Question 23Refrigeration & AC - 1st Asst/Chief

You are correct, the answer is A) 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 system to have a higher than normal discharge pressure. This is because the excessive refrigerant charge will flood the condenser, resulting in a higher condensing temperature and pressure. The other options are incorrect because: B) the compressor will not run continuously, as the high discharge pressure will cause the system to short-cycle; C) the box temperature will not be lower than normal, as the excessive refrigerant charge will actually cause the box temperature to be higher; and D) oil foaming in the compressor is not a direct result of an excessive refrigerant charge.