Question 116Refrigeration/AC - QMED70% 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
The correct answer is C) higher than normal discharge pressure.
When there is an excessive charge of refrigerant in a thermostatically controlled, air-cooled, refrigeration system using a thermostatic expansion valve (TXV), it can cause the discharge pressure to be higher than normal. This is because the excessive refrigerant charge leads to a higher pressure in the system, which the compressor must work against, resulting in a higher discharge pressure.
The other options are incorrect because: A) oil foaming is caused by a low refrigerant charge, not an excessive charge; B) the compressor would not run continuously, as the high discharge pressure would eventually trip the high-pressure switch; and D) a higher than normal refrigerant charge would result in a lower than normal box temperature, not the other way around.
Related Questions
#114 Leaking suction valves in a refrigeration compressor are indicated by which of the following? #115 A refrigeration unit will tend to short cycle when operating under what conditions? #117 Which of the listed statements describes the reason why oil foaming occurs when starting a refrigeration compressor? #118 When a refrigeration compressor has developed a high head pressure as a result of a refrigerant overcharge, what should be done to compensate for or to correct this situation? #119 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?