Mitsubishi Electric FR-E700 Instruction Manual page 276

(4) Fault
When a fault occurs, the inverter trips and a fault signal is output.
Operation panel
E.OC1
indication
Name
Overcurrent trip during acceleration
When the inverter output current reaches or exceeds approximately 230% of the rated current during acceleration, the
Description
protective circuit is activated and the inverter trips.
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/ground fault.
Check point
4. Check that stall prevention operation is appropriate.
5. Check that regeneration is not performed frequently. (Check that the output voltage becomes larger than the V/F
reference value at regeneration and overcurrent occurs due to the high voltage.)
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.
Corrective action
3. Check the wiring to make sure that output short circuit/ground fault does not occur.
4. Perform stall prevention operation appropriately. (Refer to page 84).
5. Set base voltage (rated voltage of the motor, etc.) in Pr. 19 Base frequency voltage. (Refer to page 90)
Operation panel
E.OC2
indication
Name Overcurrent trip during constant speed
When the inverter output current reaches or exceeds approximately 230% of the rated current during constant speed
Description
operation, the protective circuit is activated and the inverter trips.
1. Check for sudden load change.
Check point
2. Check for output short-circuit/ground fault.
3. Check that stall prevention operation is appropriate.
1. Keep load stable.
Corrective action 2. Check the wiring to make sure that output short circuit/ground fault does not occur.
3. Perform stall prevention operation appropriately. (Refer to page 84).
Operation panel
E.OC3
indication
Name Overcurrent trip during deceleration or stop
When the inverter output current reaches or exceeds approximately 230% of the rated inverter current during
Description
deceleration (other than acceleration or constant speed), the protective circuit is activated and the inverter trips.
1. Check for sudden speed reduction.
2. Check for output short-circuit/ground fault.
Check point
3. Check for too fast operation of the motor's mechanical brake.
4. Check that stall prevention operation is appropriate.
1. Increase the deceleration time.
2. Check the wiring to make sure that output short circuit/ground fault does not occur.
Corrective action
3. Check the mechanical brake operation.
4. Perform stall prevention operation appropriately. (Refer to page 84).
Operation panel
E.OV1
indication
Name Regenerative overvoltage trip during acceleration
If regenerative energy causes the inverter's internal main circuit DC voltage to reach or exceed the specified value,
Description the protective circuit is activated and the inverter trips. The circuit may also be activated by a surge voltage produced
in the power supply system.
1. Check for too slow acceleration. (e.g. during downward acceleration in vertical lift load)
Check point
2. Check that the setting of Pr. 22 Stall prevention operation level is not too small.
1. Decrease the acceleration time.
Corrective action Check that regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886) is used. (Refer to page 246).
2. Set the Pr.22 Stall prevention operation level correctly.
Causes and corrective actions
FR-PU04
OC During Acc
FR-PU07
FR-PU04
Stedy Spd OC
FR-PU07
FR-PU04
OC During Dec
FR-PU07
FR-PU04
OV During Acc
FR-PU07
5
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