Question 171Refrigeration & AC - Assistant Engineer

The correct answer is D) Bring the part of the system to be opened to 0 psig. This is the correct answer because it is a critical safety precaution when working on a refrigeration system. Before opening any part of the system, the pressure must be brought down to 0 psig (pounds per square inch gauge) to ensure there is no residual pressure or refrigerant that could be released, which could be hazardous. The other options are not appropriate precautions, as bringing the system to ambient pressure (A), using the hot gas defrost line (B), or setting the high-pressure cutout to manual (C) do not properly depressurize the system before service.