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Causes and corrective actions
Operation panel
indication
E.OC3
FR-PU04
FR-PU07
OC During Dec
Name
Overcurrent trip during deceleration or stop
Description
When the inverter output current reaches or exceeds approximately 200% of the rated inverter current during
deceleration (other than acceleration or constant speed), the protective circuit is activated and the inverter trips.
Check point
1. Check for sudden speed reduction.
2. Check for output short-circuit/ground fault.
3. Check for too fast operation of the motor's mechanical brake.
4. Check that stall prevention operation is appropriate.
Corrective action
1. Increase the deceleration time.
2. Check the wiring to make sure that output short circuit/ground fault does not occur.
3. Check the mechanical brake operation.
4. Perform stall prevention operation appropriately. (Refer to page 79).
Operation panel
indication
E.OV1
FR-PU04
FR-PU07
OV During Acc
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
1. Check for too slow acceleration. (e.g. during downward acceleration in vertical lift load)
2. Check that the setting of Pr. 22 Stall prevention operation level is not too small.
Corrective action
1. Decrease the acceleration time.
Use regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886). (Refer to page 226).
2. Set the Pr.22 Stall prevention operation level correctly.
Operation panel
indication
E.OV2
FR-PU04
FR-PU07
Stedy Spd OV
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
1. Check for sudden load change.
2. Check that the setting of Pr. 22 Stall prevention operation level is not too small.
Corrective action
1. Keep load stable.
Use regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886). (Refer to page 226).
Use the brake resistor, brake unit or power regeneration common converter (FR-CV) as required.
2. Set the Pr.22 Stall prevention operation level correctly.
Operation panel
indication
E.OV3
FR-PU04
FR-PU07
OV During Dec
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)
Make the brake cycle longer.
Use regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886). (Refer to page 226).
Use the brake resistor, brake unit or power regeneration common converter (FR-CV) as required.