Mitsubishi Electric FR-F700 Series Instruction Manual page 72

(4) Major fault
When the protective function is activated, the inverter output is shut off and an alarm is output.
Operation Panel
Indication
Name Overcurrent shut-off during acceleration
When the inverter output current reaches or exceeds approximately 170% of the rated current during
Description
acceleration, the protective circuit is activated to stop the inverter output.
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.
Check point
5. Check that stall prevention operation is correct
6. Check that the regeneration is not performed frequently. (Check that the output voltage becomes
1. Increase the acceleration time.
2. When "E.OC1" is always lit at starting, disconnect the motor once and start the inverter.
3. Check the wiring to avoid output short circuit.
Corrective action
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
Operation Panel
Indication
Name Overcurrent shut-off during constant speed
When the inverter output current reaches or exceeds approximately 170% of the rated current
Description
during constant speed operation, the protective circuit is activated to stop the inverter output.
1. Check for sudden load change.
Check point
2. Check for output short circuit.
3. Check that stall prevention operation is correct
1. Keep load stable.
Corrective action
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
Name Overcurrent shut-off during deceleration or stop
When the inverter output current reaches or exceeds approximately 170% of the rated inverter
Description
current during deceleration (other than acceleration or constant speed), the protective circuit is
activated to stop the inverter output.
1. Check for sudden speed reduction.
2. Check for output short circuit.
Check point
3. Check for too fast operation of the motor's mechanical brake.
4. Check that stall prevention operation setting is correct.
1. Increase the deceleration time.
2. Check the wiring to avoid output short circuit.
Corrective action
3. Check the mechanical brake operation.
4. Check that stall prevention operation setting is correct. (Refer to the Instruction Manual (applied).)
Operation Panel
Indication
Name Regenerative overvoltage shutoff during acceleration
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the
Description
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.
E.OC1
larger than the V/F reference voltage at regeneration and overcurrent due to increase in motor
current occurs.)
(Shorten the downward acceleration time in vertical lift application.)
If "E.OC1" is still lit, contact your sales representative.
Instruction Manual (applied).)
E.OC2
E.OC3
E.OV1
Causes and corrective actions
FR-PU04 OC During Accs
FR-PU04 Stedy Spd OC
FR-PU04 OC During Dec
FR-PU04 OV During Acc
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