Refrigerant Circuit

Air Conditioning

Air conditioning
The air conditioning system is switched on by pressing the air conditioning button. The function LED lighting indicates that the air conditioning system is in standby mode.

The compressor only cuts in if the switch-on conditions are fulfilled. The evaporator then produces cold air which is raised to the required temperature in reheat mode with the aid of the heat exchanger.

If a mechanically controlled compressor is installed, the evaporator cut-out temperature will be dependent on the outside temperature. The cut-out temperature drops by 1 degree C if the outside temperature increases above 20 degree C.

To protect the evaporator from icing up, the outlet temperature is monitored by means of a sensor (evaporator sensor) and the compressor is controlled by means of an electromagnetic clutch.

Switching conditions for the electromagnetic clutch







Pressure sensor
Based on the coolant pressure, the pressure sensor determines the start-up torque of the A/C compressor and the necessary auxiliary fan stage and passes on this information in the form of a telegram on the K-bus to the DME/DDE.

Full load cutout
In order to shorten the rev-up time of the engine from idle up to full load, the electromagnetic clutch is switched off for a limited period of time at full throttle. The cut-out time is 3 seconds.