Question 67Refrigeration & AC - QMED

The correct answer is C) prevent the entrance of air into the chiller when the chiller is idle. The pressure maintenance system shown in the illustration GS-RA-40 is designed to prevent the entrance of air into the chiller when the chiller is not in operation. This is important to maintain the system's integrity and prevent contamination of the refrigerant. When the chiller is idle, the pressure maintenance system uses a small pump to circulate the refrigerant and maintain a positive pressure, which prevents air from being drawn into the system. The other options are incorrect because they do not accurately describe the primary function of the pressure maintenance system in this context. Option A is incorrect as the system is not intended to maintain a low compression ratio under low heat load conditions. Option B is incorrect as the system is not intended to prevent air entrance under low heat load conditions specifically, but rather when the chiller is idle. Option D is incorrect as the system is not intended to prevent surging.