Model YLAA Air-Cooled Scroll Compressor Liquid Chillers Style B

FORM 150.62-EG5 (509)sense and display discharge pressure.2. Suction Pressure Transducers: Permits unit tosense and display suction pressure.2.02 COMPRESSORSCompressors: Shall be hermetic, scroll-type, including:1. Compliant design for axial and radial sealing2. Refrigerant flow through the compressor with100% suction cooled motor.3. Large suction side free volume and oil sump toprovide liquid handling capability.4. Compressor crankcase heaters to provide extraliquid migration protection.5. Annular discharge check valve and reverse ventassembly to provide low-pressure drop, silentshutdown and reverse rotation protection.6. Initial Oil charge.7. Oil Level sightglass.8. Vibration isolator mounts for compressors.9. Brazed-type connections for fully hermetic refrigerantcircuits.10. Compressor Motor overloads capable of monitoringcompressor motor current. Provides extraprotection against compressor reverse rotation,phase-loss and phase imbalance2.03 REFRIGERANT CIRCUIT COMPONENTSEach refrigerant circuit shall include: a discharge serviceball type isolation valve, high side pressure relief, liquidline shutoff valve with charging port, low side pressurerelief device, filter-drier, solenoid valve, sight glass withmoisture indicator, thermostatic expansion valves, andflexible, closed-cell foam insulated suction line and suctionpressure transducer.2.04 HEAT EXCHANGERSA. Evaporator: YLAA1. Direct expansion type with refrigerant inside highefficiency copper tubes, chilled liquid forced overthe tubes by brass baffles.2. Constructed, tested, and stamped in accordancewith applicable sections of ASME pressure vesselcode for minimum 450 psig (3103 kPa)refrigerantside design working pressure and150 PSIG (1034kPa) water side design working pressure.3. Shell covered with 3.4” (19mm), flexible, closedcell insulation, thermal conductivity of 0.26k ([BTU/HR-Ft2 -°F]/in.) maximum. Water nozzles withgrooves for mechanical couplings, and insulatedby Contractor after pipe installation.4. Provide vent and drain fittings, and thermostaticallycontrolled heaters to protect to -20°F (29°C)jOHNSON CONTROLSambient in off-cycle.B. Air Cooled Condenser:1. Coils: Coils: Internally enhanced, seamless coppertubes, mechanically expanded into aluminumalloy fins with full height collars. Subcooling coilan integral part of condenser. Design workingpressure shall be650 PSIG (45 bar).2. Low Sound Fans Shall be dynamically and staticallybalanced, direct drive, corrosion resistantglass fiber reinforced composite blades moldedinto a low noise, full-airfoil cross section, providingvertical air discharge and low sound. Eachfan in its own compartment to prevent crossflowduring fan cycling. Guards of heavy gauge, PVC(polyvinylchloride) coated or galvanized steel.3. Fan Motors: High efficiency, direct drive, 6 pole,3 phase, insulation class “F”, current protected,Totally Enclosed Air-Over (TEAO), rigid mounted,with double sealed, permanently lubricated, ballbearings.2.05 CONTROLSA. General: Automatic start, stop, operating, and protectionsequences across the range of scheduled conditionsand transients.B. Microprocessor Enclosure: Rain and dust tight NEMA3R/12 (IP55) powder painted steel cabinet with hinged,latched, and gasket sealed door.C. Microprocessor Control Center:1. Automatic control of compressor start/stop, anticoincidenceand anti-recycle timers, automaticpumpdown shutdown, condenser fans, evaporatorpump, evaporator heater, unit alarm contacts,and chiller operation from 0°F to 125°F (-18°C to52°C) ambient. Automatic reset to normal chilleroperation after power failure.2. Remote water temperature reset via up to twosteps of demand (load) limiting.3. Software stored in non-volatile memory, withprogrammed setpoints retained in lithium batterybacked real time clock (RTC) memory for minimum5 years.4. Forty character liquid crystal display, descriptionsin English (or Spanish, French, Italian, or German),numeric data in English (or Metric) units.Sealed keypad with sections for Setpoints, Display/Print,Entry, Unit Options & clock, and On/OffSwitch.5. Programmable Setpoints (within Manufacturerlimits): display language; chilled liquid temperature67