Start Mode - ABB PST30 Installation And Commissioning Manual

Chapter 10
Functions
U
Start
rpm
Start
Figure 1: Voltage ramp
U
Start
rpm
Start
Figure 2: Torque ramp
132

10:2 Start mode

Time
Time
Time
Parameter
text
Start Mode Volt
Time
Path in menu:
Menu/SETTINGS/Functional Settings/
Torque control/ Start Mode
Using the PST softstarter it is possible to choose between
two different types of start ramps. These are voltage ramp
and torque ramp.
Voltage ramp When using the voltage ramp, the voltage
is increased linearly from the start level to
full voltage during start. Since the torque
depends on both the voltage and the
current, the torque curve does not always
follow the voltage curve. This has the
effect that the torque curve will not
increase or decrease linearly.
Torque ramp When using the torque ramp, the output
voltage to the motor is controlled so that
the torque will follow a predefined optimal
curve from the start 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 than when using voltage
ramp.
Default value Setting range Description
Volt, Torque Type of start
ramp
1SFC132003M0201