Question 171Refrigeration & AC - Assistant Engineer
70% to passWhich of the precautions listed should be taken before opening any part of a refrigeration system for the purpose of accomplishing non-major repairs?
ABring the part of the system to be opened to a pressure corresponding to the ambient temperature.
BUse the hot gas defrost line to remove any frost on the evaporator coils.
CSet the high-pressure cutout on manual to prevent automatic starting.
DBring the part of the system to be opened to 0 psig.
AI Explanation
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.
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