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.

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.

There are times when a DC motor or generator experiences a catastrophic failure and the customer wants to know why it happened. One type of failure that seems to stimulate lively conversation is when the failure involves dramatic damage to the brushholders and commutator. The term "flashover" describes the appearance of the failure; the very name conveys an accurate mental image of the failure. The questions that arise next are predictable: "What caused this?" and "What can be done to prevent a recurrence?" Or, if the motor was recently repaired: "What did you do to my motor to cause this?!" The purpose of this article is to help you answer those questions.

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.

The repair of the various types of pumps represents an important segment of the service center repair market. Electric motors and pumps are the two most widely used industrial machine components.                                                                                                                                                                                                                       

Although there are two principle pump types (dynamic and positive displacement), this manual focuses on dynamic pumps and the fundamentals of dynamic pump repair. The information it contains will be helpful to both novice and experienced pump repair technicians, to supervisors and managers of pump repair operations, and to customer service and sales personnel who communicate with customers about pump repair issues.

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.

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

Two common scenarios that service centers deal with regarding belt drive applications are failure of a motor drive end ball bearing or breakage of the shaft at the drive end bearing shoulder. The cause of these failures often is over-tensioning of the v-belts. However, there are many other faults or undesirable practices that can lead to premature bearing failure, belt wear and sheave wear.  Due to practical space limitations, this article isn't exhaustive in its coverage but deals with common scenarios other than motor bearing failure and shaft breakage.

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.

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.