OCA1: U Phase Short Circuit

    Main circuit components are faulty (U phase). Solution: Call for service.

OCA2: V Phase Short Circuit

    Main circuit components are faulty (V phase). Solution: Call for service.

OCA3: W Phase Short Circuit

    Main circuit components are faulty (W phase). Solution: Call for service.

OCL: Overcurrent at Startup on Load Side

    Insulation or motor fault at the main circuit output.
    Motor impedance is too low.
    The driver circuit board in the inverter is damaged.

    Solutions:
        Check the cables and wires for insulation faults.
        Check the short circuit detection option at startup with parameter F613.
        If this error occurs when no motor is connected to the inverter, the inverter itself may be faulty, call for service.

OCr: Overcurrent in Dynamic Braking Element (for 200V-55kW or larger, 400V-90kW or larger)

    The PB-PC circuit has short-circuited.
    A resistor with a resistance value lower than the minimum allowable value has been connected.
    The Pb parameter is set to 1 or 2, but the regenerative braking circuit is not connected or the regenerative braking resistor connection is open.

    Solutions:
        Check the impedance cables for the resistor, call for service.
        Check if the regenerative brake is connected.
        If regenerative braking is required, set the Pb parameter to 0.

OH: Overheating

    The cooling fan is not rotating.
    The ambient temperature is too high.
    The ventilation path is blocked.
    A heat-generating device is placed near the inverter.
    The thermistor connection inside the unit is disconnected.

    Solutions:
        Restart the inverter after it has cooled down sufficiently.
        If the cooling fan is not working, replace the fan.
        Ensure there is enough space around the inverter.
        Avoid placing heat-generating devices near the inverter.
        Call for service.

OH2: Thermal Shutdown Command from External Device

    A signal has been applied to the PTG control input terminal.
    A thermal shutdown command has been issued from an external control device (input terminal function: 46 or 47).

    Solutions:
        The motor may be overheating, check if the motor current exceeds the rated value.

OL1: Inverter Overload

    Rapid acceleration has been applied.
    The DC braking amount is too high.
    The V/f setting is incorrect.
    The motor was restarted after a short stop.
    The load is too large.

    Solutions:
        Increase the acceleration time (ACC).
        Reduce the DC braking amount (F251) and the DC braking time (F252).
        Check the V/f parameter setting.
        Use the UuS (automatic restart) and UuC (regenerative power transition control) functions.
        Use an inverter with a larger capacity.

OL2: Motor Overload

    The V/f parameter setting is incorrect.
    The motor is locked.
    Continuous low-speed operation is being applied.
    The motor is overloaded during operation.

    Solutions:
        Check the V/f parameter setting.
        Check the load (working machine).
        Check the OL1 setting and adjust F605 according to the motor's overload capacity at low speed.
        Reduce the DC braking amount (F251) and the DC braking time (F252).

OLr: Dynamic Braking Resistor Overload

    Rapid deceleration has been applied.
    The dynamic braking amount is too high.

    Solutions:
        Increase the deceleration time (dEC).
        Increase the capacity of the dynamic braking resistor and adjust the PBR capacity parameter (PbC).