Which line is connected to indicators if the liquid oil acid test kit cannot be used?

Which line is connected to indicators if the liquid oil acid test kit cannot be used?

• A. Suction line
• B. Discharge line
• C. Liquid line
• D. Oil sump

Answer: (A)

The line on the low-pressure side, the suction line, is used because it carries oil that is returning to the compressor mixed with refrigerant. If you can’t use the liquid oil acid test kit to sample oil directly from the sump, connecting the indicator to the suction line lets you observe the condition of the circulating oil in the system. The discharge line and liquid line mainly carry refrigerant gas and liquid with little usable oil sample for this purpose, and the oil sump is where oil normally sits, but with the kit unavailable you can’t easily access it. So the suction line provides a practical point to detect acidity in the oil as it circulates back to the compressor.

The line on the low-pressure side, the suction line, is used because it carries oil that is returning to the compressor mixed with refrigerant. If you can’t use the liquid oil acid test kit to sample oil directly from the sump, connecting the indicator to the suction line lets you observe the condition of the circulating oil in the system. The discharge line and liquid line mainly carry refrigerant gas and liquid with little usable oil sample for this purpose, and the oil sump is where oil normally sits, but with the kit unavailable you can’t easily access it. So the suction line provides a practical point to detect acidity in the oil as it circulates back to the compressor.