High-efficiency motors

Directive 2009/125/EC provides, through a series of intermediate steps, specific regulations for electric motors in order to improve their fuel consumption and performance.

From January 1, 2017 motors with a rated power of 0.75 kW and 375 kW must be of a minimum efficiency class IE3, or IE2 if they are driven by an inverter.

Electricity consumption in the industrial sector comes to 74% from the use of electric motors; if in Europe all the old systems that have so far worked were replaced by high efficiency drives, this would result in an annual energy savings of 135 billion kilowatt-hours.

Efficiency determines how an electric motor transforms electricity into mechanical energy.

The International Standard IEC 60034-30: 2008 defines for three-phase motors 3 performance classes:

  • IE1 = standard efficiency;
  • IE2 = high efficiency;
  • IE3 = premium efficiency.

Regulation (EC) No 640/2009 sets out the minimum requirements for eco-design for electric motors and the use of speed control; the three-phase asynchronous motors of 50 Hz and 60Hz are fitted with a cage rotor and a single speed with the following characteristics:

  • Rated voltage up to 1000 V;
  • Nominal power ranging from 0.75 KW to 375 KW;
  • 2, 4 and 6 poles;
  • For continuous service (S1).

This Regulation does NOT apply to engines fully integrated into a product (eg in a gearbox, pump, fan or compressor) for which it is not possible to test the energy performance independently of the product and to the self-braking motors. It does not apply to engines designed to operate: more than 4000 m s.l.m .; at ambient air temperatures higher than 60 ° C; at ambient air temperatures below -30 ° C.

Increasing the purchase price for energy efficient drive systems is often quickly recovered thanks to overall energy cost savings.

With the aim of achieving the high efficiencies imposed by the law, IE3 class engines are being designed.

As for the future IE4 class, permanent magnets synchronous motors are being studied.