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Translation from original instructions
5.3 Control and safety devices
The unit is integrally managed by an electronic microprocessor control that, through the various temperature and pressure
sensors installed in the unit, keeps its operation within the safety limits.
All the parameters involved with control of the unit are shown in the “Control Manual” that is an integral part of the docu
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mentation of the unit.
The manual fully describes the logic with which the checks of the unit take place during the various operating stages.
The devices are shown in the Technical Catalogue.
5.4 Principles of operation
The principle of these units is based on using the vapour compression refrigeration cycle, characterized by 4 phases (com
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pression, condensation, throttling and evaporation).
This cycle produces the transfer of heat from a fluid at lower temperature to a fluid at higher temperature, which is the op
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posite of what happens naturally.
In our specific case, these units consist of a refrigerant circuit that cools the water of a hydraulic circuit inside a heat exchan
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ger (“evaporator”) and rejects the heat through an air heat exchanger (“condenser”). This happens in units intended for
operation in cooling mode.
In units in heat pump operation, where hot water is produced, there is cycle reversal that reverses the function of the two
heat exchangers so that the water heat exchanger becomes the condenser and the air heat exchanger becomes the eva-
porator.
Refer to Fig. B.4 for the diagram illustrating the unit operating principle.
5.5 Structure
The frame is made of galvanized sheet-iron coated with polyester powder, which makes it highly resistant to weather con
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ditions. The cover of the unit is made of stainless steel. All screws and bolts are painted or made of stainless steel. Some
panels have an internal insulation made of closed-cell heat- and noise-insulating material.
The panels can be removed easily to allow full access to internal components.
5.6 Specifications
Air-condensed water chiller unit with “scroll” o “rotary” compressors, directly coupled axial or radial fans and dry-expansion
plate evaporators.