EN/
/0915/WLA Compact
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4.3. Components of the refrigerant circuit
The compressor compresses the refrigerant gas and takes it at a higher temperature and pressure. By crossing the
condenser, the hot gas is cooled and liquefied, thus releasing heat into the outdoor air. Pushed by the electronic
thermostatic expansion valve, the liquid refrigerant loses pressure in order to start evaporating. This happens inside
the evaporator, where the refrigerant absorbs the heat of the water or mixture to be treated, cooling it down.
Compressor
The compressor technology changes depending on the refrigerant power. The table indicating size-type relation is
provided below.
The compressor is provided with thermal protection against overload.
Size
Compressor
WLA 12
Piston compressor
WLA 15
Piston compressor
WLA 22
rotary vane
WLA 23
rotary vane
WLA 30
rotary vane
WLA 34
scroll
WLA 44
scroll
Condenser
The copper-aluminium condensing coil has copper pipes and aluminium fins.
The chiller is not suitable for use in environment featuring aggressive atmosphere.
Fan
Installed on the rear side of the condenser, this intake fan is not duct-type. The fan with metal blades is provided with
metal protection grid.
Evaporator
The plate heat exchangers are made of AISI 316 stainless steel and AISI 304 brazed stainless steel.
The refrigerant liquid must comply with the provisions described in paragraph
Expansion valve
This mechanical expansion valve adjusts the refrigerant flow rate to the evaporator according to the temperature
and evaporator outlet pressure (compressor suction). Adjustments for correct operation are set by default and must
never be modified.
4.4. Safety components of the refrigerant circuit
High pressure switch
A high pressure switch is installed on the refrigerant circuit and it triggers when the pressure inside the refrigerant
circuit exceeds 40.5 barg. The circuit compressor is deactivated and an alarm signal appears on the electronic
controller display. The alarm conditions stops when the pressure drops below 33 barg.
The pressure switch rearms automatically. To access the rearm button installed on the pressure switch, remove the
chiller front panel. The pressure switch is located in the low left corner, behind the compressor.