Tom Barnes
Compliance Specialists, Inc.

This document will help you examine:

• Facility general information
• Document control
• Facility audit history
• Waste management, waste minimization, hazardous waste and waste reporting
• Storm water
• Spill prevention and reporting chemical inventory
• New chemical acquisition
• PCBs and asbestos
• Underground storage tanks
• Air emissions
• Risk management plan
• Employee training
• Ozone depleting substances
• Emergency planning

Tom Barnes
Compliance Specialists,Inc.

As we enter a new and exciting year of operating EASA businesses, we must remember that almost all service centers in the U.S. with either dip or vacuum pressure impregnation (VPI) tanks will be subject to the SARA Title 3, Tier II, reporting requirements. This requirement is part of the Emergency Planning and Community Right to Know Act (EPCRA). The EPCRA involves notifying the state and local community of any hazardous chemical stored onsite in quantities over 10,000 lbs. A hazard material for the purpose of this regulation is anything hazardous under the Hazard Communication standard. In other words, if it has a Safety Data Sheet and you had more than 10,000 lbs onsite at any time during the previous year (2017), then you are subject to this reporting requirement.  For most EASA centers, this will include the VPI, the dip tank varnish, or, in some cases, both varnishes.

Other Tier II reporting
Additionally, EPCRA requires reporting of any Extremely Hazardous Substance (EHS) on the Tier II report if it exceeds either its Threshold Reporting Quantity (TPQ) or 500 lbs, whichever is less. Therefore, if you have electric forklifts (including walk-behind, pallet jacks), you must calculate the amount of sulfuric acid contained in those large batteries. If the total amount of sulfuric acid exceeds the 500 lbs threshold, then this must be reported on the Tier II reports. Note that an average 3,000-lb battery will contain about 450 lbs of sulfuric acid, so two or more lifts will require such reporting.

Must complete annually
Tier II reports must be completed annually and submitted each year by March 1st to the State Emergency Response Commission (SERC), the Local Emergency Planning Committee (LEPC) and to your local fire department.  As one service center recently found out during an ISO 14001 audit, failure to submit these reports could cost up to $20,000.  Failure to report these chemicals and experiencing an incident involving these chemicals could cost you your entire business, especially if someone was injured or killed in the incident.

Please note that these forms are quite simple to complete and, even though some states will have an annual cost associated with the filing of the reports (typically $100-$300), the cost will be minimal versus the consequences of not reporting. For assistance in determining if reporting is necessary and how to report, please check with your fellow EASA members or an environmental consultant.

Kent Henry 
Former EASA Technical Support Specialist

Editor's Note: Part 1 of this two-part series was published March 2010. Part 2 was published April 2010.

Suppose two motors came in for an emergency repair. One of the mo­tors is a steel frame and the other is an aluminum frame. Both have broken feet that need to be welded back on to frame. Which motor would you prefer to weld? I believe that most would choose steel over aluminum. But that doesn’t have to be the case.

Tom Bishop, P.E.
EASA Senior Technical Support Specialist
​ EASA’s Getting The Most From Your Electric Motors is a great marketing tool for service centers to provide to customers (end users). As such, this valuable 40-page booklet provides end users with information that will help them obtain the longest, most efficient and cost-effective operation from general and definite purpose electric motors with these characteristics: 

• Three-phase, squirrel-cage induction motors manufactured to NEMA MG1 standards 
• Power ratings from 1 to 500 hp (1 to 375 kW) 
• Speeds of 900 to 3600 rpm (8 to 2 poles) 
• Voltages up to 1000V, 50/60 Hz 
• All standard enclosures (i.e., DP, TEFC, WPI, WPII) 
• Rolling element (ball and roller) and sleeve bearings

The following is an overview of the contents of the booklet indicating some of the ways that using it can benefit end users, i.e., your customers — and potential customers.

Installation, startup and baseline information
The first of the two major sections addresses three subtopics: motor installation, startup and baseline information. Early on it recommends making sure to document the motor’s initial condition to establish a baseline for comparison with future results. Among the benefits to the end user by following this practice is that it’s often possible to recognize small or developing problems before they lead to costly motor failures and downtime.

Reference is made to the “Motor and installation baseline data” sheet (see Figure 1) found in Appendix A. Recording the nameplate data and pertinent electrical and mechanical parameters at the time of installation and startup makes that information available for reference in hard copy or, if scanned, electronic format. Review of the motor data, including the nameplate information, can provide insight into the motor’s suitability for the application.

Specific items to check include motor suitability for use with a variable frequency drive (VFD), bearing suitability if the application is a belt drive, lubrication points accessibility, and verifying that the motor control and overload protections are sized properly for the motor rating. The last two points can be critical if the motor is a replacement and of a different power rating than the motor that it replaced.

Installation considerations such as the adequacy of the foundation and base are important for motor reliability. A weak or otherwise inadequate base can result in frame distortion, rapid bearing wear and vibration.

The booklet not only provides details on these topics, it extensively covers shaft alignment, including the issues of soft foot, alignment tolerances, and alignment methods for direct-coupled and for belt-drives. The end user can find a great deal of installation related information in just a few pages of the booklet.

The information in the booklet proceeds from the installation considerations to startup procedures. In many cases the motor being installed had been in storage; details are provided to help assure that the motor functions properly. Among the storage related topics are lubrication and the lubricant, and checking winding insulation resistance (see Table 1).

Next, recommendations are provided for pre-operation startup tests. Measuring and recording vibration levels is recommended. Recommended tests with the motor under load include line to line voltage, line currents, winding temperature (if possible), bearing temperature and ambient temperature. The booklet suggests these baseline values be recorded on the motor data sheet as a basis for future trending measurements. Two examples are provided to show the importance of recording baseline and trending data.

The section on motor installation, startup and baseline information concludes with the topic of total motor management. These programs typically track purchases and spares in a database by nameplate information, facility/location, and application. Usually they also track baseline data, maintenance, storage and repair. The primary benefits for the end users are that such programs lower costs by reducing downtime (spares are readily available) and decreasing inventory (identification of spares used in multiple locations).

A key consideration here is whether the most cost-effective and reliable solution is to store spare motors on site or to outsource storage to a service center or other vendor. Motor management and spare motor (and other equipment) storage is yet another opportunity for a service center to provide a value-added service for their customers. Further, having the customer’s spare motor at your facility provides a better opportunity to receive the replaced motor to perform the needed repairs.

Operational monitoring and maintenance
The second of the two major sections deals with operational monitoring and maintenance. Primary topics include application-specific conditions, preventive and predictive maintenance, inspection and testing, and bearing relubrication. By making use of the advice in this section the end user can extend the useful life of their motors, as well as the mean time between failures requiring repair.

Abnormalities in the electrical supply such as transient voltage can result in transient currents and torques which can damage not only windings but also mechanical components of the motor or driven equipment. To help the end user avoid these abnormalities, a bullet list identifies over a half-dozen potential sources. Another source of transient conditions that is not an abnormality is motor starting. The booklet provides the end user with guidance in dealing with motor starting and emphasizes the need to limit the number of motor starts.

The subsection on preventive maintenance (PM), predictive maintenance (PdM) and reliability-based (RBM) maintenance defines and describes each. Electrical and mechanical test and inspection techniques and physical condition assessments are identified for PM, PdM and RBM [also termed reliability-centered maintenance (RCM)]. Even if an end user already has a PM, PdM or RBM program, they can benefit from review of this subsection as it may identify missing elements in their program. Also, if an end user is not familiar with any of these programs the booklet provides information to get them started on the path to more reliable motor operation. That is, it provides an opportunity for the end user to get the most from their electric motors and probably the connected equipment as well.

Additional information on PM, PdM and RBM is included in the subsequent section on motor inspection and testing. All too often we hear the statement “don’t overlook the obvious.” That describes the importance of physical inspection in detecting missing, broken or damaged parts, blocked airflow paths and contaminants. Any one of these conditions could lead to premature and perhaps rapid motor failure.

Tests that are described in detail include insulation resistance, winding resistance and motor current signature analysis (see Table 2). When available from industry standards, criteria for evaluation are provided so that the end user can determine if their levels are acceptable or warrant corrective action. Cautionary information is provided regarding high-potential and surge testing of installed motors.  Information about vibration analysis using a spectrum analyzer is also provided.

This final subsection of the main body of the booklet provides guidance to help assure long and reliable motor operation. Recommendations include not only relubricating bearings, but also monitoring lubricant levels and checking for leaks and contamination. Guidance is provided to help the end user determine the correct relubrication interval and the lubricant type and grade when the motor manufacturer instructions are not available.

The importance of grease compatibility is stressed, and a grease incompatibility chart is provided.  Sage relubrication advice is given in the statement: “The best practice is to use the same grease that’s already in the bearings–provided it’s suitable for the application." A formula is provided to determine the precise amount of grease required; a graphic illustrates grease relubrication intervals based on bearing type, size and speed.

Oil-lubricated sleeve and rolling element bearing lubrication is also addressed, including topics such as oil compatibility, viscosity, and relubrication intervals.  Specific topics such as dealing with abnormal conditions and how to replace oil are also described.

Appendices
The three appendices provide supplementary information that can help the end user get more from their motors in terms of record-keeping, understanding motor terminology and storage. Appendix A contains a two-page data form (see Figure 1) intended for use in recording motor nameplate data and electrical and mechanical test data. Initially the data form can be used for baseline information, and then updated when maintenance or repairs are made. As such it can provide invaluable historical information for the end user and service firms when it becomes necessary to perform a simple failure analysis or more comprehensive root cause failure analysis.

The information in Appendix B is a compilation of key terms associated with motor nameplate data. (Note: There is also a standalone glossary at the end of the booklet.) However, the real value of this information is in determining the meaning of terms that at times are misunderstood. Knowing the true meaning and importance of these terms can help an end user avoid a costly and time-consuming mistake in purchasing a motor that is not suited for a specific application.

Based on member inquiries, motor storage recommendations, which are the topic of Appendix C, are a common end user request. These storage recommendations alone make the booklet a valuable resource for end users. The last page of this appendix summarizes how often to perform certain storage maintenance routines. It is rare to find this time versus task information all in one place, which is something many end users will appreciate.

Ordering information
Printed copies of Getting The Most From Your Electric Motors booklet can be purchased in EASA’s Online Store or you may download a PDF copy for FREE.

Imprinting available to EASA members EASA members may also imprint their company name, logo or contact information on the cover of this booklet. This makes for an excellent marketing and educational tool to distribute to you customers. Download the imprinting guidelines and contact customer service to place you order.

 

Mike Parsons
Hupp Electric Motor Co.

In any business, whether you have two pickup trucks or 50 semi-trucks, you have a fleet. This fleet is as much a part of your business as any other asset.

Your fleet is an expense and an investment, and managing it is essential. Any business that has a fleet of vehicles should take steps to keep that fleet functioning effectively and efficiently. The right policies, combined with the right technology, can make managing a vehicle fleet much easier on your company's time and budget.

Por Mike Howell
Especialista de Soporte Técnico de EASA

Existen muchas políticas genéricas sobre el uso de los dispositivos móviles flotando en internet. Lamentablemente, muchas de ellas se centran en gran medida y de forma limitada en las desventajas de que los empleados tengan dispositivos personales en sus estaciones de trabajo. Dependiendo del entorno particular y de las herramientas utilizadas, es razonable y responsable evaluar los riesgos potenciales para la seguridad y la protección. Sin embargo, con mucha frecuencia, las organizaciones toman el camino de excluir los dispositivos móviles del área de trabajo porque es una medida fácil, en lugar de aprovechar los beneficios que ofrecen.

The challenge for every motor repair firm is twofold: to repair the equipment properly; and to demonstrate to their customers by means of adequate testing and documenta­tion that rewound motors retain their operating efficiency. Following the guidelines in the “DOs” and “DON’Ts” below will help you accomplish both.

Numerous studies have been done to determine the effect rewinding has on motor efficiency. These studies identified several variables that can impact the efficiency of a rewound motor, including core burnout temperature, winding design, bearing type, air gap and winding resistance. The following guidelines were developed as a result of those studies, which found that the efficiency of both standard and energy efficient electric motors can be maintained during rebuilding and rewinding. 

To ensure that motors retain their efficiencies when rewound, EASA also strongly recommends that electric motor repair centers comply with ANSI/EASA Standard AR100: Recommended Practice For The Repair Of Rotating Electrical Apparatus and strictly adhere to the “DOs” and “DON’Ts” that follow. These guidelines, which contain safe values (based on available data) and correct procedures, apply to both energy efficient and standard motors. Further study of the matter continues, and these guidelines will be revised if additional information warrants.

This indispensable, FREE, 93-page manual was developed to help EASA service centers navigate the difficult terrain of the Federal OSHA Hazard Communication Standard. More specifically, it will help you collect and file Material Safety Data Sheets, train your employees, and document your training as required. Included are a summary of the OSHA Hazard Communication Standard, a compliance checklist, a suggested hazard communication program, hints on how to develop a written training program, and a primer on how to read Material Safety Data Sheets. The manual also contains a glossary and samples of various OSHA forms and letters.

Table of Contents

• Introduction to Hazard Communication
  • Why was this standard put into effect?
  • How will this be done?
  • What should we be doing?
  • How can EASA service centers get this done?
  • Suppose we choose not to do anything?
  • Where can I get further information?
• Section I: Summary Outline
  • Hazard communication
  • Hazard communication compliance checklist
• Section II: Suggested Written Program
• Section III: Hints on Developing Written Training
• Section IV: How To Read & Understand MSDSs
• Section V: MSDS Glossary
• Section VI: Attachments
  • OSHA (Standard 1910.1200)
  • Checmical hazard communication
  • Voluntary training guidelines
  • Substance survey
  • Letters to manufacturers & suppliers
  • Letter re MSDSs to Seller
  • Followup letter re MSDSs to Seller
  • Chemical substance training record

Jim McKee (deceased)
Alabama Electric Motor Service
Sheffield, Alabama 
Technical Education Committee Member 

There seems to be a long and never ending list of equipment and facilities needed by most EASA service centers. But often we are constrained by cost, available space, and more urgent priorities that keep us from fulfilling some of these needs. One such (almost mandatory) need is a vacuum pressure impregnation (VPI) system. 

Normally there are two ways to provide this service. One way is to have another EASA service center do the VPI process for you. Another is to buy your own system at a consider­able capital investment. 

There is also another option. We decided that the way to provide VPI processing was to build our own system. Most EASA service centers have a talented collection of people with numerous skills. Ours is no exception. We felt that we had the skills in house to do the job. All we needed was some hardware and to do a bit of research into how the process works. 

This presentation demonstrates an easy-to-build temporary oven that can be constructed in the service center or in site. The recording covers:

• Materials to use and where to obtain
• Heating: electric, propane, or other?
• Measuring winding temperature
• Regulating oven temperature
• Storage of the parts when not in use
• Safety concerns and cautions

Target audience: This presentation will benefit service center supervisors and management.

Chuck Yung
EASA Senior Technical Support Specialist

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? While that DC machine is energized by direct current, it is also true that the armature itself sees alternating current as the current in each coil reverses while passing from pole to pole. 

A temperature-controlled burnout oven permits us to cremate a stator without worry, but an armature is another story. Because the commutator is integral to the armature, and cannot be easily removed, some repairers resort to a hand-stripping operation. Careful use of a torch to warm the windings accelerates the stripping job, but controlling the core tempera­ture can be difficult. And stripping a large armature without heat is all but impossible by conventional methods. 

Chuck Yung
EASA Technical Support Specialist 

When a service center’s test panel is designed with a limited number of incrementally stepped voltages, there are times when you need a voltage that is not available. In such cases, when you need a non-standard 3­phase voltage, one workaround is to use a 3-phase motor as an autotrans­former. This works to step down, or to step up, the available voltage. 

There are three key safety consid­erations here: 

• Never energize part of a winding with more than the voltage that portion of the winding is subject to during normal operation. 
• Do not exceed the voltage rating of the ground insulation. 
• Select a motor that can handle the no-load current of the motor to be tested. 

This EASA software is a valuable interactive training tool ideal for training your novice(s). Even experienced winders will learn from it. The CD teaches how to wind in a richly detailed, step-by-step approach. It includes narrative, animations and video clips, with tests to assess student comprehension. The training, which is divided into 13 lessons, covers data taking, core testing, coil cutoff, burnout, stripping, core preparation, coil making, stator insulation, coil insertion, internal connections, lacing and bracing, inspection and test of untreated and treated windings, and winding treatment. Features include "Pro Tips" and "Drill Downs" that enhance the learning experience and assure that even the most experienced technician will learn from this product. The course is delivered as an interactive Adobe PDF file containing text, audio, video, supporting documents and quizzes.

LEARN MORE

Gene Vogel
EASA Pump & Vibration Specialist

It happens to just about every EASA service center. A machine shows up for repair; it has leads, and there’s a motor, but the machine is a pump. Most often, it’s a close-coupled pump or a submersible pump. If your response is, “We don’t work on those here,” because you’re thinking, “We don’t know anything about repairing pumps,” you may be turning your back on some very profitable work.

As I detailed in my February Currents article, pump repair can be a very profitable expansion area for service centers that specialize in electric motor repair only. If you agree that pump repair would be a good fit for your business, the next step is to evaluate what changes your facility needs to accommodate repairing pumps. You will find that you have much of the necessary equipment from repairing electric motors. The mechanical characteristics of motors and centrifugal pumps are very similar. Depending on the type of pump, there may be very little additional that you need.

Tom Bishop, P.E., and Chuck Yung
EASA Senior Technical Support Specialists

The typical service center repairs at least 300 motors per technician annually. Saving 8 minutes (0.133 hours) per job equates to: 300 x 0.133 = 40 man-hours per year—a full week of labor per employee. It is not unrealistic to expect twice that much savings, just by implementing some of these timesaving tips.

We all know that seemingly small time savings can significantly improve the bottom line. For a service center with a 12% return on investment (ROI), shaving a few minutes off each job is the equivalent of adding 2 manmonths of billing per productive employee.

For a 10-man service center, with a shop rate of $75 per hour, 20 man-months times 75 = $258,000. To add a quarter-million dollar account usually means adding personnel, sales maintenance, and risk of bad debt/warranty expense. However, steps that streamline efficiency continue to pay dividends.

Topics covered include:

• Layout and workflow
• Time killers
• Time: Is every hour on the job billable?
• Time-saving equipment
• Attitude and productivity
• Communicating effectively
• Training
• Lighting
• Calibration
• Storage/handling/procurement
• Parts storage
• Examples from real service centers

Doug Moore
Kentucky Service Co., Inc.

Many EASA members perform service on pumps of some type and have had the customer return the pump or call back to say it leaks or it still will not pump. We solved this by making a very inexpensive test center for all types of pumps: flooded suction, immersion lube, submersible, centrifugal, deep well and many others.

Cyndi Nyberg Esau
Former EASA Technical Support Specialist

In today’s economic climate, service centers look for opportunities to expand their services to their customers, and therefore profits. End users are also looking to reduce costs as well as downtime. Predictive and preventative maintenance has become increasingly important in industry.

Infrared thermography (IR) has traditionally been associated with inspection of switchgear and motor control centers (MCCs), a service that has become highly competitive. This paper will focus on niche opportunities for the service center – offering or using IR for more specialized services. 

Monitoring the condition of electric motor systems can detect problems that otherwise would not appear until a catastrophic failure occurs. By using thermography, abnormal heat sources that are invisible to the naked eye can be detected and remedied before a failure. This monitoring is not only limited to the motor. The motor system includes the driven equipment, MCC, cable runs, protective devices and the power supply. 

While IR will be the focus of this paper, there are other tests and technologies that will be necessary to complete the evaluation of a motor system. Although a thermal image may indicate that excessive temperatures are present, more information is usually necessary to fully assess a problem. Tools like vibration analysis, current signature, insulation resistance testing, and even visual inspection, all work in conjunction with thermography to paint a complete picture. 

The use of thermography is not limited to field service. The service center can employ this technology during the repair of rotating machinery. Applications include but are not limited to testing for open rotors and assessing the condition of stator and armature cores, windings, bearings and shop equipment.

 

Luther (Red) Norris 
Quality Solutions Co. LLC 
Greenwood, Indiana 
Technical Services Committee Member
 
Brushless servo motors ARE electric motors; therefore many of the tools needed to test them are already available in an electric motor service center. In this article, I have listed some instruments and tools that will be needed to service servo motors.

For the purpose of simplifying the instruments and tools needed for brushless servo motor repair, I am going to break them into two groups. 

• Group 1—those usually found in an electric motor service center.
• Group 2—those that may not usually be found in an electric motor service center. 

This recording will help you get organized using the “5+1 S Series.”

The “5S” program covers these goals:

• Sort
• Straighten
• Shine
• Standardize
• Sustain

The additional “S” has been added by EASA and covers safety.

Starting in February 2019, members of the Management Services Committee will also write Currents articles on how each “S” can help you with a path to productivity by becoming more efficient, or lean.

Chuck Yung
Especialista Sénior de Soporte Técnico de EASA

A menudo, las inundaciones producidas por las intensas lluvias de las tormentas tropicales (huracanes, monzones y ciclones) colapsan cientos de plantas industriales a todo lo largo de la costa del golfo de México, desde la Florida hasta Texas y en otros lugares del mundo.

Para retomar las actividades productivas, los departamentos de mantenimiento y los reparadores enfrentan la difícil tarea de limpiar la suciedad y desalojar la humedad en miles de motores y generadores eléctricos. Ver Figura 1. El proceso en tales situaciones puede tomar semanas o meses y requiere procedimientos especiales para limpiar los motores contaminados con agua salada.

Aunque el problema es enorme, las fábricas pueden volver a producir más rápidamente aunando esfuerzos con centros de servicio profesionales y siguiendo algunos consejos que facilitan las tareas de limpieza. Estos incluyen, priorizar los motores que requieren ser reparados o reemplazados, almacenar adecuadamente las máquinas contaminadas y utilizar métodos contrastados para eliminar la contaminación con agua salada. Fabricar hornos provisionales in situ o en el centro de servicio también puede aumentar la capacidad de secado de los sistemas de aislamiento de los motores inundados.

Tom Bishop, P.E.
Especialista Sénior de Soporte Técnico

De vez en cuando escuchamos el término “cuarto limpio” para nombrar un área de bobinado aislada físicamente de las demás zonas del centro de servicio (Figura 1). La finalidad principal de tal encerramiento (Figura 2) es prevenir que los materiales y los bobinados se contaminen con polvo y suciedad que pueda estar presente en otros sitios del centro de servicio. Algunos centros de servicio construyen estos encerramientos porque se esfuerzan en proporcionar el ambiente práctico más limpio para los trabajos de rebobinado y otros los usan también durante el proceso de instalación de los rodamientos. Los recintos tipo cuarto limpio también pueden beneficiar a las instalaciones ayudando a minimizar problemas de calidad y aumentando el volumen de producto conforme.

Aquí, exploraremos la diferencia entre un ambiente controlado y un cuarto limpio, los requisitos para ambos y proporcionaremos detalles para ayudarle a determinar si quiere añadir a sus instalaciones un ambiente controlado o un cuarto limpio.

Gene Vogel
Especialista de Bombas y Vibraciones de EASA

Las nuevas funciones del programa AC Motor Verification and Redesign – Version 4 (ACRewind) de EASA mejoran la capacidad de los miembros de EASA para enviar datos originales de forma electrónica e incluirlos en la base de datos Motor Rewind Data – Version 4 (MotorDB). Pase directamente a la sección “mejoras” si ya está familiarizado con los programas y cómo funcionan.

El software de la Version 4 es un conjunto de herramientas poderosas que sirve para que los miembros de EASA validen los datos de un bobinado, rediseñen devanados concéntricos a imbricados y efectúen cambios en los parámetros de un motor. Una característica clave de esta última versión del programa es la integración de la base de datos MotorDB con el programa ACRewind. La disponibilidad de ambas funciones del programa dentro de una interfaz de usuario común no es por simple conveniencia. La capacidad de los programas para compartir las fuentes de datos crea nuevas capacidades que la versión de cada programa independiente no podría.

Adam Willwerth (deceased)
AEGIS, Electro Static Technology, Mechanic Falls, ME
and
Hilton Hammond
Fluke Corporation, Everett, WA

Get a better understanding of the working principles of motor and drive measurements with test equipment, analysis tools and best practices. This paper presents valuable services you can incorporate to increase services and profits. It also covers:

• Safety practices related to test equipment
• Overview of the system drive train covering measurement protocols for:
  • Drive input and output
  • Motor and drive
  • Shaft voltage measurement and assessment

Not only is the measurement protocol explained but also the technology behind the systems under discussion, such as the inverter and motor. Measuring devices discussed will include:

• ScopeMeter
• Shaft voltage test kit
• Vibration analyzer
• Insulation tester
• Thermal imager

Fundamental to every good mechanical repair is the ability to disassemble, repair and reassemble the motor correctly without unnecessary damage to any of the motor parts. This sounds simple, and yet too many costly mistakes are made in this process of taking things apart. If every motor repaired was in “as new” condition, the task would be much simpler. But this would be no guarantee that the reassembly would be correct.

​There is usually an easy way and a hard way to remove and install parts. Brute force is seldom the easiest or the correct way. The old saying of “don’t force it, get a bigger hammer” is seldom the best way.

When a service center is paid to repair equipment, the service center wants it to stay in operation. If the equipment fails again—within the warranty period—the service center pays to repair it again. It makes sense to repair it correctly the first time.

In order to improve equipment, it is important to know how and where it operates. Without understanding why a motor fails, it is impossible to deliberately improve its mean time between failures.

To do this, there must be communication between the service center and the motor user. Not only does this help the repairer decide the best course of action, but it helps the user appreciate the professionalism of the service center.

Repair procedures, like motors themselves, are affected by changes in technology. This book attempts to include the latest proven technologies. Time-honored methods of repair, in many cases, may still be the most practical option. Options presented throughout this book are intended to help the technician select the appropriate repair method, recognizing that the ultimate decision rests with the equipment owner.

Repair methods sometimes fall into disfavor, not because better methods are introduced, but because of poor techniques. Other repair methods are well-suited to some applications but not to others. It is the job of the repairer to decide what is the best method for each case.

This book is divided into sections for basic motor components with repair methods and tips dispersed throughout. Where practical, reasons for failures are also discussed. These will aid the technician in selecting the most appropriate method of repair for each unique application.

The information presented draws from EASA publications, IEEE publications, technical journals and literature supplied by vendors, motor manufacturers and established service centers.

This book contains many suggestions on how to correctly handle the various parts of a motor during the repair process so as to minimize damage. However, it is impossible to develop an all-inclusive list. Instead, the basic principle of taking the time to use the correct tool and correct procedure will usually lead the technician down the right path. Always remember, if it has to be forced beyond reason, it might be that neither the proper tool or procedure is being used or something is wrong with the parts. Step back and ask “What am I overlooking?”

Table of Contents

1. Motor Nomenclature
2. Motor Applications and Enclosures
3. Test and Inspection Procedures
4. Motor Disassembly Tips
5. Bearings
6. Bearing Housing Repair, Shaft Openings, Seals and Fits
7. Shafts
8. Rotors
9. Motor Assembly
10. Motor Accessories and Terminal Boxes
11. Motor Dynamics
12. Vibration and Motor Geometry
13. Shaft/Bearing Currents
14. Special Considerations for Explosion-Proof Motors
15. Failures in Mechanical Components
16. Miscellaneous Repairs

This book is available as part of EASA's Fundamentals of Mechanical Repair seminar.

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Chuck Yung    
EASA Technical Support Specialist    

Of all the new technology available to EASA members, one of the most visible is the digital camera. Members from around the globe used them to record specific pieces of equipment for future orders.

More progressive service centers use them to enhance repair reports to increase customer satisfaction. An embedded photograph of an unusual failure adds value for the customer. It also confirms the professionalism of the service center. Large repairs justify a comprehensive repair report, with photos documenting the repair procedures as well as the failure analysis. Electronically transmitted digital photos can save customers a round-trip that is often necessary to inspect a machinery failure.

This webinar covers :

• Quantities/qualities of measuring and test equipment utilized in the industry
• How to locate/source qualified calibration suppliers
• Costs of internal / external calibration for some measuring and test equipment

This valuable resource is available only to EASA Members.

Active and Allied members can download this software for FREE!

This version of the EASA Motor Rewind Database software takes a large leap forward with the data that it provides members. Most notably, it now has the ability to connect to a live, ever-expanding online database of more than 250,000 windings. This live database will be continuously monitored, updated and corrected as needed by EASA’s Technical Support Staff. Using the online database guarantees you’ll have the most up-to-date information available at all times. If your computer does not have an Internet connection, the software will automatically switch to the static, local database that was included and loaded during installation. (Note: The local database does not receive updates.)

The database includes:

• Three-phase, single-speed AC motors
• Three-phase, multi-speed AC motors
• Single-phase AC motors
• DC motors & generators

Mike Howell, PE
EASA Technical Support Specialist 

Many inquiries submitted to EASA technical support staff require a review of as-found winding data of three-phase machines to determine if the data is reasonable for the machine’s nameplate ratings and core size. The most common approach for accomplishing this review is to compare the as-found winding data to existing data from similarly rated and sized machines in EASA’s motor rewind database. If several existing records are very similar to the as-found data, especially from the same manufacturer, the review is straightforward. Other times, an inference, or educated guess is required. EASA will soon be releasing a new Motor Stats feature for both the AC Motor Verification & Redesign and Motor Rewind Data software to assist with the educated guesses.

Esson’s Rule
For well over a hundred years, one of the fundamental relationships used by manufacturers when sizing electric machines relates torque to rotor volume. This is often referred to as Esson’s Rule and can be written as follows 

P / N = C₀ x D²L

where P is the mechanical power, N is the rotor speed, and C₀ is referred to as the output coefficient. For our purposes, it is important to note that the output coefficient (C₀) depends in part on the magnetic flux density in the air gap, a value calculated for each machine in the motor rewind database. And, as shown in Figure 1, D is the rotor outside diameter and L is the rotor core length. 

It is reasonable when comparing machines to use stator inside diameter and stator core length in place of rotor outside diameter and rotor core length. Also, we typically use pole count in place of rotor speed, understanding that nameplate rated frequency differences must be considered. 

So, the inference we make using the motor winding database is that machines having similar mechanical power, pole count (and frequency), core length and stator bore diameter should have similar magnetic flux density in the air gap. And, while there are always exceptions, this is a reasonable approach for verifying as-found data and for developing winding data in the event as-found data is lost or incorrect. 

Motor Stats
If we wanted to know about the average height of 20-year-old males in a particular country, we could measure the height of a sample of 20-year-old males from their population and then use statistics to draw conclusions about the population based on the sample. 

Searching MotorDb will return a list of all motors in the database that match our search criteria. It would be helpful to know the average air gap flux density for this list of motors (our sample), and how likely that average is to represent the average for all motors in existence that match our criteria (the population). The Motor Stats data lets us do that. 

For example, let’s say that the population shown in Figure 2 represents all squirrel cage induction motors meeting the following criteria: 

• 100 hp (75 kW) ± 2% 
• 4 poles / 60 Hz 
• D = 7 inches (178 mm) ± 2% 
• L = 10 inches (254 mm) ± 2% 

Now, let’s say the sample shown in Figure 2 represents 25 motors in EASA’s motor rewind database that meet those criteria.

It is reasonable to assume that the air gap flux density for the population is normally distributed with a bell-shaped curve as shown in Figure 3. We base this assumption on our Esson’s Rule (D²L) discussion. 

If this is the case, the air gap flux density of most motors within the population will be reasonably close to the population mean (arithmetic average). We can calculate a confidence interval for any sample of data taken from the population. Confidence intervals for six samples are shown in Figure 3 and labeled A through F. If we take many samples from the population and calculate 95% confidence intervals for each sample, then in the long run, 95% of those intervals will contain the population mean. Also, as you might imagine, small confidence intervals are better than large confidence intervals. 

For our 100 hp (75 kW) example, EASA’s motor rewind database returned 25 motors, and the confidence interval for that sample is represented arbitrarily as Sample F of Figure 3. In our example, the Sample F confidence interval contains the population mean. Sample C in Figure 3 does not contain the population mean and when working with 95% confidence intervals, this will happen 5% of the time. 

The most convenient time to use the Motor Stats tool is when verifying or redesigning data using AC Motor Verification & Redesign. The time-saving benefit here is that you get the statistical summary without having to do a separate search in the database. Now, let’s look at a specific motor and compare it to the Motor Stats output. Figure 4 shows the winding data card, calculated densities, and Motor Stats output. If the as-found data provided a good slot fill, we can conclude it is reasonable for this machine since our calculated air gap flux density is close to the confidence interval for the mean, and both the tooth and back iron flux densities are below the maximum allowable values shown. 

The current density in the stator winding should also be evaluated to ensure it is reasonable for the assumed duty cycle of the machine. While the air gap flux density will typically fall within a reasonably small range, you will often find a wide variance with current density. For example, the current density for an intermittent duty submersible pump motor may be around 200 CMA (10 A/mm2), while a continuous duty premium efficiency motor with similar ratings might be around 800 CMA (2.5 A/mm2). Other machines will be higher or lower than these values. Slot fill should not be adjusted, especially reduced, just to hit some target arbitrary current density. 

The chord factor is the ratio of the voltage induced in a coil to the voltage that would be induced in the same coil if it were full pitch. Undesirable space harmonics are well controlled when the chord factor is in the 0.951-0.991 range, but there are designs with higher or lower values. Some two-pole motors have chord factors in the 0.707-0.866 range and for such machines, it is likely that the manufacturer has evaluated the consequences of space harmonics. Many two and four-pole generator stators have a 0.866 chord factor (2/3 pitch) to eliminate the third space harmonic. And a 0.966 chord factor (5/6 pitch) is found in many machines as it minimizes the fifth and seventh space harmonics.

Tom Bishop
EASA Senior Technical Support Specialist

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. One of the selected ratings should fit the needs of most service centers.

This article covers:

• A design example
• Determining turns and wire size
• Building the core
• Determining coil dimensions

Chuck Yung 
EASA Technical Support Specialist 

We've all faced those rush jobs, where a cus­tomer is desperate to get his motor back faster than humanly possible. It is our nature to try to do the impossible that's why we are in this business.

We enjoy a challenge and the opportunity to help people. Turning a motor around quickly, when a customer is in need, is rewarding. One of the most time-consuming steps drying the windings after they have been cleaned Ð can be frustratingly slow when an anxious customer is calling. How long does that motor need to bake to be safe? 

Most service centers have built in a safety factor, based on some long-forgotten problem we had (or heard about) with a winding that was not properly dried. "Joe" opened the oven door right before lunch and left it open, then someone pulled a stator out a couple of hours later and it megged low. Maybe it failed on the test panel. Of course, "Joe" didn't fess up to what happened.  So you told everyone: "From now on, all windings bake 2 hours longer than we used to."

Gene Vogel
EASA Pump & Vibration Specialist

Si un tercio de dólar es 33.33 centavos, entonces ¿Cuanto sería la tercera parte de un dólar y medio? Si usted se encuentra sumando 33.33 centavos con 16.66 centavos antes de darse cuenta que un tercio de $1.50 es $ 0.50, obviamente usted sufre un caso serio de “Calculitis” Afortunadamente, la cura es una dosis de ratios y proporciones.

La terminología técnica para los ratios es “números racionales”, números que literalmente son ratios. La capacidad de trabajar con números racionales es una herramienta poderosa para evaluar opciones, calcular resultados y representar valores. Este artículo es una introducción de algunos conceptos básicos y un estudio más profundo revelará características fascinantes y la parte íntima que juegan en las matemáticas, las ciencias y en cada aspecto tecnológico.

Gene Vogel
EASA Pump & Vibration Specialist

If a third of a dollar is 33.33 cents, what is a third of dollar and a half? If you find yourself adding 33.33 cents to 16.66 cents before you realize that obviously a third of $1.50 is $ 0.50, you have a serious case of “calculatoritis.” Fortunately, the cure is a healthy dose of ratios and proportions.

The technical term for ratios is “rational numbers,” literally numbers that are ratios. The ability to work with rational numbers is a powerful tool for evaluating options, calculating results and representing values. This article is an introduction of some basics; a more in depth study will reveal fascinating characteristics and the intimate part they play in math, science and every aspect of technology.

 

This presentation examines features, benefits and drawbacks of both conventional and alternative methods of cleaning electric motors.

Methods covered include:

• Immersion tanks
• Steam cleaning
• Parts-washing machines
• Pressure washers
• Abrasives
• Ultrasonic devices

Environmental options for handling waste by-products are also addressed. If you are considering changing your cleaning methods, this webinar is for you.

Blake Parker
Technical Education Committee Member
Integrated Power Services 

When handling motors, lifting devices are often needed, whether they be cranes, forklifts or otherwise. As a new technician, many times one of the first things taken for granted is a rigging device’s weight handling ability. Given the risks inherent to lifting, EASA members must exercise caution and ensure our teams are well versed in proper rigging techniques. This is accomplished through classroom and hands-on training.

Tom Bishop, P.E.
EASA Technical Support Specialist
 
Prior to rewinding it is advisable to assess the condition of the core iron of stators, armatures and wound rotors. The assessment is performed by a core test, which magnetizes the core to a pre­scribed magnetic flux density. The predominant tests used to determine core condition are the hot spot test and the core loss watts test. The hot spot test compares the hottest spot in the core to either ambient temperature or core average temperature. The watts loss test compares the core loss test watts prior to winding removal to the same test af­ter the windings have been removed and the core prepared for rewind. 

Core testing traditionally was performed by the use of the loop (ring) test. That required multiple turns of wire to be passed through a core in order to magnetize the core and test for shorted laminations. Mag­netic strength is related to the ampere-turns (amperes x turns) of the magnetizing coil. Mod­ern core testers make it possible to test a core with a single turn of wire, by using high current. Thus the core tester uses one turn and many amperes, whereas the loop test typically uses many turns and a relatively low current. 

Pat Douglas
Kirby Risk-Mechanical Solutions & Service

Un encoder es un tipo de dispositivo de retroalimentación que a menudo se instala en un motor para monitorizar el movimiento (óptico sencillo). Un encoder de cuadratura indica tanto el movimiento como la dirección del eje de salida del motor.

La Figura 1 muestra una forma de onda digital buena y la Figura 2 una forma de onda digital con ruido. Ambas han sido escaneadas desde un osciloscopio utilizado en un centro de servicio.

Jasper Fisher 
Rexel Motor Repair 
Alton, Illinois 
Technical Education Committee Member 

Though it is unlikely a typical EASA member firm can achieve OEM (Original Equipment Manufacturer) economies of scale, we can strive to improve safety and working conditions, improve quality and increase labor efficiency thereby enhancing earnings. 

This article shares tips for building several special tools and fixtures, and it identifies one commercially avail­able tool to help us achieve safety and quality goals while improving our productivity. 
After hearing complaints about the purchase cost for the last two sets of custom heat-treated long taper pinion removal wedges, our ma­chine shop staff designed and built a fixture for tapering “brake die” rectangular steel (Figure 1).

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.

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!

Technical presentations include:

• Overview, Operation, Troubleshooting, Testing & Repair of Synchronous Motors - Javier Portos, Integrated Power Services, LLC, La Porte, TX
• Understanding Corrosion in Pumps - Gene Vogel, EASA Pump & Vibration Specialist
• Tips & Tricks for Submersible Pump Repair - Gene Vogel, EASA Pump & Vibration Specialist
• Proper Field Installation of Vertical Turbine Pump Motors - Gene Vogel, EASA Pump & Vibration Specialist
• Carbon Brush Applications, Tip & Tricks - Matthew Conville, EASA Technical Support Specialist
• Generator Repair Tips - Wayne Hall, Jenkins Electric, Charlotte, NC
• Repair Best Practices to Maintain Motor Efficiency & Reliability - Tom Bishop, P.E., EASA Senior Technical Support Specialist
• Failure Modes, Troubleshooting & Maintenance Best Practices - Calvin Earp & Ron Widup, Shermco Industries, Irving, TX
• Estimating Performance of Small Induction Motors Without a Dyno - Mike Howell, EASA Technical Support Specialist
• Use the Latest Tools of the Trade for Field Testing of Electric Motors - Calvin Earp & Ron Widup, Shermco Industries, Irving, TX

En Español

• Construcción del Estator (de Principios de Motores C.A. Medianos y Grandes) - Carlos Ramirez, EASA Especialista de Soporte Técnico
• Lo Qué Necesita Saber para Comprar, Instalar, Operar & Reparar Motores Eléctricos - Carlos Ramriez, Especialista de Soporte Técnico de EASA

Sales presentations include:

• 5 Fundamentals for a Successful Sales Attack! - Mike Weinberg Speaker, Consultant, Best-Selling Author
• Getting The Meeting - Mike Weinberg Speaker, Consultant, Best-Selling Author
• Every Sales YES Begins with a KNOW - Sam Richter, SBR Worldwide, LLC, Minnetonka, MN

Management presentations include:

• EASA Research on Growing Your Business: Key Info from the Manufacturer/Supplier Community - Jerry Peerbolte, J. Peerbolte & Associates, Fort Smith, AR
• EASA 2021 and Beyond - Brian Beaulieu, ITR Economics, Manchester, NH
• Global Update: Marketplace Trends on Motor-Driven Systems (and IIoT) - Ivan Campos, Analyst, Manufacturing Technology, OMDIA (formerly IHS Markit)
• Engaged Leadership - Clint Swindall, Verbalocity, Inc., San Antonio, TX
• Connecting Generations - Clint Swindall, Verbalocity, Inc., San Antonio, TX
• Optimizing Service Center & Management Efficiency - Chuck Yung, EASA Senior Technical Support Specialist

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How do I access this content?
After purchasing, you can access the streaming content by going to the Convention or Training menus at easa.com and looking for "Past Convention Presentations" ... or you may go to https://easa.com/convention/past-convention-presentations/easa-rewind-2021.

NOTE: Access to the streaming content will be granted only to the person making the purchase.

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Ron Widup
Shermco Industries
Irving, TX

Learn from an industry veteran about safety topics you may think you know but that can cost your firm substantially if you’re not diligent.

• Fall protection
• Fork lift hazards and relevant regulations
• Material handling/lifting
• Cranes and hoists
• Machine shop hazards
• Cautions regarding abrasive blasting
• Painting irritants

Industry expert Tom Barnes of Compliance Specialists, Inc. focuses on electrical safety, arc flash and lockout/tagout – defining the regulations for each and what your service center needs to do to protect your workers AND your pocketbook.