VLT ® 2900 Series deviation between the reference/setpoint and the ac- tual process mode. If the frequency converter is to reduce the output fre- quency in case the feedback signal increases, select Normal [0].If the frequency converter is to increase the output frequency in case the feedback signal increa- ses, select Inverse [1]. f MIN - f MAX (parameter 201/202) Par. 201 Output fre- quency, low limit, f MIN When the start signal comes, the frequency converter will react in the form of Open loop and will not change to Closed loop until the programmed start frequency is reached.
This makes it possible to set a frequency that corresponds to the speed at which the process nor- mally runs, which will enable the required process conditions to be reached sooner. Not active (DISABLE) [0] Active (ENABLE) [1] Set the required start frequency. It is possible to select whether the process regulator is to continue regulating on a deviation even if it is not possible to increase/reduce the output frequency. NB! If the frequency converter is running a the current limit before the required start fre- quency is obtained, the process regulator will not be activated. For the regulator to be activated anyway, the start frequency must be lower to the required output fre- quency.
This can be done during opera- tion. The factory setting is Enable [1], which means that the integration link is initialised in relation to the actual out- put frequency if either the current limit, the voltage limit or the max./min. frequency has been reached. The process regulator will not engage again until either the error is zero or its sign has changed. Select Disable [0] if the integrator is to continue integrating on the devi- ation, even if it is not possible to remove the fault by such control. 0.0 - 10.00 0.01 NB!
If Disable [0] is selected, it will mean that when the deviation changes its sign, the integrator will first have to integrate down from the level obtained as a result of the former error, before any change in output frequency occurs. The proportional gain indicates the number of times the deviation between the setpoint and the feedback signal is to be applied. Quick regulation is obtained by a high gain, but if the gain is too high, the process may become unstable due to overshoot.
0.01 - 9999.99 (OFF) OFF = factory setting, () = display text, [] = value for use in communication via serial communication port 50 MG.29.A3.02 - VLT ® is a registered Danfoss trademark 439 Process PID start frequency (PROC START VALUE) Value: Description of choice: Function: 438 Proces PID anti windup (proc anti windup) Value: Description of choice: Function: Description of choice: 440 Proces PID proportioanl gain (PROC. PROP. GAIN) Value: Function: Description of choice: 441 Process PID integration time (PROC. INTEGR. T.) Value: