RXA-I PLUS

> REFRIGERANT CIRCUIT

It is contained in a protected compartment to simplify the maintenance operations. A DC inverter compressor, twin rotary type, ensures great dynamic balance and reduces vibrations. It is placed on vibration-damping rubber supports and wrapped by a double layer of sound-absorbing material to minimise the noise. Furthermore, the compressor is equipped with crankcase oil heater. The circuit includes a stainless steel brazed plates heat exchanger complete with antifreeze heater, electronic expansion valve, 4-way valve, finned coil consisting in copper tubes and aluminium fins, axial fans with brushless DC motor complete with safety protection grilles. The variable speed control of the fans permits a correct operation both in case of low outdoor temperatures -in cooling mode- or warm outdoor climate in heating mode

> HYDRAULIC CIRCUIT

It is inside in a compartment, protected from the air flow, to simplify the maintenance operations. It comprises an electronic circulator (brushless DC motor), water flow switch, automatic air vent, water pressure gauge, expansion vessel, safety valve, water filter. The plate heat exchanger and water piping are thermally insulated to prevent condensation on the external surfaces and reduce temperature loss.

> ACCESSORIES

- Electrical booster (backup heater box) Suitable for indoor installation, it consists in an electric heating element (3kW, 230V-1-50) mounted inside a painted sheet metal box, complete with electrical control panel. The heat pump uses the booster for integration purposes. It is used also as a backup out of the operational limit conditions or for alarm.

- Rubber antivibration dampers

- Buffer tank 60-liter tank in painted sheet metal, thermally insulated. The cylinder is included inside a box, which can be positioned below the heat pump.

> CONTROL SYSTEM

The internal controller manages the inverter system and the correct operation of the compressor. It integrates regulation algorithms based on pre-set climatic curves, which can be selected by the user. It is then possible to handle the DHW circuit, alarm alerts, pump anti-seize cycle and integration with external heating sources. An evolved timer is included for climatic and acoustic comfort program.

The user interface - consisting in a wired panel - permits the operations listed below:

- HEATING AND COOLING SYSTEM The unit, when active in heat or cool mode, modulates the frequency of the compressor with the aim to keep system temperature to the setpoint value.

- DOMESTIC HOT WATER PRODUCTION (DHW) The unit operates in heating mode to reach and keep the temperature inside a DHW cylinder (not supplied) to the setpoint value. A 3-way diverter valve (not supplied) is needed, together with a temperature sensor (T5 probe, L = 10m, provided) to be inserted into one well of the DHW tank.

- ADDITIONAL HEATING SOURCES (boiler or electric heating element). Depending on the parameters set, these sources can intervene as integration of the heat pump, when there is requirement for space heating or for DHW production. The external sources can be automatically switched on, also as a backup, in case the heat pump cannot work for anomaly error or operational temperature limits.

- ELECTRIC HEATER IN THE DHW TANK It is possible to handle the electric heating element of the DHW cylinder as an integration/backup or for legionella protection cycle.

- FAST DHW This manual function permits to reach DHW setpoint in the shortest time, using all available heating sources.

- LEGIONELLA PROTECTION it is possible to set weekly cycles of dhw disinfection, via temperature increase. For this purpose, the heat pump needs energy supplement by heating element inside dhw tank or a boiler.

- SILENT MODE Provided the function is enabled, it is possible to schedule up to 2 periods (normally night/rest ones) when the appliance shall operate in low-noise mode. The maximum frequency of the compressor will be thus reduced, together with fan’s speed. Acoustic drop rate can be set in 2 levels.

- REMOTE ON / OFF using an external contact. The unit can be switched on and off via an external contact.

- HEATING / COOLING REQUEST via external contacts. The unit can be activated in heating or cooling mode via two external contacts (eg. room thermostats).

- ECO/COMFORT It is possible to define daily time bands and corresponding set point for ECO and COMFORT modes, either in heating or cooling operation

- WEEKLY TIMER Scheduling on 6 time bands per each day of the week, with specification of the operating mode

(COOL / HEAT / DHW) and the required setpoint.

- ANTIFROST PROTECTION Guaranteed for outdoor air temperature down to -20°C, thanks to the intervention of all the available sources inside the heat pump: the machine operating in heating mode, together with the onboard electric heating element (as a standard on the plate heat exchanger) and the electric booster (if installed).