HWA1-A & HWA1-H
Air/Water chillers and heat pumps with axial fans
7
5
TECHNICAL CHARACTERISTICS
The
HWA1/HWA1-H
air-water chiller/heat pump units are designed for commercial and industrial applications, they are very
compact and still equipped with large-surface air side exchangers ensuring a high efficiency with the highest ratings of EER and
COP. The use of scroll compressors with high efficiency and particularly robust together with the patented system of oil recovery
and distribution used on tandem circuits ensure high reliability with consistent performances.
The units are all equipped with high and low pressure transducers, NTC sensors at the compressors’ inlet and a controller with
microprocessor with integrated driver for the management of an electronic expansion valve
to further improve the
performances of the units for non-standard applications.
5.1
CARPENTRY
The
HWA1-A/HWA1-H
units are all made up of hot-galvanised thick sheet metal, painted with polyurethane powder enamels at
180°C to ensure the best resistance against atmospheric agents. The front panel is hinged to the lift side to allow access to the
internal components for inspection and maintenance. The screws and the inserts are made up of galvanized steel.
5.2
REFRIGERANT CIRCUIT
The refrigerant circuit has been manufactured according to the UNI EN 13134 directive concerning welding procedures. The
refrigerant gas employed in these units is R410A type. The refrigerant circuit includes in its basic version: electronic expansion
valve, liquid separator, liquid receiver, check valves for maintenance and control, safety device according to PED regulation (high
pressure switch), relief valve for the refrigerant, pressure transducers to accurately measure the evaporating and condensing
pressures, high capacity drier unclogging drier filter for lamination valve and remove any moisture inside the circuit, the liquid
indicator for controlling the refrigerant charge. The “
H
” heat pump versions are equipped with 4 way valve for refrigerant cycle
inversion and an outdoor air temperature measurement sensor.
5.3
COMPRESSORS
The compressors are scroll type, especially designed for operation with R410A refrigerant, and are mounted on a rubber material
acting as a shock absorber. The crankcase heater operates when the compressor is off and stops when the compressor restarts
operation.
We recommend to turn ON the unit and to put it in standby mode at least 6 hours before the start-up.
The inspection of the compressors is possible through the front panel of the unit which allows also the monitoring of the inner
components.
5.4
AIR-SIDE HEAT EXCHANGER
The air-side heat exchanger for chiller units is made entirely of aluminium with the new
microchannel technology
which allows to
reduce significantly both the losses on the air side and the refrigerant charge; with this technology, the heat transfer across the
front surfaces is more equally effective compared to conventional heat exchangers. The heat pump models equipped with finned
heat exchangers with optimized fin pitch for operation at low temperatures.
5.5
FAN MOTOR
The fan motor is axial type with plastic aerofoil blades. It is statically and dynamically balanced and supplied with safety fan guard
and inlet and outlet airflow of double flared profile specially shaped to increase the efficiency and to reduce the noise level. The
fan motor is AC type designed to operate at one or two speeds with star/delta (Y-Δ) connection regulated in pressure, or is a speed
modulation brushless EC motor directly coupled and equipped with an integrated overheat protection device. The protection class
of the motor is IPX4 according to CEI EN 60529.
5.6
USER-SIDE HEAT EXCHANGER
The user-side heat exchanger is made up of AISI 316 stainless steel braze-welded plates type, and is factory insulated with flexible
close cell material, as for the heat pump models, the heat exchanger could be equipped with an antifreeze electric heater
(optional KA accessory only for heat pump models). Each evaporator is equipped with a temperature sensor for antifreeze
protection that activates the circulator, even in the case where the unit is turned off when meeting the setting parameters by
controller.
5.7
ELECTRICAL PANEL
The electrical panel is manufactured according to European Union directives currently in force. To reach the electrical panel, put
the disconnecting switch in off position, (presence of a door lock system) and open the front plate of the electrical panel after
removing the fixing screws. The protection degree is IP34. The electrical panel is supplied with a terminal block with free contacts
for the remote control ON-OFF switch.
5.8
CONTROL SYSTEM
The
HWA1-A
and
HWA1-H
units are all equipped with a central system adopting a microprocessor with overheat control logic
managed by the signals sent by the pressure transducers and temperature sensors. The CPU also manages the following functions:
water temperature regulation, antifreeze protection, compressors’ time setting and start-up, management of fan motor and
circulating pump (if present), alarms reset, alarms notifications and operation LED. Upon request, the microprocessor can be
connected to a BMS remote control system.
