Functions
7.6 Soft torque
SIRIUS 3RW50 soft starter
Manual, 09/2019, A5E35628455002A/RS-AA/001
131
Speed curve
n
e
Rated operating speed of the motor
①
Motor speed without Soft Torque
②
Motor speed with Soft Torque
Principle of operation of Soft Torque during stopping
The Soft Torque function enables the motor to coast down smoothly at an almost constant
rate of deceleration. Ensuring that the motor coasts down smoothly is particularly useful for
stopping pumps in order to prevent water hammers in the connected piping. The Soft Torque
function for stopping can only be activated when a stopping time of more than 3 s is set.
