What to know when repairing electric motors


A recently published research study from the Electrical Apparatus Service Association (EASA) tested premium-efficiency/IE3 motors, from 40 to 100 horsepower (30 to 75 kilowatts), both before and after they were repaired/rewound. Each motor was performance tested at full load when new, then repaired (rewound) and finally retested. All testing was performed in accordance with IEEE Standard 112B at North Carolina Advanced Energy Corp., the only independent Laboratory Accreditation Program (NVLAP) lab accredited for motor efficiency testing.

The motor repairs performed followed the ANSI/EASA Standard AR100-2015: Recommended Practice for the Repair of Rotating Electrical Apparatus. Further, the repairs were performed at a motor repair facility that was recognized under the EASA Accreditation Program.

Post-rewind efficiency changes ranged from an increase of 0.3%, to a reduction of 0.5%, with an overall average decrease of 0.1%. Therefore, following industry best practices maintains and sometimes even improves the efficiency and reliability of premium efficiency and IE3 motors.

Learning objectives:

  • Understand the purpose and value of electric motor repair best practices established by ANSI/EASA Standard AR100-2015.
  • Learn how the recent EASA research study evaluated key electric motor performance characteristics after repair.
  • Know how to make an informed electric motor repair or replace decision, and understand best practices.
  • Review the requirements for a motor repair facility that has attained EASA accreditation.

Course Instructors:
Thomas Bishop, Senior Technical Support Specialist, EASA