Diagnostic and Protective/Diagnostic Functions for Omron J7 Inverter:

This section describes the screens of alarms and errors, explanations of error conditions, and corrective actions to be taken in case of malfunction of the J7 VS mini.

Corrective actions for digital operatorless models:

Perform input error reset or turn the power supply OFF and ON.
If an error is not corrected:
Turn the power supply OFF and check the cable connections and control logic.

Corrective actions for digital operator models:
Alarm Screen and Content:

UV (Main circuit undervoltage): The main circuit DC voltage drops below the undervoltage detection level while the inverter output is OFF.

OV (Main circuit overvoltage): The main circuit DC voltage exceeds the overvoltage detection level while the inverter output is OFF.

    200V class: Approximately 410V or higher

    400V class: Approximately 820V or higher

OH (Cooling fin overheat): The input air temperature rises while the inverter output is OFF.

    Check:
    Power supply voltage
    Are the main circuit power supply cables connected?
    Are terminal screws tightened?

OP? (Fixed setting error during MEMOBUS communication):

    OP1: Multiple values are set for multifunction input selection.

    OP2: The relationship between V/f constants is incorrect.

    OP3: The set value of the motor's rated current exceeds 120% of the inverter's rated current.

    OP4: The upper/lower limit of the frequency reference is reversed.

    OP5: The set values of jump frequencies 1 and 2 are inappropriate.

    OP9: The carrier frequency setting is incorrect.

    Check the set values.

OL 3 (Over-torque detection): The motor current exceeds the pre-set value at fixed speed n60.

    Reduce the load and extend the acceleration/deceleration time.

SER (Sequence error): The inverter outputs while receiving the LOCAL/REMOTE selection command from the multifunction terminal or the communication/control circuit terminal change signals.

    Check the external circuit (sequence).

BB (External baseblock): The baseblock command is active on the multifunction terminal, and the inverter output is OFF (the motor is free to rotate). The temporary condition is cleared when the input command is removed.

STP (Operator function stop): The inverter stops according to n04 when the STOP RESET is pressed while the control circuit terminals are operating with FWD/REV command or operation command from communications.

    The inverter stops according to n04.

STP (Emergency stop): The inverter stops according to n04 when it receives the emergency stop alarm signal.

FAN (Cooling fan failure): The cooling fan is locked.

Check:
    Cooling fan
    Is the cooling fan cable connected?

CE (MEMOBUS communication error): Check the communication devices or signals.

OC (Overcurrent): The inverter output current momentarily exceeds approximately 200% of the rated current.

GF (Ground fault): The ground fault current in the inverter output exceeds the rated current of the inverter. The output is turned OFF, and the motor stops rotating freely.

Check:
    Short circuit or grounding on the inverter output side
    Overload GD2
    Excessively rapid acceleration/deceleration time
    Use of special motor
    Starting the motor during free rotation
    Running a motor with a capacity greater than the inverter's capacity.
    Opening and closing of the magnetic contactor on the inverter output side

Perform power cycle. If the error persists, replace the inverter.

OV (Main circuit overvoltage): Due to excessive regenerative energy of the motor, the main circuit DC voltage exceeds the overvoltage detection level.


Check:
    Insufficient deceleration time
    Reduction of the negative load (elevator, etc.)

Increase the deceleration time.
    Detection level:

    200V: The main circuit DC voltage stops when it drops below approximately 410V.

    400V: The main circuit DC voltage stops when it reaches approximately 820V or higher.

UV1 (Main circuit undervoltage): The main circuit DC voltage drops below the undervoltage detection level while the inverter output is ON.

Check:
    Decrease in input power supply voltage
    Phase loss in input power supply
    Instantaneous power loss

Check:
    Power supply voltage
    Are the main circuit power supply cables connected?
    Are terminal screws tightened?

    200V: The main circuit DC voltage stops when it drops below approximately 200V (160V for single phase).

    400V: The main circuit DC voltage stops when it reaches approximately 400V or higher.

Make sure the motor insulation is not damaged.

Check the connection between the inverter and the motor.

OH (Cooling fin overheat): The temperature rises due to the overload operation of the inverter or the increase in input air temperature. The output is turned OFF, and the motor stops rotating freely.