Mitsubishi Air Conditioner Error Code E.OV2

E.OV2 indicates a regenerative overvoltage trip that occurred while the unit was operating at constant speed. The internal main circuit DC bus voltage exceeded the allowable limit, causing the system to shut down as a protective measure. This is different from an overvoltage fault during deceleration and points specifically to sudden load changes or drive parameter issues.

Yes, continuing to operate a unit with a recurring E.OV2 fault can lead to damage to the inverter drive's power electronics, including the DC bus capacitors and transistor modules. The system shuts down specifically to prevent this kind of damage. Repeated faults without diagnosis and correction can result in costly component failures.

Repair costs vary significantly depending on the root cause. A parameter adjustment or refrigerant recharge may cost relatively little, typically in the range of $75 to $200 for a service visit. If an expansion valve, inverter board, or compressor requires replacement, costs can range from $300 to over $1,500 depending on the component and labor involved.

Start by checking for sudden load changes in the refrigerant system, including abnormal pressures caused by refrigerant charge issues or a failing expansion valve. Then review the Pr.22 stall prevention operation level parameter in the drive settings and adjust it if it is set too low. Also inspect the incoming power supply for voltage instability or surges. If the fault persists after addressing these factors, a qualified technician should inspect the inverter board and compressor.

A power reset may clear the fault temporarily and allow the unit to restart, but if the underlying cause is not corrected, the error will return. Resetting alone is not a repair. The fault will continue to occur until the load conditions, parameter settings, or faulty components responsible for the DC bus overvoltage are addressed.