Comparative Study of Energy Consumption of 15 kW Induction Motors of IE1 and IE2 Efficiency Classes in Pump Applications

In this work, the energy consumption of two 15 kW pump units employing induction motors of IE1 and IE2 energy efficiency classes is compared. The induction motors are powered directly from the mains. In both cases, the pump system has identical time-flow charts typical for open type hydraulic installations. The fluid flow is adjusted by throttling. The results on daily and annual energy consumption are obtained. It is shown that the system with the IE2-class motor provides savings of 7.9 thousand rubles per year and of 126 thousand rubles per the system life cycle, compared with the IE1-class motor. In addition, the payback time of the IE2-class motor was assessed to be 9 months in the case of commissioning a new pump unit and 3 years and 8 months in the case of replacing the IE1-class motor as a part of a pump installation in operation.