Danfoss VACON NXP Air Cooled Fault Codes List

Access the complete reference guide for Danfoss VACON NXP Air Cooled drive fault codes. Learn to diagnose F1 Overcurrent subcodes, use VACON NCDrive, and troubleshoot system bus errors.

VACON NXP Fault Codes Reference Table

VACON NX All-in-One Faults and Alarms

VACON NX Fault Tracing Guide

Fault Code and Meaning Cause and Remedy
Fault 1, Subcode S1

Overcurrent - Hardware trip		 Cause: There is too high a current in the motor cable. Its cause can be 1 of the following:
  • a sudden heavy load increase
  • a short circuit in the motor cables
  • the motor is not the correct type

Remedy:

  • Check the load.
  • Check the motor.
  • Check the cables and connections.
  • Make an identification run.
Fault 1, Subcode S2

Overcurrent - Current cutter supervision (VACON® NXS)		 Cause: There is too high a current in the motor cable. Its cause can be 1 of the following:
  • a sudden heavy load increase
  • a short circuit in the motor cables
  • the motor is not the correct type

Remedy:

  • Check the load.
  • Check the motor.
  • Check the cables and connections.
  • Make an identification run.
Fault 1, Subcode S3

Overcurrent - Current limit controller supervision		 Cause: There is too high a current in the motor cable. Its cause can be 1 of the following:
  • a sudden heavy load increase
  • a short circuit in the motor cables
  • the motor is not the correct type

Remedy:

  • Check the load.
  • Check the motor.
  • Check the cables and connections.
  • Make an identification run.
Fault 1, Subcode S4

Overcurrent - Software-based overcurrent fault		 Cause: There is too high a current in the motor cable. Its cause can be 1 of the following:
  • a sudden heavy load increase
  • a short circuit in the motor cables
  • the motor is not the correct type

Remedy:

  • Check the load.
  • Check the motor.
  • Check the cables and connections.
  • Make an identification run.
Fault 2, Subcode S1

Overvoltage - Hardware trip		 Cause: The DC-link voltage is higher than the limits.
  • Too short a deceleration time
  • High overvoltage spikes in the supply
  • Start/Stop sequence too fast

Remedy:

  • Set the deceleration time longer.
  • Use the brake chopper or the brake resistor. They are available as options.
  • Activate the overvoltage controller.
  • Do a check of the input voltage.
Fault 2, Subcode S2

Overvoltage - Overvoltage control supervision		 Cause: The DC-link voltage is higher than the limits.
  • Too short a deceleration time
  • High overvoltage spikes in the supply
  • Motor load is generative
  • Start/Stop sequence too fast

Remedy:

  • Set the deceleration time longer.
  • Use the brake chopper or the brake resistor. They are available as options.
  • Activate the overvoltage controller.
  • Do a check of the input voltage.
Fault 2, Subcode S3

Overvoltage - LCL capacitor overvoltage ripple		 Cause: AFE LCL filter capacitor ripple voltage is too high.

Remedy:

  • Check the capacitance rating and measure the capacitance value of the LCL filter capacitors and make sure that the value and rating is according to specifications.
Fault 3

Earth fault		 Cause: The measurement of current tells that the sum of the motor phase current is not zero.
  • Insulation malfunction in the cables or in the motor.
  • (It is possible to set different responses in the application for this fault).

Remedy:

  • Do a check of the motor cables and the motor.
Fault 5

Charging switch		 Cause: The charging switch is open, when the START command is given.
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 6

Emergency stop		 Cause: Stop signal has been given from the option board.

Remedy:

  • Do a check of the emergency stop circuit.
Fault 7

Saturation trip		 Cause:
  • Defective component
  • Brake resistor short circuit or overload

Remedy:

This fault cannot be reset from the control panel.
  • Switch off the power.
  • DO NOT RESTART THE DRIVE OR CONNECT THE POWER!
  • Ask instructions from the factory. If this fault shows at the same time with Fault 1, do a check of the motor cable and the motor.
Fault 8, Subcode S1

System fault - ASIC phase feedback		 Cause:
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S4

System fault - ASIC trip		 Cause:
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S5

System fault - Disturbance in VaconBus		 Cause:
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S6

System fault - Feedback of charging switch		 Cause:
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S7

System fault - Charging switch		 Cause:
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S8

System fault - No power to driver card		 Cause:
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S9

System fault - Power unit communication (TX)		 Cause:
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S10

System fault - Power unit communication (Trip)		 Cause:
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S11

System fault - Power unit comm. (Measurement)		 Cause:
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S12

System fault - System bus fault (slot D or E)		 Cause: Error in system bus option board (OPTD1 or OPTD2) in slot D or E.
  • Operation malfunction
  • Defective component

Remedy:

  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
  • Check the cables and connections.
Fault 8, Subcode S30

System fault - OPTAF: STO channels are different from each other		 Cause: The Safe Disable inputs are in different states. It is not allowed according to EN954-1, category 3. This fault occurs when the Safe Disable inputs are in different states for more than 5 s.

Remedy:

  • Check the S1 switch.
  • Check the cabling to the OPTAF board.
  • If the fault shows again, ask instructions from the local distributor.
Fault 8, Subcode S31

System fault - OPTAF: Thermistor short circuit detected		 Cause: Thermistor short circuit detected.

Remedy:

  • Correct the cable connections.
  • Check the jumper for the thermistor short circuit supervision, if the thermistor function is not used and the thermistor input is short-circuited.
Fault 8, Subcode S32

System fault - OPTAF board has been removed		 Cause: OPTAF board has been removed. It is not allowed to remove the OPTAF board once the software has recognized it.

Remedy:

  • The system requires a manual acknowledgement using System menu parameter 6.5.5 OPTAF Remove. Ask help from the local distributor.
Fault 8, Subcode S33

System fault - OPTAF: EEPROM error		 Cause: OPTAF board EEPROM error (checksum, not answering and so on).

Remedy:

  • Change the OPTAF board.
Fault 8, Subcode S34

System fault - OPTAF: Voltage problem		 Cause: OPTAF supply voltage hardware problem detected.

Remedy:

  • Change the OPTAF board.
Fault 8, Subcode S35

System fault - OPTAF: Overvoltage		 Cause: OPTAF supply voltage hardware problem detected.

Remedy:

  • Change the OPTAF board.
Fault 8, Subcode S36

OPTAF: Undervoltage		 Cause:
OPTAF supply voltage hardware problem detected.

Remedy:
  • Change the OPTAF board.
Fault 8, Subcode S37

OPTAF: Test pulse is not detected in both STO channels		 Cause:
Single hardware problem detected in Safe Disable inputs.

Remedy:
  • Change the OPTAF board.
  • Change the control board.
Fault 8, Subcode S38

OPTAF: Test pulse is not detected in STO channel 1		 Cause:
Single hardware problem detected in Safe Disable inputs.

Remedy:
  • Change the OPTAF board.
  • Change the control board.
Fault 8, Subcode S39

OPTAF: Test pulse is not detected in STO channel 2		 Cause:
Single hardware problem detected in Safe Disable inputs.

Remedy:
  • Change the OPTAF board.
  • Change the control board.
Fault 8, Subcode S40

OPTAF: ASIC trip ETR is not set, even if STO channel 1 is active		 Cause:
Single hardware problem detected in Safe Disable inputs.

Remedy:
  • Change the OPTAF board.
  • Change the control board.
Fault 8, Subcode S41

OPTAF: STO channels are not active when the thermistor trip is active		 Cause:
Single hardware problem detected in the thermistor input.

Remedy:
  • Change the OPTAF board.
Fault 8, Subcode S42

OPTAF: Test pulse low is not detected on thermistor		 Cause:
Single hardware problem detected in the thermistor input.

Remedy:
  • Change the OPTAF board.
Fault 8, Subcode S43

OPTAF: Test pulse high is not detected on thermistor		 Cause:
Single hardware problem detected in the thermistor input.

Remedy:
  • Danfoss A/S © 2020.12 AB296635287482en-000201 / DPD00903
Fault 8, Subcode S44

OPTAF: STO channel 1 is not active, even if the analog input supervision indicates		 Cause:
Single hardware problem detected in Safe Disable inputs or in the thermistor input.

Remedy:
  • Change the OPTAF board.
  • Change the control board.
Fault 8, Subcode S45

OPTAF: STO channel 2 is not active, even if the analog input supervision indicates		 Cause:
Single hardware problem detected in Safe Disable inputs or in the thermistor input.

Remedy:
  • Change the OPTAF board.
  • Change the control board.
Fault 8, Subcode S46

OPTAF: Thermistor or analog input is not set, even if STO is active		 Cause:
Single hardware problem detected in Safe Disable inputs or in the thermistor input.

Remedy:
  • Change the OPTAF board.
  • Change the control board.
Fault 8, Subcode S47

OPTAF: Board mounted in old NXP control board with no safety hardware		 Cause:
OPTAF board mounted in old VACON® NXP control board, which is not equipped with the Safe Disable function.

Remedy:
  • Change the control board to VB00561 revision H or newer.
Fault 8, Subcode S48

OPTAF: Mismatch between Therm Trip (HW) parameter and jumper setting		 Cause:
The parameter Expander boards/ SlotB/ Therm Trip(HW) is set to OFF even though the jumper X12 is not cut.

Remedy:
  • Correct the parameter 7.2.1.1 Therm Trip (HW) to match the X12 jumper setting.
Fault 8, Subcode S49

OPTAF: Board mounted in VACON NXS control board		 Cause:
OPTAF is only compatible with VACON® NXP.

Remedy:
  • Remove the OPTAF board.
Fault 8, Subcode S50

OPTAF: Filter discharge resistor fault		 Cause:
Problem with the control board.

Remedy:
  • Ask instructions from the local distributor.
Fault 8, Subcode S70

False fault activated		 Cause:
Fault in application.

Remedy:
  • Ask instructions from the local distributor.
Fault 9, Subcode S1

Undervoltage: DC-link too low during run		 Cause:
The DC-link voltage is lower than the limits.
Possible reasons:
  • Too low a supply voltage.
  • AC drive internal fault.
  • A defective input fuse.
  • The external charge switch is not closed.


Remedy:
  • If there is a temporary supply voltage break, reset the fault and start the drive again.
  • Do a check of the supply voltage. If the supply voltage is sufficient, there is an internal fault.
  • Ask instructions from the local distributor.
Fault 9, Subcode S2

Undervoltage: No data from power unit		 Cause:
The DC-link voltage is lower than the limits.
Possible reasons:
  • Too low a supply voltage.
  • AC drive internal fault.
  • A defective input fuse.
  • The external charge switch is not closed.


Remedy:
  • If there is a temporary supply voltage break, reset the fault and start the drive again.
  • Do a check of the supply voltage. If the supply voltage is sufficient, there is an internal fault.
  • Ask instructions from the local distributor.
Fault 9, Subcode S3

Undervoltage: Undervoltage control supervision		 Cause:
The DC-link voltage is lower than the limits.
Possible reasons:
  • Too low a supply voltage.
  • AC drive internal fault.
  • A defective input fuse.
  • The external charge switch is not closed.


Remedy:
  • If there is a temporary supply voltage break, reset the fault and start the drive again.
  • Do a check of the supply voltage. If the supply voltage is sufficient, there is an internal fault.
  • Ask instructions from the local distributor.
Fault 10, Subcode S1

Input line supervision: Phase supervision diode supply		 Cause:
The input line phase is missing.

Remedy:
  • Do a check of the supply voltage, the fuses, and supply cable.
Fault 10, Subcode S2

Input line supervision: Phase supervision active front-end		 Cause:
Line sync fault. AFE is not able to synchronize to line after five trials.

Remedy:
  • Check that input contactor closes.
  • Check all fuses.
  • Check that LCL filter is not broken.
  • Try to activate a longer sync pulse with AFEOptions1.B8.
Fault 10, Subcode S3

Input line supervision: Phase supervision active front end, Microgrid		 Cause:
Frequency exceeds the line frequency min/max limits.
Underfrequency appears if: DC-link voltage is too low or not enough power in grid.
Overfrequency appears if: Overvoltage control activates or too much power generation.

Remedy:
  • Check that DC-link voltage is in proper range.
  • Check that limiters (e.g., Power and Current limits) are not activated.
Fault 11, Subcode S1

Output phase supervision: Common output phase supervision		 Cause:
The measurement of current tells that there is no current in 1 motor phase.

Remedy:
  • Do a check of the motor cable and the motor.
Fault 11, Subcode S2

Output phase supervision: Additional closed loop control output phase fault		 Cause:
The measurement of current tells that there is no current in 1 motor phase.

Remedy:
  • Do a check of the motor cable and the motor.
Fault 11, Subcode S3

Output phase supervision: Additional open loop control output phase fault during start DC brake		 Cause:
The measurement of current tells that there is no current in 1 motor phase.

Remedy:
  • Do a check of the motor cable and the motor.
Fault 11, Subcode S4

Output phase supervision: Additional closed loop output phase fault during PM StartAngleID run		 Cause:
The measurement of current tells that there is no current in 1 motor phase.

Remedy:
  • Do a check of the motor cable and the motor.
Fault 12

Brake chopper supervision		 Cause:
  • There is no brake resistor.
  • The brake resistor is broken.
  • A defective brake chopper.


Remedy:
  • Do a check of the brake resistor and the cabling.
  • If they are in good condition, there is a fault in the resistor or the brake chopper. Ask instructions from the local distributor.
Fault 13

AC drive undertemperature		 Cause:
Too low a temperature in the heat sink of the power unit or in the power board. The heat sink temperature is below -10 °C (14 °F).

Remedy:
  • Add an external heater near the AC drive.
Fault 14, Subcode S1

AC drive overtemperature: Overtemperature warning in unit, board, or phases		 Cause:
Overheating detected in AC drive.
Heat sink temperature is over 90 °C (194 °F).
Alarm issued over 85 °C (185 °F).
(Different limits apply for 525–690 V, FR6).

Remedy:
  • Do a check of the actual amount and flow of cooling air.
  • Examine the heat sink for dust.
  • Do a check of the ambient temperature.
  • Make sure that the switching frequency is not too high in relation to the ambient temperature and the motor load.
  • For FR10-FR11 Standalone: check door filters, and clean or replace if needed.
Fault 14, Subcode S2

AC drive overtemperature: Overtemperature in power board		 Cause:
Overheating detected in AC drive.
Heat sink temperature is over 90 °C (194 °F).

Remedy:
  • Do a check of the actual amount and flow of cooling air.
  • Examine the heat sink for dust.
  • Do a check of the ambient temperature.
  • Make sure that the switching frequency is not too high in relation to the ambient temperature and the motor load.
  • For FR10-FR11 Standalone: check door filters, and clean or replace if needed.
Fault 14, Subcode S3
AC drive overtemperature - Liquid flow		 Cause: Appears when the liquid flow supervision is activated, and problems in cooling liquid flow are detected.

Remedy:
  • Check the correct cooling liquid flow and temperature.
  • Check the circulation for possible leaks.
  • Do a check of the ambient temperature.
  • Make sure that the switching frequency is not too high in relation to the ambient temperature and the motor load.
Fault 14, Subcode S4
AC drive overtemperature on ASIC board or driver boards		 Cause: Overheating detected in AC drive. Heat sink temperature is over 90 °C (194 °F). Overtemperature alarm is issued when the heat sink temperature goes over 85 °C (185 °F).
In 525–690 V, FR6: Heat sink temperature is over 77 ºC (170.6 °F). Alarm issued over 72 ºC (161.6 °F).

Remedy:
  • Do a check of the actual amount and flow of cooling air.
  • Examine the heat sink for dust.
  • Do a check of the ambient temperature.
  • Make sure that the switching frequency is not too high in relation to the ambient temperature and the motor load.
  • For FR10-FR11 Standalone: check door filters, and clean or replace if needed.
Fault 15
Motor stalled		 Cause: The motor stalled. It is possible to set different responses in the application for this fault. See parameter group Protections.

Remedy:
  • Check the motor and the load.
  • Insufficient motor power, check motor stall protection parameterization.
Fault 16
Motor overtemperature		 Cause: There is too heavy a load on the motor. It is possible to set different responses in the application for this fault. See parameter group Protections.

Remedy:
  • Decrease the motor load.
  • If there is no motor overload, do a check of the temperature model parameters.
Fault 17
Motor underload		 Cause: Motor underload protection has tripped. It is possible to set different responses in the application for this fault. See parameter group Protections.

Remedy:
  • Check the load.
  • Check underload protection parameterization.
Fault 18, Subcode S1
Unbalance - Current unbalance		 Cause: Unbalance between power modules in paralleled power units. This fault is type A fault (Alarm).

Remedy:
  • If the fault occurs again, ask instructions from the local distributor.
Fault 18, Subcode S2
Unbalance - DC voltage unbalance		 Cause: Unbalance between power modules in paralleled power units. This fault is type A fault (Alarm).

Remedy:
  • If the fault occurs again, ask instructions from the local distributor.
Fault 19
Current overload		 Cause: Motor current overload warning.

Remedy:
  • Ask instructions from the local distributor.
Fault 22, Subcode S1
Parameter fault - Firmware interface power down variable checksum error		 Cause:
  • Parameter save fault.
  • Operation malfunction.
  • Defective component.


Remedy:
  • If the fault occurs again, ask instructions from the local distributor.
Fault 22, Subcode S2
Parameter fault - Firmware interface variable check sum error		 Cause:
  • Parameter save fault.
  • Operation malfunction.
  • Defective component.


Remedy:
  • If the fault occurs again, ask instructions from the local distributor.
Fault 22, Subcode S3
Parameter fault - System power down variable check sum error		 Cause:
  • Parameter save fault.
  • Operation malfunction.
  • Defective component.


Remedy:
  • If the fault occurs again, ask instructions from the local distributor.
Fault 22, Subcode S4
Parameter fault - System parameter checksum error		 Cause:
  • Parameter save fault.
  • Operation malfunction.
  • Defective component.


Remedy:
  • If the fault occurs again, ask instructions from the local distributor.
Fault 22, Subcode S5
Parameter fault - Application-defined power-down, variable checksum error		 Cause: Parameter save fault.

Remedy:
  • If the fault occurs again, ask instructions from the local distributor.
Fault 22, Subcode S6
Parameter fault - Application-defined power-down, variable check sum		 Cause:
  • Parameter save fault.
  • Operation malfunction.
  • Defective component.


Remedy:
  • If the fault occurs again, ask instructions from the local distributor.
Fault 22, Subcode S10
Parameter fault - System parameter checksum error		 Cause:
  • Parameter save fault.
  • Operation malfunction.
  • Defective component.


Remedy:
  • If the fault occurs again, ask instructions from the local distributor.
Fault 22, Subcode S13
Parameter fault - Checksum error in application-specific parameter set		 Cause: Parameter save fault.

Remedy:
  • Recommission the application.
  • Check parameters.
Fault 24
Counter fault		 Cause: Values that showed on the counters are incorrect.

Remedy:
  • Have a critical attitude towards values shown on counters.
Fault 25, Subcode S1
Microprocessor watchdog fault - CPU watchdog timer		 Cause:
  • Operation malfunction.
  • Defective component.


Remedy:
  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 25, Subcode S2
Microprocessor watchdog fault - ASIC reset		 Cause:
  • Operation malfunction.
  • Defective component.


Remedy:
  • Reset the fault and start the drive again.
  • If the fault shows again, ask instructions from the local distributor.
Fault 26, Subcode S1
Start-up prevented - Prevention of accidental start-up		 Cause: Start-up of the drive has been prevented. Run request is ON when new application is downloaded to the drive.

Remedy:
  • Cancel prevention of start-up if it can be done safely.
  • Remove Run request.
Fault 26, Subcode S2
Start-up prevented - RUN request is kept active after drive returns to READY		 Cause: Start-up of the drive has been prevented. START command is ON when returning to READY state after Safe Disable has been active.

Remedy:
  • Cancel prevention of start-up if it can be done safely.
  • Remove Run request.
Fault 26, Subcode S30
Start-up prevented - RUN request given too quickly		 Cause: Start-up of the drive has been prevented. START command is ON after system software or application was downloaded, or after application was changed.

Remedy:
  • Cancel prevention of start-up if it can be done safely.
  • Remove Run request.
Fault 29, Subcode S1
Thermistor fault - Thermistor input activated on OPTAF board		 Cause: The thermistor input of option board has detected increase of the motor temperature. It is possible to set different responses in the application for this fault.

Remedy:
  • Do a check of the motor cooling and loading.
  • Do a check of the thermistor connection.
  • (If thermistor input of the option board is not in use it has to be short-circuited).
Fault 29, Subcode S2
Thermistor fault - Special application		 Cause: The thermistor input of option board has detected increase of the motor temperature. It is possible to set different responses in the application for this fault.

Remedy:
  • Do a check of the motor cooling and loading.
  • Do a check of the thermistor connection.
  • (If thermistor input of the option board is not in use it has to be short-circuited).
Fault 30
Safe disable		 Cause: The input on OPTAF board has opened. STO inputs SD1 and SD2 are activated through the OPTAF option board.

Remedy:
  • Cancel Safe Disable if it can be done safely.
Fault 31
IGBT temperature (hardware)		 Cause: IGBT Inverter Bridge overtemperature protection has detected too high a short-term overload current.

Remedy:
  • Check the load.
  • Check the motor frame size.
  • Make an identification run.
Fault 32
Fan cooling		 Cause: Cooling fan of the AC drive does not start, when ON command is given.

Remedy:
  • Ask instructions from the local distributor.
Fault 34
CAN bus communication		 Cause: Sent message not acknowledged.

Remedy:
  • Make sure that there is another device on the bus with the same configuration.
Fault 35
Application		 Cause: Problem in application software.

Remedy:
  • Ask instructions from the local distributor.
  • For an application programmer: do a check of the application program.
Fault 36
Control unit		 Cause: The software needs newer version of the control unit.

Remedy:
  • Change the control unit.
Fault 37, Subcode S1
Device changed (same type) - Control board		 Cause: A new option board has replaced the old one in the same slot. The parameters are available in the drive.

Remedy:
  • Reset the fault. The device is ready for use. The drive starts to use the old parameter settings.
Fault 38, Subcode S1
Device added (same type) - Control board		 Cause: The option board was added. The same option board has been used in the same slot before. The parameters are available in the drive.

Remedy:
  • Reset the fault. The device is ready for use. The drive starts to use the old parameter settings.
Fault 39
Device removed		 Cause: An option board was removed from the slot.

Remedy:
  • The device is not available. Reset the fault.
Fault 40, Subcode S1
Device unknown		 Cause: An unknown or mismatching device was connected (the power unit or option board).

Remedy:
  • Ask instructions from the local distributor.
Fault 40, Subcode S2
Device unknown - StarCoupler: power sub units are not identical		 Cause: An unknown or mismatching device was connected (the power unit or option board).

Remedy:
  • Ask instructions from the local distributor.
Fault 40, Subcode S3
Device unknown - StarCoupler is not compatible with the control board		 Cause: An unknown or mismatching device was connected (the power unit or option board).

Remedy:
  • Ask instructions from the local distributor.
Fault 40, Subcode S4
Device unknown - Wrong PropertiesType in control board EEPROM		 Cause: An unknown or mismatching device was connected (the power unit or option board).

Remedy:
  • Ask instructions from the local distributor.
Fault 40, Subcode S5
Device unknown - Wrong VACON NXP control board EEPROM size detected		 Cause: An unknown or mismatching device was connected (the power unit or option board).

Remedy:
  • Ask instructions from the local distributor.
Fault 40, Subcode S6
Device unknown - Old power unit (Asic) and new software mismatch		 Cause: An unknown or mismatching device was connected (the power unit or option board).

Remedy:
  • Ask instructions from the local distributor.
Fault 40, Subcode S7
Device unknown - Old ASIC detected		 Cause: An unknown or mismatching device was connected (the power unit or option board).

Remedy:
  • Ask instructions from the local distributor.
Fault 41, Subcode S1
IGBT temperature - Calculated IGBT temperature too high		 Cause: IGBT Inverter Bridge overtemperature protection has detected too high a short-term overload current.

Remedy:
  • Check the load.
  • Check the motor frame size.
  • Make an identification run.
Fault 41, Subcode S2
IGBT temperature - AFE current is higher than defined EON current limit during the grid fault		 Cause: AFE EON-function current limiter (cutter) has been active longer than 50 ms during the grid fault.

Remedy:
  • Ask instructions from the factory to check the settings.
Fault 41, Subcode S3
IGBT temperature - Calculated IGBT temperature too high (long-term protection)		 Cause: IGBT Inverter Bridge overtemperature protection has detected too high a short-term overload current.

Remedy:
  • Check the load.
  • Check the motor frame size.
  • Make an identification run.
Fault 41, Subcode S4
IGBT temperature - Peak current too high		 Cause: IGBT Inverter Bridge overtemperature protection has detected too high a short-term overload current.

Remedy:
  • Check the load.
  • Check the motor frame size.
  • Make an identification run.
Fault 41, Subcode S5
IGBT temperature - BCU: Filtered current too high for some time		 Cause: IGBT Inverter Bridge overtemperature protection has detected too high a short-term overload current.

Remedy:
  • Check the load.
  • Check the motor frame size.
  • Make an identification run.
Fault 41, Subcode S6
IGBT temperature - BCU: Current momentarily too high		 Cause: IGBT Inverter Bridge overtemperature protection has detected too high a short-term overload current.

Remedy:
  • Check the load.
  • Check the motor frame size.
  • Make an identification run.
  • Check brake resistor resistance.
Fault 42, Subcode S1
Brake resistor overtemperature - Internal brake chopper overtemperature		 Cause: Brake resistor overtemperature protection has detected too heavy braking.

Remedy:
  • Reset unit.
  • Set the deceleration time longer.
  • Dimensioning of the brake chopper is not correct.
  • Use external brake resistor.
Fault 42, Subcode S2
Brake resistor overtemperature - Brake resistance too high (BCU)		 Cause: Brake resistor overtemperature protection has detected too heavy braking.

Remedy:
  • Reset unit.
  • Set the deceleration time longer.
  • Dimensioning of the brake chopper is not correct.
  • Use external brake resistor.
Fault 42, Subcode S3
Brake resistor overtemperature - Brake resistance too low (BCU)		 Cause: Brake resistor overtemperature protection has detected too heavy braking.

Remedy:
  • Reset unit.
  • Set the deceleration time longer.
  • Dimensioning of the brake chopper is not correct.
  • Use external brake resistor.
Fault 42, Subcode S4
Brake resistor overtemperature - Brake resistance not detected (BCU)		 Cause: Brake resistor overtemperature protection has detected too heavy braking.

Remedy:
  • Reset unit.
  • Set the deceleration time longer.
  • Dimensioning of the brake chopper is not correct.
  • Use external brake resistor.
Fault 42, Subcode S5
Brake resistor overtemperature - Brake resistance leakage (earth fault) (BCU)		 Cause: Brake resistor overtemperature protection has detected too heavy braking.

Remedy:
  • Reset unit.
  • Set the deceleration time longer.
  • Dimensioning of the brake chopper is not correct.
  • Use external brake resistor.
Fault 43, Subcode S1
Encoder fault - Encoder 1 channel A is missing		 Cause: Problem detected in encoder signals. Encoder channel A is missing.

Remedy:
  • Do a check of the encoder connections.
  • Do a check of the option board.
  • Measure the encoder pulses.
  • If the pulses are correct, the option board is faulty.
  • If the pulses are not correct, the encoder/cabling is faulty.
Fault 43, Subcode S2
Encoder fault - Encoder 1 channel B is missing		 Cause: Problem detected in encoder signals. Encoder channel B is missing.

Remedy:
  • Do a check of the encoder connections.
  • Do a check of the option board.
  • Measure the encoder pulses.
  • If the pulses are correct, the option board is faulty.
  • If the pulses are not correct, the encoder/cabling is faulty.
Fault 43, Subcode S3
Encoder fault - Both encoder 1 channels are missing		 Cause: Problem detected in encoder signals. Encoder channels A and B are missing.

Remedy:
  • Do a check of the encoder connections.
  • Do a check of the option board.
  • Measure the encoder pulses.
  • If the pulses are correct, the option board is faulty.
  • If the pulses are not correct, the encoder/cabling is faulty.
Fault 43, Subcode S4
Encoder fault - Encoder reversed		 Cause: Problem detected in encoder signals. The encoder is reversed. The output frequency has been set to the positive value, but the encoder signal is negative.

Remedy:
  • Change the frequency value polarity so that the encoder signal is positive.
  • With some encoders, interchanging the encoder channels can be used to change the indicated rotation direction.
Fault 43, Subcode S5
Encoder fault - Encoder board missing		 Cause: The encoder board is missing.

Remedy:
  • Do a check of the encoder board.
  • Do a check of the terminals.
  • Do a check of the board connections.
Fault 43, Subcode S6
Encoder fault - Serial communication fault		 Cause: Problem detected in encoder signals. Serial communication fault. The encoder cable is not connected or there are interferences in the cable.

Remedy:
  • Check cabling between encoder and OPTBE, especially Data and Clock signals.
  • Check that actual encoder type matches with OPTBE "Operating mode" parameter.
Fault 43, Subcode S7
Encoder fault - Ch A / Ch B Mismatch		 Cause: Problem detected in encoder signals. Encoder channels A and B are mismatched.

Remedy:
  • Do a check of the cable connections and terminals.
Fault 43, Subcode S8
Encoder fault - Resolver/Motor pole pair mismatch		 Cause: Problem detected in parameterization of option board. There is a mismatch of the resolver/motor pole pair number.

Remedy:
  • Check that OPTBC parameter "Resolver Poles" and possible Gear Ratio parameters in application match motor pole count.
Fault 43, Subcode S9
Encoder fault - Missed Start Angle		 Cause: Encoder zero positioning identification run has not been made. The encoder start angle is missing.

Remedy:
  • Make encoder identification run.
Fault 43, Subcode S10
Encoder fault - Sin/Cos encoder feedback is missing		 Cause: Problem detected in encoder signals. For the closed loop control, encoder modes "EnDat only" or "SSI only" (absolute channel only) are not allowed.

Remedy:
  • Do a check of the wiring, jumper settings, and encoder mode.
  • Change OPTBE "Operating mode" parameter is either "EnDat+SinCos", "SSI+SinCos" or "SinCos only", or avoid using closed loop control.
Fault 43, Subcode S11
Encoder fault - Encoder angle is drifting		 Cause: Error angle between the angle read from the absolute channel and the angle calculated from the incremental channels.

Remedy:
  • Check the encoder cable, cable shield, and grounding of the cable shield.
  • Check the mechanical mounting of the encoder and make sure that the encoder is not slipping.
  • Check the encoder parameters (for example, encoder ppr).
Fault 43, Subcode S12
Encoder fault - Dual speed supervision fault		 Cause: Encoder speed supervision. The difference between the encoder speed and estimated speed is too large.

Remedy:
  • Check the encoder speed signal ShaftFrequency vs. EstimatedShaftFrequency.
  • If the ShaftFrequency is incorrect, check the encoder, cable, and encoder parameters.
  • If the EstimatedShaftFrequency is incorrect, check the motor parameters.
Fault 43, Subcode S13
Encoder fault - Encoder angle supervision fault		 Cause: The estimated shaft position error (estimated angle - encoder angle) is more than 90° electrical.

Remedy:
  • Repeat the encoder ID run (absolute encoders).
  • Check the mechanical mounting of the encoder and make sure that the encoder is not slipping.
  • Check the encoder ppr number.
  • Check the encoder cable.
Fault 43, Subcode S14
Encoder fault - Encoder estimated missing pulse fault, switch from the CL ctrl to the OL sensorl		 Cause: Problem detected in encoder signals. Software has detected too many missing pulses in the encoder.

Remedy:
  • Do a check of the encoder.
  • Do a check of the encoder cable, cable shield, and grounding of the cable shield.
  • Do a check of the mechanical mounting of the encoder.
  • Do a check of the encoder parameters.
Fault 44, Subcode S1
Device changed (different type) - Control board		 Cause: Option board or power unit changed. New device of different type or different power rating.

Remedy:
  • Reset.
  • If option board was changed, set the option board parameters again.
  • If power unit was changed, set AC drive parameters again.
Fault 45, Subcode S1
Device added (different type) - Control board		 Cause: Option board of different type added.

Remedy:
  • Reset.
  • Set the power unit parameters again.
Fault 49
Division by zero in application		 Cause: Division by zero has occurred in application program.

Remedy:
  • If the fault shows again while the AC drive is in run state, ask instructions from the local distributor.
  • For an application programmer: do a check of the application program.
Fault 50
Analogue input Iin < 4 mA (sel. signal range 4 to 20 mA)		 Cause: Current at the analog input is < 4 mA. Control cable is broken or loose, or signal source has failed.

Remedy:
  • Do a check of the current loop circuitry.
Fault 51
External fault		 Cause: Digital input fault. Digital input has been programmed as external fault input and this input is active.

Remedy:
  • Check the programming.
  • Check the device which the error message indicates.
  • Check the cabling for the respective device.
Fault 52
Keypad communication fault		 Cause: The connection between the control panel (or VACON NCDrive) and the drive is defective.

Remedy:
  • Do a check of the control panel connection and the control panel cable.
Fault 53
Fieldbus fault		 Cause: The data connection between the fieldbus master and the fieldbus board is defective.

Remedy:
  • Do a check of the installation and fieldbus master.
  • If the installation is correct, ask instructions from the local distributor.
Fault 54
Slot fault		 Cause: Defective option board or slot.

Remedy:
  • Do a check of the board and slot.
  • Ask instructions from the local distributor.
Fault 56
Measured Temperature		 Cause: Shows temperature measurement fault for option board OPTBH or OPTB8. Temperature exceeded set limit, Sensor disconnected, or Short circuit.

Remedy:
  • Find the cause of temperature rise.
Fault 57
Identification		 Cause: Identification run has failed. This fault is type A fault (Alarm).

Remedy:
  • Run command was removed before completion of identification run.
  • The motor is not connected to the AC drive.
  • There is load on motor shaft.
Fault 58
Brake		 Cause: Actual status of the brake is different from the control signal. It is possible to set different responses in the application for this fault.

Remedy:
  • Do a check of the mechanical brake state and connections.
Fault 59
Follower communication		 Cause: SystemBus or CAN communication is broken between Master and Follower.

Remedy:
  • Do a check of the option board parameters.
  • Do a check of the optical fiber cable or CAN cable.
Fault 60
Cooling		 Cause: External cooling has failed. Normally this fault comes from the heat exchanger unit.

Remedy:
  • Do a check of the reason for the failure on the external system.
Fault 61
Speed error		 Cause: Motor speed is unequal to reference.

Remedy:
  • Do a check of the encoder connection.
  • PMS motor has exceeded the pull-out torque.
Fault 62
Run disable		 Cause: Run enable signal is low.

Remedy:
  • Do a check of the reason for the Run enable signal.
Fault 63
Quick stop		 Cause: Command for quick stop received from digital input or fieldbus.

Remedy:
  • Reset the fault.
Fault 64
Input switch open		 Cause: Drive input switch is open.

Remedy:
  • Do a check of the main power switch of the drive.
Fault 65
Measured Temperature		 Cause: Shows temperature measurement fault for option board OPTBH or OPTB8. Temperature exceeded set limit, Sensor disconnected, or Short circuit.

Remedy:
  • Find the cause of temperature rise or sensor malfunction.
Fault 70
Active filter fault		 Cause: Fault triggered by digital input.

Remedy:
  • Remove fault situation on active filter.
Fault 74
Follower fault		 Cause: When using normal Master Follower function this fault code is given if one or more follower drives trips to fault.

Remedy:
  • Correct the fault cause on follower and reset fault.
Fault 85
Baseline Run		 Cause: There was a failure during the baseline run.

Remedy:
  • Check parameters in the baseline run settings.
Fault 86, Subcode A1
Condition-based Monitoring - Motor Stator Winding Current Fault		 Cause: Current unbalance has exceeded the detection high limit.

Remedy:
  • Check motor stator windings.
Fault 86, Subcode A2
Condition-based Monitoring - Motor Stator Winding Voltage Fault		 Cause: Voltage unbalance has exceeded the detection high limit.

Remedy:
  • Check motor stator windings.
Fault 86, Subcode A3
Condition-based Monitoring - Motor Stator Winding Current Warning S2		 Cause: Current unbalance has exceeded the detection high limit.

Remedy:
  • Check motor stator windings.
Fault 86, Subcode A4
Condition-based Monitoring - Motor Stator Winding Voltage Warning S2		 Cause: Voltage unbalance has exceeded the detection high limit.

Remedy:
  • Check motor stator windings.
Fault 86, Subcode A5
Condition-based Monitoring - Motor Stator Winding Current Warning S1		 Cause: Current unbalance has exceeded the detection high limit.

Remedy:
  • Check motor stator windings.
Fault 86, Subcode A6
Condition-based Monitoring - Motor Stator Winding Voltage Warning S1		 Cause: Voltage unbalance has exceeded the detection high limit.

Remedy:
  • Check motor stator windings.
Fault 86, Subcode A7
Condition-based Monitoring - Vibration Fault		 Cause: Vibration has exceeded the detection high limit.

Remedy:
  • Check root cause for increased vibration.
Fault 86, Subcode A8
Condition-based Monitoring - Vibration Warning S2		 Cause: Vibration has exceeded the detection high limit.

Remedy:
  • Check root cause for increased vibration.
Fault 86, Subcode A9
Condition-based Monitoring - Vibration Warning S1		 Cause: Vibration has exceeded the detection high limit.

Remedy:
  • Check root cause for increased vibration.
Fault 86, Subcode A10
Condition-based Monitoring - Load Fault		 Cause: Load outside of the window limits.

Remedy:
  • Check root cause for excessive overload or underload.
Fault 86, Subcode A11
Condition-based Monitoring - Load Warning S2		 Cause: Load outside of the window limits.

Remedy:
  • Check root cause for excessive overload or underload.
Fault 86, Subcode A12
Condition-based Monitoring - Load Warning S1		 Cause: Load outside of the window limits.

Remedy:
  • Check root cause for excessive overload or underload.
 

How to Read VACON NXP Faults via NCDrive

The VACON NXP is a complex drive often used in closed-loop control. In 2026, relying on the keypad is rarely enough; you need to analyze the subcodes and data logs:

  • VACON NCDrive (PC Software): This is the dedicated engineering tool for the NXP family. Connect your PC via the RS-232 service cable or USB adapter.
    • Fault History: Unlike the basic list, NCDrive displays the Fault Time (operating hours), Subcode, and the state of the drive (Frequency, Current, Voltage) at the exact moment of the trip.
    • Datalogger: The NXP has an internal datalogger. You can trigger it to record signals before a fault occurs, allowing you to see if a torque spike caused an “F1 Overcurrent” trip.
  • Control Panel (Keypad):
    • Navigate to Menu M4 (Fault History).
    • Active Faults (F): Issues currently stopping the drive.
    • Fault History (H): The last 30 faults stored in memory.
  • Fault Subcodes (ID): This is critical for NXP drives. For example, an F1 (Overcurrent) fault will have a subcode (e.g., S1 = Output Phase U, S2 = Output Phase V). This tells you exactly which IGBT or cable to check.

Frequently Asked Questions (FAQ)

Q: What is the difference between an Alarm (A) and a Fault (F)?

A:

  • Alarm (A-Codes): The drive indicates a warning (e.g., A16 “Motor Overtemperature Calculated”) but continues modulation. The yellow “Ready” LED blinks.
  • Fault (F-Codes): The drive stops modulation immediately (e.g., F31 “IGBT Temperature”). The red “Fault” LED is lit solid.

Q: How do I reset a VACON NXP fault?

A:

  1. Press the Reset button on the control panel (Keypad).
  2. Toggle the I/O Input programmed for “Fault Reset” (typically DIN3 or DIN4).
  3. Send a Reset command via the Fieldbus (Profibus, Profinet, Modbus).

Q: Why do I get “F54” (Slot Fault) or “F53” (Fieldbus Fault)?

A: The NXP is modular and uses option cards in slots A, B, C, D, and E.

  • F54: Indicates a configuration mismatch between the option card installed and the application software expectation.
  • F53: Indicates communication loss. Check the terminating resistors on your fieldbus plug or the fiber optic cables if using System Bus.

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