Cause of Trip, Warning Indication (in detail and countermeasures)

If there is something abnormal in the inverter or system, troubleshoot by referring to the following steps before calling service. If the inverter needs to replace some part or the cause of the trouble cannot be removed by the measures mentioned, consult the dealer of the inverter about the trouble.

OC1 / OC1P (Overcurrent during acceleration - DC current):
+ Acceleration time (#ACC) is too short.
+ V/f parameter is improperly set.
+ Running motor is started during momentary power failure.
+ Special motor (low impedance) is used.
+ Manual torque boost value (υ_b) is large.
+ Output cable or motor falls into ground-fault.
    Countermeasures:
+ Extend acceleration time (#ACC).
+ Check V/f parameter.
+ Use F301 (Auto-restart) or F302 (Regenerative power ride-through control).
+ Raise carrier frequency (#300).
+ Decrease υ_b setting value.
+ Check units and connections if there is ground-fault or not.

OC2 / OC2P (Overcurrent during deceleration - DC current):
+ Deceleration time (#dEC) is too short (in deceleration).
+ Running motor is started during momentary power failure.
+ Output cable or motor falls into ground-fault.
    Countermeasures:
+ Extend deceleration time (#dEC).
+ Use F301 (Auto-restart) or F302 (Regenerative power ride-through control).
+ Check units and connections if there is ground-fault or not.

OC3 / OC3P (Overcurrent during fixed speed - DC current):
+ Load rapidly varied.
+ Load is abnormal.
+ Output cable or motor falls into ground-fault.
    Countermeasures:
+ Reduce load variation.
+ Check loading unit.
+ Check units and connections if there is ground-fault or not.

OC1P, OC2P, OC3P (Overcurrent caused by other factors):
+ A device of main circuit is faulty.
+ Overheat protection is activated (5.5 to 15 kW, 30 kW or more).
+ Control voltage drop prevention function is activated (5.5 to 15 kW, 30 kW or more).
    Countermeasures:
+ Make a service call.
+ Check operation of cooling fan.
+ Check cooling fan control mode parameter (#620).

OCL (Loaded side overcurrent at start time):
+ Failure in wiring of main output circuit or motor insulation.
+ Motor impedance is too low.
    Countermeasures:
+ Check the wiring and motor insulation.
+ Properly set output short-circuit detection parameter (#613 and #614).

OCA1 (U-phase arm short-circuit):
+ Something abnormal in some device of main circuit (U-phase).
    Countermeasures:
+ Make a service call.

OCA2 (V-phase arm short-circuit):
+ Something abnormal in some device of main circuit (V-phase).
    Countermeasures:
+ Make a service call.

OCA3 (W-phase arm short-circuit):
+ Something abnormal in some device of main circuit (W-phase).
    Countermeasures:
+ Make a service call.

EPH1 (Phase failure - input side):
+ Phase lacking in input side of main circuit.
    Countermeasures:
+ Check connection of main input circuit for phase lacking in input side.

EPH0 (Phase failure - output side):
+ Phase lacking in output side of main circuit.
    Countermeasures:
+ Check connection of main output circuit and motor for phase lacking in output side.
+ Select output phase failure detection parameter (#605) for checking.

OP1 (Overvoltage during acceleration):
+ Input voltage abnormally varied.
+     Power-factor improving capacitor was turned on/off.
+     Some unit using thyristor is connected with the same power supply line.
+ Running motor is started during momentary power failure status.
    Countermeasures:
+ Try to insert input reactor.
+ Use F301 (Auto-restart) and F302 (Regenerative power ride-through control).

OP2 (Overvoltage during deceleration):
+ Deceleration time (#dEC) is too short (too much regenerated energy).
+ PBR resistance is too high.
+ Dynamic braking mode (#304) is disabled.
+ Over-voltage stall protection (#305) is disabled.
+ Input voltage abnormally varied.
+     Power-factor improving capacitor was turned on/off.
+     Some unit using thyristor is connected with the same power supply line.
    Countermeasures:
+ Extend deceleration time (#dEC).
+ Install dynamic braking resistor.
+ Decrease dynamic braking resistance.
+ Set dynamic braking mode parameter (#304) properly.
+ Set over-voltage stall protection (#305) properly.
+ Try to insert input reactor.

OP3 (Overvoltage during fixed speed):
+ Input voltage abnormally varied.
+     Power capacity is 500 kVA or more.
+     Power-factor improving capacitor was turned on/off.
+     Some unit using thyristor is connected with the same power supply line.
+ Motor falls into regeneration status because it is rotated fast exceeding inverter's output frequency by power of loaded side.
    Countermeasures:
+ Try to insert input reactor.
+ Install dynamic braking resistor.

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