Softstarters Type PSE18...PSE370 Installation and commissioning manual 1SFC132057M0201
64 Chapter 7
7.5.6
Torque Control during start ramp
It is possible to use the torque control during the start by activating this parameter.
Torque control results in a more linear accelerating of the speed in a majority of
applications.
When using the torque control the output voltage to the motor is controlled so
that the motor torque will follow a predefined optimal curve from the initial
voltage
level to full voltage during start.
This has the benefit that the mechanical starting behavior of the equipment driven
by the motor will be much softer compared to the use of voltage ramp. During the
torque controlled start the motors voltage and RPM will follow the graph in figure
7.15.
During start ramp, the output voltage to the motor is controlled so that the torque
will follow a predefined optimal curve from the initial voltage level to full, voltage
during start. This has the benefit that the mechanical starting behavior of the
equipment driven by the motor will be much softer compared to the use of voltage
ramp. During the torque controlled start the voltage U and RPM of the motor will
appear as the graphs in figure 7.15.
Display
Default
value
Setting
range
Description
OFF
On/OFF
Torque Control during start
The time for the Torque Control during start ramp is set in the parameter
Start Ramp time.
Figure 7.15: The function of Torque Control
during start
U
RPM
1SFC132161F0001
Figure 7.14: Torque Control during start
ramp parameter displayed
