Question 86Refrigeration/AC - Assistant Engineer70% to pass
After the refrigerant has been recovered, leaks repaired if necessary, the system ideally should undergo a dehydration evacuation prior to recharging with refrigerant. As shown in the illustration, besides the vacuum pump suction manifold isolation valve being opened, what would be the proper valve positions to accomplish and prove the evacuation? Illustration GS-RA-51
AI Explanation
The correct answer is D.
To accomplish and prove the evacuation, the proper valve positions would be: Valves 1, 2, and 3 should be in the mid-position, the low-side gauge manifold hand valve should be closed, and the high-side gauge manifold hand valve should be open. This allows the vacuum pump to draw a vacuum through the high-side of the system, effectively evacuating and removing any air or moisture. The closed low-side valve prevents air from re-entering the system during the evacuation process.
The other options are incorrect because they do not properly isolate the low-side of the system or allow the vacuum pump to effectively evacuate the entire system.
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