American Standard CH530 manual Restart Inhibit Free Starts

Page 80

Machine Protection

and Adaptive

Control

Restart Inhibit

This function provides short cycle protection for the motor, and indirectly also short cycling protection for the starter since the starter is designed to operate the motor under all the conditions of motor performance.

The operation of the restart inhibit function is dependent upon two setpoints. The Restart Inhibit Free Starts (1-5, 3 default), and the Restart Inhibit Start to Start Timer (10-30min, 20 default). These settings are adjustable via the service tool.

Restart Inhibit Free Starts

This setting will allow a number of rapid restarts equal to its value. If the number of free starts is set to “1”, this will allow only one start within the time period set by the Start to Start Time Setting. The next start will be allowed only after the start to start timer has expired. If the number of free starts is programmed to “3”, the control will allow three starts in rapid succession, but thereafter, it would hold off on a compressor start until the Start to Start timer expired.

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Restart Inhibit Start to Start Time Setting

This setting defines the shortest chiller cycle period possible after the free starts have been used. If the number of free starts is programmed to “1”, and the Start to Start Time Setting is programmed to 10 minutes, then the compressor will be allowed one start every 10 minutes. The start-to-start time is the time from when the motor was commanded to energize to when the next command to enter prestart is given.

Clear Restart Inhibit

A Clear Restart Inhibit “button” is provided within Settings; Manual Override on the DynaView display. This provides a way for an operator to allow a compressor start when there is a currently active Restart Inhibit that is prohibiting such a start. The “button” press will have no other function than to remove the restart inhibit if there is one active. It does not change the count of any internal restart inhibit timers or accumulators.

The restart inhibit function, setpoints and clear features exist for each compressor and operate independently of other compressors on that chiller.

During the time the start is inhibited due to the start-to-start timer, the DynaView shall display the mode ‘Restart Inhibit’ and the also display the time remaining in the restart inhibit.

A “Restart Inhibit Invoked” warning diagnostic will exist when the attempted restart of a compressor is inhibited

If all three motor winding temperatures are less than the “Restart Inhibit Temperature” Setpoint (default 165°F/74°C) then restart is allowed.

Restart inhibit mode exist when at least one of the three motor winding temperatures is greater than or equal to the “Restart Inhibit Temperature” Setpoint but less than 265°F/129.4°C. Restart inhibit mode is entered until all three motor winding temperatures are less than the ‘Restart Inhibit Temperature’ Setpoint

Note: When one of the three motor winding temperatures is 265°F/ 129.4°C or greater, a High Motor Winding Temperature diagnostic will occur.

Note: When the start is inhibited by the restart inhibit function, the time remaining will be displayed along with the restart inhibit mode.

CDHF-SVU01C-EN

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Contents X39640670030CDHF-SVU01C-EN Read these carefully Contents General Information Literature changeAbout this manual Unit NameplateGeneral Information = 560 3 stage 935 2 stage Y = 500 3 stage 835 2 stage Commonly Used Acronyms Control Optional PackagesOverview General Duplex unit components front viewGeneral Duplex unit components 2 stage compressor Cooling Cycle Compressor 1 or 2 2 StagePressure enthalpy curve 3 stage compressor Pressure enthalpy curve 2 stage compressor TechView Chiller Service Tool DynaView Human InterfacePower Up Diagram Software Operation Overview DiagramSoftware States Figure Timeline Text FiguresCDHE/F/G sequence of operation auto to running Staging Second Compressor OnStaging Second Compressor Off Satisfied SetpointCDHF/G sequence of operation lead 1/lag Fixed Sequence Compressor 2 / Compressor CDHE/F/G sequence of operation lead 2 lagSequencing Balanced Starts and Hours CDHF/G sequence of operation equalize starts and hoursSimultaneous Compressor Start/ Stop CDHF/G sequence of operation combined startRestart Inhibit Start to Start Time Setting Restart InhibitRestart Inhibit Free Starts Clear Restart InhibitSurface Temperatures Oil and Refrigerant PumpOil refrigerant pump circuit 1 or Base Loading Control Algorithm 20 100 percent RLAGeneral Information Ice Machine Control Sequence of operation ice making running to ice makingHot Water control Unit Control Panel UCP Unit Control Panel UCPControl Panel Devices and Unit Mounted Devices Variable water flow through the evaporator User-defined language supportOperator Interface DynaView main processorOperator Interface Chiller Stop Prevention/Inhibit Feature How It WorksTop Level Mode Description System Reset Reference Chiller Operating Mode Circuit Operating ModeMain Screen Main Screen Data Fields TableDiagnostic Screen Back button provides navigation back to the chiller screen Operator Interface Report Menu ReportsReport name System Evaporator Report name Circuit EvaporatorReport name System Condenser Report name Circuit CondenserHistoric Diagnostics Log Report name System Ashrae Chiller LogSetting Tab screens provides a user Header ScreenFeature Settings ChillerSystem Mode Overrides Circuit Mode OverridesDisplay Settings PurgeOperator Interface Operator Interface Operator Interface Operator Interface Operator Interface Interprocessor Communication Inter Processor Communications IPC3IPC3 Definitions Bus Management BindingControl System Components Control panel components layoutControl System Components Control Panel Devices Machine Shutdown Manual Reset MMR Head Relief Request OutputMaximum Capacity Relay Compressor Running RelayRefrigerant Monitor Input 1A17 ExopEpro Enhanced Protection Trmm TRM4 Tracer Comm 4 interfaceCdrp Condenser Refrigerant Pressure Output Temperature based Cdrp Refrigerant Pressure Output Option 1A15Condenser Pressure Output Pressure basedRefrigerant Differential Pressure Indication Output Gbas Generic Building Automation System Percent RLA OutputModule Characteristics External Chilled Water Setpoint EcwsExternal 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 Control Sequence Operation Test and start timing sequenceAFD Momentary Power Loss MPL Protection Machine Protection Adaptive ControlCurrent Overload Protection Overload trip time versus percent RLAReverse Rotation Protection Phase Loss ProtectionCurrent Limit Protection Minimum and Maximum Capacity Limit Differential to Start or StopSoftLoading Leaving Water Temperature Cutout Evaporator Limit Low Refrigerant Temperature Cutout Head Relief RelayCutout strategy Condenser Limit Restart Inhibit High Vacuum Lockout Oil Temperature Control Controls Chilled Water Reset CWR Outdoor Air TemperatureMaximum Reset Return WaterValues for start reset types Degrees of ResetConstant Return EquationReset Ratio Outdoor air temperature versus degrees of resetReset function for return CWR Reset Ratio = 50% Return CWR Daily Unit Start-Up Unit Start-Up ProceduresUnit Startup Live Electrical Components Toxic HazardsSeasonal Unit Start-Up ModeUnit Shutdown Procedures Unit ShutdownOil Pump Heater Operation Seasonal Unit ShutdownPeriodic Maintenance Daily Maintenance and ChecksMoisture Contamination Record Keeping FormsWeekly Maintenance Normal Chiller Operating CharacteristicsHazardous Voltage w/Capacitors Every 3 MonthsOff-Season Maintenance Annual MaintenanceOil Maintenance Oil Change ProcedureHeater Damage Compressor Oil ChangeOil Filter Replacement Replacing Oil FilterMaintenance Oil Supply System ProblemsOther Maintenance Requirements Hazardous Voltage w/ CapacitorsRotary valve in drain position Front View with Refrigerant PumpContains Refrigerant Refrigerant ChargeRecovery and Recycle Connections Leak TestingCleaning the Condenser Proper Water TreatmentUnit Corrosion Damage Cleaning the EvaporatorControl Settings Adjustments Purge System Unit Preparation103 104 105 106 107 108 109 110 111 112 113 114 115 Trane
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