Chapter 14 Fault Codes and DescriptionsME300
14-2
ID No. Display on LCM Keypad Fault Name Fault Descriptions
2
Over-current during
deceleration
(ocd)
Output current exceeds 2.5 times of the rated current
during deceleration. When ocd occurs, the drive closes
the gate of the output immediately, the motor runs freely,
and the display shows an ocd error.
Action and Reset
Action level 250% of the rated current
Action time Immediately act
Fault treatment parameter N/A
Reset method Manual reset
Reset condition Reset in 5 sec. after the fault is cleared.
Record Yes
Cause Corrective Actions
Deceleration time is too short.
1. Increase the deceleration time
2. Increase the deceleration time of S-curve
3. Set auto-acceleration and auto-deceleration parameter (Pr.01-44)
4. Set over-current stall prevention function (Pr.06-03)
5. Replace the drive with a larger capacity model
Check if the mechanical brake of
the motor activates too early
Check the action timing of the mechanical brake
Short-circuit at motor output due to
poor insulation wiring.
Without considering the short circuits, check the motor cable or replace the
cable before turning on the power.
Check for possible burnout or
aging insulation of the motor
Check the motor insulation value with megger. Replace the motor if the
insulation is poor.
The load is too large.
Check if the output current during the whole working process exceeds the
C
motor drive’s rated current. If yes, replace the AC motor drive with a larger
capacity model.
Impulsive change of the load Reduce the load or increase the capacity of the AC motor drive.
Use special motor or motor with
larger capacity than the drive
Check the motor capacity (the rated current on the motor’s nameplate should ≤
the rated current of the drive)
Use ON/OFF controller of an
electromagnetic contactor at the
output (U/V/W) of the drive
Check the action timing of the contactor and make sure it is not turned ON/OFF
when the drive outputs the voltage.
V/F curve setting error
Adjust V/F curve settings and frequency/voltage. When the fault occurs, and the
frequency voltage is too high, reduce the voltage.
Torque compensation is too large.
Adjust the torque compensation (refer to Pr.07-26 torque compensation gain)
until the output current reduces and the motor does not stall.
Malfunction caused by interference
Verify the wiring of the control circuit and wiring/grounding of the main circuit to
prevent interference.
The length of motor cable is too
long.
Increase the AC motor drive’s capacity.
Install AC reactor(s) on the output side (U/V/W).
Hardware failure
The ocd occurs due to short circuit or ground fault at the output side of the drive.
Check for possible short circuits between terminals with the electric meter:
B1 corresponds to U, V, W; DC- corresponds to U, V, W;
corresponds to U,
V, W.
If short circuits occur, return to the factory for repair.
Check if the setting for stall
prevention is correct.
Set the stall prevention to the proper value.
ID No. Display on LCM Keypad Fault Name Fault Descriptions
3
Over-current during
steady operation (ocn)
Output current exceeds 2.5 times of the rated current
during constant speed. When ocn occurs, the drive
closes the gate of the output immediately, the motor
runs freely, and the display shows an ocn error.
Action and Reset
Action level 250% of the rated current
Action time Immediately act
Fault treatment parameter N/A
Reset method Manual reset
Reset condition Reset in 5 sec. after the fault is cleared.
Record Yes