Danfoss MCO 101 Manual
                                                   | |
Contents
| 
DO DIDIDO DIDIPin 27 Pin 29Pin 294.1.4 Closed-loop ControlThe master drive is the primary controller for the system. It monitors the output pressure, adjusts the speed of the adjustable frequency drives anddecides when to add or remove stages. To perform this function the master drive must be set up in closed-loop mode with a feedback sensor connectedto an analog input of the drive.The PID controller of the master drive must be set up to match the needs of the installation. Setting up the PID parameters is described in theVLT AQUADrive Programming Guide and will not be covered in this manual. Please also refer to the application note Master/Follower Operation included in thismanual.4.1.5 Staging /De-staging of Variable Speed Pumps Based on Drive SpeedIn master/follower configurations and mixed-pump configurations, the variable speed pumps are staged and de-staged based on the speed of the drives.Staging occurs when the speed of the drives has reached the value in parameter 27-31 (27-32) Stage on Speed. At this speed the system pressure is stillmaintained, but the pumps begin to operate outside of their peak efficiency points. Staging on an additional pump will lower the speed of all of the runningpumps and provide a more energy efficient operation.De-staging occurs when the speed of the drives drops below the value in parameter 27-33 (27-34) Stage Off Speed. At this speed the system pressureis still maintained, but the pumps begin to operate below their peak efficiency points. De-staging a pump will cause the speed of the drives to increaseto a more energy-efficient range.Parameters 27-31 (27-32) Stage on Speed and 27-33 (27-34) Stage Off Speed are installation dependent. These parameters are indexed parameterswith one set of entries for each pump stage.The stage on and de-stage off speed can be auto-tuned during automation or set manually. If auto-tune is enabled, the system will start operation usingdefault settings or the pre-settings set by the user in P27-31 (27-32) and 27-33 (27-34) before enabling auto-tune.The goal is to find the stage on and off speeds where the system is most energy efficient. See the drawing below.4 Configuring the SystemExtended and Advanced Cascade ControllerOption4-2 MI.38.C2.22 - VLT® is a registered Danfoss trademark4 |
Related manuals for Danfoss MCO 101
manualsdatabase
Your AI-powered manual search engine