Siemens SIMATIC ET 200pro Series Operating Instructions Manual page 145

In applications with a high break loose torque, you must also increase parameter p1312 in
order to achieve a satisfactory motor response.
You have set the voltage boost.
Figure 7-26
The inverter boosts the voltage corresponding to the starting currents p1310 ... p1312.
Parameter
p1310
p1311
p1312
You will find more information on this function in the parameter list and in function diagram
6301 in the List Manual.
SIMATIC ET 200pro FC-2 converter
Operating Instructions, 09/2017, FW V4.7 SP9, A5E34257324B AE
The resulting voltage boost using a linear characteristic as example
Description
Starting current (voltage boost) permanent (factory setting 50%)
Compensates for voltage drops caused by long motor cables and the ohmic losses in
the motor.
Starting current (voltage boost) when accelerating (factory setting 0%)
Provides additional torque when the motor accelerates.
Starting current (voltage boost) when starting (factory setting 0%)
Provides additional torque, however, only when the motor accelerates for the first time
after it has been switched on ("break loose torque").
Advanced commissioning
7.11 Motor control
145