The engine manufacturer is dedicated to another series of tests Groschopp the optimization of its engines in terms of energy efficiency. Even for asynchronous motors with a performance below 0,75 kW, which are not covered by the valid EuP directive as of 2012, and beyond the energy aspect, it is worthwhile to increase energy efficiency. Lower costs and longer run times due to lower heat output provide another incentive to switch to energy efficient drives. The subject of the most recent series of experiments was the IGK Induction Enclosure Motors, whose rated power ranges from 9 to 370 W - in 2-pole or 4-pole design.
Basically effective measures to improve the efficiency, are both the extension of the active laminated core and the replacement of the aluminum cage against a copper cage. In this way an optimal efficiency can be achieved, which even exceeds the efficiency class IE3. For example, the I80-80 2p originally had an efficiency of 71,52% and a power output of 238,56 W. With an iron extension of 20 mm combined with a copper cage, the efficiency increases to 75,71% and the output power to 351,16 W. This corresponds to an increase of the original Efficiency by 4,19% and an increase of the output power by 47,2%.
Another way of optimization is an alignment to the IEC standard. This determines iron length, power output and sheet diameter for the different sizes. The maximum efficiency of the asynchronous motors in their original design was compared with the maximum efficiency of the asynchronous motors with iron lengths according to the IEC standard and with copper or aluminum cages. From this experiment, it was found that, for example, the I90-80 4p The Groschopp series achieves a maximum efficiency of almost 180% at about 70 W rated output. Extend the iron and replace the aluminum cage against a copper cage, thus improving efficiency and rated power. With an iron length of 60 mm, the I90-80 4p achieves its maximum efficiency but below the prescribed power. With an iron length of 45 mm and a copper cage surpasses the I90-80 4p the power required by IEC standard to reach maximum efficiency. However, the actual power output must comply with the required output power according to the IEC standard of the respective size. In some engines, the operating point can not be met under this requirement.