PROTECTIVE FUNCTIONS
142
FR-PU04 Indication
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 to stop the inverter output. It
may also be activated by a surge voltage generated in the
power supply system.
Check point
Check for too slow acceleration.
Corrective action
Decrease the acceleration time.
FR-PU04 Indication
Stedy Spd Ov
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.
It may also be activated by a surge voltage generated in the
power supply system.
Check point
Check for sudden load change.
Corrective action
•
Keep load stable.
•
Use the brake unit or high power factor converter (FR-HC)
as required.
FR-PU04 Indication
Ov During Dec
Name
Regenerative overvoltage shut-off during deceleration or stop
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.
It may also be activated by a surge voltage generated in the
power supply system.
Check point
Check for sudden speed reduction.
Corrective action
•
Increase the deceleration time. (Set the deceleration time
which meets load GD
2
)
•
Decrease the braking duty.
•
Use the brake unit or high power factor converter (FR-HC)
as required.
FR-PU04 Indication
Motor Overload
Name
Motor overload shut-off (electronic overcurrent protection)
(Note 1)
Description
The electronic overcurrent protection in the inverter detects
motor overheat due to overload or reduced cooling capability
during constant-speed operation to stop the inverter output.
When a multi-pole motor or two or more motors are run,
provide a thermal relay in the output side of the inverter.
Check point
Check the motor for use under overload.
Corrective action
•
Reduce the load weight.
•
For the constant-torque motor, change the Pr. 71 setting to
the constant-torque motor setting.
To Next Page
Loading...
