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 33 page image

Use the three additional and independent controllers forcontrolling other process equipment, such as chemical feedpumps, valve control or for aeration with different levels.2.6.5 Automatic RestartThe adjustable frequency drive can be programmed toautomatically restart the motor after a minor trip, such asmomentary power loss or fluctuation. This featureeliminates the need for manual resetting and enhancesautomated operation for remotely controlled systems. Thenumber of restart attempts as well as the durationbetween attempts can be limited.2.6.6 Flying StartFlying start allows the adjustable frequency drive tosynchronize with an operating motor rotating at up to fullspeed, in either direction. This prevents trips due toovercurrent draw. It minimizes mechanical stress to thesystem since the motor receives no abrupt change inspeed when the adjustable frequency drive starts.2.6.7 Full Torque at Reduced SpeedThe adjustable frequency drive follows a variable V/Hzcurve to provide full motor torque even at reduced speeds.Full output torque can coincide with the maximumdesigned operating speed of the motor. This is unlikevariable torque drives that provide reduced motor torqueat low speed, or constant torque drives that provide excessvoltage, heat, and motor noise at less than full speed.2.6.8 Frequency BypassIn some applications, the system may have operationalspeeds that create a mechanical resonance. This cangenerate excessive noise and possibly damage mechanicalcomponents in the system. The adjustable frequency drivehas four programmable bypass-frequency bandwidths.These allow the motor to step over speeds that inducesystem resonance.2.6.9 Motor PreheatTo preheat a motor in a cold or damp environment, a smallamount of DC current can be trickled continuously into themotor to protect it from condensation and a cold start.This can eliminate the need for a space heater.2.6.10 Four Programmable Set-upsThe adjustable frequency drive has four set-ups that canbe independently programmed. Using multi-setup, it ispossible to switch between independently programmedfunctions activated by digital inputs or a serial command.Independent set-ups are used, for example, to changereferences, or for day/night or summer/winter operation, orto control multiple motors. The active set-up is displayedon the LCP.Set-up data can be copied from adjustable frequency driveto adjustable frequency drive by downloading theinformation from the removable LCP.2.6.11 Dynamic BrakingDynamic Brake is established by:• Resistor brakeA brake IGBT keeps the overvoltage under acertain threshold by directing the brake energyfrom the motor to the connected brake resistor(2-10 Brake Function = [1]).• AC brakeThe brake energy is distributed in the motor bychanging the loss conditions in the motor. TheAC brake function cannot be used in applicationswith high cycling frequency since this overheatsthe motor (2-10 Brake Function = [2]).2.6.12 DC BrakingSome applications may require braking a motor to slow orstop it. Applying DC current to the motor brakes the motorand can eliminate the need for a separate motor brake. DCbraking can be set to activate at a predeterminedfrequency or upon receiving a signal. The rate of brakingcan also be programmed.2.6.13 Sleep ModeSleep mode automatically stops the motor when demandis low for a specified period of time. When the systemdemand increases, the drive restarts the motor. Sleepmode provides energy savings and reduces motor wear.Unlike a setback clock, the drive is always available to runwhen the preset wake-up demand is reached.2.6.14 Run PermissiveThe drive can wait for a remote system ready signal beforestarting. When this feature is active, the drive remainsstopped until receiving permission to start. Run permissiveProduct Overview Design GuideMG20N622 Danfoss A/S © 09/2014 All rights reserved. 312 2