Mitsubishi Electric FR-E700EX Instruction Manual page 274

Causes and corrective actions
(4) Fault
When a fault occurs, the drive unit trips and a fault signal is output.
Operation panel
E.OC1
indication
Name Overcurrent trip during acceleration
When the drive unit output current reaches or exceeds approximately 230% of the rated current during acceleration,
Description
the protective circuit is activated and the drive unit trips.
 Check for sudden acceleration.
 Check that the downward acceleration time is not long for the lift.
 Check for output short-circuit/ground fault.
 Check if the torque limit operation level is set too high.
Check point
 Check that the drive unit capacity matches with the motor capacity.
 Check if a start command is given to the drive unit while the motor is coasting.
 Check if the three-phase (U, V, and W) wiring on the output side (load side) of the drive unit is correct. (Check for
phase loss.)
 Increase the acceleration time. (Shorten the downward acceleration time for the lift.)
 When "E.OC1" is always lit at starting, disconnect the motor once and start the drive unit.
If "E.OC1" is still ON, contact your sales representative.
Corrective
 Check the wiring to make sure that output short circuit/ground fault does not occur.
 Lower the setting of torque limit operation level. (Refer to page 111)
action
 Choose drive unit and motor capacities that match.
 Input a start command after the motor stops.
 Wire the cables properly.
Operation panel
E.OC2
indication
Name Overcurrent trip during constant speed
When the drive unit output current reaches or exceeds approximately 230% of the rated current during constant
Description
speed operation, the protective circuit is activated and the drive unit trips.
 Check for sudden load change.
 Check for output short-circuit/ground fault.
 Check if the torque limit operation level is set too high.
Check point
 Check that the drive unit capacity matches with the motor capacity.
 Check if a start command is given to the drive unit while the motor is coasting.
 Check if the three-phase (U, V, and W) wiring on the output side (load side) of the drive unit is correct. (Check for
phase loss.)
 Keep load stable.
 Check the wiring to make sure that output short circuit/ground fault does not occur.
Corrective
 Lower the setting of torque limit operation level. (Refer to page 111)
 Choose drive unit and motor capacities that match.
action
 Input a start command after the motor stops.
 Wire the cables properly.
Operation panel
E.OC3
indication
Name
Overcurrent trip during deceleration or stop
When the drive unit output current reaches or exceeds approximately 230% of the rated drive unit current during
Description
deceleration (other than acceleration or constant speed), the protective circuit is activated and the drive unit trips.
 Check for sudden speed reduction.
 Check for output short-circuit/ground fault.
 Check for too fast operation of the motor's mechanical brake.
 Check if the torque limit level is set too high.
Check point
 Check that the drive unit capacity matches with the motor capacity.
 Check if a start command is given to the drive unit while the motor is coasting.
 Check if the three-phase (U, V, and W) wiring on the output side (load side) of the drive unit is correct. (Check for
phase loss.)
 Increase the deceleration time.
 Check the wiring to make sure that output short circuit/ground fault does not occur.
 Check the mechanical brake operation.
Corrective
 Lower the setting of torque limit level. (Refer to page 111)
action
 Choose drive unit and motor capacities that match.
 Input a start command after the motor stops.
 Wire the cables properly.
272
FR-PU07 OC During Acc
FR-PU07 Stedy Spd OC
FR-PU07 OC During Dec