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.

Revised September 2022!
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There are several methods to operating a three-phase motor using single-phase power to make what would be an otherwise expensive and arduous process a little easier.

This manual, a companion to EASA's 2-day seminar of the same name, 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 NEMA motors.

Las versiones impresas y en forma de descarga del valioso manual didáctico / recurso de EASA, “Principios de Motores C.A. Medianos y Grandes”, se  ahora disponibles en inglés y en español. El manual incluye gráficos e ilustraciones, fotografías y mucha información técnica sobre máquinas C.A., incluyendo como funcionan, información específica sobre los tipos de encerramientos, fabricación de componentes y aplicaciones.  Muchos de los principios incluidos en el libro aplican a todos los motores C.A., especialmente a aquellos accesorios que fueron asociados en el pasado con las máquinas más grandes (como encoders, RTDs, termostatos, calentadores de espacio, sensores de vibración, etc.).

This webinar explains what shaft currents are, what causes them, and differentiate between the two common causes. It also discusses and compares methods to mitigate shaft currents and explains why the different causes of shaft currents require different solutions.

The slip ring or wound rotor induction motor (WRIM) has been used in a variety of applications. Many of these applications use the WRIM's high starting torque capability while limiting current to start and run very high inertia loads such as hammer mills, rolling mills, centrifuges, and rotary kilns. Other applications utilize the variable speed capability of the WRIM. Probably the most common use of WRIMs for variable speed is in crane and hoist service. Other variable speed uses for the WRIM include wiredraw machines, fans, blowers, pumps and refrigeration compressors. Many of these applications, if designed today, would utilize a standard induction motor and variable frequency drive (VFD), particularly those where speed control is the desired end result. When older WRIMs or their controllers fail, the best solution often is to replace both motor and control. There are situations, however, where the best solution may be to replace the old controller with a VFD and continue to use the WRIM. As always, the more knowledge we have about the equipment we work on the better equipped we are to make good choices about repairing, replacing or upgrading this equipment for our customers. With this in mind, a review of how the WRIM and some of its control schemes work seems appropriate.

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

There are a few areas of concern involving the misapplication variable frequency drives (VFDs) on a standard induction motor. This article looks at some of those.

Revisit EASA's 2021 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 22 hours of training. Downloadable PDFs of slides and technical papers are included!