York YK M3 M3 G4 General, Compressor Lubrication System See Fig, Speed Increasing Gears

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GENERAL

The YORK Model YK Millennium Centrifugal Liquid Chiller is completely factory-packaged including cooler, condenser, compressor, motor, lubrication system, MicroComputer Control Center, and all interconnect- ing unit piping and wiring.

The initial charge of refrigerant and oil is supplied for each unit. Oil is shipped in containers with the chiller. Refrigerant is shipped to the jobsite in cylinders at the time of installation.

The services of a YORK factory-trained, field service representative are included to supervise the final leak testing, charging and the initial start-up and concur- rent operator instructions.

COMPRESSOR

The compressor is a single-stage centrifugal type pow- ered by an open-drive electric motor.

The rotor assembly consists of a heat-treated alloy steel drive shaft and impeller shaft with a cast alumi- num, fully shrouded impeller. The impeller is designed for balanced thrust and is dynamically balanced and over-speed tested.

The inserted type journal and thrust bearings are fabri- cated of aluminum alloy. Single helical gears with crowned teeth are designed so that more than one tooth is in contact at all times. Gears are integrally as- sembled in the compressor rotor support and are film lubricated. Each gear is individually mounted in its own journal and thrust bearings.

The open-drive compressor shaft seal consists of a spring-loaded, precision carbon ring, high temperature elastomer “O” ring static seal, and stress-relieved, pre- cision lapped collars. The seal is oil-flooded at all times and is pressure-lubricated during operation.

CAPACITY CONTROL

Prerotation vanes (PRV) modulate chiller capacity from 100% to as low as 15% of design for normal air condi- tioning applications. Operation is by an external, elec- tric PRV actuator which automatically controls the vane position to maintain a constant leaving chilled liquid temperature.

COMPRESSOR LUBRICATION SYSTEM (See Fig. 18)

The chiller lubrication system consists of the oil pump, oil filter, oil cooler and all interconnecting oil piping and passages. There are main points within the motor-com-

pressor which must be supplied with forced lubrication as follows:

1.COMPRESSOR DRIVE SHAFT (Low Speed)

a.Shaft seal.

b.Front and rear journal bearings – one on each side of driving gear.

c.Low speed thrust bearing (forward and reverse).

2.COMPRESSOR DRIVEN SHAFT (High Speed)

a.Forward and reverse high speed thrust bearing.

b.Two journal bearings.

3.SPEED INCREASING GEARS

a.Meshing surfaces of drive and pinion gear teeth.

To provide the required amount of oil under the neces- sary pressure to properly lubricate these parts, a mo- tor driven submersible oil pump is located in a remote oil sump.

Upon pressing of the COMPRESSOR START switch on the Control Center, the oil pump is immediately en- ergized. After a 50 second delay to allow the system oil pressure to stabilize, the compressor motor will start. The oil pump will continue to run during the entire op- eration of the compressor, and for 150 seconds during compressor coastdown.

The submerged oil pump takes suction from the sur- rounding oil and discharges it to the oil cooler where heat is rejected. The oil flows from the oil cooler to the oil filter. The oil leaves the filter and flows to the emer- gency oil reservoir where it is distributed to the com- pressor bearings. The oil lubricates the compressor rotating components and is returned to the oil sump.

Since the emergency oil reservoir is at the highest point in the lubrication system, it provides an oil sup- ply to the various bearings and gears in the event of a system shutdown due to power failure. The reservoir, located on the top of the compressor, allows the oil to be distributed through the passages by gravity flow, thus providing necessary lubrication during the com- pressor coastdown.

OIL PUMP

For normal operation, the oil pump should operate at all times during chiller operation. Manual pump opera- tion may be used to establish stable oil pressure be- fore starting. When depressed and released, the MANUAL OIL PUMP key will operate the oil pump for 10 minutes and then automatically shut off. To stop the

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YORK INTERNATIONAL

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Contents Centrifugal Liquid Chillers With Microcomputer Control CenterTable of Contents Nomenclature System Operation Description See Fig SectionDescription of System and Fundamentals of Operation Detail a Compressor Prerotation Vanes Capacity ControlSection Microcomputer Control Center Microcomputer Control Center and KeypadIntroduction Condenser Refrigerant LevelDisplaying System Parameters Control CenterOperation Psid = HOP LP Offset Pressure To Display Chilled Liquid TemperaturesTo Display OIL Pressure System Setpoints To Display Motor CurrentTo Display Operating Hours and Starts Counter See Programming System Setpoints, Displaying System Setpoints To Display Undervoltage setpoints Microcomputer Control Center Press Access Code keyProgramming Programming System SetpointsElectro-Mechanical Starter, refer to Fig Solid State Starter, refer to FigKeypad Programming Pull Down Demand Setpoint SetpointKeypad Programming Daily Schedule Setpoint Keypad Programming Holiday Service Keys PRE-ROTATION Vanes KeysOther Service Keys Pulldn Level = XXX% Setp = XXX% Actual = XXX%Operating Modes Compressor Switch Display MessagesSystem RUN Auto Vanes System Shutdown Messages When Control Center is in Remote mode MON Xxxx AM Evap Trans or Probe Error Therefore Function Jumper PositionThen MON Xxxx AM High Line Voltage MON Xxxx AM High Speed Drain Temp OIL Heaters Checking the OIL Level in the OIL System Operating ProceduresSTART-UP Procedure ReservoirSTART-UP Chiller OperationCondenser Water Temperature Control Chiller Starting Sequence & Shutdown SequenceChecking Operation EcwtLchwt Operating LOG SheetWeekly Operating Inspections See SectionDaily QuarterlySafety Shutdowns Need for Maintenance or ServiceNormal and Safety System Shutdowns Cycling ShutdownsProlonged Shutdown START-UP After Prolonged ShutdownSystem Components Description System ComponentsCompressor Lubrication System See Fig GeneralCompressor Speed Increasing GearsSchematic Drawing YK Compressor Lubrication System Heat Exchangers OIL HeaterMotor Driveline Refrigerant Flow ControlVariable Speed Drive Optional Microcomputer Control Center See SectionSolid State Starter Optional Changing the Dehydrator Operational MaintenanceOIL Return System OIL Charging Procedure OIL ChargeTroubleshooting RiseLEP Operating Setpoints System After Service Symptom High Cooler Pressure Operating Analysis ChartSymptom Abnormally LOW Suction Pressure Symptom no OIL Pressure When System Start Button PushedSymptom Reduced OIL Pump Capacity Symptom OIL Pump Vibrates or is NoisySymptom OIL Pump Fails to Deliver OIL Pressure OIL Pressure display keyConducting R-22 Pressure Test MaintenanceLeak Testing During Operation Vacuum Testing System PressuresVacuum Dehydration OperationRefrigerant Charge Refrigerant ChargingChecking the Refrigerant Charge During Unit Shutdown Handling Refrigerant for Dismantling and Repairs Megging the MotorMotor Stator Temperature and Insulation Resistances Condensers and Coolers Testing for Cooler and Condenser Tube Leaks Compressor Electrical ControlsCompressor Motor Preventive MaintenancePressure Testing Cooler and CondenserElectrical Controls ALL Rights Reserved

YK M3 M3 G4 THRU YK S6 S4 J2, YK LB LB G4 THRU YK SE SC J4, YK M3 M3 G4 specifications

The York YK M3 M3 G4, YK M3 M3 G4 THRU YK S6 S4 J2, and YK LB LB G4 THRU YK SE SC J4 represent a sophisticated line of HVAC systems engineered for modern commercial applications. These models are celebrated for their innovative designs, energy efficiency, and advanced features, making them a preferred choice among facility managers and building owners.

One of the standout characteristics of the York YK series is its modular construction, which provides unparalleled flexibility in system configuration. This design allows for easy upgrades and expansions as building demands evolve. The YK M3 series, in particular, is equipped with advanced controls that enhance system performance while minimizing energy consumption. With features like variable speed drives and sophisticated control algorithms, these units optimize airflow and refrigerant use, significantly reducing operational costs.

Another notable aspect of the YK M3 M3 G4 is its robust refrigeration technology. Utilizing high-efficiency scroll compressors, these chillers deliver impressive cooling capacities while maintaining high energy efficiency ratings. Integrated with low GWP (Global Warming Potential) refrigerants, they meet modern environmental standards, ensuring compliance with regulations while promoting sustainability.

The YK LB LB G4 and YK SE SC J4 models further enhance York’s portfolio with their compact designs and lower installation footprints. These chillers are ideal for applications where space is at a premium. Additional features include advanced noise reduction technology, allowing for quieter operation compared to traditional HVAC systems, making them suitable for urban environments or buildings where noise control is a priority.

Furthermore, York's commitment to continuous innovation is evident in the incorporation of smart technology across its chiller series. Features such as connectivity options for monitoring and diagnostics through mobile apps or web interfaces empower users to maintain optimal system performance proactively. This connectivity aids in predictive maintenance, enabling timely interventions that extend equipment life and reliability.

Finally, all these high-efficiency chillers are backed by York's renowned service support network, ensuring that customers have access to expert assistance and maintenance services whenever needed. With their exceptional features, modern technologies, and commitment to sustainability, the York YK M3 M3 G4, YK M3 M3 G4 THRU YK S6 S4 J2, and YK LB LB G4 THRU YK SE SC J4 models stand out as leaders in the commercial HVAC market, setting new standards for performance and efficiency.
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