American Standard CH530 manual Hot Water control

Page 27

General Information

Hot Water control

Occasionally CTV chillers are selected to provide heating as a primary mission. With hot water temperature control, the chiller can be used as a heating source or cooling source. This feature provides greater application flexibility. In this case the operator selects a hot water temperature and the chiller capacity is modulated to maintain the hot water setpoint. Heating is the primary mission and cooling is a waste product or is a secondary mission. This type of operation requires an endless source of evaporator load (heat), such as well or lake water. The chiller has only one condenser.

Note: Hot water temperature control mode does not convert the chiller to a heat pump. Heat pump refers to the capability to change from a cooling- driven application to a heating-driven application by changing the refrigerant path on the chiller. This is impractical for centrifugal chillers as it would be much easier to switch over the water side.

This is NOT heat recovery. Although this feature could be used to recover heat in some form, there’s not a second heat exchanger on the condenser side.

The DynaView™ Main Processor provides the hot water temperature control mode as standard. The leaving condenser water temperature is controlled to a hot water setpoint between 80 and 140°F (26.7 to 60°C) The leaving evaporator water temperature is left to drift to satisfy the heating load of the condenser. In this application the evaporator is normally piped into a lake, well, or other source of constant temperature water for the purpose of extracting heat.

In hot water temperature control mode all the limit modes and diagnostics operate as in normal cooling with one exception; The leaving condenser water temperature sensor is an MMR diagnostic when in hot water temperature control mode. (It is an informational warning in the normal cooling mode.)

In the hot water temperature control mode the differential-to-start and differential-to-stop setpoints are used with respect to the hot water setpoint instead of with the chilled water setpoint.

UCP provides a separate entry at the DV to set the hot water setpoint. Tracer is also able to set the hot water setpoint. In the hot water mode

the external chilled water setpoint is the external hot water setpoint; that is, a single analog input is shared at the 1A16 –J2-1 to J2-3 (ground)

An external binary input to select external hot water control mode is on the EXOP OPTIONAL module 1A18 terminals J2-3 to J2-4 (ground). Tracer also has a binary input to select chilled water control or hot water temperature control.

There is no additional leaving hot water temperature cutout; the HPC and condenser limit provide for high temperature and pressure protection.

In hot water temperature control the softloading pulldown rate limit operates as a softloading pullup rate limit. The setpoint for setting the temperature rate limit is the same setpoint for normal cooling as it is for hot water temperature control.

The hot water temperature control feature is not designed to run with HGBP, AFD, or ice making.

The factory set PID tuning values for the leaving water temperature control are the same settings for both normal cooling and hot water temperature control.

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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 Unit Control Panel UCP Control Panel Devices and Unit Mounted DevicesUnit 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 1A17Trmm TRM4 Tracer Comm 4 interface Cdrp Condenser Refrigerant Pressure OutputEpro 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 Setpoint1A8, 1A9, 1A11, 1A12 Quad Relay Output Status 1A13, 1A18, 1A19, 1A20 Dual Binary input module1A14 Communication interface Module Recommended Length to Run external Output signals 1A15, 1A16, 1A17, 1A21 Dual Analog Input/output ModuleAnalog Input Unit mounted devices Control System Components Control System Components Control Sequence of Operation Electrical SequenceUCP 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 ProtectionPhase Loss Protection Current Limit ProtectionReverse Rotation Protection Differential to Start or Stop SoftLoadingMinimum 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 Start-Up Procedures Unit StartupDaily 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 CondenserCleaning the Evaporator Control Settings AdjustmentsUnit Corrosion Damage Unit Preparation Purge System103 104 105 106 107 108 109 110 111 112 113 114 115 Trane
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