Mitsubishi Electric 800 Series Instruction Manual page 638

Abbreviation E.OV1
Name
Regenerative overvoltage trip during acceleration
If regenerative power causes the inverter's internal main circuit DC voltage to reach or exceed the specified
Description
value, the protection 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 downward acceleration in vertical lift load)
Check point
• Check that the Pr.22 Stall prevention operation level is not set to the no load current or lower.
• Check if the stall prevention operation is frequently activated in an application with a large load inertia.
• Set the acceleration time shorter.
Use the regeneration avoidance function (Pr.882 to Pr.886). (Refer to
Corrective action
• Set a value larger than the no load current in Pr.22.
• Set Pr.154 Voltage reduction selection during stall prevention operation = "10, 11". (Refer to
332.)
Abbreviation E.OV2
Name
Regenerative overvoltage trip during constant speed
If regenerative power causes the inverter's internal main circuit DC voltage to reach or exceed the specified
Description
value, the protection 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.
• Check that the Pr.22 Stall prevention operation level is not set to the no load current or lower.
Check point
• Check if the stall prevention operation is frequently activated in an application with a large load inertia.
• Check that acceleration/deceleration time is not too short.
• Keep the load stable.
• Use the regeneration avoidance function (Pr.882 to Pr.886). (Refer to
• Use the brake unit as required.
• Set a value larger than the no load current in Pr.22.
Corrective action
• Set Pr.154 Voltage reduction selection during stall prevention operation = "10, 11". (Refer to
332.)
• Set the acceleration/deceleration time longer. (Under vector control or Advanced magnetic flux vector
control, the output torque can be increased. However, sudden acceleration may cause an overshoot in
speed, resulting in an occurrence of overvoltage.)
Abbreviation E.OV3
Name
Regenerative overvoltage trip during deceleration or stop
If regenerative power causes the inverter's internal main circuit DC voltage to reach or exceed the specified
Description
value, the protection 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.
Check point
• Check if the stall prevention operation is frequently activated in an application with a large load inertia.
• Set the deceleration time longer. (Set the deceleration time which matches the moment of inertia of the
load.)
• Make the brake cycle longer.
Corrective action
• Use the regeneration avoidance function (Pr.882 to Pr.886). (Refer to
• Use the brake unit as required.
• Set Pr.154 Voltage reduction selection during stall prevention operation = "10, 11". (Refer to
332.)
Causes and corrective actions
FR-LU08
OV During Acc
FR-PU07
page 614.)
FR-LU08
OV During Cnst Spd
FR-PU07
page 614.)
FR-LU08
OV During Dec
FR-PU07
page 614.)
PROTECTIVE FUNCTIONS
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