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Causes and corrective actions
Operation panel
indication
E.OC3
Name
Overcurrent trip during deceleration or stop
Description
When the inverter output current reaches or exceeds approximately 230% of the rated inverter current during
deceleration (other than acceleration or constant speed), the protective circuit is activated and the inverter trips.
Check point
Check for sudden speed reduction.
Check for output short-circuit/ground fault.
Check for too fast operation of the motor's mechanical brake.
Check if the stall prevention operation level is set too high.
Check if the fast-response current limit operation is disabled.
Corrective action
Increase the deceleration time.
Check the wiring to make sure that output short circuit/ground fault does not occur.
Check the mechanical brake operation.
Lower the setting of stall prevention operation level. (Refer to page 101).
Activate the fast-response current limit operation.
Operation panel
indication
E.OV1
Name
Regenerative overvoltage trip during acceleration
Description
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the specified value,
the protective circuit is activated and the inverter trips. The circuit may also be activated by a surge voltage produced
in the power supply system.
Check point
Check for too slow acceleration. (e.g. during downward acceleration in vertical lift load)
Check that the setting of Pr. 22 Stall prevention operation level is not too small.
Corrective action
Decrease the acceleration time.
Check that regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886) is used. (Refer to page 174).
Set the Pr.22 Stall prevention operation level correctly.
Operation panel
indication
E.OV2
Name
Regenerative overvoltage trip during constant speed
Description
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the specified value,
the protective circuit is activated to stop the inverter output. The circuit may also be activated by a surge voltage
produced in the power supply system.
Check point
Check for sudden load change.
Check that the setting of Pr. 22 Stall prevention operation level is not too small.
Corrective action
Keep load stable.
Check that regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886) is used. (Refer to page 174).
Use the brake resistor, brake unit or power regeneration common converter (FR-CV) as required.
Set the Pr.22 Stall prevention operation level correctly.
Operation panel
indication
E.OV3
Name
Regenerative overvoltage trip during deceleration or stop
Description
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the specified value,
the protective circuit is activated to stop the inverter output. The circuit may also be activated by a surge voltage
produced in the power supply system.
Check point
Check for sudden speed reduction.
Corrective action
Increase the deceleration time. (Set the deceleration time which matches the moment of inertia of the load)
Longer the brake cycle.
Use regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886). (Refer to page 174).
Use the brake resistor, brake unit or power regeneration common converter (FR-CV) as required.