LG Air Conditioner Error Code 50

Error code 50 on an LG air conditioner means the outdoor unit is not detecting a complete three-phase power connection across all three input lines, designated R, S, and T. The system shuts down automatically to prevent compressor damage from phase loss. This fault must be diagnosed at the electrical supply level and is not related to a refrigerant or sensor issue.

Resetting the unit will not clear error code 50 unless the underlying power supply problem is corrected first. The control board will re-detect the missing phase immediately on restart and display the fault again. The three-phase supply must be fully restored and verified before the outdoor unit will operate normally.

If the fix is simply tightening a loose terminal or replacing a blown fuse, costs are typically in the range of $75 to $200 for a service call. If a supply conductor needs replacement or a breaker must be replaced, costs can rise to $200 to $600 or more depending on the extent of the wiring work involved. In rare cases where the compressor was damaged by prior phase-loss operation, repair or replacement costs can be significantly higher.

Resolving error code 50 involves working with three-phase electrical wiring, which carries serious shock and arc flash hazards. A qualified electrician or licensed HVAC technician should inspect the outdoor unit terminal block, disconnect switch, and supply panel. Homeowners should not attempt to open the electrical enclosures of the outdoor unit or the main panel without proper training and protective equipment.

No. Error code 50 is a protective shutdown, and the outdoor unit will not run while it is active. Attempting to force the system to operate on an incomplete three-phase supply would cause rapid and severe compressor motor winding damage. Leave the unit off until a technician has confirmed all three phases are correctly supplied and connected.