Hi everyone,

This information you have provided is about the fault diagnostic system of an AC motor drive, which is used to control the operation of an AC motor. The system includes several different alarms and fault messages that are displayed on the drive's digital keypad display. The five most recent faults can be read from the keypad or through communication. It's important to wait 5 seconds after a fault has been cleared before resetting the system via the keypad or input terminal.


oc : The "OC" fault message is the Over Current fault, which indicates an abnormal increase in the current. The following are some steps that can be taken to troubleshoot and resolve this issue:

    Verify that the motor power corresponds with the AC motor drive output power.
    Inspect the wiring connections between the AC motor drive and the motor, as well as to the U/T1, V/T2, and W/T3 terminals, for any short circuits.
    Ensure that the wiring connections between the AC motor drive and the motor are secure and free from short circuits and grounding issues.
    Check for loose contacts between the AC motor drive and the motor.
    Increase the acceleration time to allow the motor to ramp up to its operating speed more gradually.
    Check for excessive loading conditions at the motor.
    If the issue persists after following these steps, it may be necessary to send the AC motor drive back to the manufacturer for repair.

This information should be used as a starting point for troubleshooting the Over Current fault. If you continue to experience issues or have any additional questions, it may be best to consult the manufacturer's documentation or technical support.


ov (ou): The "OV" fault message is the Over Voltage fault, which indicates that the DC bus voltage has exceeded its maximum allowable value. The following are some steps that can be taken to troubleshoot and resolve this issue:

    Verify that the input voltage falls within the rated AC motor drive input voltage range.
    Check for possible voltage transients that may be causing the DC bus voltage to exceed its maximum value.
    Over voltage of the DC bus may also be caused by motor regeneration, which occurs when the motor generates electricity when it slows down. To address this, you can either increase the deceleration time or add an optional brake resistor and brake unit.

    Ensure that the required brake power is within the specified limits.

This information should be used as a starting point for troubleshooting the Over Voltage fault. If you continue to experience issues or have any additional questions, it may be best to consult the manufacturer's documentation or technical support.

oH1,Oh2: The "OH" fault message is the Overheating fault, which indicates that the heat sink temperature is too high. The following are some steps that can be taken to troubleshoot and resolve this issue:

- Verify that the ambient temperature falls within the specified temperature range.
- Ensure that the ventilation holes are not obstructed and that there is enough space for adequate ventilation.
- Remove any foreign objects from the heatsinks and check for dirty heat sink fins.
- Check the fan and clean it if necessary.
- Ensure that there is enough spacing for adequate ventilation.

This information should be used as a starting point for troubleshooting the Overheating fault. If you continue to experience issues or have any additional questions, it may be best to consult the manufacturer's documentation or technical support.

Lu: The "LU" fault message is the Low Voltage fault, which indicates that the AC motor drive has detected that the DC bus voltage has fallen below its minimum value. The following are some steps that can be taken to troubleshoot and resolve this issue:

- Verify that the input voltage falls within the AC motor drive's rated input voltage range.
- Check for an abnormal load on the motor, which may be causing the DC bus voltage to fall below its minimum value.
- Ensure that the input power is wired correctly to the R-S-T terminals (for 3-phase models), and that there is no phase loss.

This information should be used as a starting point for troubleshooting the Low Voltage fault. If you continue to experience issues or have any additional questions, it may be best to consult the manufacturer's documentation or technical support.

oL: The "OL" fault message is the Overload fault, which indicates that the AC motor drive has detected excessive drive output current. The following are some steps that can be taken to troubleshoot and resolve this issue:

    Verify that the motor is not overloaded.
    Reduce the torque compensation setting in Pr.07.02.
    Consider using the next higher power AC motor drive model to handle the excessive current.

It's important to note that the AC motor drive can withstand up to 150% of the rated current for a maximum of 60 seconds.

This information should be used as a starting point for troubleshooting the Overload fault. If you continue to experience issues or have any additional questions, it may be best to consult the manufacturer's documentation or technical support.

oL1: The "OL1" fault message is the Overload 1 fault, which indicates an internal electronic overload trip. The following are some steps that can be taken to troubleshoot and resolve this issue:

- Verify that the motor is not overloaded.
- Check the electronic thermal overload setting.
- Consider using a higher power motor.
- Reduce the current level so that the drive output current does not exceed the value set by the Motor Rated Current Pr.07.00.

This information should be used as a starting point for troubleshooting the Overload 1 fault. If you continue to experience issues or have any additional questions, it may be best to consult the manufacturer's documentation or technical support.


oL2: The "OL2" fault message is the Overload 2 fault, which indicates a motor overload. The following are some steps that can be taken to troubleshoot and resolve this issue:

- Reduce the motor load.
- Adjust the over-torque detection setting to an appropriate setting in Pr.06.03 to Pr.06.05.

This information should be used as a starting point for troubleshooting the Overload 2 fault. If you continue to experience issues or have any additional questions, it may be best to consult the manufacturer's documentation or technical support.

bb: The "bb" fault message refers to an External Base Block fault. The following are some steps that can be taken to troubleshoot and resolve this issue:

- When the external input terminal (B.B) is active, the AC motor drive output will be turned off.
- Deactivate the external input terminal (B.B) to operate the AC motor drive again.

The external base block is a control signal used to turn off the AC motor drive output. It is likely that the external base block signal is active, which is causing the AC motor drive to shut down. To resolve the issue, simply deactivate the external input terminal (B.B).

For more information on the external base block and the Pr.08.07 setting, refer to the manufacturer's documentation.

ocA : The "ocA" fault message refers to an Over-current during Acceleration fault. The following are some steps that can be taken to troubleshoot and resolve this issue:

    Short-circuit at motor output: Check for possible poor insulation at the output lines.
    Torque boost too high: Decrease the torque compensation setting in Pr.07.02.
    Acceleration Time too short: Increase the Acceleration Time.
    AC motor drive output power is too small: Replace the AC motor drive with the next higher power model.

An over-current during acceleration fault indicates that there is an excessive increase in current during the acceleration phase. This can be caused by a number of factors, such as a short-circuit at the motor output, a torque boost that is too high, an acceleration time that is too short, or an AC motor drive output power that is too small.

To resolve the issue, it is recommended to check for any short-circuits at the motor output, adjust the torque compensation setting, increase the acceleration time, or replace the AC motor drive with a higher power model if necessary. For more information on the recommended settings, refer to the manufacturer's documentation.

ocd:  Over-current during deceleration   
Braking too fast: Increase the Decel. Time or  add an optional brake resistor (and brake unit).
    Abnormal load during deceleration: Reduce  the load during deceleration.

ocn: Over-current during constant speed operation
    Check the motor's rated current and compare it with the setting in Pr.07.00 (Motor Rated Current) to ensure that it is within the specified limit.
    Reduce the acceleration and deceleration time in Pr.04.00 and Pr.05.00 respectively to minimize the peak current during operation.
    Make sure that the frequency setting in Pr.03.00 is not too high, as this can increase the motor current.
    Consider adding a heat sink to dissipate heat from the drive and ensure proper cooling.

EF: External Fault
    Check the external fault signal input and make sure it's within the specified voltage range.
    Check the wiring of the external fault input terminal to make sure it

GFF: Ground fault
    Check for proper wiring of the output terminal and make sure it is not grounded.
    Check for any foreign objects or debris near  the output terminal that may cause a ground fault.
    Replace the AC motor drive power module if it is damaged.

cFA:  Auto Ramp fault
    Check for correct wiring and connections of
    the AC motor drive and motor.
    Check the acceleration/deceleration time
    setting (Pr.06.00/Pr.06.01) and adjust if
    necessary.
    Check the torque compensation setting
    (Pr.07.02) and adjust if necessary.
    Check if the power supply voltage falls
    within the AC motor drive's rated input
    voltage range.

CE--: Communication Error
The steps you listed are typical troubleshooting steps for a communication error between an AC motor drive and an RS485 master. These steps can help you identify the source of the issue and resolve it.

    Checking the RS485 connection for loose wires and proper wiring to correct pins can help ensure that the connection is secure and the data being transmitted is accurate.

    Verifying that the communication protocol, address, transmission speed, etc. are properly set is crucial for successful communication. The communication protocol defines how data is transmitted between the devices, while the address determines which device is being communicated with. The transmission speed determines the speed at which data is transmitted, and it must be set appropriately to ensure that data is not lost or corrupted.

    The checksum calculation is used to verify that the data being transmitted has not been altered or corrupted during transmission. Using the correct checksum calculation is essential to ensuring accurate and reliable communication.

    Referring to group 9 in chapter 5 for detailed information can provide you with additional information and guidance on how to resolve communication issues between an AC motor drive and an RS485 master.


code: The message "Software protection failure. Return to the factory" indicates that there is a problem with the software protection mechanism on the device. This can be due to several reasons such as corruption of the software, tampering with the device, or a hardware issue.

Returning the device to the factory is usually the recommended solution as the issue may be beyond the capability of a user to resolve. The factory technicians will have access to specialized tools, software, and technical knowledge to diagnose and resolve the issue.

If you are encountering this message, it is important to contact the manufacturer or the vendor of the device for further assistance. They will be able to provide you with additional guidance and support on how to proceed with returning the device to the factory.

AErr: Analog signal error
The message "AErr: Analog signal error. Check the wiring of ACI" suggests that there is an issue with the analog signal being transmitted between the device and the ACI wiring. This error can cause inaccuracies in the readings or complete loss of data.

To resolve this issue, you should check the wiring of the ACI system to ensure that it is properly connected and secured. Verify that the connections are tight and not corroded. Check the wiring for any signs of damage, such as cuts or fraying.

If the wiring appears to be in good condition, you may need to check other components of the system, such as the analog signal amplifier or analog-to-digital converter. If you are unable to resolve the issue, you may need to seek assistance from a professional who is familiar with the system.

It is important to resolve this issue promptly, as an incorrect or unstable analog signal can cause incorrect readings or data loss, which can negatively impact the performance and reliability of the system.

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