In a refrigeration system, once the gage manifold hoses are attached to the compressor service valve connections and properly purged, what should be the status of the manifold valves and the service valves when the purpose for attachment is to read system pressures?

Correct Answer: Option A — both manifold hand valves should be closed and the compressor Service Valves should be cracked-off their back seats

Reading system pressures requires closed manifold hand valves to isolate gauge heads, while compressor service valves are cracked off their back-seats to communicate system pressure.