5
7425MUM753
Model: CWE-Q
- Use and Maintenance Manual
Rev. 15
2.2
W
ATER CIRCUIT
The water circuit mainly consists of: evaporator, water strainer and hydraulic pipes.
The water flows first into the evaporator, where it is chilled, and then it is sent to the system.
A differential pressure switch on the evaporator checks that the flow of water is sufficient and
stops the compressors if the flow-capacity of the water does not ensure the good functioning
of the exchanger.
A fine mesh metal water strainer at the entrance to the evaporator catches any solid residues
that could damage the evaporator.
As option, units can be equipped with P3 pump, atmospheric tank, mechanical water level
switch and manual regulating bypass valve.
A manometer completes the unit's water circuit.
2.3
F
ANS
The fans force air through the condenser’s fins to remove the heat from the condensation of
the refrigerant gas, thus limiting the pressure inside the condenser.
CWE-Q
chillers use external-rotor axial fans with thermal protection inside the motor winding.
2.4
C
ONDENSATION CONTROL
When the ambient air temperature decreases air flow cooling capacity increases
considerably, lowering the pressure within the condenser. The fans are switched off (or
slowed down in case of CA, CE and CL options) to reduce air flow and prevent the
condensation pressure going below the acceptable limits for correct chiller circuit operation.
With CA, CE and CL the fans are actually managed electronically by the condensation
pressure, enabling correct machine operation even when the external air temperature is very
low (see section
7
Operating limits
).
2.5
C
ONTROL OF THE WATER TEMPERATURE
The purpose of the chiller is to maintain the temperature of the water produced within a
desired interval as the load on the system varies; this is handled by an electronic controller
and a temperature probe that turn the compressor on and off appropriately (also see
paragraph
5.3 Controlling water temperature
).
2.6
P
ROTECTING THE INTEGRITY OF THE MACHINE
In addition to controlling the temperature, the electronic controller uses pressure switches,
thermostats and timers to prevent and handle situations that could compromise the integrity
of the machine (also see Chapter 6
Safety Devices
).
Summary of Contents for PURESTREAM CHILLERS CWE-Q 041
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