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Daikin EWAPC10AJYNN [9/41] Specifications

• Hydronic Systems • Chillers

• Chillers • R-407C • EWAP-AJYNN

3 Specifications

Evaporator

9 The units shall be supplied with shell and tubes counter-flow evaporator single refrigerant pass. It will be direct expansion with refrigerant inside the

tubes and water outside (shell side) with carbon steel tube sheets, with straight copper tubes that are spirally wound internally for higher efficiencies,

expanded on the tube plates.

9 The external shell, shall be linked with an electrical heater to prevent freezing up to -28°C ambient temperature, commanded by a thermostat and

shall be insulated with flexible, closed cell polyurethane insulation material.

9 The evaporator will have 2 or 3 circuits, one for each compressor and shall be single refrigerant pass to ensure a simplier oil circulation so to ensure

always a perfect oil return to the compressor.

9 If a plate to plate heat exchanger is used, the manufacturer shall provide to furniture an adequate buffer tank to avoid frequently compressors star-

stop and to allow a good evaporator leaving water temperature control. The manufacturer also shall provide to furniture a feed water line filter, a

monitoring system of the refrigerant pressure drop inside the plat to plate heat exchanger and a system to protect the component from hydraulic

pressure waves caused by water circulation pump stop.

9 Evaporator is manufactured in accordance to PED approval.

Condenser coil

9 The condenser coils are constructed with internally enchanced seamless copper tubes having a "W" configuration and arranged in a staggered row

pattern and mechanically expanded into lanced and rippled aluminium fins with full fin collars for higher efficiencies. The space between the fins are

given by a collar that will increase the surface area in connection with the tubes, protecting them from ambient corrosion.

9 The coils will have an integral subcooler circuit which provides sufficient subcooling to effectively eliminate the possibility of liquid flashing and

increase the unit's efficiency of 5-7% without an increase in power absorbed, and the surface area will be designed in order to have an air velocity

not higher than 2.8 m/sec.

Condenser fans

9 The fans used in conjunction with the condenser coils, shall be helical type with aerofoil blades for higher efficiencies and lower noise. Each fan

shall be equipped with a heavy-gauge fan guard.

9 The air discharge shall be vertical and each fan must be coupled to the electrical motor, supplied as standard to IP54 and capable to work to ambient

temperatures of -40°C to +55°C. There is also an accident protection within the motors.

Refrigerant circuit

9 The unit must have refrigerant circuits completely independent of each other with one compressor per circuit.

9 Each circuit shall include an: electronic expansion valve, compressor discharge shut-off valve, a liquid line shut-off valve with charging connection,

replaceable core filter-drier, sight glass with moisture indicator and insulated suction line. Suction line shut-off valve should be available as option.

Regulation of cooling capacity

9 Each unit will have a microprocessor for the control of compressor slide valve’s position (2 slide valves, one for each compressor’s cycles).

9 The slides shall have a stepless

motion that allows a unit’s operation with infinitely variable capacity control down to 12,5% (2 compressors) or down

to 8,3% (3 compressors) of the cooling capacity. The chiller shall be capable of stable operation to a minimum of 12,5% (2 compressors) or 8,3%

(3 compressors) of full load without hot gas bypass.

9 Step unloading unacceptable because of evaporator leaving water temperature fluctuation and low compressor’s efficiency at partial load.

9 The system shall stage the unit based on the leaving water temperature.

Electronic expansion valve

9 Electronic expansion valve allows a simple and perfect control system that quickly interacts at load variations. This valve combines two functions:

liquid solenoid and electronic expansion valve.

9 It is managed directly by a microprocessor to mach exactly the plant thermal load.

9 Thermostatic valve unacceptable because of its limited load range, higher refrigerant pressure drop and because of leaving evaporator water

temperature control less good than an electronic device.

Condensation control

9 The units will be provided with an automatic control for condensing pressure which ensures the working at low external temperatures down to +10°C,

because of the ON/OFF of the condenser fans, to maintain condensing pressure. Fan speed control, to allow unit’s operation with very low ambient

temperature, should be available as option.

Daikin EWAPC10AJYNN [9/41] Specifications

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