Mitsubishi Electric FR-A700 Instruction Manual page 730

Causes and corrective actions
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
7 - 12
E.OC3
Over current shut-off during deceleration or stop
When the inverter output current reaches or exceeds approximately 220% of the rated
inverter current during deceleration (other than acceleration or constant speed), the protec-
tive circuit is activated to stop the inverter output.
1) Check for sudden speed reduction.
2) Check for output short circuit.
3) Check for too fast operation of the motor's mechanical brake.
4) Check that stall prevention operation setting is correct.
5) Check that the power supply for RS-485 terminal is not shorted. (under vector control)
1) Increase the deceleration time.
2) Check the wiring to avoid output short circuit.
3) Check the mechanical brake operation.
4) Check that stall prevention operation setting is correct. (Refer to section 6.7.4.)
5) Check RS-485 terminal connection. (under vector control)
E.OV1
Regenerative over voltage shutoff during acceleration
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 for too slow acceleration. (e.g. during descending acceleration with lifting load)
Decrease the acceleration time.
Use regeneration avoidance function (Pr. 882 to Pr. 886). (Refer to section 6.24.8.)
E.OV2
Regenerative over voltage shut-off during constant speed
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 for sudden load change.
Keep load stable.
Use the brake unit or power regeneration common converter (FR-CV) as required.
Use regeneration avoidance function (Pr. 882 to Pr. 886). (Refer to section 6.24.8.)
E.OV3
Regenerative over voltage shut-off during deceleration or stop
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 for sudden speed reduction.
Increase the deceleration time. (Set the deceleration time which matches the inertia
moment of the load)
Decrease the braking duty.
Use the brake unit or power regeneration common converter (FR-CV) as required.
Use regeneration avoidance function (Pr. 882 to Pr. 886). (Refer to section 6.24.8.)
FR-PU04
OC During Dec
FR-PU07
FR-PU04
OV During Acc
FR-PU07
FR-PU04
Stedy Spd OV
FR-PU07
FR-PU04
OV During Dec
FR-PU07
Troubleshooting