Electric motor efficiency: The ideal choice for energy savings.

What is motor efficiency?

The efficiency of an electric motor measures how effectively it converts electrical energy into mechanical energy. It is generally expressed as a percentage or as a value between 0 and 1.

It is calculated using this simple formula:

Efficiency = Useful Power / Absorbed Power

The closer the efficiency value is to 1 or 100%, the better the efficiency.

Certain losses affect the efficiency of an electric motor, such as:

•         Mechanical losses: Friction in the bearings and other motor components.
•         Rotor losses: Due to the induced current in the motor's rotor.
•         Ventilation losses: Caused by the air circulation that cools the motor.
•         Resistance losses: Due to electrical resistance in the motor's conductors, leading to energy conversion into heat.

The different energy classes.

Electric motors (three-phase induction) are classified according to their energy efficiency by the IEC 60034-30-1:2014 standard. These classes are defined by the prefix IE followed by a number based on efficiency (1 being the least efficient).

IE1: Standard efficiency. This efficiency level is standard. It is no longer allowed above a certain power for machine manufacturers.

IE2: High efficiency. This efficiency level is high. You will find it on small powers (up to 55kW) and on compact motors (reduced frame).

IE3: Premium efficiency (Very high). IE3 efficiency is the most widely used and has been mandatory since 2015 for electric motors from 7.5kW to 350kW.

IE4: Super Premium. This efficiency has recently entered the market but is the most advantageous and allows for a reduction in your energy costs.

To know:

According to the statement, since 2017, all standard 2, 4, 6 pole motors with power from 0.75kW to 375kW must be at least in efficiency class IE3.

You will find IE2 efficiency class motors for powers below 0.75kW.

Motors not covered by the energy standard.

While the IEC 60034-30-1:2014 standard is mandatory for three-phase induction electric motors, some motors are not covered by this standard:

•         Single-phase motors: Single-phase motors are generally used for light domestic applications, so they may not be subject to the same efficiency standards as industrial three-phase motors.
•         Specific motors: Some motors have special designs for specific applications and cannot fall into standard efficiency categories. Example: In certain sectors such as aerospace, medical...
•         DC motors: DC motors have many specific characteristics. Their efficiency is important, but they are not classified according to IE standards.

Which efficiency to choose?

At Dymatec Industries, you will find a wide range of electric motors. From IE1 to IE4 efficiency, discover a wide selection. For this, we offer:

Motors up to 0.55kW = IE2 efficiency

Motors from 0.75kW = High Efficiency IE3

Motors from 7.5 kW = IE4 Efficiency

We do not stock IE1 motors except for small powers (from 0.06kW to 0.09kW)

It is preferable that you choose a high efficiency (IE3 or IE4). Higher efficiency motors convert electrical energy into mechanical energy more effectively. They therefore more easily reduce energy consumption and operating costs.

Premium IE3 efficiency motors are currently the most widely used since they are mandatory for machine manufacturers from 0.75kW power. Discover our article: why prefer the IE3 motor.

Dymatec Industries has recently started offering efficiency higher than IE3. The IE4 class will further reduce CO2 emissions and also reduce your energy costs in the long term. Here are the motors offered in IE4:

•         3000 rpm - 2 pole motors: From 45kW to 250kW
•         1500 rpm - 4 pole motors: From 7.5kW to 315kW
•         1000 rpm - 6 pole motors: From 18.5kW to 200kW
•         750 rpm - 8 pole motors: From 55kW to 132kW

IE4 motors are a range with superb optimization of performance and costs. It should be noted that motors of this class have had a reduction in losses of up to 20% compared to IE3 motor efficiency.

To summarize, IE4 motors have a better efficiency class and will reduce your costs; you will see a considerable difference in your energy consumption. You can do a simulation using our energy savings calculator, an easy-to-use tool.

Find all our three-phase and single-phase motors on our website.

Do not hesitate to contact us for further information.