Sturdy construction: in 3 PH squirrel- cage design; free from electric brushes; minimized trouble. Simple structure and easy maintenance. Simple operation and easy control. Characteristics:. Small starting current, large starting torque and superior adaptability to speed. . With its superior fixed tension, the winding fabric, bands and thread can obtain moderate tension with no need of re-regulation of tension during operation. . With moderate tension, neat and unbroken winding can be obtained.