Danfoss VLT 3500 Drive

Danfoss VLT 3500 Drive Fault Codes:

Fault Code and MeaningCause and Remedy
Error code 1
Inverter Fault (INVERT FAULT)
Cause: There is a fault on the power side of the drive.

Remedy:

  • Check the power section of the drive.

  • Contact service if the issue persists.
Error code 2
Overvoltage (OVER VOLTAGE)
Cause: The DC bus voltage is above the overvoltage limit of the drive.

Remedy:

  • Check for high mains voltage.

  • Check for deceleration times that are too short (regenerative energy).

  • Refer to the voltage limit table in the manual.
Error code 3
Undervoltage (UNDER VOLTAGE)
Cause: The DC bus voltage is below the undervoltage limit of the drive.

Remedy:

  • Check the input supply voltage.

  • Check for phase loss.

  • Refer to the voltage limit table in the manual.
Error code 4
Overcurrent (OVER CURRENT)
Cause: The peak current limit of the inverter (approx. 250% of rated current) has been exceeded for more than 7 to 11 seconds. This causes a Trip Locked fault.

Remedy:

  • Remove and reapply AC power to reset (Trip Locked).

  • Check for short circuits or motor issues.

  • Check if the load is too heavy.
Error code 5
Ground Fault (GROUND FAULT)
Cause: There is a current path from the output phases to the ground, either in the wiring between the drive and the motor, or within the motor.

Remedy:

  • This causes a Trip Locked fault (requires power cycle to reset).

  • Check the motor wiring for ground faults.

  • Check the motor insulation.
Error code 6
Overtemperature (OVER TEMP)
Cause: Too high a temperature has been measured within the drive.

Remedy:

  • Allow a cool-down period before resetting.

  • Check the ambient temperature and ventilation.

  • This causes a Trip Locked fault.
Error code 7
Inverter Overloaded (OVERLOAD)
Cause: The electronic thermal inverter protection reports that the drive has tripped because of overload (too high a current for too long). The counter has reached 100%.

Remedy:

  • Reduce the load on the motor/drive.

  • Check parameter settings related to limits.
Error codes 8 and 15
Motor Overloaded (MOTOR TRIP)
Cause: The motor electronic thermal relay (ETR) protection reports that the motor is too hot.

Remedy:

  • Ensure “Trip” is selected in parameter 315 for this alarm to activate.

  • Check motor cooling and load.
Error code 9
Current Limit (CURRENT LIMIT)
Cause: The motor current has exceeded the value of parameter 209 for a longer time than that permitted in parameter 310.

Remedy:

  • Check the load on the motor.

  • Adjust Current Limit (param 209) or time delay (param 310) if appropriate.
KEY DISABLED
Prohibited Parameter Change
Cause: An attempt is made to change a parameter when Factory Setup has been selected in parameter 001.

Remedy:

  • Change parameter 001 to setup 1, 2, 3, or 4 to allow changes.
ONLY IN STOP
Prohibited Function Change
Cause: An attempt is made to change data that cannot be changed while the drive is running.

Remedy:

  • Press Stop/Reset to stop the drive.

  • Change the parameter.
LOCK OPEN
Keypad Lockout
Cause: An attempt is made to change a parameter, but the mechanical keypad lockout is open.

Remedy:

  • Switch pin 01 must be closed before any parameter is changed.
LIMIT
Range Limit
Cause: A parameter is being changed and one end of the permissible range has been reached.

Remedy:

  • Do not exceed the minimum or maximum values defined for the parameter.
VOLTAGE LOW
Low Voltage Warning
Cause: The DC bus voltage is below the warning limit. The inverter is still operating.

Remedy:

  • Monitor mains supply voltage.
VOLTAGE HIGH
High Voltage Warning
Cause: The DC bus voltage is above the warning limit. The inverter is still operating.

Remedy:

  • Monitor mains supply voltage.

  • Check for regenerative energy from the load.
REF FAULT
Reference Fault
Cause: An analog input signal with a “live zero” (e.g., 4-20 mA, 1-5 V) is below half the minimum level.

Remedy:

  • Check the signal source and wiring to terminal 53 or 60.
NO MOTOR
No Motor
Cause: The motor check function in parameter 313 detects that no motor has been connected to the drive’s output.

Remedy:

  • Check motor connections.
LO FREQ WARN
Low Frequency Warning
Cause: The output frequency is lower than the value selected in parameter 210.

Remedy:

  • Check process requirements or adjust parameter 210.
HI FREQ WARN
High Frequency Warning
Cause: The output frequency is higher than the value selected in parameter 211.

Remedy:

  • Check process requirements or adjust parameter 211.
LO CURR WARN
Low Current Warning
Cause: The output current is lower than the value selected in parameter 212.

Remedy:

  • Check for load loss (e.g., broken belt).

  • Adjust parameter 212.
HI CURR WARN
High Current Warning
Cause: The output current is higher than the value selected in parameter 213.

Remedy:

  • Check for mechanical binding or high load.

  • Adjust parameter 213.
NO 24 VOLT
24 V Fault
Cause: The 24 V DC supply to the control card is not present.

Remedy:

  • Check the internal power supply or external 24V inputs.
EEPROM ERROR
EEPROM Fault
Cause: EEPROM fault. Data changes are not saved when AC power is removed.

Remedy:

  • Cycle power.

  • If the fault persists, the control card may require replacement.
Start-up Test (CONTROL CARD FAULT)
Control card problem
Cause: The drive carries out a self-test when AC power is applied. This message indicates a control card problem.



Remedy:

  • Contact a Danfoss service center.
Inverter Fault
Power section defective
Cause: An operational problem caused the Inverter to fault trip to protect itself or the motor. The power section of the drive is defective.



Remedy:

  • The cause of the fault must be found and eliminated.
Overvoltage
DC bus voltage too high
Cause: The voltage in the DC bus is too high. Possible causes include:

  • Input voltage too high.

  • Transients on the input.

  • Regenerative motor operation (energy returned to drive during deceleration).




Remedy:

  • If caused by deceleration, extend ramp time using parameters 216 and 218.
Undervoltage
DC bus voltage too low
Cause: The voltage of the DC bus is too low. Possible causes include:

  • Input voltage too low.

  • Failure of the charging circuit/rectifier of the drive.




Remedy:

  • Check the input line voltage before calling for service.
Overcurrent
Rectifier peak current exceeded
Cause: Upper limit of the rectifier peak current has been exceeded, possibly because of a short circuit in the output of the drive.



Remedy:

  • Check for an output short circuit before calling for service.
Ground Fault
Ground fault on drive output
Cause: Indicates a ground fault on the drive’s output. Possible causes include:

  • Motor or motor wiring problems.

  • Motor wiring is too long (over 1,000 feet).




Remedy:

  • Check motor and motor wiring.

  • Ensure wiring is as short as possible.

  • Reduce output carrier frequency to 4.5 kHz or lower.
Critical Temperature
Internal temperature too high
Cause: The temperature inside the drive is too high. Possible causes include:

  • Ambient temperature is above 104°F (40°C).

  • The heat sink of the drive is dirty or obstructed.

  • The fan(s) is not operating.

  • The drive is not mounted vertically directly against a solid surface.
Overload
Electronic thermal overload protection tripped
Cause: The motor has consumed more than 110% of the rated current of the drive for too long.



Remedy:

  • Reduce the motor load.

  • If not possible, the application may require a larger drive.

  • Ensure the motor is not overloaded before installing a larger drive.
Motor Trip
Motor electronic thermal relay (ETR) active
Cause: Current consumed by the motor at low speed has been too high for too long (loaded excessively at low speed).



Remedy:

  • Try to reduce the load at low speed.

  • Make the motor run at a higher speed.

  • Replace motor with a larger one or provide extra cooling.

  • Note: Protection can be turned off in parameter 315 (risk of burning up motor).