Often when we are dealing with three-phase squirrel cage motors we ask ourselves “Is there a standard or a rule of thumb for this motor characteristic?” The 10 characteristics that follow apply to conditions associated with motor starting as well as steady state operation. Examples are provided for each of the characteristics.

A menudo, cuando trabajamos con motores trifásicos jaula de ardilla, nos preguntamos: "¿Existe una norma o regla general para esta característica del motor?". Las siguientes 10 características aplican tanto al arranque del motor como al funcionamiento en estado estacionario.

This recording provides an overview of common different thrust bearing arrangements, with end play guidance tips for each.

Concentric to lap winding conversions are common practice in many EASA service centers. For most stators, this change is feasible and can be made with little difficulty. In some cases, however, it can be quite challenging and result in undesired outcomes due to reduction in copper or insulation.

Las conversiones de devanados concéntricos a imbricados son una práctica común en muchos centros de servicio de EASA y en la mayoría de los estatores, este cambio es factible y se puede realizar sin dificultad. Sin embargo, en algunos casos, puede resultar muy complicado y generar resultados no deseados debido a la reducción del cobre o la pared de aislamiento.

The video provides a comprehensive guide on performing a single-phase rotor test on a three-phase squirrel cage motor to check for open rotor bars.

From the manufacturer’s perspective, a random-wound, 2300-volt motor represents a substantial reduction in manufacturing cost. For the service center, the challenge is to successfully rewind them while providing a reliable repair. Here are some techniques which will enhance your success rate.

Desde la perspectiva del fabricante, un motor de 2300 voltios con bobinado aleatorio representa una reducción sustancial en el costo de fabricación. Para el centro de servicio, el reto es rebobinarlos con éxito y ofrecer una reparación confiable. Aquí hay algunas técnicas que mejorarán su tasa de éxito.

When there is a need for cleaning the contact surfaces of commutators and slip rings with brushes, emery cloth with aluminum oxide is NOT recommended, as conductive abrasive particles will cause arcing and damage to the surface. Many times, stone cleaning, garnet paper and machining are not a convenient, sufficient, or cost-effective option for machines as the priority is to keep the downtime to a minimum. This is when the carbon brush can be designed to clean up the contact surface.

Cuando sea necesario limpiar las superficies de contacto de los colectores y anillos rozantes, NO se recomienda usar tela de esmeril con óxido de aluminio, ya que las partículas abrasivas conductoras pueden causar arcos eléctricos y dañar la superficie. Muchas veces, la limpieza con piedra, el papel granate (Garnett) y el mecanizado no son una opción conveniente, suficiente ni rentable para las máquinas, ya que la prioridad es minimizar el tiempo de parada. En este caso, la escobilla de carbón se puede diseñar para limpiar la superficie de contacto.

Sewage and wastewater treatment pumps are common machines repaired in EASA service centers. While both odor and biohazard are real problems, there are ways to deal with each, and service centers looking to broaden their repair market should not shy away from a profitable market because of the odor and biohazard. 

Las bombas de tratamiento de aguas residuales y residuales son máquinas habituales que se reparan en los centros de servicio de EASA. Si bien tanto el olor como el riesgo biológico son problemas reales, hay maneras de abordar cada uno de ellos, y los centros de servicio que buscan ampliar su mercado de reparación no deberían rehuir un mercado rentable debido al olor y el riesgo biológico.

This video shows the proper way to lubricate the deep-groove, open ball bearing before assembling a horizontal induction motor.

This video shows the proper procedure for seating carbon brushes in a DC machine.

This video will walk you through how to check the relative polarity of DC machine interpoles and the armature and correct it if necessary using a simple interpole polarity test.

This video demonstrates the correct way to use an induction bearing heater to install an interference fit ball bearing on a machine shaft.

When working with DC machines, it’s not uncommon to find a customer who runs different products requiring a range of armature current. Unlike other conductors, where lower current is a good thing, carbon brushes are designed for a narrow range of current density. A unique aspect of carbon brush life is that brushes operating at a much lower current density than they are designed for do not last nearly as long as expected.

Al trabajar con máquinas de CC, no es raro encontrar un cliente que fabrica diferentes productos que requieren un rango de corriente de armadura. A diferencia de otros conductores, donde una corriente más baja es algo bueno, las escobillas de carbón están diseñadas con poco margen de densidad de corriente.

This article looks at the installation and removal of quick detachable (QD) and taper lock pulleys.

En este artículo discutiremos dos tipos de poleas: poleas de desmontaje rápido (QD) y poleas con bloqueo cónico y se proporcionarán instrucciones para instalar y desmontar ambos tipos.

This presentation focusses on critical close fit tolerances and certain surface finish specifications.

When a core loss test reveals localized hot spots, or visual inspection identifies physical damage, the ability to repair the damage in a cost-effective manner means the difference between repair or replacement.

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!

Cuando la resonancia causa una vibración excesiva, es importante identificar la frecuencia natural y la forma modal de la vibración. Una simple prueba de impacto (bump test), realizada a máquina parada, es un buen primer paso para identificar la frecuencia natural.

When resonance does cause excessive vibration, it is important to identify the natural frequency and the mode shape of the vibration. A simple bump test, conducted with the machine not running, is a good first step in identifying the natural frequency.

Learn how to effectively use EASA's live, ever-expanding online database of more than 250,000 windings.

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

The insulation system chosen for any rewind should be suitable for the application, the voltage class, and the winding process capability of the service center. In most cases, adherence to “equal to or better than” selection is a good practice.

El sistema de aislamiento escogido para cualquier rebobinado debe ser el adecuado para la aplicación, el voltaje y la capacidad del proceso de rebobinado del centro de servicio. En la mayoría de los casos, seleccionar una opción "igual o mejor" es una buena práctica.

When preparing to rewind random or form-wound status, sometimes there just doesn’t seem to be enough room in the stator slot for the desired conductor area and insulation quantities. This presentation looks at balancing stator copper losses against insulation reliability.