PROTECTIVE FUNCTIONS
164
Operation Panel Indication
E. OC3
FR-PU04
OC During Dec
Name
Overcurrent shut-off during deceleration
Description
When the inverter output current reaches or exceeds
approximately 200% of the rated current during deceleration
(other than acceleration or constant speed), the protective
circuit is activated to stop the inverter output.
Check point
Check for sudden speed reduction.
Check for output short-circuit/ground fault.
Check for too fast operation of motor's mechanical brake.
Corrective action
Increase the deceleration time.
Adjust brake operation.
Operation Panel Indication
E. OV1
FR-PU04
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.
Operation Panel Indication
E. OV2
FR-PU04
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.
Operation Panel Indication
E. OV3
FR-PU04
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 matches the inertia moment of the load.)
•
Decrease the braking duty.
•
Use the brake unit or high power factor converter (FR-HC)
as required.
5