Humidity associated with halogenated refrigerants, oil and high temperatures causes the following system problems:
- Freezing in the expansion valve seat - prevents the passage of refrigerant to the evaporator, reducing the pressure in this and turning the compressor off by the low pressure switch. Once the compressor is switched off, the ice in the valve is melted, the temperature and pressure near the valve rises, the compressor starts again and the cycle repeats.
With frequent starts and shutdowns, the compressor motor tends to burn.
- Formation of hydrochloric acid and hydrofluoric acid - these acids attack metallic parts of the system, glass visors and insulation varnish, occurring then deposition of copper, which causes mechanical defects and weakening of the insulation of the motor that results in its burning.
- Decomposition of the lubricating oil - the decomposed oil forms a thick mud, which clogs the lubrication channels and eventually locks compressor moving parts. The result of this is the encripamento or burning of the engine.
- Copper deposition - Copper is removed from the tubes in small particles and then deposited in high temperature areas such as crankshafts, discharge valves and oil pumps. This increase of material in the moving parts reduces the gaps, causing mechanical failures.
The existence of moisture can be verified by checking the color of the hygroscopic element of the liquid display. The hygroscopic display element changes color as it absorbs moisture. When moisture is detected in the system, the liquid drier filter should be replaced immediately.
