6
GENERAL FEATURES
Description of components
External structure
. Basement, supporting structure and
lateral panels are made of galvanized and painted sheet-steel
(colour RAL 7035) to guarantee good resistance to atmospheric
agents. Accessibility to internal parts is possible removing the
frontal panel. For extraordinary manteinances also the rear
panel can be removed.
Refrigerant circuit
. It is contained inside a compartment
separated from the air flow to simplify maintenance and control
operations.
The hermetic rotary or scroll (according to the model)
compressor
(1) is mounted on damper supports and is
protected against overtemperatures and overcurrents. It is
equipped with an electrcal heater, that is activated when the
compressor turns off, to keep the compressor crankcase oil
temperature high enough to prevent migration of the refrigerant
during winter stops and to evaporate any liquid present in
the crankcase, in order to prevent possible liquid rushes on
starting (only heat pump models).
The
plant side heat exchanger
(2) is a brazed stainless steel
plate heat exchanger, properly insulated to avoid condensate
generation and to minimize thermal losses, and protected by
a differential pressure switch that detects whatever water flow
lack. It is moreover protected against freeze danger by an
antifreeze electrical heater.
The
source side heat exchanger
(3) is a finned coil realized
with grooved copper pipes and aluminium fins with notched
profile to increase the heat exchange coefficient. A tray is
obtained in the basement to collect the condensate generated
in heating mode.
The
expansion device
(4), a thermostatic expansion valve with
external equalizer, allows the unit to adjust itself to the different
operating conditions keeping steady the set superheating.
The refrigerant circuit of each unit contains moreover solid
core hermetic
filter dryer
(5) to restrain impurity and moisture
residuals that could be present in the circuit,
high and low
pressure switches
in order to assure the compressor to
operate inside the permitted limits,
4 way reverse cycle
valve
(6) to allow operating mode change reversing the
refrigerant flow (only heat pump models),
liquid receiver
(7) to compensate the different refrigerant charge required
in heating and in cooling mode (only heat pump models) and
pressure connections
SAE 5/16” - UNF 1/2” - 20 equipped
with pin, gasket and blind nut, as required for the use of R410A
refrigerant (they allow the complete check of the refrigerant
circuit: compressor inlet pressure, compressor outlet pressure
and thermostatic expansion valve upstream pressure).
The axial
fans
(8) are contained in a sheet nozzle and are
equipped with a safety grille. The fans rotational speed is
modulated continuosly by a phase cut device to control the
condensation pressure (in cooling) and the evaporation
pressure (in heating) in order to extend the operating limits of
the unit and to reduce noise emissions.
Hydraulic circuit
. All the pipes are thermally insulated to
avoid condensate generation and minimize thermal losses.
The circuit can be equipped with different kind of circulation
pump (option). In that case the circuit is also equipped with
expansion vessel and air vents. It is also possible to integrate
inside the unit a buffer tank arranged as buffer on the flow
towards the plant (option). In that case the circuit is equipped
not only with expansion vessel and air vents, but also with
safety valve, automatic air vent and drain cock.
Electrical panel
. It contains all the power, control and security
components necessary to guarantee the unit to work properly.
The unit is managed by a microprocessor controller to which all
the electrical loads and the control devices are connected. The
user interface, placed on the frontal panel, allows to view and
to modify, if necessary, all the parameters of the unit.
All the units are supplied with an outdoor temperature sensor,
already installed on the unit, in order to realize the climatic
control.
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