IE3 and IE4 are the top two tiers of the IEC 60034-30-1 efficiency classification and the two options most often compared when choosing a motor. The difference between them concerns not only the efficiency figure but also investment and duty profile. DRG Motor supplies both classes.

The Difference Between IE3 and IE4

IE3 defines the "Premium" level and IE4 the "Super Premium" level. At the same power and speed, IE4 runs with lower losses, achieved through more active material and an optimised winding. Because mechanical mounting dimensions usually stay the same, adapting to an existing machine is straightforward.

Which One for Which Application?

For intermittent loads that run a few hours a day, IE3 is often a balanced choice. For continuous loads such as fans, pumps and compressors that turn thousands of hours a year, the lower losses of IE4 recover the cost difference through operation.

Shared Technical Features

DRG's IE3 and IE4 motors come with a cast iron frame, IP55 protection and F-class insulation. They are supplied for 400 V / 50 Hz, at two-pole 3000 rpm, four-pole 1500 rpm and six-pole 1000 rpm speeds, with foot-mounted B3 or flange-mounted B5 connection.

Choosing the Right Efficiency Class

The choice depends on the motor's annual running hours and load profile. Offering both classes from 0.55 to 355 kW, DRG Motor helps you determine the efficiency-to-price balance best suited to your application.