Valeo CITYSPHERE Instructions De Montage Et D'entretien page 49

Rooftop Air Conditioning System Citysphere
The compressor with integrated electric motor runs up. It compresses the refrigerant gas and delivers it to
the condenser where it condenses and gives off heat.
The resultant condensation heat is transferred to the outside air flowing through the condenser. In this
process the axial fan maintains a sufficient ventilation even when the vehicle is stationary. The liquid
refrigerant flows through the receiver-drier to the expansion valve, where it expands as a result of the
controlled pressure drop and then reverts to the gaseous state in the evaporator.
The warm circulating air in the passenger cabin is drawn in by the evaporator fan, mixed with fresh air,
cooled in the evaporator, dried and returned to the cabin via the air-diffusor. Resulting condensation water
is discharged via drains.
During operation, the refrigerant circuit is monitored by the anti-icing switch and the pressure switch. These
switches may switch off the compressor (if required).
If a defect occurs at one of the units, the other units continue normal operation.
When the air conditioning system is switched off at the control panel, the fan motors and the compressor
are stopped, the power supply of all components however, will be maintained.
Rainwater entering the rooftop system is discharged via several drain holes (20, Fig. 2.3).
Heating operation (comfort version only)
Once the system is switched on, the outside air temperature and the inside air temperature will be measured
by the control system. A soon as the following conditions are complied the heating function of the unit starts:
– The vehicle motor is running (signal from D+/61)
– The outside temperature is less than +17°C
– The inside temperature is between +10°C and +22°C
Fresh air
Warm air
Warm air
Circulating air
* Ref. to Fig. 2.3
Fig. 2.5 Heating operation of the unit
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