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.

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.

Tres de los problemas más comunes en los motores trifásicos por los que somos consultados son:

1. “El motor toma mucha corriente en vacío”
2. “La corriente en las tres líneas no está balanceada”
3. “ El motor trabaja caliente”

Incluso si nunca te has enfrentado a uno de estos problemas, sigue leyendo porque es casi inevitable que lo hagas y querrás saber qué hacer al respecto.

Three of the most common three-phase motor problems we receive inquiries about are:

1. “The motor is drawing high no-load current.”
2. “The current of the three line leads is not balanced.”
3. “The motor is running hot.”

Even if you have never faced one of these issues, read on because it is almost inevitable that you will, and you will want to know what to do about it.

This video walks through the steps to adjust and set end play on a typical vertical hollow shaft pump motor.

Unless great care is taken, pulling magnet wire from a motor stator often bends or splays the lamination’s end teeth. Bent teeth, or teeth that have been splayed outward at the ends of the core stack, will likely compromise the quality of the repair job. Therefore, we have designed and implemented the use of disc clamps to hold the stator tooth tips in place while pulling magnet wire from the slots. The clamping fixtures described in the photos have helped ensure that we avoid damaging the stator teeth during the stripping process.

A no ser que se tenga mucho cuidado, tirar del alambre magneto al desmantelar el estator de un motor a menudo deforma o dobla los dientes de las laminaciones. Estos dientes deformados comprometerán la calidad de la reparación y hay estudios que demuestran que este problema puede reducir la eficiencia del motor. Sin embargo, aunque esta reducción puede ser pequeña, genera altos costos y desperdicio de energía.

General guidance for performing brush seating or comutator reprofiling in the field.

Cuando trabaje con bombas, seguramente encontrará instancias en las que se hace referencia a la curva de la bomba, junto con una serie de parámetros asociados con ella. Un parámetro clave de la curva de la bomba es el Punto de Mejor Eficiencia (BEP). Este concepto simple de un punto de operación que produce la operación más eficiente no es difícil de visualizar. Para motores eléctricos, la eficiencia varía con la carga; la mejor eficiencia está en alrededor del 75% de carga. Sin embargo, con las bombas rotodinámicas, que incluyen bombas centrífugas y de flujo axial, hay que considerar cuatro parámetros clave, uno de los cuales es la eficiencia. Estos cuatro parámetros son cabeza, caudal (también conocido como capacidad o volumen), potencia y eficiencia.

If you mention harmonics, engineers get excited while the eyes of non-engineers glaze over. The truth is that harmonics can be easily understood when explained in layman’s terms.

There are many factors to consider when re-stacking a stator. Those include the materials, core compression, length of the core, vents, spacers, vent construction and more. This article focuses on taking proper measurements when re-stacking a stator core and how to go about stacking the stator to ensure those dimensions are met.