Mitsubishi Electric FR-CS82S-025 Instruction Manual page 216

Operation panel
E.OV1
indication
Regenerative overvoltage trip during acceleration
Name
If regenerative power causes the inverter's internal main circuit DC voltage to reach or exceed the specified
value, the protection circuit is activated to stop the inverter output. The circuit may also be activated by a surge
Description
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, Pr.883, Pr.885, Pr.886). (Refer to
Corrective action
• Set a value larger than the no load current in Pr.22.
Operation panel
E.OV2
indication
Regenerative overvoltage trip during constant speed
Name
If regenerative power causes the inverter's internal main circuit DC voltage to reach or exceed the specified
value, the protection circuit is activated to stop the inverter output. The circuit may also be activated by a surge
Description
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, Pr.883, Pr.885, Pr.886). (Refer to
• Use a brake unit or the power regeneration common converter (FR-CV) as required.
Corrective action • Set a value larger than the no load current in Pr.22.
• Set the acceleration/deceleration time longer. (Under General-purpose magnetic flux vector, the output torque
can be increased. However, sudden acceleration may cause an overshoot in speed, resulting in an occurrence
of overvoltage.)
Operation panel
E.OV3
indication
Regenerative overvoltage trip during deceleration or stop
Name
If regenerative power causes the inverter's internal main circuit DC voltage to reach or exceed the specified
value, the protection circuit is activated to stop the inverter output. The circuit may also be activated by a surge
Description
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, Pr.883, Pr.885, Pr.886). (Refer to
• Use the brake unit or power regeneration common converter (FR-CV) as required.
• Enable the increased magnetic excitation deceleration.
Operation panel
E.THT
indication
Name
Inverter overload trip (electronic thermal O/L relay function)
If the temperature of the output transistor elements exceeds the protection level with a rated output current or
Description
higher flowing without the overcurrent trip (E.OC[]), the inverter output is stopped. (Overload capacity 150% 60 s)
• Check that acceleration/deceleration time is not too short.
• Check that torque boost setting is not too large (small).
Check point
• Check that load pattern selection setting is appropriate for the load pattern of the machine.
• Check that the motor is not used under overload.
• Set the acceleration/deceleration time longer.
• Adjust the torque boost setting.
Corrective action
• Set the load pattern selection setting according to the load pattern of the using machine.
• Reduce the load.
*1 Resetting the inverter initializes the internal cumulative heat value of the electronic thermal relay function.
FR-LU08 indication OV During Acc
FR-LU08 indication Steady spd OV
FR-LU08 indication OV During Acc
FR-LU08 indication Inv. Overload
*1
6. PROTECTIVE FUNCTIONS
6.5 Causes and corrective actions
1
2
3
page 199.)
5
6
7
page 199.)
8
9
10
page 199.)
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