Product description3.2 Functional principle of the SIRIUS 3RW30 and 3RW40 soft startersSIRIUS 3RW30 / 3RW40Manual, 10/2018, NEB535199502000/RS-AB/005 25The diagrams below show the starting current and torque characteristics for a three-phaseinduction motor in combination with a soft starter:Figure 3-1 Reduced current characteristic of a three-phase induction motor during starting with aSIRIUS 3RW30 or 3RW40 soft starterFigure 3-2 Reduced torque characteristic of a three-phase induction motor during starting with aSIRIUS 3RW30 or 3RW40 soft starterSoft start /soft stopThis means that, since the motor voltage is controlled by the electronic soft starter during thestartup process, the consumed starting current and the starting torque generated in themotor are also controlled.The same principle is applied during the stop process. This ensures that the torquegenerated in the motor is gradually reduced, so that the application can stop smoothly (thesoft stop function is only supported by the 3RW40).
