Overcurrent Protection - Siemens SINAMICS G120 Operating Instructions Manual

8.7.3

Overcurrent protection

During vector control, the motor current remains within the torque limits set there.
During U/f control, the maximum current controller (I
inverter against overload by limiting the output current.
Method of operation of I
If an overload situation occurs, the speed and stator voltage of the motor are reduced until
the current is within the permissible range. If the motor is in regenerative mode, i.e. it is
being driven by the connected machine, the I
voltage of the motor to reduce the current.
Note
The inverter load is only reduced if the motor torque decreases at lower speeds (e.g. for
fans).
In the regenerative mode, the current only decreases if the torque decreases at a higher
speed.
Settings
You only have to change the factory settings of the I
oscillate when it reaches the current limit or it is shut down due to overcurrent.
Table 8- 25
Parameter
P0305
P0640
P1340
P1341
r0056.13
r1343
For more information about this function, see function diagram 1690 in the List Manual.
SINAMICS G120C Inverter
Operating Instructions, 01/2011, FW 4.4, A5E02999804A AB
controller
max
I controller parameters
max
Description
Rated motor current
Motor current limit
Proportional gain of the I
Integral time of the I
Status: I controller active
max
Speed output of I
max
Shows the amount to which the I-max controller reduces the speed.
max
controller increases the speed and stator
max
max
controller for speed reduction
max
controller for speed reduction
max
controller
8.7 Protection functions
controller) protects the motor and
controller if the drive tends to
Functions
193