What conditions allow for a system to be opened and repaired without recovering the refrigerant to the required vacuum level?

The correct choice highlights a situation where a system can be opened and repaired without needing to recover the refrigerant to the required vacuum level. When a system has a large leak and an internal pressure of 0 psig, it indicates that the refrigerant has already escaped, and the system is essentially in a state where there is negligible or no refrigerant pressure remaining.

In such a scenario, since the system is effectively empty, it does not pose the same risks associated with refrigerant recovery that would normally apply when there is still refrigerant present or when the system is under pressure. This situation eliminates the requirement to achieve a specified vacuum level before opening the system for repairs, as there is no refrigerant that could leak out during the process.

Other scenarios mentioned, such as replacing major components or dealing with a non-operational compressor, generally require the refrigerant to be evacuated to prevent contamination and ensure safety during the repair process. Additionally, the type of refrigerant, such as CFC, does not impact the requirement to achieve a vacuum level for repairs, as this is more about handling of refrigerants in compliance with regulations related to recovery and systems under pressure. Therefore, the first option accurately describes the conditions under which the vacuum requirement can be bypass