General Description YR,YRKS,YRKK series medium-sized high voltage Wound rotor three phase asynchronous motors are our latest products, there are totally 6 frame size ranging H355 to H630. To develop these series motors, advanced analytic and calculation technology is used, fine materials and excellent workmanship are also adopted during manufacturing. All of those give series motors high efficiency, low noise and low vibratility. All motors in basic design are of horizontal with feet mounting type (IMB3), and duty type is continuous operation (S1). Normally, the motors have three types of enclosure protection degree:IP: 23, IP44 or IP54. In respect to cooling type, the motors basically have IC01, IC81W, IC611 or IC616 Series motors may be used to drive rolling mills, grinders, hoists, be four types to be ed. lt conveyers, heavy load blowers, etc. Briefing of construction A steel plate welded construction has been used to reduce the frame weight and increase the rigidity optimum construction design also makes series motors convenience for installation and maintenance. One piece laminations for the stator and rotor are precision-stamped low loss electrical steel, thus the iron loss is minimized and the efficiency is improved. The insulation class of series motors is class F. The stator coil is a double layer formed coil, the stator core is stacked and assembled with coils outside the frame, and coil braces are applied on the circumference of the stator coil ends with spacers ed between coils to improve rigidity. After the connection between coils is made, the completed stator winding is placed in a vacuum tank and impregnated, then the stator winding is put the stator frame and fixed with it. The rotor cores are shrunk onto the shaft and rotor coils are tightly fitted the slots to minimize vibration. Advanced brazing technology of the rotor coils to coils insures high mechanical strength and good electrical conductivity at the brazed joints. The coil ends are supported by bandage. The rotor winding is vacuum pressure impregnated (VPI) and connected to the slip ring unit. This construction gives the rotor an excellent fit against centrifugal forces. The slip ring unit is mounted outside