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The operating principle of the air conditioner
| Fig. 10.5. Compressor (sectional) with swinging discs and six-piston: 1 - the main control valve; 2 - electromagnetic clutch; 3 - pulley; 4 - Swinging disc; 5 - the piston; 6 - compression chamber
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By car mounted compressor with the swash plate. It is located on the left side of the engine and serves to compress the refrigerant pressure (about 1 kg) which is in the gaseous state. The compressor is driven by a belt drive from the crankshaft. During compression in the compressor refrigerant changes to a liquid state and is supplied to the evaporator disposed in the housing under the heater panel. There refrigerant evaporates again with the absorption of energy, thereby forming the cold. Flowing past the evaporator the air is cooled on its plate. The refrigerant is then again supplied to the compressor (Fig. 10.5). For his best condensation after compression to two additional condenser fan. The cooling power is regulated by the air conditioning electronics and depends on the outside temperature, the temperature in the cabin and the desired setpoint temperature. For more information about the air conditioner
| Fig. 10.6. Access to both the auxiliary fan is opened after removing the grille
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The additional fan (Fig. 10.6) provides two speeds. At a pressure of 20 bar coolant circuit breaker is triggered. Then the relay, and additional fans get through the preliminary voltage resistors. When the coolant temperature is more than +107 ?� C the fans run at maximum speed. When the compressor is changed immediately setting the engine idling speed, so that he did not stop. The compressor consumes about 9 kW. In order to avoid thermal overload of the engine coolant temperature of about +115 ?� C compressor is switched off. The control unit receives information on the air conditioner compressor speed by the inductive sensor. Data on the frequency of the motor shaft receives a signal from the TD-Motronic system. If we obtain the relation between the two values is outside a predetermined area, it could mean that the compressor rotates with difficulty and accessory drive belt slipping on pulleys. In this case the safety shutdown of the compressor. When removing the engine closed circulation system air conditioner working fluid under high pressure, do not open without special equipment. Topping up the coolant in the system is possible only at the service station. Therefore, when removing the engine it is recommended to turn away from the compressor and piping system with brackets and fix them in the side of the engine compartment wire. The control unit air conditioner has a self-diagnostic system. Information about any faults can then be read from the memory device to a service station.
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