Mitsubishi FR-A721-11K Instruction Manual page 156

Operation Panel
E.OV1
Indication
Name
Regenerative overvoltage trip 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
Description activated by a surge voltage produced in the power supply system. Protective circuit may activate even
if the regeneration converter is not activated due to power supply failure (Input phase failure and
instantaneous power failure).
Check for power supply fault or wrong wiring.
Check point
Check for too slow acceleration. (e.g. during descending acceleration in vertical lift load)
Check that the Pr. 22 Stall prevention operation level is not lower than the no load current.
Perform wiring correctly.
Decrease the acceleration time.
Corrective action
Use regeneration avoidance function (Pr. 882 to Pr. 886). (Refer to Chapter 4 of
Manual (Applied).)
Set a value larger than the no load current in Pr. 22 Stall prevention operation level.
Operation Panel
E.OV2
Indication
Name
Regenerative overvoltage trip 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
Description activated by a surge voltage produced in the power supply system. Protective circuit may activate even
if the regeneration converter is not activated due to power supply failure (Input phase failure and
instantaneous power failure).
Check for power supply fault or wrong wiring.
Check point Check for sudden load change.
Check that the Pr. 22 Stall prevention operation level is not lower than the no load current.
Perform wiring correctly.
Keep load stable.
Corrective action
Use regeneration avoidance function (Pr. 882 to Pr. 886). (Refer to Chapter 4 of
Manual (Applied).)
Set a value larger than the no load current in Pr. 22 Stall prevention operation level.
Operation Panel
E.OV3
Indication
Name
Regenerative overvoltage trip 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
Description
activated by a surge voltage produced in the power supply system. Protective circuit may activate even
if the regeneration converter is not activated due to power supply failure (Input phase failure and
instantaneous power failure).
Check for power supply fault or wrong wiring.
Check point
Check for sudden speed reduction.
Perform wiring correctly.
Increase the deceleration time. (Set the deceleration time which matches the moment of inertia of
the load)
Corrective action
Decrease the braking duty.
Use regeneration avoidance function (Pr. 882 to Pr. 886). (Refer to Chapter 4 of
Manual (Applied).)
Causes and corrective actions
FR-PU04
OV During Acc
FR-PU07
FR-PU04
Stedy Spd OV
FR-PU07
FR-PU04
OV During Dec
FR-PU07
the Instruction
the Instruction
the Instruction
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