Classification of Electric Motors

The former CEMEP voluntary EU agreement (CEMEP is the European Committee of Manufactures of Electrical Machine sand Power Electronics) has been replaced by the EuP Directive, which must be implemented in the national legislation in all member states of the European Union. It classifies the following three levels of energy efficiency: IE1—standard efficiency; IE2—high efficiency; IE3—premium efficiency.

IE stands for International Efficiency. The new IE coding replaces the former EFF1 and EFF2 classifications. The relationship between the different efficiency classifications is shown in Figure 1.

The new EuP Directive applies to:

• 2 to 6—pole electric motors


• with a nominal UN voltage of up to 1,000 V


• a nominal PN power between 0.75 kW and 375 kW


• classified on the basis of continuous operation (S1)

 

During the electric motor life-cycle, the operating costs are determined mainly by the energy costs. These are 95% to 99% of the total cost of the electric motor during its life-cycle. Besides the better energy efficiency the IE2 and IE3 electric motors provide also other benefits:

• The higher efficiency results in less heat needed to be dissipated so a smaller fans are used.


• The smaller fans result in less ventilation losses and a reduction of noise level.


• The other benefit is the lower motor temperature as it is a direct result of the improved electric motor design, making IE2 and IE3 electric motors suitable for applications with ambient temperatures exceeding 40°C.

 

The new Directive ensures that only improved design motors are placed on the market, which means that the IE1 motors (formerly EFF2) became the lowest efficiency limit, the old EFF3 efficiency class completely eliminated and the new more efficient “premium efficiency” IE3 motors will supersede the current standard of “high efficiency” IE2 motors (formerly EFF1). The efficiency of IE3 electric motors is higher than that of lower class electric motors such as IE2 (EFF1) and IE1 (EFF2) electric motors. Please note that the greater the power output of an electric motor the higher the efficiency and the smaller the differences in efficiency between the individual classes (IE1, IE2, IE3). See Figure 2.

 

As from 1st June 2011 Rotor is longer able to supply 5RN electric motors that do not meet the criteria set out in the new EuP standard. The new 6RN electric motors will replace the old range. The new 6RN electric motors contain more copper and other materials in order to reduce energy losses and improve electric motor efficiency. The 6RN electric motors meet the new IE2 standard. The 6RN electric motors are being marketed at higher prices to reflect the additional material used. Because of the higher efficiency of the 6RN electric motors, the capital cost payback period is shorter.

 

 

 

16th June 2011: All new manufactured electric motors must be of the IE2 efficiency standard or higher

1st January 2015: Electric motors with the nominal power output of 7.5kW to 375 kW must be of the IE3 efficiency standard (IE2 motors can be used for a frequency inverter duty)

1st January 2017: Electric motors with the nominal power output of 0.75kW to 375 kW must be of the IE3 efficiency standard (IE2 motors can be used for a frequency inverter duty)