Motors & Motion
Industry best practice repairs maintain—maybe even improve—premium-efficiency/IE3 motor performance
By Anthony Capkun
July 11, 2020 – The Electrical Apparatus Service Association (EASA, U.S.) and AEMT (Association of Electrical & Mechanical Trades, U.K.) say an independent study shows that industry best practice repairs/rewinds maintain the energy efficiency and reliability of premium efficiency/IE3 electric motors.
The study involved testing 10 new low-voltage, premium-efficiency/IE3 motors before and after they were rewound by an EASA Accredited Service Center in accordance with ANSI/EASA AR100-2015 “Recommended Practice for the Repair of Electrical Apparatus”.
The motors studied ranged from 40 hp to 100 hp (30 kW to 75 kW). Each motor was performance-tested at full load when new, then repaired (rewound), and retested. All testing was performed in accordance with IEEE 112B at North Carolina Advanced Energy Corp., an independent lab accredited for motor efficiency testing.
The post-rewind efficiency values ranged from an increase of 0.3% to a reduction of 0.5%, with an overall average decrease of 0.1%. The average efficiency change for the entire test group falls within the range of accuracy for the test method (±0.2%); thus, rewinding caused no efficiency change in individual motors or overall, say EASA and AEMT, beyond what would be expected due to inaccuracies in the testing method.
“Maintaining efficiency and reliability in repaired/rewound electric motors is very important to end users. Electric motors consume as much as 2/3 of the electricity generated in industrialized nations,” said Linda Raynes, CAE, EASA President and CEO. “This study demonstrates that using industry best practices maintains—and sometimes even improves—the efficiency and reliability of premium-efficiency and IE3 motors.”