Instruction manual

75
Errors (Alarms)
ERRORS AND PROTECTIVE FUNCTIONS
6
*2: E. OV3 appears if the over voltage shutoff occurs during positioning.
Control Panel
Indication
E.OC3 FR-PU04V OC During Dec
Name
Overcurrent shut-off during deceleration
Description
When the inverter output current reaches or exceeds approximately 200% of the rated inverter
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.
• Check for too fast operation of the motor's mechanical brake.
Corrective action
• Increase the deceleration time.
• Check the mechanical brake operation.
Control Panel
Indication
E.OV1 FR-PU04V OV During Acc
Name
Regenerative overvoltage shut-off during acceleration (*2)
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. The circuit may also be
activated by a surge voltage produced in the power supply system.
Check point
Check for too slow acceleration.(i.e. during descending acceleration with lifting load)
Corrective action
• Decrease the acceleration time.
• Use the brake unit or power regeneration common converter (FR-CV) as required.
Control Panel
Indication
E.OV2 FR-PU04V Stedy Spd OV
Name
Regenerative overvoltage shut-off during constant speed (*2)
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. The circuit may also be
activated by a surge voltage produced in the power supply system.
Check point
Check for sudden load change.
Corrective action
• Keep load stable.
• Use the brake unit or power regeneration common converter (FR-CV) as required.
Control Panel
Indication
E.OV3 FR-PU04V 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. The circuit may also be
activated by a surge voltage produced in the power supply system.
Check point
Check for sudden speed reduction.
Corrective action
• Increase the deceleration time.
(Set the deceleration time that meets the moment of inertia of the load)
• Decrease the braking duty.
• Use the brake unit or power regeneration common converter (FR-CV) as required.
Control Panel
Indication
E.THM FR-PU04V Motor Overload
Name
Motor overload shut-off (electronic overcurrent protection (electronic thermal relay function)) (*3)
Description
The electronic thermal relay function built in the inverter detects motor overheat due to overload or
reduced cooling capability during low-speed operation to stop the inverter output. When running a
multi-pole motor or two or more motors during V/F control, provide a thermal relay in the inverter
output side since such motor(s) cannot be protected.
Protection against burnout due to motor temperature rise
Check point
Check the motor for use under overload.
Corrective action
• Reduce the load weight.
• For a constant-torque motor, set the constant-torque motor in Pr. 71 "applied motor".