OP1: Overvoltage During Acceleration

    The input voltage fluctuates abnormally.

    Power supply capacity is 500kVA or more.

    Power factor correction capacitor is switching on and off.

    A thyristor is connected to the same power distribution line.

    The motor was restarted after a short stop.

    Solutions:
        Install a suitable input reactor.
        Use the UuS (automatic restart) and UuC (regenerative power transition control) functions.

OP2: Overvoltage During Deceleration

    Deceleration time (dEC) is too short (regenerative energy is too high).

    The dynamic braking resistor has a very high resistance value.

    Pb (dynamic braking resistor) is off. Overvoltage limit function (F305) is off.

    The input voltage fluctuates abnormally.
        Power supply capacity is 500kVA or more.
        Power factor correction capacitor is switching on and off.
        A thyristor is connected to the same power distribution line.

    Solutions:
        Increase the deceleration time (dEC).
        Install a dynamic braking resistor.
        Reduce the dynamic braking resistor (adjust Pb parameter and Pbr setting).
        Set the dynamic braking mode parameter (Pb) correctly.
        Set the overvoltage limit function (F305) correctly.
        Install a suitable input reactor.

OP3: Overvoltage During Constant Speed Operation

    The input voltage fluctuates abnormally.
        Power supply capacity is 500kVA or more.
        Power factor correction capacitor is switching on and off.
        A thyristor is connected to the same power distribution line.

    The motor is in regenerative mode due to the load and is running at a frequency higher than the inverter output frequency.

    Solutions:
        Install a suitable input reactor.
        Install a dynamic braking resistor.

OL: Over Torque

    The torque reaches the detection level during operation.

    Solutions:
        Check for system errors.
        Check if the motor is overloaded or if the brake is applied.

UC: Low Current Operation

    The output current falls to the low current detection level during operation.

    Solutions:
        Check the appropriate detection level for the system (F611).
        If the setting is correct, call for service.

UP1: Low Voltage (Main Circuit)

    The input voltage (main circuit) is too low. Solution: Check the input voltage.

E: Emergency Stop

    The inverter has been stopped via the panel during automatic or remote operation.

    A stop command has been issued from an external control device (input terminal function: 20 or 21).

    Solution: Reset the inverter.

EEP1: EEPROM Error

    A data writing error occurred. Solution: Turn the inverter off and back on. If the error persists, call for service.

EEP2: Initial Read Error

    Some internal data has been corrupted. The power was interrupted while setting the TYP. Solution: Call for service.

EEP3: Initial Read Error

    Some internal data has been corrupted. Solution: Call for service. If the inverter does not recover from the error, call for service.

EF1: Ground Fault

    Leakage current has occurred from one of the output cables or the motor to the ground. Solution: Check the cable and motor for ground faults.

EPH0: Output Phase Error

    A phase error has occurred in the main circuit output line.

    Solution: Check the main circuit output line, motor, etc., for phase errors. Select the output phase fault detection option from parameter F505.