This 4-page motor service order form provides fields to record:

• Customer contact information
• Nameplate data
• Reason for service
• Inspection activity checklist for the stator and rotor
• Incoming inspection notes
• Winding tests
• Rotor single-phase test
• No-load test
• Mechanical inspection before and after repair
• Winding tests after rewind but prior to treatment
• Winding tests prior to assembly
• No-load run test
• Shipping details

By Tom Bishop, P.E.
EASA Senior Technical Support Specialist

Most plant engineers and maintenance staff can attest to the reliability of standard-efficiency motors that have been repaired or rewound using industry best practices. They also know repair can cost far less than replacement, especially when the motor has special features. Despite this, some of them hesitate to have failed energy-efficient motors (NEMA Premium models, in particular) repaired because they’ve heard it degrades efficiency.

So, what’s the right answer? Is the decision to repair, rewind or replace a failed energy-efficient motor as simple and straightforward as you may have heard?

Topics in the article include:

• What makes a motor more energy-efficient?
• Repaired motor efficiency
• Review the motor application
• Catastrophic failure (present)
• Catastrophic failure (prior)
• Rotor condition
• Mechanical parts condition
• Higher-efficiency motors

READ THE FULL ARTICLE

7 presentations

$35 for EASA members

 

A special discounted collection of 7 webinar recordings focusing on various aspects of electromechanical repair.

Once purchased, all 7 recordings will be available on your "Downloadable products purchased" page in your online account.

Downloadable recordings in this bundle include:

Time-Saving Repair Tips
Presented August 2014

This webinar shares:

• The secrets used by other service centers to gain a competitive edge in the repair process.
• Mechanical, winding and machining tips reduce repair time, help avoid unnecessary rework, and decrease turn-around time.

Target audience: Supervisors, machinists, mechanics, winders, and sales personnel who interact with the end user.

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Repair Best Practices to Maintain Motor Efficiency
Presented June 2012

There are certain repair processes, such as winding removal and replacement, that can impact the efficiency and reliability of electric motors. Prudent repair practices must not increase overall losses, and preferably should maintain or reduce them.

This presentation explains how those repair processes affect efficiency and reliability, and gives the best repair practices in order to maintain or improve efficiency.

Target audience: This presentation is most useful for service center inside and outside sales representatives, customer service personnel, engineers, supervisors and managers. The content will be beneficial for beginners through highly experienced persons.

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Practical Problem Solving for the Entire Service Center
Presented August 2013

This presentation focuses on a report format developed by Toyota for a simple, yet methodical approach to document improvement. Whether you're dealing with problems related to sales, purchasing, repair or testing, if all team members can learn to speak the same, simple problem-solving language, they can tackle problems efficiently and effectively.

Target audience: This presentation is best suited for executives, managers, team leaders and front line supervisors from the office and service center who want to understand and implement such a program.

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Induction Motor Speed Control Basics
Presented March 2019

Induction motors are most often applied to what are essentially constant speed drive applications. However, the use of induction motors in variable speed applications continues to grow, primarily due to technology advances in power electronics. This webinar will review speed control basics for induction machines.

• Wound-rotor motor speed control
• Squirrel-cage speed control by pole changing
• Squirrel-cage motor speed control by variable voltage, fixed frequency
• Squirrel-cage speed control by variable voltage, variable frequency

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AC Motor Assembly and Testing
Presented August 2018

This webinar recording focuses on:

• Motor assembly issues
• Electrical and mechanical inspection
• Static and run testing
• AC motors with ball, roller and sleeve bearings

Target audience: This webinar recording is most useful for service center mechanics, supervisors and engineers. The content will also be beneficial for machinists, managers and owners.

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On-Site Testing & Inspection of Electric Motors
Presented July 2015

This webinar covers electrical testing and inspection of installed electric motors, including:

• Condition assessment for continued service
• Diagnostic fault testing and interpretation
• Physical inspection key points

 

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Selecting Replacement DC and 3-Phase Squirrel Cage Motors
Presented September 2019

On many occasions, a different motor type is desired or needed. In these cases it is essential that the replacement motor provides the required performance, and do so reliably.

This presentation focuses primarily on the electrical aspects of selecting replacement motors. It also addresses speed and torque considerations.

• DC motor to DC motor
• DC motor to 3-phase squirrel cage motor
• AC motor to 3-phase squirrel cage motor

Target audience: Anyone involved with selecting replacement motors or diagnosing issues with replacement motor installations.

By Tom Bishop, P.E.
EASA Senior Technical Support Specialist

The Electrical Apparatus Service Association (EASA) has published two documents to help users and service providers ensure that motor repairs performed reflect good practices that maintain or improve a machine's energy efficiency and reliability: ANSI/EASA Standard AR100-2015: Recommended Practice for the Repair of Rotating Electrical Apparatus and the "Good Practice Guide" of the 2003 study The Effect of Repair/Rewinding on Motor Efficiency, by EASA and the Association of Electrical and Mechanical Trades (AEMT). These documents serve as tools by which service centers and end users can speak the same language when it comes to level-setting service and performance expectations on motor repair and rewind.

Also, a little more than a year ago, EASA launched its electric motor repair accreditation program, based on AR100 and the "Good Practice Guide." The program benefits both end-users and service providers by ensuring that electric motor repairs conform to the good practices identified in the aforementioned documents."

Electric motor efficiency can be maintained during repair and rewind by following defined good practices. This article builds on my previous discussion of PM and PdM for three-phase squirrel-cage motors ("PM and PdM for electric motors") by outlining some of the expectations and good practices for repairs of these types of motors.

READ THE FULL ARTICLE

By Mike Howell
EASA Technical Support Specialist

For many industrial plants, maintenance strategies and decisions relating to the electric motors in use are among their most critical. Without question, motors are the primary workhorses for many of these plants—driving machinery, pumps, conveyors, and other vital equipment. So when they don’t work properly or fail, the impact on regular plant operations can be enormous.

When faced with an ailing or failed motor, plant operators typically consider whether to repair or replace it. According to a 2014 study conducted by Plant Engineering magazine for the Electrical Apparatus and Service Association (EASA), just more than one-half of plants have a policy of automatically replacing failed electric motors below a certain horsepower rating. While that horsepower rating varied depending upon the plant’s installed motor population, the average rating was 30 hp.

While such policies address a portion of the motors used at most plants, they do not cover what occurs with those motors. That question was addressed in a more recent research project commissioned by EASA that focused on the disposition of electric motors considered for repair. The research showed that just over three-quarters (79%) were repairable, with the remainder (21%) replaced. Within the repaired electric motor group, mechanical repairs were the most common (49%), compared with electrical rewinds (30%). Further, over the past three years, mechanical repairs are trending higher, while the electrical rewinds are declining.

The article looks at some of the reasons for these motor repair trends:

• Availability of a suitable replacement
• Cost of repair vs. replacement
• Repair provides opportunity to determine (and address) root cause
• Regular preventive and predictive maintenance practices can provide “early warning”
• ANSI/EASA standard establishes motor repair best practices
• EASA accreditation provides third-party assurance of motor repair practices

READ THE ARTICLE

Selection of replacement motors is usually straightforward if the ratings are equivalent. Sometimes, however, a different type of motor is necessary or desirable. For success in these cases, it is essential that the replacement motor provide the required performance — and do so reliably.

READ THE FULL ARTICLE

Presented by Tom Bishop, P.E.
EASA Senior Technical Support Specialist

On many occasions, a different motor type is desired or needed. In these cases it is essential that the replacement motor provides the required performance, and do so reliably.

This webinar will focus primarily on the electrical aspects of selecting replacement motors. It also will address speed and torque considerations.

• DC motor to DC motor
• DC motor to 3-phase squirrel cage motor
• AC motor to 3-phase squirrel cage motor

This webinar will benefit anyone selecting replacement motors or diagnosing issues with replacement motor installations.

This valuable publication explains the findings of a major study that analyzed the impact of repair/rewinding on the energy efficiency of Premium Efficiency/IE3 electric motors. This study was a follow up to a 2003 study.

The 2019 study reaffirms the results of the 2003 study.

Abstract
In response to various opinions about the feasibility of maintaining motor efficiency during repair, including replacement of the stator winding, the Electrical Apparatus Service Association (EASA) and the Association of Electrical and Mechanical Trades (AEMT) conducted two comprehensive rewind studies using third-party testing laboratories.

The results of the first study, which were published in 2003 (see Part 2 on Page 2-1 of this document), clearly showed that the efficiency of energy efficient and IE2 motors ranging from 7.5 hp to 200 hp (5.5 kW to 150 kW) can be maintained (and sometimes improved) if the stator is rewound using established good practice procedures.

The increasing use of premium efficient motors mandated by various countries led to a second rewind study in 2019, this time to determine if the efficiency of premium efficiency and IE3 motors can be maintained when they are rewound using the good practices described in the 2003 rewind study and ANSI/EASA AR100-2015: Recommended Practice for the Repair of Electrical Apparatus.

As with the 2003 study, the results of the 2019 rewind study that follow clearly show the answer is YES–with the average efficiency change for the entire test group falling within the range of accuracy for the test method (± 0.2%). In several instances, motor efficiency actually improved.

Overview of the Table of Contents

• Part 1: 2019 Rewind Study–The Effect of Repair/Rewinding on Premium Efficiency/IE3 Motors
  • Objective
  • Products evaluated
  • Standards for evaluating losses
  • Third-party testing protocol
  • Results of efficiency tests on rewound motors
  • Conclusion
• Part 2: 2003 Rewind Study – The Effect of Repair/Rewinding on Motor Efficiency
  • Objectives
  • Products evaluated
  • Standards for evaluating losses
  • Third-party testing protocol
  • IEEE Std. 12B test method: Input - output with loss segregation
  • Core loss testing
  • Results of efficiency tests on rewound motors
  • Significance of test results
  • Conclusion

Download a PDF of the complete study or the Executive Summary for free using the links below. Printed copies are also available in EASA's Online Store.

 

Chuck Yung 
EASA Technical Support Specialist 

You may have experienced this situation before: Your best customer just called to say he has a plant down and is in desperate need of a 100 HP, 6-pole, 460-volt motor.  And he needs it now! 

You check your stock and find one that's pretty close. The frame is right, but it's a 125 HP unit at 575 volts. What can you do? You know that the motor will run at 460 volts, but how much horsepower will it produce?