Danfoss vlt FC 102 Operating Instructions Manual

Also see for VLT HVAC Drive FC 102: Operating instructions Service guide Programming guide Installation guide Installation guide

20-20 Feedback FunctionThis parameter determines how the three possible feedbacks will be used to control the output frequency of thefrequency converter.[0] SumSum [0] sets up the PID Controller to use the sum of Feedback 1, Feedback 2 and Feedback 3 asthe feedback.NB!Any unused feedbacks must be set toNo Function in par. 20-00, 20-03, or 20-06.The sum of Setpoint 1 and any other references that are enabled (see par. group 3-1*) will be usedas the PID Controller’s setpoint reference.[1] DifferenceDifference [1] sets up the PID Controller to use the difference between Feedback 1 and Feedback 2as the feedback. Feedback 3 will not be used with this selection. Only setpoint 1 will be used. Thesum of Setpoint 1 and any other references that are enabled (see par. group 3-1*) will be used asthe PID Controller’s setpoint reference.[2] AverageAverage [2] sets up the PID Controller to use the average of Feedback 1, Feedback 2 and Feedback3 as the feedback.NB!Any unused feedbacks must be set toNo Function in par. 20-00, 20-03, or 20-06.The sum of Setpoint 1 and any other references that are enabled (see par. group3-1*) will be used as the PID Controller’s setpoint reference.[3] * MinimumMinimum [3] sets up the PID Controller to compare Feedback 1, Feedback 2 and Feedback 3 anduse the lowest value as the feedback.NB!Any unused feedbacks must be set toNo Function in par. 20-00, 20-03, or 20-06.Only setpoint 1 will be used. The sum of Setpoint 1 and any other references thatare enabled (see par. group 3-1*) will be used as the PID Controller’s setpointreference.[4] MaximumMaximum [4] sets up the PID Controller to compare Feedback 1, Feedback 2 and Feedback 3 anduse the highest value as the feedback.NB!Any unused feedbacks must be set toNo Function in par. 20-00, 20-03, or 20-06.Only Setpoint 1 will be used. The sum of Setpoint 1 and any other references that are enabled (seepar. group 3-1*) will be used as the PID Controller’s setpoint reference.[5] Multi setpoint minMulti-setpoint minimum [5] sets up the PID Controller to calculate the difference between Feedback1 and Setpoint 1, Feedback 2 and Setpoint 2, and Feedback 3 and Setpoint 3. It will use the feedback/setpoint pair in which the feedback is the farthest below its corresponding setpoint reference. If allfeedback signals are above their corresponding setpoints, the PID Controller will use the feedback/setpoint pair in which the difference between the feedback and setpoint is the least.NB!If only two feedback signals are used, the feedback that is not to be used mustbe set toNo Function in par. 20-00, 20-03 or 20-06. Note that each setpoint ref-erence will be the sum of its respective parameter value (20-11, 20-12 and 20-13)and any other references that are enabled (see par. group 3-1*).[6] Multi setpoint maxMulti-setpoint maximum [6] sets up the PID Controller to calculate the difference between Feedback1 and Setpoint 1, Feedback 2 and Setpoint 2, and Feedback 3 and Setpoint 3. It will use the feedback/setpoint pair in which the feedback is farthest above its corresponding setpoint reference. If allfeedback signals are below their corresponding setpoints, the PID Controller will use the feedback/setpoint pair in which the difference between the feedback and the setpoint reference is the least.VLT® HVAC Drive Operating Instructions 6. How to programme the frequency converterMG.11.A6.02 - VLT® is a registered Danfoss trademark 956