The International Efficiency IE classes for electric motors

IEC 60034-30-1:2014:

This standard defines four International Efficiency (IE) classes for single-speed electric motors that comply with either IEC 60034-1 or IEC 60079-0 (explosive atmospheres) standards and are designed for operation at sinusoidal voltage.

• IE4 = Super Premium Efficiency
• IE3 = Premium Efficiency, equivalent to the table in 10CFR431 ("NEMA Premium") in the United States and CSA C390-10:2015 for 60 Hz
• IE2 = High Efficiency
• IE1 = Standard Efficiency

Nominal efficiency limits as defined in IEC 60034-30-1:2014 (reference values at 50 Hz, based on the test methods specified in IEC 60034-2-1:2014):