Question 23Refrigeration/AC - 1st Asst/Chief70% to pass
An excessive charge of refrigerant in a thermostatically controlled, air-cooled, refrigeration system using a TXV as an expansion device can cause which of the following?
AI Explanation
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.
Related Questions
#21 During the initial cooling down of a box temperature in a refrigeration system, which of the devices listed is used to prevent excessive gas pressure at the compressor suction for the purpose of prevention of overloading of the compressor driver? #22 Which of the conditions listed could cause excessively low refrigerant pressure at the compressor suction of a TXV controlled refrigeration system? #24 Low compressor head pressure in a refrigeration system can be caused by which of the following? #25 A reciprocating refrigeration compressor may be tested for leaking discharge valves by stopping the compressor, turning the discharge service valve all the way in, and then turning the compressor over by hand. If the discharge valves are leaking, the compound gage will show pressures which react in which way? #26 In an operating, water-cooled, multi-box refrigeration system, both low discharge and high suction pressures are being simultaneously experienced. The probable cause for this condition is which of the following?