Efficiency classes IE1 to IE5 (IEC 60034-30-1)
The IE code on a motor nameplate is its efficiency class, defined in IEC 60034-30-1 for line-operated AC motors from 0.12 kW to 1000 kW with 2, 4, 6 or 8 poles. Each class sets a minimum efficiency that depends on the power, the number of poles and the supply frequency (50 or 60 Hz), so there is no single percentage per class.
Classes
| Class | Name |
|---|---|
| IE1 | Standard efficiency |
| IE2 | High efficiency |
| IE3 | Premium efficiency |
| IE4 | Super premium efficiency |
| IE5 | Ultra premium efficiency |
IE5 was added to IEC 60034-30-1 in its second edition (2025); the 2014 first edition defined IE1 to IE4. Efficiency is measured by the methods in IEC 60034-2-1.
EU minimum efficiency (Regulation (EU) 2019/1781)
In the EU the ecodesign regulation for motors and variable speed drives, Regulation (EU) 2019/1781, sets which class a motor must at least reach to be sold. It covers induction motors rated above 50 V up to 1000 V, from 0.12 kW to 1000 kW, with 2, 4, 6 or 8 poles, rated for continuous duty. Annex I sets these minimums:
| From | Motors | Minimum |
|---|---|---|
| 1 July 2021 | Three-phase, 0.75 kW to 1000 kW | IE3 |
| 1 July 2021 | Three-phase, 0.12 kW to below 0.75 kW | IE2 |
| 1 July 2023 | Three-phase, 75 kW to 200 kW, 2, 4 or 6 poles (not brake motors, not Ex motors) | IE4 |
| 1 July 2023 | Increased-safety Ex eb motors, 0.12 kW to 1000 kW | IE2 |
| 1 July 2023 | Single-phase motors, 0.12 kW and up | IE2 |
From 1 July 2021 variable speed drives in scope must also meet the IE2 level for drives, a limit on their power losses (drives have their own IE classes, defined in IEC 61800-9-2). The regulation has exemptions and was amended by Regulation (EU) 2021/341, so check the current consolidated text for a specific motor.
Permanent-magnet servo motors are not induction motors and fall outside this regulation.
Converting power ratings: kW to hp.
Summarised from the standard named above. For a design decision, check the motor maker's datasheet and the current edition of the standard. More datasheet reference pages.