🔍 Key Concepts

• Behavior of refrigerant and oil in the compressor crankcase • How liquid refrigerant returning to the crankcase affects mechanical parts • Relationship between crankcase oil condition and compressor operation

💭 Think About

• Think about what foaming oil in the crankcase really means: what is mixed with the oil, and how does that affect how the compressor runs mechanically? • Which of the listed components (expansion valve, compressor, water regulating valve, crankcase drains) is directly affected by what happens inside the crankcase? • If the oil is full of bubbles and not providing solid lubrication, what kind of mechanical symptom would you expect from the compressor?

✅ Before You Answer

• Identify which option is located inside or closely associated with the compressor rather than elsewhere in the system. • Ask yourself: does foaming oil more likely change a flow setting (like a valve) or cause a mechanical operating problem? • Eliminate any choices that are controlled mainly by pressure or temperature signals in the refrigerant line, not by the condition of the crankcase oil.