Stall torque and starting torque of three-phase asynchronous motors
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How are stall torque and starting torque defined? Should the stall torque multiplier be greater than 1, or is it why many sources indicate a value less than 1? Are the stall current multiplier and starting current multiplier the same thing?
The stall torque is higher than the rated torque, and the stall current is not the same as the starting current
Starting torque: the electromagnetic torque at the moment the motor starts; its magnitude is equal to the static frictional torque of the motor’s load, and it corresponds to the moment when the motor’s starting current is at its highest； 2. Maximum torque refers to the highest torque that a motor can generate. An asynchronous motor reaches its maximum torque at the critical slip rate, at which point the inductive reactance of the motor is equal to its impedance, and the power factor angle is 45 degrees ； 3. Lock-up torque: Lock-up occurs during the operation of an asynchronous motor when the load torque increases to exceed the motor’s maximum torque. As a result, the motor moves from a stable state to an unstable state, its speed drops and its torque decreases until it finally stops. The torque that occurs when the motor stalls during operation is called stall torque, and this stall torque is greater than the maximum torque
By definition, the stall torque is greater than the motor’s maximum torque; then why is the stall torque multiplier listed in some manufacturers’ data less than 1? Is the stall torque mentioned by these manufacturers the same as the stall torque as defined in the standards?