Causes and corrective actions
Troubleshooting
7 - 10
Operation Panel
Indication
E.OC3
FR-PU04
FR-PU07
OC During Dec
Name
Overcurrent shut-off 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 protec-
tive 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.
Activate the fast-response current limit operation. (Refer to section 6.2.4).
Operation Panel
Indication
E.OV1
FR-PU04
FR-PU07
OV During Acc
Name
Regenerative overvoltage shut-off 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 cir-
cuit 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 Pr. 22 "Stall prevention operation level" is not too low.
Corrective action
Decrease the acceleration time.
Check that regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886) is used.
(Refer to section 6.19.4)
Set a correct value in Pr. 22 "Stall prevention operation level".
Operation Panel
Indication
E.OV2
FR-PU04
FR-PU07
U>>N = konst
Name
Regenerative overvoltage shut-off 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 Pr. 22 "Stall prevention operation level" is not too low.
Corrective action
Keep load stable.
Check that regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886) is used.
(Refer to section 6.19.4)
Use the brake resistor, brake unit or power regeneration common converter (FR-CV)
as required.
Set a correct value in Pr. 22 "Stall prevention operation level".
Summary of Contents for FR-D720S SC EC
Page 2: ......
Page 4: ......
Page 24: ...Description of the case Product checking and part identification 1 4 ...
Page 108: ...Operation panel Operation 4 20 ...
Page 436: ...Setting for the parameter unit and operation panel Parameter 6 286 ...
Page 484: ...Measurements on the main circuit Maintenance and inspection 8 14 ...
Page 504: ...Specification change Appendix A 20 ...
Page 505: ......
Page 506: ......
Page 510: ...Index Appendix A 24 ...
Page 511: ......