External Fault (EF)
An external fault input is made from a multifunctional input.
A multifunctional input is set to 3 or 4 among 1 to 7.
The EF number indicates the number of the relevant input (from S1 to S7).
• An external fault input is made from a multifunctional input.
→ Remove the cause of the external fault.
• Wrong sequence.
→ Check and change the external fault input sequence, including input timing and NO or NC contact.

Digital Operator Transmission Error 1 (F00)
Communication with the Digital Operator could not be established for 5 seconds or more after the inverter is turned on.
• The Digital Operator may not be properly mounted.
→ TURN OFF the inverter, remove and mount the Digital Operator, then TURN ON the inverter.
• There may be a fault in the Digital Operator.
→ Replace the Digital Operator.
• There may be a fault in the inverter.
→ Replace the inverter.

Digital Operator Transmission Error 2 (F01)
After the communication with the Digital Operator fails, a transmission error continues for 5 seconds or more.
• The Digital Operator may not be properly mounted.
→ TURN OFF the inverter, remove and mount the Digital Operator, then TURN ON the inverter.
• There may be a fault in the Digital Operator.
→ Replace the Digital Operator.
• There may be a fault in the inverter.
→ Replace the inverter.

First Memory Error (F04)
An error is detected in the inverter's internal EEPROM.
• There may be a fault in the internal circuits of the inverter.
→ Start the inverter by setting n001 to 8, 9, 10, or 11 and TURN OFF and ON the inverter.
→ If the same error occurs again, replace the inverter.

Analog-Digital Converter Error (F05)
An analog-digital converter error is detected.
• There may be a fault in the internal circuits of the inverter.
→ TURN OFF and ON the inverter.
→ If the same error occurs again, replace the inverter.

Option Unit Error (F06)
An Option Unit error is detected. The inverter detects this error when there is a fault in the output or verification signal of the Unit.
• The Option Unit may not be properly connected.
→ TURN OFF the inverter, remove and mount the Option Unit or attachment, then TURN ON the inverter.
• There may be a fault in the Option Unit.
→ Replace the Option Unit.
• There may be a fault in the attachment.
→ Replace the attachment.

Digital Operator Error (F07)
An error is detected in the internal control circuit of the Digital Operator. The EEPROM or analog-digital converter of the Digital Operator is faulty.
• There may be a fault in the internal circuits of the Digital Operator.
→ TURN OFF and ON the Digital Operator.
→ If the same error occurs again, replace the Digital Operator.

Option Unit Self-diagnosis Error (F21)
The Option Unit could not start the startup process 2 seconds after the power is turned ON.
• The Option Unit may not have power.
→ Ensure that the connectors are properly connected.
• The Option Unit may be faulty.
→ Replace the Option Unit.

Option Unit Model Code Error (F22)
The Option Unit stopped trying to recognize the inverter during communication initialization.
• The Option Unit may not be compatible with the inverter.
→ Replace with the correct Option Unit.
• Connectors may not be properly connected.
→ Ensure that the connectors are properly connected.
• The Option Unit may be faulty.
→ Replace the Option Unit.

Option Unit Cross-diagnosis Error (F23)
• Ensure that the connector is properly connected to the chassis.
• Ensure that the frame grounding wire for the Option Unit is properly connected.
• Take appropriate noise prevention measures.
→ Refer to the noise prevention measures in the Compliance with EU Directives section.

Digital Operator Connection Error (OPR)
The inverter detects this error when a Digital Operator connection error processing selection is set to n010 1.
• The Digital Operator may not be properly mounted.
→ TURN OFF the inverter, remove and mount the Digital Operator, then TURN ON the inverter.

Communication Timeout (CE)
Normal RS-422/485 communication could not be established within 2 seconds. The inverter detects this error when the RS-422/485 communication timeout detection selection is set to n151 0, 1, or 2.
• There may be a short circuit, ground fault, or disconnection in the communication line.
→ Check and correct the line.
• Incorrect termination resistor setting.
→ In RS-422 communication, set SW2's 1 pin of all inverters to the ON position. In RS-485 communication, set only SW2's 1 pin of the inverter at each end of the network to the ON position.
• Noise effect.
→ Do not lay the communication line in the same conduit as power lines.
→ Use twisted pair shielded cable for the communication line and ground it at the Main Computer.
• Program error in the Main Computer.
→ Check and correct the program to ensure that communication is performed multiple times in a 2-second period.
• Communication circuit damage.
→ If the same error is detected in the self-diagnosis test, replace the inverter.

Emergency Stop (STP)
An emergency stop alarm is input to a multifunctional input.
A multifunctional input is set to 19 or 21 among 1 to 7.
• An emergency stop alarm is input.
→ Remove the cause of the fault.
• Wrong sequence.
→ Check and change the sequence of the external fault input, including input timing and NO or NC contact.

Feedback Loss Error (FbL)
A feedback input is interrupted while PID control is being executed. This error is detected when the input level falls below the feedback loss detection level set in n137 and lasts longer than the feedback loss detection time set in n138.
• Feedback wiring error.
→ Check for any cable disconnection or incorrect wiring and correct it.
• Feedback sensor error
→ Check the sensor status and replace faulty sensors.
• PID setpoint input error or feedback loss detection setting error
→ Correct the setpoint input to be outside the feedback loss detection range. Correct the feedback loss detection parameter settings (n137, n138).
• Feedback input circuit error
→ Replace the inverter.

Fault Code: PF
Description: The DC voltage on the main circuit has fluctuated incorrectly when regeneration is not performed.

- Momentary power failure.
- Take precautions against momentary power failures or disable the input phase loss detection.
- Open phase in the input power supply.
- Check and correct the connections and faulty wiring of the main circuit power supply.
- Excessive voltage fluctuation or poor line voltage balance in the input power supply.
- Check the power supply voltage. Take measures to stabilize the power supply or disable the input phase loss detection.
- Fault in the main circuit capacitor.
- If this fault occurs frequently and there is no problem with the power supply, replace the inverter or disable the input phase loss detection. (Also, check the accumulated operating time function for usage time control.)

Output Phase Loss Fault (LF)

Fault Code: LF
Description: An open phase occurred in the output of the inverter.

- Output cable connection is cut.
- Check and correct any cut output cable connections or faulty wiring.
- Motor winding connection is cut.
- Check the insulation resistance of the motor. If abnormal, replace the motor.
- Output terminal screws are loose.
- Check and tighten the output terminal screws.
- Open circuit fault of the inverter output transistor.
- Replace the inverter.

Ground Fault (GF)

Fault Code: GF
Description: Ground current in the inverter exceeded approximately 50% of the nominal output current of the inverter.

- Motor is burnt or has insulation damage.
- Check the insulation resistance of the motor. If conductive, replace the motor.
- Cable is damaged.
- Check the resistance between the cable and FG. If conductive, replace the cable.
- Cable and FG have floating capacitance.
- If the cable is longer than 100 meters, reduce the carrier frequency.
- Take measures to reduce floating capacitance. Do not use metal conduits, use a separate cable for each phase, add an AC reactor to the output side, etc.

Short Circuit on Load (SC)

Fault Code: SC
Description: The inverter output or load is short-circuited.

- Motor is burnt or has insulation damage.
- Check the resistance between the motor phases. If abnormal, replace the inverter.
- Cable is damaged.
- Check the resistance between the cables. If conductive, replace the cable.

Communication Error (Option Unit) (BUS)

Fault Code: BUS
Description: A communication error occurred in the option unit.

- Communication cable is incorrectly connected, shorted, or disconnected.
- Check and correct the communication cable connection.
- Data is destroyed by noise.
- Switch to a special communication cable or shielded cable and mask or ground the screen in the power supply.
- Use a special communication power supply and connect a noise filter to the power supply input.
- The option unit is damaged.
- If communication errors occur frequently and there is no problem with the connection, replace the option unit.

Control Power Supply Fault

Fault Code: (Not specified in the provided text)
Description: The control power supply voltage is insufficient.

- Power supply is not provided.
- Check and correct the power supply cable and voltage.
- Terminal screws are loose.
- Check and tighten the terminal screws.
- Operator connectors are faulty.
- If only the Operator indicator is not lit (i.e., the RUN and ALARM indicators are lit), check and correct the Operator connectors.
- Inverter is damaged.
- Replace the inverter.