WDE
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© STULZ SpA . – all rights reserved EN/36B/08.2018
Compressor (CO)
A reciprocating compressor is used for the WDE40 model with 400V/3Ph+N/50Hz power
supply. WDE40 with 230V/1Ph/50Hz power supply is provided with a rotary compressor. Scroll
compressors are used for all the other models.
Compressors are basically composed of an electric motor and a mechanical section which is
powered by this motor for pumping the refrigerant gas.
In reciprocating compressors the pumping unit consists of a piston which slides inside a cylinder and
which generates, depending on its phase, compression and aspiration.
In rotary compressors, the pumping unit consists of a rotor with sliding blades, inside a stator. As the
rotor turns, compression is obtained with space reduction between rotor, blades and stator.
In scroll compressors the pumping unit consists of two spirals positioned one inside the other. One
spiral is fixed while the other performs orbital motion which aspirates and compresses the gas.
Condenser (BC)
This part allows the release of the heat of the coolant gas in the environment. It’s a microchannel
type, completely made of aluminium, with copper connections to the external piping. It’s not suitable
for acid and salt environments and it cannot be exposed to metal dust projections. For optimal
protection against salt spray, see option "Protective treatment on condenser and evaporator –
TREATW".
Liquid receiver (RL)
The liquid receiver, positioned between the condenser and the drying filter, keeps the subcooling
level of the refrigerant at a constant level and ensures maximum efficiency over varying operating
conditions.
Filter dryer (FG)
This is a mixed mechanical/chemical filter that separates out all particles of humidity from the
refrigerant that passes through it.
Thermostatic valve (VT)
The thermostatic expansion valve keeps the superheating at a constant value, adapting coolant
evaporation pressure to the real thermal load. This component is factory set during testing and must
not be tampered with.
Evaporator (EV)
This component is where heat from inner air passes to the refrigerant gas. It is a heat exchanger with
copper pipes and aluminium fins (designed for use in non-acid and non-saline environments only).
Surface has hydrophilic treatment. For optimal protection against salt spray, see option "Protective
treatment on condenser and evaporator – TREATW".
