The International Electrotechnical Commission (IEC) has put in place energy-efficiency classifications for electric motors across four levels of motor efficiency: IE1 Standard Efficiency, IE2 High Efficiency, IE3 Premium Efficiency and IE4 Super Premium Efficiency.

The IE codes help regulators determine the minimum efficiency levels for electric motor energy performance in their regulations, and therefore could lead to improved efficiency and cost savings.

In the European Union (EU), Directive 640/2009 came into effect in January 2015 for motors with a rated output from 7.5-375 kilowatt (kW) and from 2017 for motors with a rated output from 0.75-375 kW. This measure, which is generally referred to as the EU Minimum Energy Performance Standard (MEPS), is expected to result in energy efficiency improvements of 20-30%, according to IEC.

In the U.S, since 1997 (Energy Policy Act), the minimum required level was set at the equivalent of IE2. In 2007, MEPS was raised to the equivalent of the IE3 level (NEMA premium).

Australia and New Zealand set MEPS levels for electric motors at IE2 effective in 2001.

In China, MEPS for small and medium three-phase asynchronous motors have been in place since 2002 (GB 18693). The standard was updated in 2006, and in 2012 was harmonized with IEC standards. At the same time, the MEPS was increased from IE1 to IE2 and now IE3.

Japan has harmonized its national regulations with IEC efficiency classes and has included electric motors at the IE2 and IE3 level in its "Toprunner" program in 2014.

India has had a comparative efficiency label since 2009 and a voluntary national standard on IE2 level since 2012.

The IEC has also developed an International Standard, IEC 60034-2-1:2014, for the testing of electric motors. Many countries use national test standards but also reference the International Standard IEC 60034-2-1.

More information on the IEC website section on measuring energy efficiency of electric motors.