York YK M3 M3 G4 THRU YK S6 S4 J2, YK LB LB G4 THRU YK SE SC J4 Solid State Starter Optional

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age to the Micro Board that represents this level (0% = empty; 100% = full). Under program control, the Micro Board modulates a variable orifice to control the con- denser refrigerant level to a programmed setpoint. Other setpoints affect the control sensitivity and response. These setpoints must be entered at chiller commis- sioning by a qualified service technician. Only a quali- fied service technician may modify these settings. Manual operation of the refrigerant level control can be selected. This allows the prerotation vanes keypad keys to manually control the variable orifice. This manual control can also be used to position the variable orifice in a fixed position. Instructions for selecting manual level control and entering the level control setpoints are contained in the “Special Setpoints and Program- ming Procedures” section of Service manual, Form 160.49-M3.

While the chiller is shut down, the orifice will be in the fully open position causing the sensed level to be ap- proximately 0%. When the chiller is started, after the vane motor end switch (VMS) opens when entering “SYSTEM RUN”, if actual level is less than the level setpoint, a linearly increasing ramp is applied to the level setpoint. This ramp causes the setpoint to go from the initial refrigerant level (approximately 0%) to the programmed setpoint over a period of 15 minutes. While this ramp is in effect,

PULLDN LEVEL = XXX%; SETP = XXX%; ACTUAL = XXX% is

one of the scrolled messages under the DISPLAY DATA key. “PULLDN LEVEL” is the ramping setpoint that will ramp up to the programmed setpoint “SETP”. “SETP” is the level setpoint programmed by the service tech- nician. “ACTUAL” is the present refrigerant level in the condenser. After the 15 minute pulldown period has elapsed, this message is replaced by

ACTUAL LEVEL = XXX%; LEVEL SETP = XXX% .

If the actual level is greater than the setpoint when the VMS opens, there is no pulldown period, it immedi- ately begins to control to the programmed setpoint.

While the chiller is running, the refrigerant level is nor- mally controlled to the level setpoint. However, any- time the vanes fully close (VMS closes), normal level control is terminated, any refrigerant level setpoint pulldown in effect is cancelled and the outputs to the level control will be opposite that which is supplied to the vane motor (i.e., when a close pulse is applied to the vane motor, an open pulse is applied to the level

FORM 160.49-O2

control, etc.). When the VMS opens, if the refrigerant level is less than the level setpoint, a refrigerant level setpoint pulldown is initiated as described above. Oth- erwise, the level is controlled to the programmed setpoint.

If the refrigerant level sensor output ever goes to greater than 4.4VDC, indicating a level greater than 100%,

WARNING-REFRIGERANT LEVEL OUT OF RANGE is dis- played and the level control actuator is driven open until the level has decreased to a level within range. When within range, the warning message is automati- cally cleared and normal control is resumed.

MICROCOMPUTER CONTROL CENTER (See Section 2)

The MicroComputer Control Center is factory mounted, wired and tested. The electronic panel automatically controls the operation of the unit in meeting system cooling requirements while minimizing energy usage. For detailed information on the Control Center, refer to “Section 2” of this manual.

SOLID STATE STARTER (Optional)

The Solid State Starter is a reduced voltage starter that controls and maintains a constant current flow to the motor during start-up. It is mounted on the chiller. Power and control wiring between the starter and chiller are factory installed. Available for 380-600 volts, the starter enclosure is NEMA-1 with a hinged access door with lock and key. Electrical lugs for incoming power wiring are provided.

VARIABLE SPEED DRIVE (Optional)

A 460V – 3-Ph – 60/50Hz Variable Speed Drive can be factory packaged with the chiller. It is designed to vary the compressor motor speed and prerotation vane po- sition by controlling the frequency and voltage of the electrical power to the motor. Operational information is contained in Form 160.00-O1. The control logic au- tomatically adjusts motor speed and compressor prerotation vane position for maximum part load effi- ciency by analyzing information fed to it by sensors located throughout the chiller.

YORK INTERNATIONAL

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Contents With Microcomputer Control Center Centrifugal Liquid ChillersTable of Contents Nomenclature System Operation Description See Fig SectionDescription of System and Fundamentals of Operation Capacity Control Detail a Compressor Prerotation VanesMicrocomputer Control Center and Keypad Section Microcomputer Control CenterCondenser Refrigerant Level IntroductionDisplaying 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 Programming Press Access Code keyMicrocomputer Control Center Programming System SetpointsSolid State Starter, refer to Fig Electro-Mechanical Starter, refer to FigSetpoint Keypad Programming Pull Down Demand SetpointKeypad Programming Daily Schedule Setpoint Keypad Programming Holiday PRE-ROTATION Vanes Keys Service KeysPulldn Level = XXX% Setp = XXX% Actual = XXX% Other Service KeysOperating Modes Display Messages Compressor SwitchSystem 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 START-UP Procedure System Operating ProceduresOIL Heaters Checking the OIL Level in the OIL ReservoirChiller Operation START-UPChiller Starting Sequence & Shutdown Sequence Condenser Water Temperature ControlLchwt EcwtChecking Operation Operating LOG SheetDaily Operating Inspections See SectionWeekly QuarterlyNormal and Safety System Shutdowns Need for Maintenance or ServiceSafety Shutdowns Cycling ShutdownsSTART-UP After Prolonged Shutdown Prolonged ShutdownSystem Components System Components DescriptionCompressor GeneralCompressor Lubrication System See Fig Speed Increasing GearsSchematic Drawing YK Compressor Lubrication System Motor Driveline OIL HeaterHeat Exchangers Refrigerant Flow ControlVariable Speed Drive Optional Microcomputer Control Center See SectionSolid State Starter Optional Changing the Dehydrator Operational MaintenanceOIL Return System OIL Charge OIL Charging ProcedureRise TroubleshootingLEP Operating Setpoints System After Service Symptom Abnormally LOW Suction Pressure Operating Analysis ChartSymptom High Cooler Pressure Symptom no OIL Pressure When System Start Button PushedSymptom OIL Pump Fails to Deliver OIL Pressure Symptom OIL Pump Vibrates or is NoisySymptom Reduced OIL Pump Capacity OIL Pressure display keyConducting R-22 Pressure Test MaintenanceLeak Testing During Operation System Pressures Vacuum TestingOperation Vacuum DehydrationRefrigerant Charge Refrigerant ChargingChecking the Refrigerant Charge During Unit Shutdown Megging the Motor Handling Refrigerant for Dismantling and RepairsMotor Stator Temperature and Insulation Resistances Condensers and Coolers Testing for Cooler and Condenser Tube Leaks Electrical Controls CompressorPressure Testing Preventive MaintenanceCompressor Motor 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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