Advanced commissioning
7.5 Motor control
Converter with control units CU250D-2
146
Operating Instructions, 04/2015, FW V4.7.3, A5E34261542B AB
Requirements
●
Set the ramp-up time of the ramp-function generator to a value 1 s (< 1 kW) … 10 s
(> 10 kW), depending on the power rating of the motor .
●
Increase the starting current in steps of
≤
5 %. Excessively high values in p1310 ... p1312
can cause the motor to overheat and switch off (trip) the inverter due to overcurrent.
If the message A07409 appears, you must not increase any of the parameters.
Procedure
Proceed as follows to set the voltage boost:
1.
Switch off the motor with a setpoint of just a few revolutions per minute.
2.
Check whether the motor rotates smoothly.
3.
If the motor rotates eccentrically or even stops, increase the voltage boost p1310 until the
motor rotates smoothly.
4.
Accelerate the motor to the maximum speed with maximum load.
5.
Check whether the motor is following the setpoint.
6.
If necessary, increase the voltage boost p1311 until the motor accelerates without
problem.
In applications with a high break loose torque, you must additionally set parameter p1312
higher to achieve a satisfactory response.
You have set the voltage boost.
Parameter Description
p1310
Starting current (voltage boost) permanent (factory setting 50 %)
Compensates for voltage drops caused by long motor cables and the ohmic losses in
the motor.
p1311
Starting current (voltage boost) when accelerating (factory setting 0 %)
Provides additional torque when the motor accelerates.
p1312
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").
You will find more information on this function in the parameter list and in function diagram
6301 in the List Manual.