High superheat indicates what about the liquid level in the evaporator?

High superheat in an evaporator is indicative of a low liquid level in the evaporator. Superheat refers to the temperature of a vapor above its saturation temperature, meaning that when the refrigerant is in a superheated state, it has already absorbed heat and transitioned fully from a liquid to vapor state. In a well-functioning evaporator, the refrigerant should boil off and maintain a certain level of liquid to ensure efficient heat absorption.

When the liquid level is low, the evaporator may not be able to adequately transfer heat, leading to the refrigerant exiting the evaporator in a vapor state that is hotter than the saturation temperature. This condition reflects that there is not enough liquid refrigerant present to maintain proper liquid-vapor equilibrium, thus resulting in high superheat readings. This indicates either an inadequate supply of refrigerant or an issue with the evaporator's operational parameters, necessitating further investigation or corrective measures.