Siemens SIRIUS 3RW44 User Manual page 98

Device Functions
Typical applications for torque control
6-6
Note
The torque generated in the motor and controlled by the soft starter can at no
time be higher than the value of a similar direct on line start at the same speed.
Motor
torque (M)
Nm
Parameterizable
limiting torque
N
Nom
Parameterizable
start voltage
Figure 6-3: Function principle of torque control
Torque control is suitable for all applications, especially in cases where a
consistent and smooth start is required. For machines requiring a breakaway
pulse (inverse load response, e.g. in mills or crushers), the breakaway pulse
must be set as described in Chapter 6.2.3 "Breakaway Pulse in Combination
with the Voltage Ramp or Torque Control Starting Mode". The "Torque
control+current limiting (M+current limiting)" starting mode is recommended for
heavy starting (refer to Chapter 6.2.4 "Current Limiting in Combination with the
Voltage Ramp or Torque Control Starting Mode").
Acceleration
torque
Motor has run up and is
Parameterizable
in nominal operation (n
ramp time
The runup is detected and the
bypass contacts close.
).
Nom
SIRIUS 3RW44 manual
GWA 4NEB 535 2195-02 DS 06