NEMA Standard Adds Efficiency Test for Air-Over Motors

The National Electrical Manufacturers Association (NEMA) released a new efficiency test method for air-over (AO) motors as part of its MG 1 Motors and Generators standard.

Part 34: Air-Over Motor Efficiency Test Method covers AO motors that operate in and are cooled by the airstream of a fan or blower that is not supplied with the motor, and whose primary purpose is providing airflow to an application rather than the primary purpose of cooling the motor. There are three temperature test procedures recognized by the NEMA Motors and Generators (1MG) Technical Committee.

“AO motors require special procedures to reach an appropriate temperature. These test procedures replace the temperature test portion of the applicable efficiency test method,” said Tim Schumann service manager of SEW-Eurodrive, Inc., and chair of 1MG.