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Articles: Motor and Power System Testing
A Better Understanding of Rotor Dynamics and Support Stiffness
More Data Provides More Answers
by Ron Brook
A Closer Look at Air Gap Eccentricity
by Douglas E. Swinskey & Peter M. Bechard
The first step in evaluating test data is understanding the relationship to the circuit's Fault Zones and how abnormalities in a specific Fault Zone affect the performance of the motor. The six Fault Zones (Power Quality, Power Circuit, Stator, Insulation, Rotor, and Air Gap) are derived from the most common electrically related motor failures in industrial environments. The Air Gap Fault Zone describes the measurable distance between the rotor and stator within the motor. Air gap eccentricity is a condition that occurs when a non-uniformity in the air gap between the rotor and stator exists.
A Cradle to Grave Approach - Motor Management at Its Best
by Noah Bethel, CMRP
Ask a motor manufacturer how long one of its motors is expected to live, and the response will be something like, "20-plus years in the right environment." Ask the same question in a facility that uses such a motor and the answer is more likely to be, "If we get five years out of it, we'll be happy!" Why does this discrepancy exist? Why do motors die of an infant mortality instead of living to the ripe old age for which they are designed and built? The answer has to do with the failure to optimize motor management and maintenance.
Adventures in Engineering Standards - Behind the Scenes of Creating IEEE Std 43-2000
by Howard W. Penrose, PhD, CMRP
Engineering can be a boring career with everyone working with known measurements and absolutes. There is never any doubt that the information contained in a standard or textbook is fact because everything is static, mathematical, and measurable. At least, that is what most people tend to think.
Applying Power Quality Measurements to Predictive Maintenance
You may already be using predictive maintenance (PdM) techniques on your motors and drives. But how often do you inspect the power to your equipment? By adding basic power quality measurements to production equipment maintenance procedures you can head off unexpected failures in both production equipment and your power system.
Are you smarter than your electric motors?
Test your knowledge with this PdMA Sponsored Quiz on Electric Motors.
Defects in Nonceramic Insulators: Can They be Detected in a Timely Manner?
by S. Gorur and S. Sivasubramaniyam Department of Electrical Engineering, Arizona State University, Tempe, AZ, USA
This work was performed under a PSERC (Power Systems Engineering Research Center) funded project at Arizona State University
This paper is a continuation of the work reported during the Daycor users meeting. The electric field measurement method has been explored to determine its potential for timely detection of defects in nonceramic insulators. Various types of defects were simulated and the external electric field was computed. It is shown that the electric field method used presently is not sensitive enough to permit early detection of defective. There is a need for an improved method, perhaps periodic corona inspection could be the answer.
Diagnosing Rotor Bar Issues with Torque and Current Signature Analysis
by Drew Norman
Over the years rotor bar problems have been a diagnostic challenge for motor maintenance professionals. Now with current signature, spectral torque analysis and automated computer diagnostic software, defining rotor health problems has been made fairly simple. However, problems arise when professionals do not understand the underlying principles of the what’s, whys and how’s of dynamic rotor testing.
Evaluating Winding Connections With Infrared
Introduction
An area that is often overlooked in the rewinding of an electric motor are the internal connections of the winding. Most coils have multiple wires making up one ‘conductor' (Figure 1). The reason for this is to allow the wire to be more flexible for installation while allowing enough cross section for the amount of current that the conductor must carry. This generates a situation where improper brazing, crimping or other methods of making the connections will generate a hot-spot due to IR losses.
Guidelines to a Good Motor Repair
A Good Motor Repair is a Two-Way Street
created through a collaborative effort led by Advanced Energy
In the late 1990s a group of industry experts worked collaboratively to produce a document that any facility can use to better understand and communicate with their motor repair vendors. This group consisted of utilities, government, motor manufacturers, and the motor repair industry and energy efficiency advocates. Each participating company is noted in the resulting document “Guidelines to a Good Motor Repair.”
Implementing ESA as Part of Your Predictive Maintenance Program to Improve Electrical Reliability
By William Kruger
Why Predictive Maintenance?
Predictive Maintenance (PdM) resulted from studies that determined that Preventive Maintenance (PM) programs are only efiec-tive for the 11 percent of machine failures that are age related. This means approximately 89 percent of machine failures are random in nature and time-based maintenance programs are inefiective on these random types of failures.
Maintaining The Long Term Reliability of Critical Power Systems in Water Processing Plants
By Reza Tajali
Schneider Electric
The critical applications in water and wastewater processing plants require uninterruptible power of a high quality. The most basic of these systems utilize automatic throw-over switches. The most advanced systems include UPS (Uninterruptible Power Supply) and generator equipment that maintain the continuity of power without one cycle of interruption.
Managing the Complete Motor System
Modern management practices often do not take into account the importance of motor systems maintenance and management requirements. Through efforts in cost control, many industrial and commercial firms reduce maintenance staffs, take least cost approaches to corrective actions and sacrifice preventive maintenance programs.
Motor Current Analysis (MCA) Test Results Can be Misleading if Drive Train Load Isn’t Considered
By: Jason Bolte, CMRP, Allied Reliability, Inc.
A constant issue when applying Condition Monitoring technologies is buy-in that the technology is capable of detection of failure modes in machinery. It is as critical to ensure that readings are interpreted properly to determine that a fault does not exist as much as that one does. Nothing sabotages buy-in more than the knowledge that repair activity has taken place that was unnecessary. One of the keys to effective data analysis is that we take consistent repeatable data. This is particularly of note when considering motor loading when performing Motor Current Signature Analysis (MCSA) testing.
Motor Management Programs and an Auto Industry Success Story
by Howard W Penrose, Ph.D., CMRP and Robert Varcoe
A variety of concepts related to the term ‘motor management’ have been presented within industry since the 1990s. Many of these programs are actually ‘energy-efficient electric motor retrofit or repair versus replace’ ideas which make up only a small portion of the overall opportunities when properly managing electric motor systems.

- May 21
Maintenance Planning and Scheduling - Charleston, SC - May 22
R5 Cause Analysis - May 22
Reliability Excellence for Managers - May 23
Web Workshop: Do I Really Need This in My Storeroom? - May 24
Web Workshop: How to Launch a Successful Reliability Initiative - May 31
Web Workshop: The Field Balancing Mine Field - May 31
Web Workshop: Discover the Hidden Value of Your CMMS - June 1
Web Workshop: The Absolute Basics of Analyzer Settings: Fmax and Lines of Resolution - June 5
3 - Day Practical Machinery Lubrication Training - Chicago, Illinois - June 5
CBM-2012 Condition Monitoring and Predictive Maintenance Forum

- IR Windows: Compare and Save with Exiscan
- MRO Inventory and Purchasing Books
- The One-Stop Source for Lubricants & Reliability Solutions
- Motor Testing Books
- Belt/Sheave Alignment Laser, Custom Shim and Gaskets
- R300S for When Good Enough – Isn’t Enough!
- Reliability Centered Maintenance for SAP Plant Maintenance
- New AT33IND Perfect for QC & Troubleshooting
- Request Your Des-Case Complimentary Breather Now
- Become an Aladon Certified RCM2 Facilitator
- “Free eBook Download on Effective Problem Solving”
- Integrating Your CBM Just Makes Sense
- Total Productive Maintenance Books
- Job Postings for Maintenance and Reliability Professionals
- Join The Association For Maintenance Professionals
- Commtest - Affordable Vibration Analysis
- GPAllied Inspired Training: Hard-Hitting, Impactful Courses and Workshops.
- Reliability Engineering Services

- Alignment and Balancing
- Asset Management
- CMMS and EAM
- Green Reliability
- Human Asset Management
- Infrared Thermal Imaging
- KPIs - Reliability Performance Metrics
- Lean Maintenance
- Lubrication
- Maintenance Management
- Motor and Power System Testing
- MRO - Spares Management
- Oil and Fluid Analysis
- Planning and Scheduling
- PM Optimization
- Predictive Maintenance and Condition Monitoring Management
- Reliability-Centered Maintenance
- Reliability Engineering
- Reliability Leadership
- Root Cause Analysis
- Shutdowns and Turnarounds
- Total Productive Maintenance (Asset Care)
- Training
- Ultrasonics
- Vibration Analysis

- Things To Think About and Do in 2012
- Uptime Magazine - April/May 2012 Index
- Reliability Polls and Quizzes
- Book Review: Handbook to Achieve Operational Excellence
- Integrating Vibration and Temperature Measurements in Condition Monitoring
- Operator-Driven Reliability Best Practices Series: “Leadership Wanted”
(2) - When Decibels Aren’t Enough
- Strong Predictive Maintenance Program Boosts UPTIME to Meet Growing Demand for Recycled Papers
- Failure Modes: A Closer Look at Ductile and Brittle Overload Fractures
- Understanding the Limitations of Oil Analysis
(2)
- Reliability Polls and Quizzes
- Things To Think About and Do in 2012
- Uptime Magazine - April/May 2012 Index
- Electric Motor Bearing Greasing Basics
(5) - Asset Management: concepts and practices
(8) - CBM 2011 Video Proceedings
(2) - Maintenance of Hydraulic Systems
(2) - The 5S Method of Improvement - Enhancing Safety, Productivity and Culture
- Reliabilityweb.com 100 Top Web Sites
- Aerial Infrared – An Asset Management Tool for District Heating System Operators
