NEMA Publishes Motor, Generator Standard

May 4, 2010—

The National Electrical Manufacturers Association (NEMA) has published MG 1-2009 Motors and Generators.

MG 1 is the definitive standard for practical information concerning performance, safety, testing, construction and manufacture of alternating-current and direct-current motors and generators. The standard was last revised in 2007 and is produced by NEMA's Motor and Generator Section.

MG 1 has been updated to include the latest in international motor efficiency requirements. The section revised the motor efficiency tables for 50 Hz products to reflect those of IEC IE Code as per IEC 60034-30. Other significant changes include revised minimum insulation resistance, clarification of motor efficiency values, the addition of sections on auxiliary devices, ratings tests and performance for AC and DC motors.

MG 1-2009 includes a summary of changes for the current revision as well as the three previous editions with color coded lines throughout the document to mark affected sections.

NEMA members continually work to keep MG 1 updated for manufacturers and users of motors and generators to match changes in technology and the global marketplace," says Roger Daugherty, of Baldor Electric Company and chair of the Motor and Generator Technical Committee. "This latest revision represents significant industry expertise and time dedicated to the pursuit of standardization. We have also increased our efforts to mark technical modifications between revisions to assist readers with tracking the standard's journey."

MG 1 may be purchased in hardcopy or electronic format for $290 by visiting

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