Overcurrent Protection - Siemens SIMATIC ET 200pro Original Instructions Manual

Parameter
p0615
p0621
p0622
p0625
More information on temperature calculation can be found in function plans 8016 and 8017
and the list manual.
8.6.4

Overcurrent protection

The vector control ensures that the motor current remains within the set torque limits.
If you use U/f control, you cannot set any torque limits. The U/f control prevents too high a
motor current by influencing the output frequency and the motor voltage (I-max controller).
I_max controller
Requirements
The torque of the motor must decrease at lower speeds, which is the case, for example, with
fans.
The load must not drive the motor continuously, e.g. when lowering hoisting gear.
Function
The I-max controller influences the output frequency and the motor voltage.
If the motor current reaches the current limit during acceleration, the I-max controller extends
the acceleration operation.
SIMATIC ET 200pro FC-2 converter
Operating Instructions, 04/2015, FW V4.7.3, A5E34257324B AB
Description
.00 1 signal: Activate motor temperature model 1 (I2t) for permanently excited
synchronous motors
.01 1 signal: Activate motor temperature model 2 for asynchronous motors
.02 1 signal: Activate motor temperature model 3 for 1FK7 encoderless synchro-
nous motors
.09 1 signal: Activate motor temperature model 2 expansions
Mot_temp_mod 1 (I2t) Interference threshold (factory setting: 180 °C)
Interference threshold for monitoring the motor temperature in motortemperature
model 1.
After exceeding the interference threshold, the converter reports fault F07011.
Identification of stator resistance (Rs) when switched on again (factory setting: 0)
The converter measures the current stator resistance and from this calculates the
current motor temperature as the start value of the thermal motor model.
0: No Rs identification
1: Rs identification on first switching on the motor
2: Rs identification each time the motor is switched on
Motor excitation time for Rs_ident on switching on again
The converter sets the parameter value to the corresponding result of the motor data
identification.
Motor ambient temperature during commissioning (factory setting: 20 °C)
Motor ambient temperature given in °C at the time of motor data identification.
Setting functions
8.6 Protection and monitoring functions
139