Facebook Twitter LinkedIn YouTube Menu Search Arrow Right Arrow Left Arrow Down Arrow Up Home Arrow Next Arrow Previous RSS Icon Calendar Icon Warning Icon
Proper Repair/Rewind Practices Maintain Efficiency/Reliability of Premium Efficiency/IE3 Motors  DOWNLOAD THE EXECUTIVE SUMMARY

Filter the results

  • Enter one or more words to find resources containing any of the words entered
  • Enter words or phrases between " " to find exact match

Resource categories

Resource Library

Two case history examples point to need for caution with metal spray

  • June 2018
  • Number of views: 1014
  • Article rating: No rating
Article

Two case histories point out the need for caution when working with metal sprayed shafts:

  • Example 1: When measuring the bearing fit shaft size, the micrometer didn’t feel right; mushy, not solid, although the journal was very close to the specified size. After using two micrometers to experiment with one of these frosted fits, it was discovered that the measurement on one micrometer changed when tightening down the other micrometer and vice versa.
  • Example 2: The bearing journals on a large armature began to fail while the armature was coming up to speed in balance stand.

Power supply considerations when building a large growler

  • July 2017
  • Number of views: 883
  • Article rating: No rating
Article

When considering building a large growler for testing armatures and rotors, the initial decision typically is to select a kVA rating. A primary reason for this is that the growler will need to be connected to a power supply of sufficient ampacity at the supply voltage. To help simplify a complex design process, four kVA ratings have been selected for this article.

Flashover: Causes and cures for damage to brushholders, commutators

  • April 2013
  • Number of views: 3541
  • Article rating: 3.3
Article

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.

How to strip an armature without degrading the core

A simple and efficient method to improve quality and save labor

  • January 2008
  • Number of views: 817
  • Article rating: 5.0
Article

We all know that stator cores should be burned at a controlled temperature to prevent lamination deterioration that can lead to harmful eddycurrent losses. But what about armatures?

Surge testing of DC motor and generator armatures

  • July 2007
  • Number of views: 1261
  • Article rating: 5.0
Article

In the April 2007 issue of CURRENTS, we covered surge testing anomalies, specifically for AC windings. The surge test can be used for DC windings as well. It can be a useful tool for evaluating armatures and some DC fields. A note of caution: If a winding does not have a minimum insulation resistance per ANSI/EASA AR100-2006, it is not safe to apply an overpotential test (surge or high potential). Surge testing shunt fields may not provide meaningful results if the surge pulse decays too quickly - if it dissipates through only the first few hundred turns. To obtain a test voltage high enough to test every turn would require too high a voltage. That high voltage would overstress the groundwall insulation.

Troubleshooting tips for armature rewinds

  • April 2003
  • Number of views: 555
  • Article rating: No rating
Article

When an armature is rewound, there is always a slim chance that it may be connected incorrectly. If two coil leads are switched, or if the error results in an armature where each coil closes on itself, normal tests will detect the problem. The trouble arises when the misconnection results in a uniform winding. When that happens, the result may be—in effect—an accidental redesign for a different voltage.

A case of uneven brush wear

  • October 1998
  • Number of views: 1476
  • Article rating: No rating
Article

The brushes on a 4-pole, 700 hp DC motor were not wearing at the same rate. In this case, rapid brush wear occurred on two adjacent brush rows - one positive and one negative polarity. The other brushes had minimal wear. Electrical tests found no winding faults, and the air supply was clean. Most of us suspect low current-density when rapid brush wear occurs. A lightly loaded DC motor can "dust" a set of brushes in short order. Changing the brush grade (or removing some of the brushes) will usually solve the problem.

Training Film 14: Taking Data From a Hand-Wound DC Armature

  • June 1984
  • Number of views: 126
  • Article rating: No rating
Video

Describes the correct procedure for taking data from hand-wound DC armatures. Shows how to record the data on typical DC data sheets, and explains the terminology used describing DC data. Points out differences between lap and wave windings.

Training Film 15: Hand Winding a DC Armature

  • June 1980
  • Number of views: 124
  • Article rating: No rating
Video

Provides step-by-step instructions on winding a DC armature, including how to install end fibres and slot liners, how to wind and shape the armature coils and how to make the commutator connections.

Getting The Most From Your Electric Motors

Getting The Most From Your Electric Motors - coverThis 40-page booklet provides great advice for obtaining the longest, most efficient and cost-effective operation from general and definite purpose electric motors.

This booklet covers topics such as:

  • Installation, startup and baseline information
  • Operational monitoring and maintenance
  • Motor and baseline installation data
  • How to read a motor nameplate
  • Motor storage recommendations

LEARN MORE AND DOWNLOAD MÁS INFORMACIÓN Y DESCARGAR

READ MORE ABOUT THE FEATURES AND BENEFITS

EASA Technical Manual

EASA Technical Manual cover

The EASA Technical Manual is the association's definitive and most complete publication. It's available FREE to members in an online format. Members can also download PDFs of the entire manual or individual sections.

VIEW & DOWNLOAD

ANSI/EASA AR100-2020

ANSI/EASA AR100-2015 cover

Recommended Practice for the Repair of Rotating Electrical Apparatus
This is a must-have guide to the repair of rotating electrical machines. Its purpose is to establish recommended practices in each step of the rotating electrical apparatus rewinding and rebuilding processes.

DOWNLOAD - ENGLISH

EASA AR200

EASA AR200: Guide for the Repair of Power and Distribution Transformers cover

Guide for the Repair of Power and Distribution Transformers
This document establishes guidelines for each step of the repair of power transformers, describing record keeping, tests, analysis, and general guidelines for the repair of power transformers.

LEARN MORE