Danfoss VLT AQUA Operating Instructions Manual

Also see for vlt aqua: Instructions Design guide Instruction manual Operating instructions Design guide

flow condition and activate Sleep Mode, the action takesplace at raising edge of the external signal applied(otherwise the frequency converter would never come outof Sleep Mode again as the signal would be steadyconnected).Implementation and configuration of Sleep Mode dependson the hardware configuration and the requirements.2.3.1 Basic Cascade ControllerFor Basic Cascade applications can be used and configuredexactly as it is described for single pump applications inthe Programming Guide. See descriptions of the parametergroups 22-2*, 22-3* and 22-4* for further details.Low Speed Detection as well as Low Power Detection incombination with the timers for minimum run time,minimum sleep time and the boost feature are supported.The feedback from the pressure transducer is monitoredand when this pressure has dropped with a set percentagebelow the normal set point for pressure (22-44 Wake-upRef./FB Difference), the motor will ramp up again andpressure will be controlled for reaching the set value.2.3.2 Master/Follower and Mixed PumpConfigurationsIn multiple drive applications two different ways of theSleep Mode can be used.It is possible to use the Sleep Mode as it is described forthe Basic Cascade Controller. For this configuration it isessential, that the drive with the cascade controller optionis the last drive running after de-staging. This is achievedby giving the connected pump the highest priority in theparameters for runtime balancing ( e.g. by programmingthe drive with the MCO 101 or the MCO 102 as ”BalancedPriority 1” and all other drives/pumps as ”Balanced Priority2” in 27-16 Runtime Balancing).The other way makes usage of the Stage Off speeds inparameter group 27-3* Staging Speed. This method requiresno special priority settings and therefore allows thebalancing of the running hours for all pumps.In the following example the Sleep Mode in a Master/Follower application is entered at 30 Hz.Stage ON [Hz] Stage OFF [Hz]Stage 1 48.5 (i.e. parameter 2732.1) 30 (i.e. parameter 2734.1)Stage 2 48.5 (i.e. parameter 2732.2) 40 (i.e. parameter 2734.2)Stage 3 48.5 (i.e. parameter 2732.3) 42 (i.e. parameter 2734.3)Table 2.4This mode is activated by programming the correspondingspeed in 27-33 Stage Off Speed [RPM] or 27-34 Stage OffSpeed [Hz] respectively.The value for this speed has to be higher than theminimum speed in 4-11 Motor Speed Low Limit [RPM] or4-12 Motor Speed Low Limit [Hz].The value for the override limit in 27-21 Override Limitcauses the frequency converter to wake-up again. Thevalue is entered as a % of the Maximum Reference asprogrammed in 3-03 Maximum Reference.See also 6 Configuration Examples for further details andthe entire description of the required programming stepsfor a Master/Follower application.Application Types VLT® AQUA Drive MCO 101/MCO 102MI38C402 - VLT® is a registered Danfoss trademark 112 2