Chillers Alpenta SAC

Standard features

Selected features of standard execution of the unit includes:

• Compressors – hermetic high efficiency scroll compressors with axial and radial compliance, crankcase heaters, internal overheat protection and discharge temperature control.
• Fans – highest efficiency with optimized full bell mouth with guide vane and diffusor (meets requirements of the current ErP Directive)
• Evaporator – efficient braze welded stainless steel plate exchanger.
• Condenser – reliable aluminium fins and copper pipes exchanger.
• Cooling circuit – condensation controlled by high pressure transducer.
• Hydronic circuit – differential pressure switch and water IN/OUT pressure gauge.
• Casing – galvanized steel sheet metal painted RAL7035 provide long lasting resistance against corrosion.
• Electrical panel – made in accordance with standards of EN 60204-1, phase failure protection relay
• Communication – RS485 Insulated interface for ModBUS® Master/Slave, BacNET® MS/TP

Accessories available on request includes:

• Soft starters
• Remote control panel (HMI)
• Control panel electric heating
• Epoxy coated condensing coils
• Refrigerant gauges
• Electronic expansion valve
• Desuperheater or full recovery
• Fan speed control – EC fans or cut phase speed control
• Low noise execution – compressor jackets
• Low temperature execution – electrical box heaters, fan speed control and refrigerant circuit adaptation
• Hydronic circuit accessories – water pump, reserve water pump, expansion vessel, accumulation vessel, relief valve, shut-off valves, check valves, Victaulic kit
• Rubber or spring anti vibration mounts

Unit description

Operating limits

Standard execution cooling works at full load down to 0°C, with fan speed control (EC fans) and Low temperature option works down to -20°C. In summer season the unit works up to 45°C. Protection during extreme temperatures is supervised by ACS limitations functions. Cold water setpoint depend on fluid type used, for water the minimal setpoint is 4°C (for more details refer to the technical documentation ACS).

Heating mode is effective up to -15°C and the water temperature is controlled by override function during very low temperatures. Maximal hot water production setpoint is 55°C.

Condensing unit control

CU unit version is externally controlled via digital or analog signals to the unit main controller. There are one or two steps of digital control, depending on compressor quantity or 0-10V analog control with pre-defined switching levels (for more details refer to the technical documentation ACS).

External control

Every unit could be controlled by external On/Off signal to the main controller and also sends alarm signal to the external controls.

Alpenta Control System (ACS)

Sophisticated control system ensures data collection and subsequent control in real time to ensure maximum operating efficiency with respect to energy savings and service life of technological components of the unit. Main functions of the application take care of:

• Cooling / heating power control based on measured parameters while simultaneously dynamically adapting the unit's power to maximize energy efficiency.
• Limitation of cooling / heating capacity in situations leading to operation at the limit of technological possibilities of the unit equipment.
• 3-level alarm system protection against damage caused by operation beyond the technological capabilities of the unit equipment.

Control panel

Control panel, components and wiring made in accordance with standards EN 60204-1 electrical directive. Single point of power connection, IP 54 protection class, power phase sequence protection and optionally heated control box. Main on/off switch mounted on front panel, numbered, and signed electrical wires to facilitate maintenance and service. All power components (compressors, fans, pumps) are thermally protected.

HMI interface panel with protective cover mounted or supplied for remote installation on request.

Controller

Main microprocessor controller pre-configured during factory test with default settings helps fast commissioning on site. Intuitive user interface with 3 level of access – user, skilled user and technician.

RS485 serial communication port allows remote management through control protocols ModBUS® or BacNET®. Optionally Ethernet port available.

Compressors

Recognized brand hermetic scroll compressors with axial and radial compliance for superior reliability and efficiency, equipped with crankcase heaters. Low sound and vibration level compressors installed on anti-vibration mountings, optionally equipped with sound jackets.

Electronic control of discharge temperature and motor protection device against high temperature. Discharge check-valve. Compressor operating time and number of starts helps optimize sequencing and service diagnostics.

Water heat exchanger

Stainless steel AISI 316 plate copper brazed heat exchanger externally insulated with thermal foam and located inside of the chiller casing. Threaded or Victaulic type of water hydraulic connection is located outside of the unit casing.

3 step antifreeze protection by water pressure differential switch, leaving water temperature NTC sensor and refrigerant low pressure transducer with limitation function of control system.

Air heat exchanger with fans

Reliable copper tubes / aluminium fins heat exchanger optionally protected with metallic grid protection.

Highest efficiency fans with optimized full bell mouth with guide vane and diffusor (meets requirements of directive ErP 2015). Safety fan guard fitted on air flow discharge. Fans are fully installed inside of the unit casing – flat top, reducing noise distribution and increasing condenser effectiveness. With flat top installation the suction point of the fan is closer to the condenser’s central point.

Fan motor protection class F and internal temperature sensor guarantees reliability during high ambient temperatures. Fix speed and optionally variable speed via EC fans or cut phase controller.

Heat recovery

Partial (desuperheater) or full heat recovery stainless steel brazed plate type exchangers located inside of the unit casing. The unit is equipped with an additional water heat exchanger fitted to the compressor discharge line in series or parallel to the air condenser coil. This solution allows to get energy recovery up to 25% with desuperheater or 100% of condensing heat with full recovery option. The heated water could be used for sanitary or other applications.

Refrigerant circuit

Brazing of refrigerant circuits made under nitrogen by certified personnel. Each unit refrigerant circuit is factory pressure and leak tested and thereafter vacuumed before being charged with R410A refrigerant.

Each chiller unit is subjected to a complete functional run test to guarantee operational quality.

Cooling circuit is standardly equipped with hermetic or replaceable cartridge type of drier filter, solenoid valve, thermostatic or optionally electronic expansion valve, sight glass with moisture indicator, low pressure switch, high pressure switch with manual reset, discharge temperature sensor, high pressure and optionally low pressure transducer, pressure relief valves where required (EN 378-2) and suction line insulation.

Additionally, depending on execution of the unit, there are suction line temperature sensor, 4-way reverse valve, check valves, liquid receiver and accumulator on suction line.

Hydronic circuit

All parts of hydraulic module are located completely inside of the chiller.

Standard parts of hydraulic circuit of a chiller consists of water entering and leaving NTC temperature sensors, water antifreeze protective differential pressure switch, water gauge with shut-off valves enabling of measurement pressure difference on the evaporator.

Optionally the chiller could be equipped with centrifugal pump (available static pressure about 200 kPa), reserve centrifugal pump with operating balancing and automatic changeover, check valves, shut-off ball valves, membrane expansion vessel with shut-off valve for maintenance, pressure relief valve, water strainer, automatic air valve and drain valve. All piping and vessels are thermally insulated with close-cell foam.

Casing

State of the art design of the external construction of the unit. Flat top fan installation decrease unit height and increase efficiency.

Unit casing made of galvanized steel sheet metal painted RAL 7035 powdered polyester paint. Optional rubber or spring anti vibration mounts reduce transfer of vibrations to the supporting structure.

 

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