Refrigerator Commissioning. Contaminants

During the installation, the system must be clean and dry, with the least exposure to air. Avoid the entry of foreign matter, such as solder, flux, solvents, metal and dirt particles, and carbon deposits; the latter are the result of soldering without passing a neutral atmosphere through pipelines.

Failure to take precautionary measures may lead to corrosion caused by air and moisture, or oxidizer at high temperature. Other problems include:

1. Copper plating of contaminated oil. It forms on the bearings and planed surfaces in high temperature areas. Moisture in the system can also be the cause.

2. Frosts, which may take place in the system components, if the procedure of correction of dehydration (evacuation) is not adopted.
3. Sludging that the chemical decomposition of oil at high temperatures in the presence of non-condensables.

Chemical accident or thermal decomposition of both refrigerant and oil at a temperature of 150^o C (300^o F)are more likely to happen with refrigerants R22, and those in R500 group. In the presence of hydrogencontaining molecules thermal decomposition produces hydrochloric and hydrofluoric acids, a condition that is totally undesirable, if hermetic or semi-hermetic compressors are. For this reason, it is imperative that the evacuation period is adequate.

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