Danfoss VLT AQUA Drive FC 202 Programming Manual

Also see for VLT AQUA Drive FC 202: Service guide Installation guide Installation guide Operating guide Installation guide

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25-26 Destage At No-FlowOption: Function:This parameter ensures that when a no-flowsituation occurs, the fixed speed pumps aredestaged 1 by 1 until the no-flow signaldisappears. This requires that no-flow detection isactive. See parameter group 22-2* No-FlowDetection.If [0] Disabled is selected, the cascade controllerdoes not change the normal behavior of thesystem.[0] * Disabled[1] Enabled25-27 Stage FunctionOption: Function:If the stage function is set to [0] Disabled,parameter 25-28 Stage Function Time is notactivated.[0] Disabled[1] Enabled25-28 Stage Function TimeRange: Function:15s*[0 -300 s]The stage function time is programmed to avoidfrequent staging of the fixed speed pumps. Thestage function time starts if it is [1] Enabled byparameter 25-27 Stage Function, and when thevariable speed pump runs at motor speed highlimit, parameter 4-13 Motor Speed High Limit [RPM]or parameter 4-14 Motor Speed High Limit [Hz], withat least 1 fixed speed pump in the stop position.When the programmed value of the timer expires, afixed speed pump is staged.25-29 Destage FunctionOption: Function:The destage function ensures that the lowestnumbers of pumps are running to save energy andto avoid dead head water circulation in thevariable speed pump. If the destage function is setto [0] Disabled, parameter 25-30 Destage FunctionTime is not activated.[0] Disabled[1] Enabled25-30 Destage Function TimeRange: Function:15s*[0 -300 s]The destage function timer is programmable toavoid frequent staging/destaging of the fixed speedpumps. The destage function time starts when theadjustable speed pump is running atparameter 4-11 Motor Speed Low Limit [RPM] orparameter 4-12 Motor Speed Low Limit [Hz], with 1 ormore fixed speed pumps in operation and system25-30 Destage Function TimeRange: Function:requirements satisfied. In this situation, theadjustable speed pump contributes a little to thesystem. When the programmed value of the timerexpires, a stage is removed, avoiding dead headwater circulation in the adjustable speed pump.e75za640.12(4-12)(27-27)F minF VLT pumpDestagetimer periodPumpswitch-offIllustration 3.87 Destage Function Time3.22.3 25-4* Staging SettingsParameters determining conditions for staging/destagingthe pumps.25-40 Ramp Down DelayRange: Function:10 s* [0 -120 s]When adding a fixed speed pump controlled bya soft starter or a star-delta starter, it is possibleto delay the ramp down of the lead pump untila preset time after the start of the fixed speedpump. This delay eliminates pressure surges orwater hammer in the system.Use this option only if [1] Soft Starter or [2] StarDelta is selected in parameter 25-02 Motor Start.25-41 Ramp Up DelayRange: Function:2 s* [0 -12 s]When removing a fixed speed pump controlled bya soft starter, it is possible to delay the ramp up ofthe lead pump until a preset time after the stop ofthe fixed speed pump. This delay eliminatespressure surges or water hammer in the system.Only to be used if [1] Soft Starter is selected inparameter 25-02 Motor Start.Parameter Description Programming GuideMG20OB02 Danfoss A/S © 05/2018 All rights reserved. 2113 3