Danfoss VLT Midi Drive FC280 Fault Codes List

Access the complete reference guide for Danfoss VLT Midi Drive FC 280 fault codes. Learn to diagnose Safe Stop (Alarm 68), use the Memory Module for cloning, and retrofit VLT 2800 units.

Danfoss FC 280 Fault Codes Reference Table

Danfoss VLT® Midi Drive FC 280 Warnings and Alarms

Fault Code and Meaning	Cause and Remedy
2 Live zero error	Cause: Signal on terminal 53 or 54 is less than 50% of value set in parameter 6-10 Terminal 53 Low Voltage, parameter 6-12 Terminal 53 Low Current, parameter 6-20 Terminal 54 Low Voltage, and parameter 6-22 Terminal 54 Low Current. Remedy: Check the connections to terminals 53 and 54. Verify the settings of parameters 6-10, 6-12, 6-20, and 6-22. Ensure the input signal is within the expected range.
3 No motor	Cause: No motor has been connected to the output of the drive. Remedy: Ensure the motor is properly connected to the drive's output terminals (U, V, W). Check for any open connections or breaks in the motor cable.
4 Mains phase loss	Cause: Missing phase on the supply side, or the voltage imbalance is too high. This can also indicate a fault in the input rectifier. Remedy: Check the supply voltage and the supply currents to the frequency converter. Consider installing a Danfoss line filter to rectify mains distortions.
7 DC overvoltage	Cause: DC-link voltage exceeds the limit. Remedy: Check for overhauling loads or high inertia. Increase the ramp-down time. Consider installing a brake resistor.
8 DC undervoltage	Cause: DC-link voltage drops below the voltage warning low limit. Remedy: Check the mains supply for sags or interruptions. Ensure the drive is correctly sized for the application.
9 Inverter overloaded	Cause: More than 100% load for too long. Remedy: Check for mechanical binding or overload on the motor. Reduce the load on the motor. Ensure the drive is correctly sized for the application.
10 Motor ETR overtemperature	Cause: The motor is too hot due to more than 100% load for too long. Remedy: Check for motor overheating and mechanical overload. Verify that the motor current set in parameter 1-24 is correct. Ensure motor data in parameters 1-20 to 1-25 are set correctly. If an external fan is used, ensure it is selected in parameter 1-91.
11 Motor thermistor overtemperature	Cause: Thermistor or thermistor connection is disconnected, or the motor is too hot. Remedy: Check the thermistor connection. Select whether the frequency converter gives a warning or an alarm in parameter 1-90 Motor Thermal Protection.
12 Torque limit	Cause: Torque exceeds value set in either parameter 4-16 Torque Limit Motor Mode or parameter 4-17 Torque Limit Generator Mode. Remedy: Check for sudden increases in load. Adjust the torque limit parameters if necessary.
13 Overcurrent	Cause: Inverter peak current limit is exceeded. If this alarm occurs on power-up, check whether power cables are mistakenly connected to the motor terminals. Remedy: Check for short circuits in the motor or motor cable. If the fault occurs during ramp-up, extend the ramp-up time. If the fault occurs during ramp-down, extend the ramp-down time.
14 Ground fault	Cause: Discharge from output phases to ground, either in the cable or the motor. Remedy: Disconnect the motor from the drive and check if the fault persists. If the fault disappears, the issue is with the motor or cable. Use a megohmmeter to test the motor and cabling for ground faults. If the drive trips with the motor disconnected, the issue is likely a bad current sensor in the drive.
16 Short circuit	Cause: Short circuit in the motor or on motor terminals. Remedy: Power down the drive and lock out the system before troubleshooting. Disconnect the motor cable from the VFD to isolate the components. Visually inspect the motor cable and terminals for damage. Remove power to the frequency converter and repair the short circuit.
17 Control word timeout	Cause: No communication to the drive. Remedy: Check the communication cable and connections. Verify the communication settings in the drive and the master device.
25 Brake resistor short-circuited	Cause: Brake resistor is short-circuited, thus the brake function is disconnected. Remedy: Replace the brake resistor. Check the brake resistor wiring for any short circuits.
26 Brake overload	Cause: The power transmitted to the brake resistor over the last 120 s exceeds the limit. Remedy: Decrease brake energy via lower speed or longer ramp time.
27 Brake IGBT/Brake chopper short-circuited	Cause: Brake transistor is short-circuited, thus the brake function is disconnected. Remedy: The drive may need to be repaired or replaced. Contact your supplier.
28 Brake check	Cause: The brake resistor is not connected or not working. Remedy: Check the connection of the brake resistor. Ensure the brake resistor is not faulty.
30 U phase loss	Cause: Motor phase U is missing. Remedy: Check the motor connection for phase U.
31 V phase loss	Cause: Motor phase V is missing. Remedy: Remove power from the frequency converter and check motor phase V.
32 W phase loss	Cause: Motor phase W is missing. Remedy: Check the motor connection for phase W.
34 Fieldbus fault	Cause: Fieldbus communication issues have occurred. Remedy: Check the Fieldbus connections and settings. Verify the status of the Fieldbus master.
35 Option fault	Cause: Fieldbus detects internal faults. Remedy: Cycle power to the drive. If the fault persists, the option card may be faulty.
36 Mains failure	Cause: This warning/alarm is only active if the supply voltage to the drive is less than the value set in parameter 14-11 Mains Fault Voltage Level, and parameter 14-10 Mains Failure is NOT set to No Function. Remedy: Check the incoming power supply. Adjust parameter 14-11 or 14-10 if necessary.
38 Internal fault	Cause: An internal fault has occurred. Remedy: Contact the local supplier.
40 Overload T27	Cause: Check the load connected to terminal 27 or remove short-circuit connection. Remedy: Inspect the load and wiring connected to terminal 27.
46 Gate drive voltage fault	Cause: Internal power supply issue. Remedy: The drive may need to be repaired. Contact your supplier.
47 24 V supply low	Cause: 24 V DC may be overloaded. Remedy: Check the external 24V DC supply and the load connected to it.
49 Speed limit	Cause: The motor speed is below the specified limit in parameter 1-87 Trip Speed Low [Hz]. Remedy: Check for mechanical issues preventing the motor from reaching the set speed. Adjust parameter 1-87 if the lower speed is acceptable.
50 AMA calibration failed	Cause: A calibration error has occurred. Remedy: Ensure the motor is not running during AMA. Check motor data parameters. Attempt to run the AMA again.
51 AMA check Unom and Inom	Cause: Wrong setting for motor voltage and/or motor current. Remedy: Correct the motor voltage and current settings in the drive's parameters to match the motor's nameplate data.
52 AMA low Inom	Cause: Motor current is too low. Remedy: Check the motor data parameter settings. Inspect motor wiring and connections. Use a multimeter to check the motor phases.
53 AMA big motor	Cause: The power size of the motor is too large for the AMA to operate. Remedy: Ensure the drive is correctly sized for the motor.
54 AMA small motor	Cause: The power size of the motor is too small for the AMA to operate. Remedy: Ensure the drive is correctly sized for the motor.
55 AMA parameter range	Cause: The parameter values of the motor are outside of the acceptable range. AMA does not run. Remedy: Verify and correct the motor parameter settings.
56 AMA interrupt	Cause: The AMA is interrupted by the user. Remedy: For a reset, first factory reset the drive and then reprogram it. Re-run the AMA calibration.
57 AMA timeout	Cause: AMA is taking too long to complete. Remedy: Check for any issues with the motor or load that might be prolonging the AMA process. Try restarting the AMA.
58 AMA internal	Cause: Internal fault during AMA. Remedy: Contact your local supplier.
59 Current limit	Cause: Drive overload. The current is higher than the value in parameter 4-18 Current Limit. Remedy: Check for mechanical overload. Ensure that motor data in parameters 1-20 to 1-25 is set correctly.
60 External Interlock	Cause: External interlock has been activated. Remedy: Check the external interlock circuit and the reason for its activation.
61 Encoder loss	Cause: The drive is not receiving a signal from the encoder. Remedy: Check the encoder wiring and connections. Verify the encoder is functioning correctly.
63 Mechanical brake low	Cause: Actual motor current has not exceeded release brake current within the start delay time window. Remedy: Check the mechanical brake for proper operation. Adjust the brake release parameters if necessary.
65 Control card temp	Cause: The cutout temperature of the control card has exceeded the upper limit. Remedy: Check the ambient temperature and ensure proper cooling of the drive. Check for blocked fans or airflow obstructions.
67 Option change	Cause: A new option is detected or a mounted option is removed. Remedy: Cycle power to the drive to allow it to recognize the change.
68 Safe Torque Off	Cause: STO is activated. Remedy: If in manual restart mode, apply 24V DC to terminals 37 and 38 and initiate a reset. If in automatic restart mode, applying 24V DC to terminals 37 and 38 automatically resumes operation.
69 Power card temp	Cause: The cutout temperature of the power card has exceeded the upper limit. Remedy: Check for excessive load or high ambient temperature. Ensure proper ventilation and cooling of the drive.
80 Drive initialized to default value	Cause: All parameter settings are initialized to default settings. Remedy: Reprogram the drive with the correct parameter settings for your application.
87 Auto DC brake	Cause: Occurs in IT mains when the drive coasts, and the DC voltage is higher than 830 V for 400 V units and 425 V for 200 V units. The motor consumes energy on the DC link. Remedy: This function can be enabled/disabled in parameter 0-07 Auto DC Braking.
88 Option detection	Cause: The option is removed successfully. Remedy: This is an informational message. No action is required.
95 Broken belt	Cause: A broken belt has been detected. Remedy: Inspect the belt and replace it if necessary. Check the broken belt detection parameters.
99 Locked rotor	Cause: Rotor is blocked. Remedy: Check for any mechanical obstruction preventing the motor from turning.
120 Position control fault	Cause: An error has occurred in the position control. Remedy: Check the position feedback device and its wiring. Verify the position control parameters.
126 Motor rotating	Cause: PM motor is rotating when AMA is performed. Remedy: Ensure the motor has come to a complete stop before starting the AMA.
127 Back EMF too high	Cause: The back EMF of the PM motor is too high before starting. Remedy: Check for any external force rotating the motor before it starts.
188 STO internal fault	Cause: 24 V DC supply is connected to only 1 of the 2 STO terminals (37 and 38), or a failure in STO channels is detected. Remedy: Ensure that both terminals are powered by a 24 V DC supply, and that the discrepancy between the signals at the 2 terminals is less than 0.5 s. If the fault still occurs, contact the local supplier.
nw run Not while running	Cause: Parameters can only be changed when the motor is stopped. Remedy: Stop the motor before attempting to change the parameter.
Err. A wrong password was entered	Cause: Occurs when using a wrong password for changing a password-protected parameter. Remedy: Enter the correct password.

 

How to Read FC 280 Faults via LCP & Memory Module

The FC 280 brings modern connectivity to the “Midi” drive segment. In 2026, diagnostics are streamlined using these tools:

• LCP Options (Numerical vs. Graphical):
  • LCP 21 (Numerical): Standard on many units. Displays simple codes (e.g., “AL 13”).
  • LCP 102 (Graphical): You can plug in the advanced LCP 102 from an FC 302 to get full-text error descriptions and a “Help” button feature during commissioning or troubleshooting.
• VLT Memory Module (MCM 102): The FC 280 stores its firmware and parameters on a removable memory module.
  • Rapid Replacement: If a drive fails with a “Hardware Trip” (e.g., Alarm 16 Short Circuit), you can simply pull the MCM 102 module out and plug it into a new FC 280. The new drive will be up and running in seconds without needing a PC to reprogram it.
• Built-in USB Port: Unlike the older VLT 2800 which required RS-485 adapters, the FC 280 has a dedicated USB port. Connect MCT 10 software directly to view the Alarm Log and Scope real-time motor data.

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Frequently Asked Questions (FAQ)

Q: What is “Alarm 68” (Safe Stop / Safe Torque Off)?

A: The FC 280 includes dual-channel Safe Torque Off (STO).

• Alarm 68: Indicates the 24V safety signal is missing on Terminal 37 (and Terminal 38 if dual-channel is used).
• Action: Check your safety relays, door switches, or E-Stops. If STO is not required, ensure the factory jumpers are installed correctly between 24V and the safety terminals.

Q: Can I replace a VLT 2800 with an FC 280 easily?

A: Yes. The FC 280 is designed as a retrofit solution.

• Danfoss offers adapter plates to fit the FC 280 into the exact footprint of the VLT 2800.
• You can use the VLT 2800 Conversion Tool in MCT 10 software to migrate your old parameter file to the new drive automatically.

Q: How do I reset a Danfoss FC 280 fault?

A:

1. Press the Reset button on the LCP.
2. Toggle the Digital Input configured for Reset (Default is Terminal 27).
3. Trip Lock: For severe faults (Earth Fault, Short Circuit), you must disconnect mains power and wait for the LED to turn off before resetting.

Q: Why does the drive show “Warning 12” (Torque Limit)?

A: This means the motor requires more torque than the drive is allowed to deliver (based on current limits).

• Check for mechanical binding (jammed conveyor).
• Verify the Ramp Up Time is not too aggressive for the load.
• Ensure the motor data (AMA) has been performed.