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 Celsius if the outside temperature increases above 20 °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 .
ON (all conditions must be fulfilled) |
OFF (one of the conditions must be fulfilled) |
Remarks |
|---|---|---|
Air conditioning button ON |
Air conditioning button OFF |
|
Air flow control wheeldriver out of zero position |
Air flow control wheeldriver in zero position |
|
Evaporator temperature > 3 o C |
Evaporator temperature < 2 o C |
Dependent on outside temperature: The cut-out threshold drops by 1 °C at temperatures above 20 °C |
Enable sent from DME (DME-KOREL) |
Full throttle signal from DME initiates shut-down with respect to time |
Cut-out temporally limited to approx. 3 seconds. |
Engine speed >600 rpm |
Speed dropped below minimum value (600 rpm) |
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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 .
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.