Mitsubishi MD-CX520 Drive

Mitsubishi MD-CX520 Drive Fault Codes:

Fault Code and Meaning	Cause and Remedy
E.OC1 Acceleration-time overcurrent	Cause: The acceleration torque is beyond the drive unit capability. Outputs U, V and W are in a short circuit or ground fault. The motor restarted during coasting. Remedy: Increase the acceleration time. Change to the S-pattern acceleration/deceleration. Check the motor winding resistance. Check the connection cables for damage. Check if drive unit capacity matches motor capacity.
E.OC2 Constant speed-time overcurrent	Cause: Excessive load was applied instantaneously. Outputs U, V and W resulted in a short circuit or ground fault during constant-speed operation. Remedy: Check the motor winding resistance. Check the connection cables for damage. Check if drive unit capacity matches motor capacity.
E.OC3 Deceleration-time overcurrent	Cause: The deceleration torque is beyond the drive unit capability. Outputs U, V and W resulted in a short circuit or ground fault during deceleration operation. The mechanical brake of the motor operates too early. Remedy: Increase the deceleration time. Change to the S-pattern acceleration/deceleration. Check the motor winding resistance. Check the connection cables for damage. Delay the brake operation timing.
E.OV1 Acceleration time overvoltage	Cause: Surge compounded with power during acceleration operation. The regenerative energy handling capability is insufficient. Remedy: Install a reactor. Fit a surge suppressor or like to the surge source. Fit the regenerative brake option.
E.OV2 Constant speed-time overvoltage	Cause: Surge compounded with power during constant speed operation. Load increased suddenly, activating the stall prevention function. The regenerative energy handling capability is insufficient. Remedy: Install a reactor. Fit a surge suppressor or like to the surge source. Fit the regenerative brake option.
E.OV3 Deceleration time overvoltage	Cause: The deceleration torque is beyond the drive unit capability. The regenerative energy handling capability is insufficient. Surge compounded with power during deceleration operation or stop. Remedy: Increase the deceleration time. Change to the S-pattern acceleration/deceleration. Fit the regenerative brake option. Install a reactor. Fit a surge suppressor or like to the surge source.
E.THT / E.THM Electronic thermal O/L relay	Cause: The motor and drive unit are operated under overload. Remedy: Reduce the load. Increase the capacities of the motor and drive unit.
E.UVT Undervoltage	Cause: An instantaneous voltage drop in the AC input power supply. The AC input power supply voltage is insufficient. Remedy: Check AC input power supply. Do not switch AC input power off while motor is running at high speed.
E.FIN Fin overheat	Cause: Heatsink temperature is higher than the permissible value. The surrounding air temperature exceeded permissible limits. The cooling fan failed. Remedy: Check cooling fan operation. Check ambient temperature.
E.OHT External failure	Cause: An external relay or another relay, which is connected to the terminal where the OH signal is assigned, turned ON. Remedy: Check the external device causing the OH signal. Refer to Control Circuit Contact Input Terminal Functions.
E.PUE PU disconnection	Cause: A connection fault of the operation panel or the parameter unit occurred. RS-485 communication was interrupted. Remedy: Check connection of the operation panel. Check RS-485 communication settings (Pr. 121).
E.OLT Stall prevention stop	Cause: Motor overload activated the stall prevention function consecutively, stopping the motor. Remedy: Reduce the load. Increase the capacities of the motor and drive unit.
E.LF Open loss	Cause: One of the output phases U, V, or W was lost. Remedy: Check wiring of output phases. Check for phase loss during motor driving.
E.CPU CPU fault	Cause: Malfunction of CPU. Remedy: If error persists after reset, replace the drive unit.
E.PE Storage device fault	Cause: The storage device failed. Remedy: If error persists after reset, replace the drive unit.
E.BE Brake circuit fault	Cause: The regenerative brake circuit failed. Remedy: Immediately switch power off if E.BE reappears after reset. Do not leave power on to prevent overheating brake resistor.
OL Overload 1 / Overload 2	Cause: Overcurrent or Main circuit DC voltage too high. (Stall prevention activated). Remedy: See remedies for Overcurrent (E.OCx) or Overvoltage (E.OVx). Reduce load.
FN Fan failure	Cause: Cooling fan fault. Remedy: Replace the cooling fan.
Err Operation error	Cause: Parameter changed during External operation. Value outside range. RES signal remains ON. Connection fault. Remedy: Check the fitting status of the panel. Check parameter settings and operation mode.
PS Emergency stop	Cause: The STOP/RESET key was pressed to make a stop during External operation. Remedy: Reset cannot be made via normal method. Refer to Pr. 75.