YPT series of variable-frequency adjustable-speed three-phase induction squirrel cage motors are the new products which has been developed by drawing the merits of the same motors at home and abroad and using the computer optimum design.This series motors have the advantages of good adjustable-frequency performance, saving energy,satisfactory starting torque characteristic, lower noise, small vibration, higher safety and reliability in operation, and beautiful appearance etc. Rated outputs and mounting dimensions are completely in accordance with International Electri-technical Committee (IEC) standards. The motors are class F insulated. Degree of protection by enclosure is IP54 or IP55. Duty type is S1.