67
Causes and corrective actions
5
TROUB
L
E
S
HOOTING
(4) Major fault
When the protective function is activated, the inverter output is shut off and an alarm is output.
Operation Panel
Indication
E.OC1
FR-PU04
OC During Accs
Name
Overcurrent shut-off during acceleration
Description
When the inverter output current reaches or exceeds approximately 170% of the rated current during
acceleration, the protective circuit is activated to stop the inverter output.
Check point
1. Check for sudden acceleration.
2. Check that the downward acceleration time is not long in vertical lift application.
3. Check for output short circuit.
4. Check that the
Pr. 3 Base frequency
setting is not 60Hz when the motor rated frequency is 50Hz.
5. Check that stall prevention operation is correct
6. Check that the regeneration is not performed frequently. (Check that the output voltage becomes
larger than the V/F reference voltage at regeneration and overcurrent due to increase in motor
current occurs.)
Corrective action
1. Increase the acceleration time.
(Shorten the downward acceleration time in vertical lift application.)
2. When "E.OC1" is always lit at starting, disconnect the motor once and start the inverter.
If "E.OC1" is still lit, contact your sales representative.
3. Check the wiring to avoid output short circuit.
4. Set the
Pr. 3 Base frequency
to 50Hz.
(Refer to page 33.)
5. Perform a correct stall prevention operation.
(Refer to the Instruction Manual (applied).)
6. Set base voltage (rated voltage of the motor, etc.) in
Pr. 19 Base frequency voltage
.
(Refer to the
Instruction Manual (applied).)
Operation Panel
Indication
E.OC2
FR-PU04
Stedy Spd OC
Name
Overcurrent shut-off during constant speed
Description
When the inverter output current reaches or exceeds approximately 170% of the rated current
during constant speed operation, the protective circuit is activated to stop the inverter output.
Check point
1. Check for sudden load change.
2. Check for output short circuit.
3. Check that stall prevention operation is correct
Corrective action
1. Keep load stable.
2. Check the wiring to avoid output short circuit.
3. Check that stall prevention operation setting is correct.
(Refer to the Instruction Manual (applied).)
Operation Panel
Indication
E.OC3
FR-PU04
OC During Dec
Name
Overcurrent shut-off during deceleration or stop
Description
When the inverter output current reaches or exceeds approximately 170% 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
1. Check for sudden speed reduction.
2. Check for output short circuit.
3. Check for too fast operation of the motor's mechanical brake.
4. Check that stall prevention operation setting is correct.
Corrective action
1. Increase the deceleration time.
2. Check the wiring to avoid output short circuit.
3. Check the mechanical brake operation.
4. Check that stall prevention operation setting is correct.
(Refer to the Instruction Manual (applied).)
Operation Panel
Indication
E.OV1
FR-PU04
OV During Acc
Name
Regenerative overvoltage shutoff 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. The circuit may also be
activated by a surge voltage produced in the power supply system.
Check point
Check for too slow acceleration. (e.g. during descending acceleration with lifting load)
Corrective action
Decrease the acceleration time.
Summary of Contents for FR-F700 Series
Page 134: ...MEMO ...
