ADVANCED MANUFACTURING OFFICE PREMIUM EFFICIENCY MOTOR SELECTION AND APPLICATION GUIDE A HANDBOOK FOR INDUSTRY DISCLAIMER This publication was prepared by the Washington State University Energy Program for the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy. Neither the United States, the U.S. Department of Energy, the Copper Development Association, the Washington State University Energy Program, the National Electrical Manufacturers Association, nor any of their contractors, subcontractors, or employees makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process described in this guidebook. In addition, no endorsement is implied by the use of examples, figures, or courtesy photos. PREMIUM EFFICIENCY MOTOR SELECTION AND APPLICATION GUIDE ACKNOWLEDGMENTS The Premium Efficiency Motor Selection and Application Guide and its companion publication, Continuous Energy Improvement in Motor-Driven Systems, have been developed by the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) with support from the Copper Development Association (CDA). The authors extend thanks to the EERE Advanced Manufacturing Office (AMO) and to Rolf Butters, Scott Hutchins, and Paul Scheihing for their support and guidance. Thanks are also due to Prakash Rao of Lawrence Berkeley National Laboratory (LBNL), Rolf Butters (AMO and Vestal Tutterow of PPC for reviewing and providing publication comments. The primary authors of this publication are Gilbert A. McCoy and John G. Douglass of the Washington State University (WSU) Energy Program. Helpful reviews and comments were provided by Rob Penney of WSU; Vestal Tutterow of Project Performance Corporation, and Richard deFay, Project Manager, Sustainable Energy with CDA. Technical editing, design, and publishing were provided by DOE’s National Renewable Energy Laboratory (NREL). DOE, CDA, WSU, and NREL thank the staff at the many organizations that generously contributed information and/or review for this publication. Contributions of the following participants are especially appreciated. • Dale Basso, Motors Manager, WEG Electric Corporation • Bruce Benkhart, Director, Applied Proactive Technologies • Thomas Bishop, PE, Senior Technical Support Specialist, Electrical Apparatus Service Association • Rob Boteler, Director of Marketing, Nidec Motor Corporation • Dave Brender, National Program Manager, Electrical Applications, Copper Development Association • Wally Brithinee, Brithinee Electric • Kitt Butler, Director, Motors and Drives, Advanced Energy • John Caroff, Marketing Manager for Low Voltage Motors, Siemens Industry, Inc. • Ken Gettman, National Electrical Manufacturers Association • Willian Hoyt, Industry Director, National Electrical Manufacturers Association • John Malinowski, Senior Product Manager, AC Motors, Baldor Electric Company • Howard Penrose, Engineering and Reliability Services, Dreisilker Electric Motors. Cover photo from iStock 23169039 PREMIUM EFFICIENCY MOTOR SELECTION AND APPLICATION GUIDE | i CONTENTS GLOSSARY . vii LIST OF ACRONYMS . x CHAPTER 1 INTRODUCTION...............................................................................1-1 Industrial Motor Population, Energy Consumption, and Uses.......................................1-2 Annual Electric Motor Sales Volume and Energy Savings Potential .................................1-4 When to Buy Premium Efficiency Motors .........................................................1-7 References .....................................................................................1-9 CHAPTER 2 PREMIUM EFFICIENCY MOTOR PERFORMANCE ............................................ 2-1 Overview of U.S. Motor Minimum Efficiency Performance Standards . 2-2 European and IEC Motor Efficiency Standards.................................................2-6 European MEPS: Efficiency Standard Levels and Implementation Timeline......................... 2-7 Motor Losses and Loss Reduction Techniques ...................................................2-8 Determining and Comparing Motor Efficiencies ................................................. 2-10 Efficiency Definitions ....................................................................... 2-10 Motor Efficiency Testing Standards ...........................................................2-12 Testing Equipment Accuracy Limitations......................................................2-13 NEMA Motor Nameplate Labeling Standards .................................................2-13 MotorMaster+ Motor Price and Performance Database ........................................2-15 References ....................................................................................2-16 CHAPTER 3 EVALUATING MOTOR ENERGY EFFICIENCY OPPORTUNITIES ............................. 3-1 Understanding Your Utility Rate Schedule .......................................................3-2 Determining Motor Load .......................................................................3-3 Using Input Power Measurements . 3-3 Using Line Current Measurements ...........................................................3-4 The Slip Method ............................................................................3-4 Determining Operating Hours ..................................................................3-4 Estimating the Performance of Old Standard Efficiency Motors ...................................3-5 Calculating Annual Energy and Demand Savings ................................................3-6 Understanding Motor Purchase Prices .......................................................... 3-7 Assessing Cost-Effectiveness ................................................................... 3-7 Making the Right Choice ....................................................................3-11 References ....................................................................................3-12 ii | PREMIUM EFFICIENCY MOTOR SELECTION AND APPLICATION GUIDE CHAPTER 4 PREMIUM EFFICIENCY MOTOR APPLICATION CONSIDERATIONS . .4-1 New Motor Purchases ..........................................................................4-2 Motor Failure and Repair/Replace Decision-Making ..............................................4-3 Motor Repair Best Practices ....................................................................4-7 Immediate Replacement of Operable Standard Efficiency Motors ................................4-8 Oversized and Underloaded Motors ............................................................4-9 Efficiency Gains and Motor Operating Speed ...................................................4-10 Motor Efficiency at Full and Part Load ......................................................... 4-14 Use MotorMaster+ to Conduct Analyses of Motor Repair or Oversized Motor Replacement Opportunities .................................................. 4-14 References ................................................................................... 4-15 CHAPTER 5 MOTOR PERFORMANCE UNDER USUAL AND ABNORMAL OPERATING CONDITIONS ..................................................... 5-1 Overvoltage Operation ........................................................................5-2 Undervoltage Operation .......................................................................5-3 Phase Voltage Unbalance ......................................................................5-4 Load Shedding ................................................................................5-6 Motor Interactions with Electronic Adjustable Speed Drives ......................................5-6 Voltage Overshoot ............................................................................. 5-7 Bearing Currents ...............................................................................5-8 References ................................................................................... 5-10 CHAPTER 6 MOTOR CHOICES: EXTERNAL ENVIRONMENT AND APPLICATION CONSIDERATIONS......................................................6-1 Motor Enclosures ..............................................................................6-2 Motor Efficiency Versus Speed and Enclosure Type ..............................................6-4 Motor Insulation Systems ......................................................................6-4 Service Factor .................................................................................6-6 Motor Speed, Slip, and Torque Relationships ....................................................6-7 Severe Duty and IEEE 841 Motors ...............................................................6-8 Inverter-Duty Motors ...........................................................................6-9 Inverter-Duty Motor Design Features ........................................................ 6-10 Guidance for Selecting Motors Controlled by an ASD ......................................... 6-10 References ................................................................................... 6-12 PREMIUM EFFICIENCY MOTOR SELECTION AND APPLICATION GUIDE | iii CHAPTER 7 ADVANCED MOTOR TECHNOLOGIES ....................................................... 7-1 Copper Rotor Motors........................................................................... 7-2 Permanent Magnet Motors ..................................................................... 7-3 Switched Reluctance Motors...................................................................