1.1.27 What are the efficiency classes for electric motors?

There are four IE efficiency classes that are relevant in the context of IEC 60034-30: IE1 (standard efficiency), IE2 (high efficiency), IE3 (premium efficiency), and IE4 (super-premium efficiency). The international designations of the individual classes are as follows: 

IE1 = Standard Efficiency
IE2 = High Efficiency
IE3 = Premium Efficiency
IE4 = Super Premium Efficiency 

Some IE5 electric motors with permanent magnet technology are already available. There is however still no obligation to use these high-priced drives.