Danfoss VLT FC 100 Service Manual

Also see for VLT FC 103: Service guide Installation guide Installation guide Operating guide Installation guide

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Danfoss VLT FC 100 Service Manual Manual pdf 51 page image

Ensure that the parameters previously mentioned areprogrammed correctly and that any digital inputprogrammed for Stop Inverse is high (logic “1”).Display indication that the unit is functioning, but nooutputIf the unit is equipped with an external 24 V DC option,check that line power is applied to the adjustablefrequency drive.NOTICE!Note: In this case, the LCP display shows [8] DC undervolt4.5.4 Incorrect Motor OperationOccasionally, there is a fault where the motor continues torun but not in the correct manner. There can be a numberof different causes for this type of fault. The following is alist of possible problems and recommended procedures fordetermining their causes.Wrong speed/unit does not respond to commandPossible incorrect reference (speed command).Ensure that the unit is programmed correctly according tothe reference signal being used, and that all referencelimits are set correctly as well. Perform chapter 6.4.14 InputTerminal Signal Tests to check for faulty reference signals.Motor speed unstablePossible incorrect parameter settings, faulty currentfeedback circuit, loss of motor (output) phase.Check the settings of all motor parameters, including allmotor compensation settings (slip compensation, loadcompensation, and so on). For closed-loop operation,check PID settings. Perform the chapter 6.4.14 InputTerminal Signal Tests to check for faulty reference signals.Perform the chapter 6.4.9 Output Imbalance of MotorVoltage and Current to check for loss of motor phase.Motor runs roughPossible over-magnetization (incorrect motor settings), oran IGBT misfiring.NOTICE!Other symptoms include motor stalling when loaded orthe adjustable frequency drive tripping on Alarm 13.Check setting of all motor parameters. Perform thechapter 6.4.9 Output Imbalance of Motor Voltage andCurrent.If output voltage is unbalanced, perform thechapter 6.4.11 IGBT Gate Drive Signals Test.Motor draws high current but cannot startPossible open winding in the motor or open phase inconnection to the motor.Perform the chapter 6.4.9 Output Imbalance of MotorVoltage and Current to ensure that the adjustablefrequency drive is providing correct output (See Motorruns rough).Run an AMA to check the motor for open windings andunbalanced resistance. Inspect all motor wiringconnections.Motor will not brake.Possible fault in the brake circuit. Possible incorrect settingin the brake parameters. The ramp-down time is too short.Note: An alarm or warning message may occur.Check all brake parameters and ramp-down time(parameter group 2–0* and 3–4*).Perform chapter 6.3.4 Brake IGBT Test.4.6 Warning/Alarm Messages4.6.1 Warning/Alarm Code ListA code on the display or the LEDs on the front of theadjustable frequency drive signal a warning/alarm.A warning indicates a condition that requires attention ora potentially alarming trend. A warning remains activeuntil the cause is no longer present. Under some circum-stances, motor operation may continue.A trip is the action when an alarm has appeared. The tripremoves power to the motor. Reset it after the conditionhas been cleared by pressing [Reset] or through a digitalinput (parameter group 5–1*). The event that caused analarm cannot damage the adjustable frequency drive orcause a dangerous condition. Alarms must be reset torestart operation once their cause has been rectified.There are three ways to reset:1. Pressing [Reset].2. A digital reset input.3. Serial communication/optional serial communi-cation bus reset signal.NOTICE!After a manual reset pressing [Reset], [Auto On] must bepressed to restart the motor.A trip lock is an action when a potentially damaging alarmoccurs. Power is removed from the motor. A trip lock canonly be reset after the condition is cleared by cyclingpower. Once the problem has been rectified, only thealarm continues flashing until the adjustable frequencydrive is reset.Troubleshooting Service ManualMG94A222 Danfoss A/S © Rev. 2014-02-10 All rights reserved. 494 4