🔍 Key Concepts

• Crankcase oil behavior when refrigerant has been idle in the system • Effect of refrigerant migration and dilution of crankcase oil • What happens in the compressor at the moment of starting under different conditions

💭 Think About

• Think about which condition would allow refrigerant to slowly migrate into and dissolve in the crankcase oil over time, without being driven off. • When the compressor starts or runs, under which listed condition would trapped refrigerant in the oil be most likely to flash off suddenly and create foam? • Which option would actually reduce foaming rather than increase it (for example, low oil level vs. normal or high level with refrigerant mixed in)?

✅ Before You Answer

• Compare situations where the compressor is running continuously versus not running for an extended time—which lets refrigerant accumulate in the oil? • Ask yourself under which condition suction pressure and refrigerant distribution favor migration into the crankcase. • Before choosing, eliminate any option that would more likely cause insufficient oil, not foaming, in the crankcase.