American Standard CH530 manual Condenser Limit

Page 79

Machine Protection

and Adaptive

Control

Condenser Limit

Condenser pressure is continuously monitored to provide a limit function that prevents High Pressure Cutout (HPC) trips. This protection is called Condenser Refrigerant Pressure Limit, or High Pressure Limit. A fully loaded compressor, operating at high Evaporator Leaving Water Temperature (ELWT) and high condenser temperatures causes high condenser pressures. The purpose of this limit is to avoid High Pressure Cutout (HPC) trips by allowing the Chiller to continue to run at a lower load instead of tripping off via HPC.

The Condenser Limit will be based from a pressure conversion from the Condenser Refrigerant Temperature sensor, unless there is a Condenser Refrigerant Pressure sensor installed (CDRP option). If the Condenser Refrigerant Pressure Sensor is installed, then the limit will be based from the Pressure sensor.

When limited by this action, “Condenser Pressure Limit” will be displayed as a sub-operating mode. The Condenser Limit Setpoint is factory set (93 percent of HPC), however can be altered via the service tool.

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Contents X39640670030CDHF-SVU01C-EN Read these carefully Contents Unit Nameplate General InformationLiterature change About this manualGeneral 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 ToolTimeline Text Figures Power Up DiagramSoftware Operation Overview Diagram Software States FigureStaging 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/ StopClear Restart Inhibit Restart Inhibit Start to Start Time SettingRestart Inhibit Restart Inhibit Free StartsOil 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 Control Panel Devices and Unit Mounted Devices Unit Control Panel UCPUnit Control Panel UCP 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 Main Screen Data Fields Table Chiller Operating ModeCircuit Operating Mode Main ScreenDiagnostic Screen Back button provides navigation back to the chiller screen Operator Interface Reports Report MenuReport name Circuit Condenser Report name System EvaporatorReport name Circuit Evaporator Report name System CondenserReport name System Ashrae Chiller Log Historic Diagnostics LogHeader Screen Setting Tab screens provides a userChiller Feature SettingsPurge System Mode OverridesCircuit Mode Overrides Display SettingsOperator Interface Operator Interface Operator Interface Operator Interface Operator Interface Binding Interprocessor CommunicationInter Processor Communications IPC3 IPC3 Definitions Bus ManagementControl panel components layout Control System ComponentsControl System Components Control Panel Devices Compressor Running Relay Machine Shutdown Manual Reset MMRHead Relief Request Output Maximum Capacity RelayExop Refrigerant Monitor Input 1A17Cdrp Condenser Refrigerant Pressure Output Trmm TRM4 Tracer Comm 4 interfaceEpro Enhanced Protection Pressure based Temperature basedCdrp Refrigerant Pressure Output Option 1A15 Condenser Pressure OutputRefrigerant Differential Pressure Indication Output Percent RLA Output Gbas Generic Building Automation SystemWpsr WFC Water Pressure Sensing Option Module CharacteristicsExternal Chilled Water Setpoint Ecws External Current Limit Setpoint1A13, 1A18, 1A19, 1A20 Dual Binary input module 1A8, 1A9, 1A11, 1A12 Quad Relay Output Status1A14 Communication interface Module 1A15, 1A16, 1A17, 1A21 Dual Analog Input/output Module Recommended Length to Run external Output signalsAnalog Input Unit mounted devices Control System Components Control System Components Electrical Sequence Control Sequence of OperationUCP and Wye-Delta Starter Control Circuits 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 ProtectionCurrent Limit Protection Phase Loss ProtectionReverse Rotation Protection SoftLoading Differential to Start or StopMinimum and Maximum Capacity Limit Evaporator Limit Leaving Water Temperature CutoutHead Relief Relay Low Refrigerant Temperature CutoutCutout strategy Condenser Limit Restart Inhibit High Vacuum Lockout Oil Temperature Control Return Water Controls Chilled Water Reset CWROutdoor Air Temperature Maximum ResetEquation Values for start reset typesDegrees of Reset Constant ReturnOutdoor air temperature versus degrees of reset Reset RatioReset function for return CWR Reset Ratio = 50% Return CWR Unit Startup Unit Start-Up ProceduresDaily Unit Start-Up Mode Live Electrical ComponentsToxic Hazards Seasonal Unit Start-UpSeasonal Unit Shutdown Unit Shutdown ProceduresUnit Shutdown Oil Pump Heater OperationRecord Keeping Forms Periodic MaintenanceDaily Maintenance and Checks Moisture ContaminationEvery 3 Months Weekly MaintenanceNormal Chiller Operating Characteristics Hazardous Voltage w/CapacitorsAnnual Maintenance Off-Season MaintenanceCompressor Oil Change Oil MaintenanceOil Change Procedure Heater DamageReplacing Oil Filter Oil Filter ReplacementHazardous Voltage w/ Capacitors MaintenanceOil Supply System Problems Other Maintenance RequirementsFront View with Refrigerant Pump Rotary valve in drain positionRefrigerant Charge Contains RefrigerantProper Water Treatment Recovery and Recycle ConnectionsLeak Testing Cleaning the CondenserControl Settings Adjustments Cleaning the EvaporatorUnit Corrosion Damage Unit Preparation Purge System103 104 105 106 107 108 109 110 111 112 113 114 115 Trane