Question 177Refrigeration & AC - 1st Asst/Chief

The correct answer is C) higher than normal discharge pressure. An excessive charge of refrigerant in a thermostatically controlled, air-cooled, refrigeration system using a thermostatic expansion valve (TXV) will cause the refrigerant to flood the condenser, resulting in a higher than normal discharge pressure. This is because the excessive refrigerant charge will reduce the subcooling of the refrigerant, leading to an increase in the condensing pressure and temperature. The other options are incorrect because: A) the compressor will not run continuously, as the excessive refrigerant charge will eventually cause the system to trip on high pressure; B) oil foaming is not a direct result of an excessive refrigerant charge; and D) the box temperature will not be lower than normal, as the excessive refrigerant charge will actually cause the system to overcool the box.