John Deere AIR CONDITIONING SYSTEM - catalog of spare parts
The air conditioning system is a closed system filled with R134A refrigerant. The system consists of a high pressure section and a low pressure section. The high pressure section goes from the compressor through the condenser and dehumidifier to the thermostatic valve. The low pressure section goes from the thermostatic valve through the evaporator to the compressor. Low pressure vapor refrigerant enters the compressor. The compressor compresses the refrigerant. As a result, the pressure and temperature of the refrigerant increase. However, the refrigerant retains its gaseous form.
After that, gaseous refrigerant at high pressure and with high temperature enters the condenser. In a condenser, refrigerant with a high temperature loses heat, giving it to relatively cooler ambient air (the condenser is located in the air stream). Due to heat loss, the refrigerant takes on a liquid form. Already in the form of a liquid, the refrigerant flows from the condenser to the dehumidifier, where moisture and dirt present in it are removed from the refrigerant.
Liquid refrigerant through a dehumidifier enters the thermostatic expansion valve. Thermostatic expansion valve is a device that provides a change in system performance. In the valve, the refrigerant expands, after which it enters the evaporator, while being under low pressure and having a low temperature. Absorbing heat from the air blown through the evaporator, the refrigerant evaporates and enters the compressor again. The whole cycle repeats first.
Evaporator temperature is measured by a sensor. If the temperature in the evaporator drops to a certain value, the temperature switch is turned off. In this case, the electric circuit is broken and, as a result, the compressor is turned off. If the temperature in the evaporator rises to a certain value, the temperature switch switches on again.
The service valve for the low pressure section is located between the compressor and the thermostatic expansion valve.
The service valve for the high pressure section is located after the dryer.