What causes the refrigerant liquid level in the evaporator to be too high?

When the refrigerant level in the evaporator is too high, it may cause the compressor to liquid refrigerant (i.e., liquid carryover in the compressor). This situation can lead to a decrease in the compressor's oil level. Specific causes include: 

◦ Excessive refrigerant charge: Too much refrigerant is charged into the system, occupying space in the evaporator and preventing the liquid from fully vaporizing. 

◦ Low superheat setting: If the superheat is set improperly, it may result in insufficient evaporation, increasing the risk of liquid carryover in the compressor.