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© STULZ S.p.A. – all rights reserved EN/06.2016/i09
WSA ExplOrEr OriginAl inStructiOnS
For additional freeze protection at low ambient temperatures consider using the optional electri-
cal heaters.
The following additional components are necessary for the external hydraulic circuit:
• Suitable connection pipes according to the drawings in this chapter.
• Stop off valves upstream the chiller to be able to take the chiller unit out of the chilled water
circuit in case of repair works without having to drain the entire circuit.
• Air relief valve at the highest point of the circuit.
• Filling valve at the lowest point of the circuit.
• Mesh strainer in the chilled water inlet with mesh size of 1600 μm.
• An appropriate insulation of the pipework to prevent condensate formation.
If the chiller is not provided with the following components, the external hydraulic circuit must be
equipped with them additionally:
• Circulating pump with sufficient delivery height according to the minimum and maximum flow
rates and corresponding pressure drop which can be found in chapter "5.4 Technical Data" at
page 41.
• Expansion tank with safety valve to ensure a possibility of expansion for the liquid at temper-
ature variations. The expansion tank must be dimensioned in such a way that the water circuit
volume can increase by 2% without draining off liquid through the safety valve.
• Storage tank as an accumulator for heat energy to reduce the on/off cycles of the compressor.
A storage tank is recommended if the water volume of the water circuit is less than 10 liters/
kW cooling capacity. The storage tank should be lined out with thermic insulation.
WArning
The heat load should not be less than half the minimum cooling capacity of the unit.
In addition to the differential pressure switch, a flow switch can be installed in the outlet of the
hydraulic circuit as an additional protection device for the evaporator, measuring whether the
fluid is circulating.
DAngEr
The discharge of the safety valve must be positioned in a proposed area so that the leaving
fluid will not endanger persons.
Evaporator drain connection of the safety valves
3/4" G male
Another criterion for the external water circuit is the water quality. Please check chapter “5.2
Chilled water quality” at page 37 for detailed information about water quality requirements.
The most sensible component in respect of pollution and corrosion is the evaporator, whose
heat transmission ability decreases in this case. The water should be free from solid particles.
For this purpose we recommend the installation of a fine mesh strainer upstream the evaporator.
