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.

In today’s ever-increasing competitive environment, end users are looking for rotating apparatus service centers to increase their offering of value-added support. One of the easiest ways for a service center to achieve this is through a thorough and detailed inspection of items in the shop requiring repair. The results of this type of inspection allow for improved reliability achieved through the results of the evaluation and recommendations the service center offers to prevent reoccurring failures and improve mean time between 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.

In a previous article in Plant Engineering ("A systematic approach to AC motor repair," Plant Engineering, April 2015), EASA highlighted the good practices for electrical repair found in ANSI/EASA Standard AR100 Recommended Practice for the Repair of Rotating Electrical Apparatus, and the significant impact they can have on motor efficiency and reliability. But that was only part of the story, because mechanical repairs—and even documentation, cleaning, and inspection—can also markedly affect motor reliability and efficiency.

Many of your customers have good in-house predictive maintenance departments and others outsource that skill. Either way, they should know when a bearing is deteriorating and remove the motor from service before it turns into a catastrophic failure. That saves a lot of maintenance dollars, which is great. But if the customer stops there, without discovering why that bearing is bad, your repaired motor could be returned with the same problem again. Defective bearings often hold a great deal of evidence, if we only look for it. The key is communication with the customer so that we repairers know that the motor was removed for bearing faults, and so that we can go a step further in the diagnostic process. Especially with the prevalence of variable frequency drives (VFDs), bearing currents cause a significant number of bearing failures. If you know the motor is operating from a drive, there are corrective measures to prevent future failures of the same type. And those extra steps are billable extras. Neglecting these additional inspection steps is like leaving money on the table, for both the service center and the customer.

Muchos de sus clientes cuentan con buenos departamentos de mantenimiento predictivo propios y otros lo subcontratan con proveedores externos calificados. En ambos casos, ellos deben saber cuando un rodamiento presenta deterioro y sacar de servicio el motor antes que el fallo se vuelva desastroso. Los rodamientos defectuosos aportan una gran cantidad de evidencias, si solamente las buscamos.

Hearing the words “OSHA inspection” will make most U.S. service center managers cringe. The Occupational Safety and Health Administration, or OSHA, is charged with the enforcement of safety and health legislation in the U.S. This past year, K&N Electric Motors was honored with an “invitation” from OSHA to provide a “tour” of our Spokane Valley location. You can’t imagine what went through our minds. Well, maybe you can. We were somewhat uneasy about what to expect, to say the least.

Shows step-by-step disassembly of a DC motor and the tools to use. Demonstrates how to mark parts, and how to label and record connections for use in assembly. Also explains how to check for shorts or opens in field and armature windings, how to test run the motor, and how to inspect parts for damage and wear.