Shred bars：there are some causes， such as high speed centrifuge,large centrifugal,so that the groove bottom is not casted fully,there are some wrong rotor plate in core,so that which prevent aluminum fluid flowing, Core preheat temperature is low, Temperature of molten aluminum drop too much, liquidity deteriorated.

    Dissatisfaction and Condensation: it is caused by The low temperature of molten aluminum, Poor liquidity, Casting speed is too slow or flow, the core and mould preheating temperature is too low, Leakage aluminum or aluminum is not enough, Low speed centrifuge, the centrifugal force is too small, as well as Liquid aluminum cannot fill to wind leaf.

    The rotor resistance is so big:there are some causes,such as the Groove Angle is greater than the specified value, so that increased resistance of conductor, there are so large amounts of impurities in liquid aluminum, and  so many pores and cracks conductor.

    large Stray loss: there are some causes, such as Slot Angle is too big, the Contact resistance between conductor and core is so small, This situation is common in Pressure cast aluminum, Dissatisfaction and Condensation, there is no significant effect on motor performance;when occurred Broken rotor bars,so Motor can not start, Pores, shrinkage,shred and crack and so on will increase the resistance and loss of rotor,reduce the efficiency and min torque, Elevate the temperature rise and slip ratio.