What condition occurs when liquid reaches the suction line to the compressor?

When liquid refrigerant reaches the suction line of the compressor, the condition known as refrigerant flooding occurs. This happens when the compressor, which is designed to handle vaporized refrigerant, is exposed to liquid refrigerant instead.

In a properly functioning system, the refrigerant should be in the gaseous state before it enters the compressor. However, if there is an excess of liquid refrigerant in the suction line—due to inadequate superheat, an overcharged system, or an inefficient evaporator—the compressor may attempt to compress the liquid. This can lead to mechanical damage or failure, as compressors are not built to handle liquid in significant amounts.

This emphasis on allowing only vapor to reach the compressor highlights the importance of maintaining the correct operating conditions, such as ensuring that proper superheating occurs in the evaporator to vaporize the refrigerant fully before it enters the suction line.