Motor Efficiencies and Power Factors

Most extruders manufactured today are built using AC vector motor systems instead of the older DC motor systems. AC motors operate at about 5% higher efficiencies, require less maintenance, and are lower in cost than a DC motor. Typical efficiencies for AC and DC motors rated at 83 kW are provided in Table 10.3. It is 

AC vector motors typically operate with a power factor In the range of 0.90 to 0.98 [20]. The power factor for a DC drive system can be considerably lower and as low as 0.5. Replacing an older DC motor with an AC vector motor can be economically attractive due to an Increase In both the efficiency and the power factor. 

---