It is possible to control parallel motors of mixed ratings with our ATV61.
The nominal current of the drive must be greater than or equal to the sum of the currents of the motors to be controlled. Refer to attached document for the recommendation of “Connecting motors in parallel”.
But, it is not possible to connect/ disconnect any of the motors while running .Because if you connect/ disconnect any of the motor while running, motor will draw the current 7 to 8 time of its nominal current (it will start like DOL starter) and drive will trip in a fault.

Released for: Schneider Electric India