Danfoss VLT Series Programming Manual

Also see for VLT series: Service manual Installation guide Operating instructions Operating instructions Service manual

Contents

Danfoss VLT Series Programming Manual Manual pdf 178 page image

3.23 Main Menu - Cascade Controller - Group 25Parameters for configuring the Basic Cascade Controller for sequence control of multiple pumps. For a more applicationoriented description and wiring examples, see Chapter Application Examples, item Basic Cascade Controller in the DesignGuide, MG20NXYY.To configure the Cascade Controller to the actual system and the desired control strategy, it is recommended to follow thebelow sequence, starting with parameter group 25-0* System Settings and next parameter group 25-5* Alternation Settings.These parameter can normally be set in advance.Parameters in 25-2* Bandwidth Settings and 25-4* Staging settings, will often be dependent on the dynamic of the systemand final adjustment to be done at the commissioning of the plant.NOTEThe Cascade Controller is supposed to operate in closed loop controlled by the built-in PI controller (Closed Loop selectedin 1-00 Configuration Mode). If Open Loop is selected in 1-00 Configuration Mode, all fixed speed pumps will be destaged, butthe variable speed pump will still be controlled by the frequency converter, now as an open loop configuration:130BA279.122 32Off AtstagingAtcommandAt stagingorcommandExternalAlt. timerintervalP 25-52SleepmodePredefinedtimerP 25-54Disabled EnabledSlow QuickNo YesDisabled EnabledDirect on lineEnabledDisabledCascade controller (P 25-00):Number of pumps (P 25-06):Motor start (P 25-02):Pump cycling (P 25-04):Fixed lead pump (P 25-05):Lead pump alternation (P 25-50):Alternation Event (P 25-51):Alt. if capacity<50% (P 25-55):Staging mode at alternation (P 25-56):Config. of cascade controllerSoft StarterConfiguration mode (P 1-00): Open Loop Closed LoopParameter Description VLT® HVAC Drive Programming GuideMG.11.CC.02 - VLT® is a registered Danfoss trademark 1773 3