Question 63Refrigeration/AC - 1st Asst/Chief70% to pass
As shown in the illustrated LP centrifugal chiller high efficiency purge recovery unit piping schematic, what statement is true concerning the vacuum pump? Illustration GS-RA-55
AI Explanation
The correct answer is D.
The vacuum pump is designed to remove refrigerant vapor from the carbon filter tank and transfer these vapors to the evaporator to minimize the loss of refrigerant to the atmosphere. This is the proper function of the vacuum pump in a centrifugal chiller high efficiency purge recovery unit, as it helps to recover and reuse the refrigerant rather than venting it to the environment.
The other options are incorrect because: A) the vacuum pump is not primarily for dehydration evacuation, B) the vacuum pump does not vent non-condensable gases to the atmosphere, and C) the vacuum pump does not transfer vapors to the purge chamber to clear the float valve.
Related Questions
#61 To add small amounts of refrigerant to the low side of an air conditioning system, the refrigerant should be introduced through a particular valve and in a particular state. What valve and state combination is correct? #62 Concerning the arrangement of equipment and associated hoses shown in the illustration, which statement is true? Illustration GS-RA-58 #64 To add refrigerant to the high side of an air conditioning system, you should close the king valve and introduce the refrigerant through what valve in what state? #65 The compressor used in a water-cooled air conditioning system is short-cycling. A service check determines that the suction pressure remains above the normal cut-in point during cycling and that the discharge pressure rapidly builds up to the cut-out point while running and gradually falls to the cut-in point during the off cycle. What is likely the cause? #66 When pumping down an air conditioning system to test the low-pressure cutout switch, assuming that the compressor is running, what should be done to initiate the test?