve production goals is a daily challenge for most maintenance professionals. Since the motor-driven system is often a critical component in this dynamic, this article looks at some best practices to help it achieve those goals and meet customer demands.

El propósito de este artículo es proporcionar suficientes fundamentos de rodamientos para que aquellos que son responsables de la aplicación, operación, mantenimiento y reparación de motores eléctricos puedan tomar las medidas necesarias para minimizar las fallas prematuras de los rodamientos y mejorar la posibilidad de que los rodamientos duren hasta el " "final de la vida útil", que normalmente se denomina vida útil del rodamiento L10.

The purpose of this article is to provide enough rolling element bearing fundamentals so those who are responsible for the application, operation, maintenance and repair of electric motors can take the necessary steps to minimize premature bearing failures and enhance the possibility of bearings lasting until the "end of life" predictions, which is normally referred to as L10 bearing life.

The most basic tool a vibration analyst uses is the vibration spectrum. The spectrum is a graphic illustration of the frequencies present in a vibration signal and their relative amplitudes. This article provides a basic overview, examines settings and provides tips.

La herramienta más básica que utiliza un analista de vibraciones es el espectro de vibraciones. El espectro es una ilustración gráfica de las frecuencias presentes en una señal de vibración y sus amplitudes relativas. Este artículo proporciona una descripción general básica, examina la configuración y ofrece sugerencias.

Determining the source of noise in a motor is often much more challenging than correcting it. However, a methodical approach to investigating the noise can narrow down the possible causes.

This PowerPoint presentation is available for members to use to present the factors that should be considered when customers are faced with making the difficult decision to repair their existing motor or purchase a replacement.

Determining the source of noise in an electric motor is often more challenging than correcting it. A methodical investigative approach, however, can narrow the possibilities and make it easier to resolve the issue—with one caveat. If the noise is due to something in the motor design (e.g., a manufacturing defect or anomaly), a solution may be impossible or impractical.

This webinar recording reviews the failures associated with 3-phase motors on Variable Frequency Drives (VFDs) and how to rewind to limit future failures.

To ensure the reliability of an RV’s electrical devices, especially electric motors, campers must know the service voltage of the hookup their RV is using. Teaching consumers to check that before they plug in the vehicle could save them many headaches.

Centrifugal pump failures are most commonly attributed to seal failure, impeller damage and bearing failures. A good understanding of failure modes for seals, impellers and bearings is essential to providing customers with reliable pump repairs.

Determining the source of noise in a motor is often much more challenging than correcting it. However, a methodical approach to investigating the noise can narrow down the possible causes and therefore make it easier to resolve the noise issue. There is a caveat. If the cause of the noise is due to something in the motor design, that is, a manufacturing defect or anomaly, a solution may not be possible or practical.

A menudo, determinar la fuente del ruido en un motor eléctrico es más un desafío que corregirla. Sin embargo, un enfoque metódico puede reducir las causas posibles y por consiguiente facilitar la resolución del problema. Una advertencia aquí es que, si el ruido está relacionado con el diseño del motor, es decir, por un defecto de fabricación, puede que no sea posible o que no sea práctico obtener una solución.

A special discounted collection of 7 webinar recordings focusing on various aspects of electromechanical repair.

Just $35 for EASA members!

This manual covers horizontal and vertical squirrel-cage induction motors in the 300 to 5,000 horsepower range, low- and medium-voltage. Most of the principles covered apply to other sizes as well. This manual focuses primarily on IEC motors and standards.

In March of 2019, EASA conducted an in-depth survey to better understand how end users decide between repairing or replacing electric motors and to identify electric motor repair/replacement trends. Internet-enabled condition monitoring has been a hot topic recently and, as a result, questions related to this were added to the list of survey questions. The survey returned some very interesting results about internet-enabled condition monitoring.

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.

The impeller is generally the most difficult pump component to repair and the most expensive to replace. This session will look at case histories of failed pumps and the steps to determine the cause of failure.

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). 

The most frequent concern about high current with a three-phase motor is high no-load current. But the broad issue of high no-load current isn’t the only three-phase motor issue to which plants should pay heed.