Mitsubishi Electric FR-E720-0.1K Instruction Manual page 47

List of fault displays
Function Name
Overcurrent trip during
Overcurrent has occurred during acceleration.
acceleration
Overcurrent trip during Overcurrent has occurred during constant speed
constant speed operation.
Overcurrent trip during Overcurrent has occurred during deceleration or
deceleration or stop at a stop.
Regenerative
overvoltage trip during Overvoltage has occurred during acceleration.
acceleration
Regenerative
Overvoltage has occurred during constant speed
overvoltage trip during
operation.
constant speed
Regenerative
Overvoltage has occurred during deceleration or
overvoltage trip during
at a stop.
deceleration or stop
Inverter overload trip
The electronic thermal relay function for inverter
(electronic thermal O/L
element protection has been activated.
relay function) 
Motor overload trip
The electronic thermal relay function for motor
(electronic thermal O/L
protection has been activated.
relay function) 
Heatsink overheat The heatsink has overheated.
43
Description Corrective action
 Set the acceleration time longer. (Shorten the downward
acceleration time in vertical lift application.)
 If "E.OC1" always appears at start, disconnect the motor once
and restart the inverter. If "E.OC1" still appears, the inverter
may be faulty. Contact your sales representative.
 Check the wiring for output short circuit and ground fault.
 When the rated motor frequency is 50Hz, set the Pr. 3 Base
frequency to 50Hz.
 Lower the stall prevention operation level.
 Activate the stall prevention operation and the fast-response
current limit operation. (Pr.156)
 For the operation with frequent regenerative driving, set the
base voltage (rated motor voltage, etc.) in Pr. 19 Base frequency
voltage.
 If the motor is coasting, stop the motor, then input a start
command. Alternatively, use the automatic restart after
instantaneous power failure/flying start function.
 Keep the load stable.
 Check the wiring to avoid output short circuit or ground fault.
 Lower the stall prevention operation level.
 Activate the stall prevention operation and the fast-response
current limit operation. (Pr.156)
 If the motor is coasting, stop the motor, then input a start
command. Alternatively, use the automatic restart after
instantaneous power failure/flying start function.
 Set the deceleration time longer.
 Check the wiring to avoid output short circuit or ground fault.
 Check if the mechanical brake is set to be activated too early.
 Lower the stall prevention operation level.
 Activate the stall prevention operation and the fast-response
current limit operation. (Pr.156)
 If the motor is coasting, stop the motor, then input a start
command. Alternatively, use the automatic restart after
instantaneous power failure/flying start function.
 Set the acceleration time shorter.
 Use the regeneration avoidance function (Pr. 882, Pr. 883,
Pr.885, Pr.886)
 Set the Pr. 22 Stall prevention operation level correctly.
 Keep the load stable.
 Use the regeneration avoidance function (Pr. 882, Pr. 883,
Pr.885, Pr.886).
 Use the brake resistor, brake unit or power regeneration
common converter (FR-CV) as required.
 Set the Pr. 22 Stall prevention operation level correctly.
 Set the deceleration time longer. (Set the deceleration time
which matches the moment of inertia of the load.)
 Make the brake cycle longer.
 Use the regeneration avoidance function (Pr. 882, Pr. 883,
Pr.885, Pr.886)
 Use the brake resistor, brake unit or power regeneration
common converter (FR-CV) as required.
 Set the acceleration time longer.
 Adjust the Pr. 0 Torque boost setting.
 Set the Pr. 14 Load pattern selection setting according to the
load pattern of the using machine.
 Reduce the load.
 Set the surrounding air temperature to within the
specifications.
 Reduce the load.
 For a constant-torque motor, set the constant-torque motor in
Pr. 71 Applied motor.
 Set the stall prevention operation level accordingly.
 Set the surrounding air temperature to within the
specifications.
 Clean the heatsink.
 Replace the cooling fan.
Display