Determining the efficiency of electric motors. Does IEC 61972 offer improvements for the European market?

The relevant characteristic for electric motors when comparing the energy consumption of different-besides the efficiency class-is the numerical value of the nominal efficiency. Therefore clear definitions, methods for proving them and prescribed tolerances are of special importance. However, as this article explains, the demands and expectations made by the draft standard IEC 61972/CDV have not been fulfilled in practice.