During a compressor burnout, which sample is collected for analysis?

• A. Refrigerant
• B. Oil
• C. Water
• D. Coolant

Answer: (B)

During a compressor burnout, the lubricating oil is collected for analysis because oil bears the direct record of the damage. The oil bath is where extreme heat and mechanical wear leave telltale signs—oxidation, varnish, sludge, and metal wear particles from bearings and gears. An oil analysis can reveal degradation of lubrication (changes in viscosity, acidity, insolubles) and contamination that indicate how severe the burn was and what components may need replacement. Refrigerant samples matter for checking charge and contamination, but they don’t reflect internal damage from burnout. Water or coolant samples aren’t representative for diagnosing a burnout in most HVAC compressors, so they won’t provide the same diagnostic value.