American Standard CH530 manual CDHF/G sequence of operation lead 1/lag

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General Information

Duplex Compressor Sequencing Four methods (Two fixed sequence methods, a balanced start and hour’s method, and a no staging method) are provided for order of a compressor sequencing on CTV Duplex chillers. The desired method is selectable at startup via the service tool. The application can decide to either balance the wear burden among the unit’s compressors, to start the most efficient compressor, or to simultaneously start and stop both compressors to minimize startup pull down time. Each method has specific applications were it can be used advantageously.

If one compressor is locked out, in restart inhibit, or generally not ready to start, the available compressor will be started.

Fixed Sequence – Compressor 1/ Compressor 2 (Default mode)

If the chiller is in the Auto mode and all interlocks have been satisfied, compressor 1 will be started based on the leaving water temperature rising above the “Differential to Start” setting. Compressors 2 will stage on when the overall chiller average capacity exceeds Stage ON Load point for 30 seconds. The stage on load point is adjustable (via service tool) up to 50%. The default is 40% which means that a single compressor would have to load to 80% (the average would be 40%) before the second compressor starts. Both compressors will run until chiller average capacity drops below Stage off Load point for 30 seconds. The Stage OFF load point is also

adjustable (via service tool) (default = 30%, range from 0 to 50%). Compressor 2 will be shut down and compressor 1 will run until water temperature drops below the differential to stop. Before shutting down, compressor 2 will be unloaded and compressor 1 will be loaded to maintain the same average capacity command.

When running chilled water temperature at selected conditions, the downstream compressor usually will be the most efficient compressor to operate at part load because compressors on Duplex chillers are not sized exactly the same.

Note: The following description assumes compressor 1 is the down stream compressor.

Figure 12. CDHF/G sequence of operation: lead 1/lag 2

CDHF-SVU01C-EN

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Contents X39640670030CDHF-SVU01C-EN Read these carefully Contents Literature change General InformationAbout this manual Unit NameplateGeneral Information = 560 3 stage 935 2 stage Y = 500 3 stage 835 2 stage Control Optional Packages Commonly Used AcronymsGeneral Duplex unit components front view OverviewGeneral Duplex unit components 2 stage compressor Compressor 1 or 2 2 Stage Cooling CyclePressure enthalpy curve 3 stage compressor Pressure enthalpy curve 2 stage compressor DynaView Human Interface TechView Chiller Service ToolSoftware Operation Overview Diagram Power Up DiagramSoftware States Figure Timeline Text FiguresStaging Second Compressor On CDHE/F/G sequence of operation auto to runningSatisfied Setpoint Staging Second Compressor OffCDHF/G sequence of operation lead 1/lag CDHE/F/G sequence of operation lead 2 lag Fixed Sequence Compressor 2 / CompressorCDHF/G sequence of operation equalize starts and hours Sequencing Balanced Starts and HoursCDHF/G sequence of operation combined start Simultaneous Compressor Start/ StopRestart Inhibit Restart Inhibit Start to Start Time SettingRestart Inhibit Free Starts Clear Restart InhibitOil and Refrigerant Pump Surface TemperaturesOil refrigerant pump circuit 1 or 20 100 percent RLA Base Loading Control AlgorithmGeneral Information Sequence of operation ice making running to ice making Ice Machine ControlHot Water control Unit Control Panel UCP Unit Control Panel UCPControl Panel Devices and Unit Mounted Devices User-defined language support Variable water flow through the evaporatorDynaView main processor Operator InterfaceOperator Interface How It Works Chiller Stop Prevention/Inhibit FeatureTop Level Mode Description System Reset Reference Circuit Operating Mode Chiller Operating ModeMain Screen Main Screen Data Fields TableDiagnostic Screen Back button provides navigation back to the chiller screen Operator Interface Reports Report MenuReport name Circuit Evaporator Report name System EvaporatorReport name System Condenser Report name Circuit CondenserReport name System Ashrae Chiller Log Historic Diagnostics LogHeader Screen Setting Tab screens provides a userChiller Feature SettingsCircuit Mode Overrides System Mode OverridesDisplay Settings PurgeOperator Interface Operator Interface Operator Interface Operator Interface Operator Interface Inter Processor Communications IPC3 Interprocessor CommunicationIPC3 Definitions Bus Management BindingControl panel components layout Control System ComponentsControl System Components Control Panel Devices Head Relief Request Output Machine Shutdown Manual Reset MMRMaximum Capacity Relay Compressor Running RelayExop Refrigerant Monitor Input 1A17Epro Enhanced Protection Trmm TRM4 Tracer Comm 4 interfaceCdrp Condenser Refrigerant Pressure Output Cdrp Refrigerant Pressure Output Option 1A15 Temperature basedCondenser Pressure Output Pressure basedRefrigerant Differential Pressure Indication Output Percent RLA Output Gbas Generic Building Automation SystemExternal Chilled Water Setpoint Ecws Module CharacteristicsExternal Current Limit Setpoint Wpsr WFC Water Pressure Sensing Option1A14 Communication interface Module 1A8, 1A9, 1A11, 1A12 Quad Relay Output Status1A13, 1A18, 1A19, 1A20 Dual Binary input module Analog Input Recommended Length to Run external Output signals1A15, 1A16, 1A17, 1A21 Dual Analog Input/output Module Unit mounted devices Control System Components Control System Components UCP and Wye-Delta Starter Control Circuits Control Sequence of OperationElectrical Sequence Delay time 200 msec. Opens 2K1 Control Sequence of Operation Test and start timing sequence Control Sequence OperationAFD Machine Protection Adaptive Control Momentary Power Loss MPL ProtectionOverload trip time versus percent RLA Current Overload ProtectionReverse Rotation Protection Phase Loss ProtectionCurrent Limit Protection Minimum and Maximum Capacity Limit Differential to Start or StopSoftLoading Evaporator Limit Leaving Water Temperature CutoutHead Relief Relay Low Refrigerant Temperature CutoutCutout strategy Condenser Limit Restart Inhibit High Vacuum Lockout Oil Temperature Control Outdoor Air Temperature Controls Chilled Water Reset CWRMaximum Reset Return WaterDegrees of Reset Values for start reset typesConstant Return EquationOutdoor air temperature versus degrees of reset Reset RatioReset function for return CWR Reset Ratio = 50% Return CWR Daily Unit Start-Up Unit Start-Up ProceduresUnit Startup Toxic Hazards Live Electrical ComponentsSeasonal Unit Start-Up ModeUnit Shutdown Unit Shutdown ProceduresOil Pump Heater Operation Seasonal Unit ShutdownDaily Maintenance and Checks Periodic MaintenanceMoisture Contamination Record Keeping FormsNormal Chiller Operating Characteristics Weekly MaintenanceHazardous Voltage w/Capacitors Every 3 MonthsAnnual Maintenance Off-Season MaintenanceOil Change Procedure Oil MaintenanceHeater Damage Compressor Oil ChangeReplacing Oil Filter Oil Filter ReplacementOil Supply System Problems MaintenanceOther Maintenance Requirements Hazardous Voltage w/ CapacitorsFront View with Refrigerant Pump Rotary valve in drain positionRefrigerant Charge Contains RefrigerantLeak Testing Recovery and Recycle ConnectionsCleaning the Condenser Proper Water TreatmentUnit Corrosion Damage Cleaning the EvaporatorControl Settings Adjustments Unit Preparation Purge System103 104 105 106 107 108 109 110 111 112 113 114 115 Trane