Danfoss VLT AQUA Drive FC 202 Design Manual

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

Contents

Danfoss VLT AQUA Drive FC 202 Design Manual Manual pdf 36 page image

2.7.2 High and Low Reference WarningIn open-loop operation, the reference signal directlydetermines the speed of the drive. The display shows aflashing reference high or low warning when theprogrammed maximum or minimum is reached.2.7.3 High and Low Feedback WarningIn closed-loop operation, the selected high and lowfeedback values are monitored by the drive. The displayshows a flashing high or flashing low warning whenappropriate. The drive can also monitor feedback signals inopen-loop operation. While the signals do not affect theoperation of the drive in open-loop, they can be useful forsystem status indication locally or via serial communi-cation. The adjustable frequency drive handles 39 differentunits of measure.2.7.4 Phase Imbalance or Phase LossExcessive ripple current in the DC bus indicates either aline phase imbalance or phase loss. When a power phaseto the drive is lost, the default action is to issue an alarmand trip the unit to protect the DC bus capacitors. Otheroptions are to issue a warning and reduce output currentto 30% of full current or to issue a warning and continuenormal operation. Operating a unit connected to animbalanced line may be desirable until the imbalance iscorrected.2.7.5 High Frequency WarningUseful in staging on additional equipment such as pumpsor cooling fans, the drive can warm when the motor speedis high. A specific high frequency setting can be enteredinto the drive. If the output exceeds the set warningfrequency, the unit displays a high frequency warning. Adigital output from the drive can signal external devices tostage on.2.7.6 Low Frequency WarningUseful in staging off equipment, the drive can warn whenthe motor speed is low. A specific low frequency settingcan be selected for warning and to stage off externaldevices. The unit will not issue a low frequency warningwhen it is stopped nor upon start up until after theoperating frequency has been reached.2.7.7 High Current WarningThis function is similar to high frequency warning, except ahigh current setting is used to issue a warning and stageon additional equipment. The function is not active whenstopped or at start up until the set operating current hasbeen reached.2.7.8 Low Current WarningThis function is similar to low frequency warning (seechapter 2.7.6 Low Frequency Warning), except a low currentsetting is used to issue a warning and stage off equipment.The function is not active when stopped or at start upuntil the set operating current has been reached.2.7.9 No Load/Broken Belt WarningThis feature can be used for monitoring a no-loadcondition, for example a V-belt. After a low current limithas been stored in the converter, if loss of the load isdetected, the drive can be programmed to issue an alarmand trip or to continue operation and issue a warning.2.7.10 Lost Serial InterfaceThe adjustable frequency drive can detect loss of serialcommunication. A time delay of up to 99 s is selectable toavoid a response due to interruptions on the serialcommunications bus. When the delay is exceeded, optionsavailable include for the unit to:• Maintain its last speed.• Go to maximum speed.• Go to a preset speed.• Stop and issue a warning.2.8 User Interfaces and ProgrammingThe adjustable frequency drive uses parameters forprogramming its application functions. Parameters providea description of a function and a menu of options to eitherselect from or for entering numeric values. A sampleprogramming menu is shown in Figure 2.23.Product Overview VLT® AQUA Drive FC 20234 Danfoss A/S © 09/2014 All rights reserved. MG20N62222