For identifying the refrigerant type in a system, what primary feature should be consulted first?

When identifying the refrigerant type in a system, the equipment name plate is the primary feature to consult first because it typically provides essential information about the system's specifications, including the type of refrigerant used. The name plate is a standard and reliable source, placed on or near the equipment, offering immediate access to critical data necessary for servicing and maintaining the system. It includes not only the refrigerant type but also other vital details such as model number, capacity, and electrical specifications.

While the other options might contain useful information about the system, they do not serve as the first point of reference for identifying the refrigerant. The expansion valve plate may provide some details regarding the system's operation but is not necessarily a definitive source for refrigerant type. The compressor model can indicate certain characteristics of the system but would require cross-referencing with other documentation to ascertain the refrigerant. The manufacturer's manual is indeed useful and can provide comprehensive information, but it may not be as readily accessible as the name plate during troubleshooting or maintenance tasks. Consulting the equipment name plate offers a quick, direct, and authoritative answer to the refrigerant type present in the system.