VLT ® 2900 Series 0.0 - 300.0% 0 - 100% of max. DC brake voltage 0% 100.0% In this parameter, the DC brake voltage is set which is to be activated at stop when the DC brake frequency set in parameter 127 DC brake cut-in frequency is reached, or if DC braking inverse is active via a digital input or via serial communication. Subsequently, the DC brake voltage will be active for the time set in pa- rameter 126 DC brake time . In this parameter, the load characteristic is set. By in- creasing the load compensation, the motor is given an extra voltage and frequency supplement at increasing loads. This is used e.g.
in motors/applications in which there is a big difference between the full-load current and idle-load current of the motor. NB! If this value is set too high, the frequency converter may cut out because of over- current. To be set as a percentage value of the max. DC brake voltage, which depends on the motor. If the factory setting is not adequate, load compensa- tion must be set to enable the motor to start at the given load. 0.00 - 100.00 V Warning: Should be set to 0% in connec- tion with synchronous and parallel-cou- pled motors and in the case of quick load changes. Too high load compensation may lead to instability.
Depends on unit A higher start torque can be obtained by increasing the start voltage. Small motors ( a high start voltage. 0.00 - 20.00 at Hz Depends on unit This parameter enables a shift in the ratio between output voltage (U) and output frequency (f) linearly, so as to ensure correct energizing of the motor and thus optimum dynamics, accuracy and efficiency. The U/f- ratio only affects the voltage characteristic if a selec- tion has been made of Constant torque [1] parameter 101 Torque characteristic. The factory setting will be suitable for must applica- tions, the value may need to be increase gradually for high torque application.
The U/f-ratio is only to be changed if it is not possible to set the correct motor data in parameter 102-109. The value programmed in the factory settings is based on idle operation. Warning: If the use of start voltage is ex- aggerated, this may lead to over-energiz- ing and overheating of the motor and the frequency converter may cut out. = factory setting, () = display text, [] = value for use in communication via serial communication port 26 MG.29.A3.02 - VLT ® is a registered Danfoss trademark 134 Load compensation (LOAD COMPENSATIO) Value: 132 DC brake voltage (DC BRAKE VOLTAGE) Value: Function: Function: Description of choice: Description of choice:
133 Start voltage (START VOLTAGE) Value: Function: 135 U/f-ratio (U/f RATIO) Value: Function: Description of choice: Description of choice: