What could cause a situation where the sight glass indicates a full charge, the liquid line is hot, and the unit is cycling on internal overloads?

The scenario describes a situation where the sight glass indicates a full charge, the liquid line is hot, and the unit is cycling on internal overloads. Each of these indicators can point to various issues within the system.

When the sight glass shows a full charge, it suggests that there is an adequate amount of refrigerant in the system, which might lead one to believe there shouldn't be any issues. However, the presence of a hot liquid line indicates that the refrigerant is not cooling effectively, which can result from insufficient heat exchange.

A dirty condenser can restrict the heat exchange process, causing higher temperatures in the refrigerant as it enters the liquid line. If the condenser coils are blocked or dirty, they won't effectively reject heat, thus leading to a hotter liquid line and potential cycling on overload as the system continues to work harder to maintain set temperatures.

Additionally, the unit cycling on internal overloads signals that the compressor is working harder than it should. This could be due to overheating caused by either a dirty condenser or other issues affecting the system's efficiency.

While low refrigerant charge and a faulty evaporator could both affect system performance, the first two indicators suggest functional problems such as a dirty condenser. Given that both a dirty condenser and low refrigerant