Mitsubishi Electric FR-F 700 EC Instruction Manual page 73

Causes and corrective actions
(3) Minor fault
When the protective function is activated, the output is not shut off. You can also output a minor fault signal by
making parameter setting. (Set "98" in any of Pr. 190 to Pr. 196 (output terminal function selection). (Refer to
Instruction Manual (applied).))
Operation Panel
Indication
Name
Description
Check point
Corrective action
(4) Major fault
When the protective function is activated, the inverter output is shut off and an alarm is output.
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
66
FN
Fan fault
For the inverter that contains a cooling fan,
stops due to a fault or different operation from the setting of Pr. 244 Cooling fan operation selection.
Check the cooling fan for a fault.
Check for fan fault. Please contact your sales representative.
E.OC1
Overcurrent shut-off during acceleration
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.
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 stall prevention operation is correct.
5. 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.)
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 make sure that output short circuit does not occur.
4. Perform a correct stall prevention operation. (Refer to
5. Set base voltage (rated voltage of the motor, etc.) in Pr. 19 Base frequency voltage. (Refer to
Instruction Manual (applied).)
E.OC2
Overcurrent shut-off during constant speed
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.
1. Check for sudden load change.
2. Check for output short circuit.
3. Check that stall prevention operation is correct.
1. Keep load stable.
2. Check the wiring to avoid output short circuit.
3. Check that stall prevention operation setting is correct. (Refer to
E.OC3
Overcurrent shut-off during deceleration or stop
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.
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.
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
FR-PU04 FN
appears on the operation panel when the cooling fan
FR-PU04 OC During Accs
Instruction Manual (applied).)
FR-PU04 Stedy Spd OC
FR-PU04 OC During Dec
Instruction Manual (applied).)
Instruction Manual (applied).)