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5
TECHNICAL CHARACTERISTICS
The
HPE
water chillers and heat pumps series are designed for residential and industrial applications, these units are extremely
versatile and can operate in heat pump mode with the ability of hot water production at a temperature up to 65°C for
environmental heating and sanitary applications with the utilization of electric heaters.
The use of brushless inverter compressor technology, matched with the electronic expansion valve and to the pump and the
variable speed blower are generally used for optimizing the power consumption and the operative efficiency of the refrigerating
components of the whole system.
5.1
FRAME
All i-HP units are 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: 4-way reversing cycle
valve, electronic expansion valve, liquid separator, liquid receiver, check and maintenance valves, pressure safety device according
to PED regulation (high pressure switch), and pressure transducers to accurately adjust the evaporating and condensing pressures,
filters for expansion valve to prevent its clogging. The versions with vapour injection also include heat exchanger to produce
vapour, electronic injector valve, and the ON-OFF valves of injection in case of two compressors.
5.3
COMPRESSORS
The compressors are scroll type DC inverter designed for use with R410A refrigerant, and are mounted on a rubber material acting
as a shock absorber. The compressors of the injection versions are designed to optimize the efficiency of the refrigerant cycle
under low ambient temperatures conditions and are supplied with connection for vapour injection.
The crankcase heater operates when the compressor remains off for at least 30 minutes and if the discharge temperature is below
20°C (with hysteresis of 2.0°C). When the compressor restarts, the crankcase heater will stop operation. We recommend to turn
on the unit and to put it in standby mode at least 6 hours before the first start-up.
The checking of the compressors is possible through the front panel of the unit that allows the maintenance of the compressors
even if the unit is in operation.
5.4
AIR-SIDE EXCHANGER
The air-side heat exchanger is made up of copper pipes and aluminium fins. The copper pipes diameter is 7,94 mm, the thickness
of the aluminium fins is 0,12 mm. The pipes are mechanically expanded into the aluminium fins in order to improve the heat
transfer coefficient. The geometry of this heat exchanger ensures a low value air-side pressure drop and then it allows the use of
fans with low number of revolutions (with the advantage of reducing the unit noise level).
5.5
FAN MOTOR
The fan motor is axial type with plastic aerofoil blades. It is statically and dynamically balanced and supplied with a safety fan
guard. The fan motor is a modulated brushless type, directly coupled and equipped with an integrated thermal overload
protection. 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 304 stainless steel braze-welded plates type, and is factory insulated with flexible
close cell material and is equipped with an antifreeze electric heater (optional accessory: KA). 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 CONTROL PANEL
The electrical control panel board is manufactured according to European Union directives currently in force. To access to the
electrical control panel board, put the disconnect switch in the Off position, (presence of a door lock system) and wait until fan
blades have come to a complete stop, open the front panel by removing the three screws with a flat-head screwdriver, turn to
open quarter-turn the two locks of the electric control panel board. The protection degree is IP34. The electric box is supplied with
a terminal block completed with free contacts for remote ON-OFF, and for winter/summer change over. The addition of the
optional module GI enables the management of further functions of the plant.
5.8
CONTROL SYSTEM
The
HPE
units are equipped with a microprocessor adopting an overheating control logic program through the electronic
thermostatic valve managed by the pressure transducers signals and temperature sensor. The CPU also manages the following
functions: water temperature regulation, antifreeze protection, compressors’ time setting, alarm reset, alarms management and
operation LED. Upon request, the microprocessor can be connected to a BMS remote control system and to the simpler HNS
system with our terminal units. The control system together with the INVERTER technology and the on board sensors can
continuously monitor and adapt the performance of the inverter compressor, of the circulator pump and of the fan motor.
5.9
CONTROL AND PROTECTION DEVICES
The units are standard equipped with the following control and protection devices: return water temperature sensor installed on
the return water pipe line from the plant, operating and antifreeze sensor installed on the outlet water pipe to the plant, high
