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EN/06.2016/i09 © STULZ S.p.A. – all rights reserved
WSA ExplOrEr OriginAl inStructiOnS
with replaceable cartridge and a sight glass with humidity indication.
Each refrigerant circuit disposes of the following safety devices:
low pressure switch
A low pressure switch is installed in each cooling circuit. It will be activated when the pressure
inside the cooling circuit drops down to 0.4 barg. The compressors of the circuit will be turned
off and an alarm signal is shown on the electronic control display. The pressure switch needs to
be reset manually.
High pressure switch
A high pressure switch is installed in each cooling circuit. It will be activated when the pressure
inside the cooling circuit exceeds 20.5 barg. The compressors of the circuit will be turned off
and an alarm signal is shown on the electronic control display. The pressure switch needs to be
reset manually.
Safety valve
A safety valve is installed in each cooling circuit. It is positioned on the pressure side of the
compressor. The safety valve will be activated when the pressure in the cooling circuit exceeds
the max. value of 24 barg. (Whether the chiller is operating or not.) In this case the safety valve
opens and the refrigerant will exit.
4.3.4 compressor
The chiller has semi-hermetic screw compressors equipped with internal capacity control. The
single compressor can be partializzed stepless from 25% to 100%.
In each unit there is one compressor per cooling circuit and can be separately switched on, off
and partializzed.
The compressor contains a crankcase heater.
4.3.5 Evaporator
The Explorer WSA is equipped with a shell & tube heat exchanger made with copper pipes and
steel shell. Fully insulated with 10 mm of thermal insulator.
Victaulic
®
connections as standard in the inlet and outlet of the water circuit.
4.3.6 condenser
The air cooled condensers are MicroChannel condensers completely made of aluminium real-
ized in W-shape modules. With having this type of condenser you avoid high pressure drops,
increase the heat transfer coefficient and reduce the amount of refrigerant needed.
For the free cooling model the MicroChannel is treated with a cataphoresis treatment which is
available for the base version as option.
4.3.7 Electrical cabinet
The electrical cabinet is divided into a load section and a control section. In the door in front of
the control section you will find a touch display with a transparent protection panel. The load
section contains a power switch operable from the outside which locks the cabinet door when
switched on.
The protection degree of the electrical cabinet is IP54.
4.3.8 Sensors
