Danfoss VLT FCM Series Manual

Also see for VLT FCM 305: Quick setup

Contents

VLT ® FCM SeriesProgramming437 Process PID Normal/inverse control(PROC NO/INV CTRL)Value:✭Normal (NORMAL) [0]Inverse (INVERSE) [1]Function:It is possible to choose whether the processregulator is to increase/reduce the output frequencyif there is a difference between the referencesignal and the feedback signal.Used together with Process, closed loopmode (parameter 100).Description of choice:If the FC motor is to reduce the output frequency incase the feedback signal increases, select Normal [0].If the FC motor is to increase the output frequency incase the feedback signal increases, select Inverse [1].438 Process PID anti windup(PROC ANTI WINDUP)Value:Disable (DISABLE) [0]✭Enable (ENABLE) [1]Function:It is possible to select whether the process regulator isto continue regulating on an error even if it is not possibleto increase/reduce the output frequency. Used togetherwith Process, closed loop mode (parameter 100).Description of choice:The factory setting is Enable [1], which means thatthe integration link is adjusted in relation to theactual output frequency if either the current limit orthe max./ min. frequency has been reached. Theprocess regulator will not engage again until eitherthe error is zero or its sign has changed.Select Disable [0] if the integrator is to continueintegrating on an error, even if it is not possible toremove the fault by such regulation.NB!:If Disable [0] is selected, it will mean that whenthe error changes its sign, the integrator willfirst have to integrate down from the levelobtained as a result of the former error, before anychange to the output frequency occurs.439 Process PID start frequency(PROC START VALUE)Value:f MIN -f MAX (PARAMETER 201 AND 202) [X.X]✭parameter 201Function:When the start signal comes, the FC motor will reactin the form of Speed, open loop mode following theramp. Only when the programmed start frequencyhas been obtained, will it change over to Process,closed loop mode. In addition, it is possible to set afrequency that corresponds to the speed at which theprocess normally runs, which will enable the requiredprocess conditions to be reached sooner.Used together with Process, closed loopmode (parameter 100).Description of choice:Set the required start frequency.NB!:If the FC motor is running at the current limitbefore the desired start frequency is obtained,the process regulator will not be activated.For the regulator to be activated anyway, the startfrequency must be lowered to the required outputfrequency. This can be done during operation.440 Process PID proportional gain(PROC. PROP. GAIN)Value:0.00 (OFF) - 10.00 [0 - 1000]✭0.01 [1]Function:The proportional gain indicates the number oftimes the error between the set point and thefeedback signal is to be applied.Used together with Process, closed loopmode (parameter 100).Description of choice:Quick regulation is obtained by a high gain, but if thegain is too high, the process may become unstable.441 Process PID integral time(PROC. INTEGR. T.)Value:0.01 - 9999 sec. (OFF) [1 - 999900]✭9999 sec. [999900]✭ = factory setting. () = display text [] = value for use in communication via serial communication portMG.03.H3.02 - VLT is a registered Danfoss trademark 65