🔍 Key Concepts

• Behavior of oil-refrigerant mixtures during compressor start-up • Purpose of crankcase lubrication in a refrigeration compressor • Effects of foaming on oil delivery to moving parts

💭 Think About

• Think about what happens to the oil level and oil pump pickup when the oil is full of bubbles instead of liquid oil. • Consider which of the choices would be most directly and immediately caused by frothy, aerated oil in the crankcase. • Ask yourself: during start-up, what is the most critical function that crankcase oil must perform for the compressor to survive?

✅ Before You Answer

• Verify which option describes an immediate mechanical risk during start-up, not a long-term maintenance issue. • Check which choices involve chemical changes over time versus a direct result of air/foam in the oil. • Focus on the choice that best matches a situation where the compressor is running but not getting solid, continuous lubrication.