YR MillenniumTM

WATER COOLEDCHILLER WITHROTARY SCREWCOMPRESSOR

R134a REFRIGERANT

COOLING CAPACITIES730 kW to 1830 kW

The YR range of chillers are designed forwater or water/glycol cooling. Heatexchangers are the flooded type withrefrigerant passing through the cooler andcondenser shells and water in the tubes.

Capacity selection is computerised so thatchiller components can be customedmatched to meet individual building loadenergy requirements.

A Cooling Tower or Dry Cooler is requiredfor heat rejection.

All units are designed for plant roominstallation

CONTENTSSpecification

Accessories and Options

AVAILABLE MODELS & NOMINAL COOLING CAPACITIES TABLE 1

FEATURES BENEFITS

Designed in accordance with European Pressure VesselDirective PED 97/23/EC and manufactured to ISO 9001EN 29001.

High standard of quality control.

High full load and part load efficiency. Low operating costs at all load conditions.

Operates at low condenser water temperatures. Coolingtower bypass not required.

Reduced energy costs during winter. Reducedcapital cost savings.

Mixed-matched components. Satisfies exact capacity/energy requirements.

High efficiency industrial type twin helical screwcompressor.

Energy efficient, long life reliable compressor.

Suction cooled direct drive semi-hermetic motor. Reliable performance.

OptiView control panel with microprocessor control. Ease of set-up and operation.

SPECIFICATIONThe YORK YR Millennium Rotary Screw Chiller is completely factory packagedincluding evaporator, condenser, subcooler, oil separator, compressor, motor,lubrication system, OptiView graphic control centre, and all interconnecting unitpiping and wiring. The unit contains the full charge of R134a and oil.

Exterior surfaces are coated with baked-on enamel powder paint (Caribbean Blue).

CompressorThe rotary twin screw compressor has been engineered and constructed to meetthe exacting requirements of the industrial refrigeration market. It utilizesstate-of-the-art technology to provide the most reliable and energy efficientcompressor available at all operating conditions. The compressor operates at 2975rpm. The compressor housing is made of cast iron, precision machined to provideminimal clearance for the rotors. The compressor housing has a design workingpressure of 16.2 bar and is hydro-tested to 37.5 barg.

The rotors are manufactured from forged steel and use asymmetric profiles. Thecompressor incorporates a complete anti-friction bearing design for reduced powerand increased reliability. Four separate cylindrical roller bearings handle radialloads. Two 4-point angular contact ball bearings handle axial loads. Together theymaintain accurate rotor positioning at all pressure ratios thereby minimizing blow-byand maintaining efficiency.

A non return valve is installed in the compressor discharge housing to preventcompressor rotor backspin due to system refrigerant pressure gradients duringshutdown.

The open-drive compressor has a double shaft seal and consists of a bellows type,spring-loaded precision lapped ceramic ring, PTFE static seal and a precisionlapped ceramic rotating collar. The entire shaft seal cavity is at low pressure, beingvented to the oil drain from the compressor. Combining low pressure with direct oilcooling provides long seal life.

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Compressor Code T0 T1 T2 T3 T4 T5Cooler/Condenser Code RangeMaximum Cooling Capacity (kW) 730 880 1030 1250 1550 1830

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SPECIFICATION (continued)Capacity ControlCapacity control is achieved by use of aslide valve which provides fullymodulating control from 100% to 25% offull load, depending upon unit selection.The slide valve is actuated by oil pressurecontrolled by external solenoid valves viathe OptiView graphic control centre.

Compressor MotorThe suction cooled direct drivesemi-hermetic motor is constructed toYORK design specifications and operatesat 2975 rpm. The motor is provided with aD-flange, factory mounted to a cast ironadaptor mounted on the compressor. Thisunique design allows the motor to berigidly coupled to the compressor toprovide factory alignment of motor andcompressor shafts.

Solid State StarterThe unit has a reduced voltage solid statestarter that controls and maintains aconstant current flow to the motor duringstartup. Power and control wiring isfactory supplied. Available for 200-600volts, the starter enclosure has a hingedaccess door with lock and key. A fuseddisconnect switch is supplied to acceptthe single power supply to the unit.

LubricationThe main oil reservoir is located in the oilseparator. The compressor also has anoil reservoir located at the rotor bearingsto provide lubrication during startup,coastdown and in the event of a powerfailure. During operation, systempressure differential provides proper oilflow without the need of an oil pump. Thisminimizes system energy consumption.

Oil Separator/ReservoirThe combined oil separator/reservoir witha design working pressure of 16.2 barshall be the high efficiency, augmentedgas impingement type to maximise oilextraction without fragile media to breakdown.

Oil EductorThe oil eductor automatically removes oilwhich may have migrated to the coolerand returns it to the compressor.

Oil FilterThe unit is fitted with an replaceablecartridge oil filter.

Oil HeaterA 500 watt (115 volt - 1 phase - 50Hz)immersion oil heater is located in the oilseparator reservoir, temperatureactuated to effectively remove refrigerantfrom the oil.

Heat ExchangersShells - Evaporator and condenser shellsare fabricated from rolled carbon steelplates with fusion welded seams. Carbonsteel tube sheets, drilled and reamed toaccommodate the tubes, are welded tothe end of each shell. Intermediate tubesupports are fabricated of 13mm carbonsteel plates. The refrigerant side of eachshell is designed for 16.2 bar designworking pressure, tested at 37.5 barg.

Tubes - Tubes are state-of-the-art, highefficiency, internally enhanced type toprovide optimum performance. Each tubeis roller expanded into the tube sheetsproviding a leak-proof seal, and areindividually replaceable. Tubes are 19mmOD copper alloy.

Evaporator - Evaporator is a shell andtube, flooded type heat exchanger. Adistributor trough provides uniformdistribution of refrigerant over the entireshell length to yield optimum heattransfer. A liquid level sight glass isconveniently located on the side of theshell to aid in determining properrefrigerant charge. A refrigerant chargingvalve is provided.

Condenser - The condenser is a shelland tube type, with a discharge gas baffleto prevent direct high velocityimpingement on the tubes. This baffle isalso used to distribute the refrigerant gasflow properly for most efficient heattransfer. The subcooler is located in thebottom of the condenser section providinghighly effective liquid refrigerantsubcooling to improve cycle efficiency.

Compact Water Boxes - Removablewater boxes are fabricated of steel. Thedesign working pressure is 10 bar (20 baravailable as an option). Integral steelwater baffles are located and weldedwithin the water box to provide requiredpass arrangements. Stub-out waternozzle connections with victaulic groovesare welded to the water boxes. Thesenozzle connections are suitable forVictaulic couplings, welding or flanges,are capped for shipment. Plugged drainand vent connections are provided ineach evaporator water box.

Refrigerant Flow ControlThe chiller is equipped with a refrigerantmetering device consisting of a fixedorifice and modulating valve controlled viathe chiller OptiView panel. This controlensures proper refrigerant flow to theevaporator over a wide range of operatingconditions, including thermal storageapplications with chilled water reset.Valve operation is programmable and canbe customised for a specific applicationvia the OptiView Control Centre.

Refrigerant IsolationThe condenser shell serves as arefrigerant receiver to store the systemcharge during servicing. Manuallyoperated isolation valves are located atthe inlet and outlet of the condenser.Valves are also provided to facilitateremoval of the refrigerant from the systemshould that be necessary.

OptiView Graphic Control Centre(GCC)Each unit is supplied complete with afactory wired and mounted YORKOptiView Graphic Control Centre. Thepanel is configured with a 26 cm diagonalcolour liquid crystal display (LCD)surrounded by "soft" keys used to selectrequired screens. The LCD displaysanimated graphics of the chiller, chillersub-systems and system parameters.The operator may also view a graphicalrepresentation of the historical operationof the chiller. The control panel iscompatible with the YORK solid statestarter.

The panel text is available in English,French, German, Spanish and Italianlanguages. Data can be displayed inMetric or English units. Security access isprovided to prevent unauthorisedchanges to setpoints.

When power is applied a visualrepresentation of the chiller (HOMEscreen) is displayed detailing: enteringand leaving chilled and condenser liquidtemperatures, motor run (LED), % FullLoad Amps, operating hours and inputpower.

ACCESSORIES & OPTIONSSpring Isolators - 25mm deflectionlevel-adjusting/spring-type vibrationisolator assemblies.

Flow Switches - Paddle-type,vapour-proof water flow switches (150 or300 psi DWP) for chilled and coolingwater circuits.

Differential Pressure Switch - 300 PSIDWP, 0-40 PSID pressure switch forchilled and cooling water circuits.

Factory Insulation - 19 mm or 38 mmflexible closed-cell plastic type anti-sweatinsulation on cooler and liquid refrigerantpiping.

Factory Water Flanges - welded to waternozzles on cooler and condenser(companion flanges and connecting partsnot included).

Dual Oil Filter - housing with isolationvalves to eliminate downtime during filterchanges.

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