Honeywell W7750A Continuous Unoccupied Mode, Occupancy Mode and Manual Override Arbitration

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EXCEL 10 W7750A,B,C CONSTANT VOLUME AHU CONTROLLER

 

RESET

 

 

 

 

 

NOT ASSIGNED

 

 

 

(LED OFF)

 

 

PRESS FOR LESS

 

 

BYPASS

PRESS FOR ONE

THAN ONE SECOND

TIMEOUT

TO FOUR SECONDS

 

 

BYPASS OCCUPIED

PRESS FOR LESS THAN ONE SECOND

(LED ON)

PRESS FOR FOUR

TO SEVEN SECONDS

UNOCCUPIED

(LED BLINK)

PRESS FOR MORE THAN SEVEN SECONDS

M8483A

Fig. 45. LED and Bypass pushbutton operation.

STANDBY MODE (StatusOcySen)

The digital input for an occupancy sensor (usually a motion detector or possibly a time clock) provides the controller with a means to enter an energy-saving Standby mode whenever people are not in the room. Standby mode occurs when the scheduled occupancy is Occupied, and the occupancy sensor detects no people currently in the room (digital input contacts Closed means people are in the room, and contacts Open means the room is Unoccupied). When in Standby mode, the Excel 10 W7750 Controller uses the Standby Cooling Setpoint for cooling (CoolStbySpt), or the Standby Heating Setpoint for Heating (HeatStbySpt) as the Actual Space Temperature Setpoint. The occupancy sensor signal can also be a network input from another LONWORKS Bus device, so that no physical sensor is required at the receiving W7750 Controller.

IMPORTANT

When the W7750 Controller is in Standby mode, the economizer minimum position setting is not observed. This means the fresh air dampers will go fully closed if there is no call for cooling.

CONTINUOUS UNOCCUPIED MODE

This mode is entered when a wall module is configured with a Bypass pushbutton that was pressed for four to seven seconds causing the wall module LED/LCD to blink. This mode can also be entered via a network command (ManualOcc set to Unoccupied). If the controller is in this mode, it reverts to the Unoccupied setpoints for temperature control, and the economizer does not observe its minimum position setting. The controller remains in this mode indefinitely until the Bypass pushbutton is pressed to exit the mode or a network command is sent to clear the mode. A configuration parameter is available to disable wall-module initiation of Continuous Unoccupied mode (OvrdType).

OCCUPANCY MODE AND MANUAL OVERRIDE ARBITRATION

The W7750 has multiple sources for occupancy schedule information and, therefore, it employs an arbitration scheme to determine the current actual mode. Time-of-day (TOD) schedule status comes from two sources, a configured digital input for OccTimeClock or the DestSchedOcc network input received from a central control. If the digital input source is configured, it has highest priority and determines the Occupancy mode. This digital input is either ON (shorted = occupied), OFF (open = unoccupied), or not active (not configured); otherwise, the status is determined by the DestSchedOcc input from the network source. The DestSchedOcc has three possible states, occupied, unoccupied or standby.

Manual Override Status can be derived from three sources and governed by two selectable arbitration schemes. The two schemes are:

Network Wins or Last-in Wins, as set in OvrdPriority.

The three sources of manual override status are: DestManOcc - Has possible states: Occupied,

Unoccupied, Bypass, Standby and Not Assigned (not active). This input source has the highest priority in determining manual override status for a Network Wins arbitration scheme, and in the event there is more than one source change at a time in the Last-in Wins arbitration scheme. Here, bypass initiates a self-timed bypass of the control unit and expires upon completion of the defined timed period. The controller then treats the bypass status of this input as Not Assigned until the next change in status.

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Contents Excel 72-2958 General Considerations W7750 ControllersAppendices List of Figures 74-2958Setpoint ramping parameters with ramp rate calculation 74-2958List of Tables Description of Devices Typical system overviewControl Application Control ProvidedProducts Covered Organization of ManualApplicable Literature Form No TitleProduct Names Agency ListingsAbbreviations and Definitions Construction ControllersW7750A DI-1Special Note for the W7750B,C Unit Performance SpecificationsPower Memory Capacity Specified Space Temperature Sensing RangeCPU Excel 10 W7750C Constant Volume AHU Controller Jack DIN rail adapters Lonmark Functional ProfileInputs/Outputs Analog InputsDigital Outputs Digital InputsTriac Outputs on the W7750B,C Models only Wall Modules Duct SensorT7770A1006 T7770CT7560A,B construction in in. mm Configurations GeneralConfiguration Options Summary For W7750A,B,C Controllers Allowable Heating and Cooling Equipment Configurations Staged HEATING/COOLING ControlHeat Pump Control Modulating HEATING/COOLING ControlEconomizer Control Pneumatic Actuator ControlOccupancy Sensor Window Open/Closed Digital InputWall Module Options MIXED-OUTPUT-TYPE ControlModes of Operation Dirty Filter MonitorIndoor Air Quality IAQ Override Smoke ControlOFF Mode DisabledNot AssignedOverview Plan the SystemDetermine Other Bus Devices Required Step No DescriptionLay Out Communications and Power Wiring Lonworks Bus LayoutExcel VAV Cvahu DeviceVA Information Obtained from Power WiringPower Budget Calculation Example VA Ratings For Transformer Sizing Device Description ML6161A/B Damper Actuator, 35 lb-in R8242A ContactorML7984B PWM Valve Actuator Line LossPower wiring details for one Excel 10 per Transformer Nema class 2 transformer voltage output limitsPrepare Wiring Diagrams General ConsiderationsW7750 Controllers Factory Default Digital Outputs Terminal Terminal Number DescriptionConstant Volume AHU Controller ML6161 Floating Actuator COM CCW Load Controller Power Heat Wall Economizer Damper PWM Actuator Power Signal W7750C Constant Lonworks Bus Termination Module Pneumatic transducer to W7750B,C Shown, see triangle noteBrown Orange Lonworks Bus termination wiring options Order EquipmentSensor with Bypass/LED and Lonworks Jack T7770 and T7560 Wall ModulesHoneywell Logo T7770D1018 Echelon Based Components and Parts Accessories SensorsAccessories Configure Controllers TroubleshootingTroubleshooting Excel 10 Controllers and Wall Modules CablingResistance Value ohms AlarmsExcel 10 Alarms Broadcasting the Service Message W7750 Controller Status LEDAppendix A. Using E-Vision to Commission a W7750 Controller Setting the Pid ParametersT7770C,D Wall Module Bypass Pushbutton and Override LED Sensor CalibrationAppendix B. Sequences of Operation Common Operations Room Temperature Sensor RmTemp HeatingEconomizer IAQ OptionBypass Mode StatusOvrd and StatusLed Remote Setpoint RmtStptPotSetpoint Limits LoSetptLim and HiSetptLim BypassTimeContinuous Unoccupied Mode Occupancy Mode and Manual Override ArbitrationNot Assigned Bypass OccupiedRecovery Ramping for Heat Pump Systems Time Clock OccTimeClockSchedule Master SchedMaster Setpoint RampingWindow Sensor StatusWndw Smoke ControlFAN Operation Demand Limit Control DLCDirty Filter Monitor Temperature Control OperationsSee for a diagram of a typical W7750 Unit Staged Cooling Control ONE StageTWO Stages Three StagesCascade Control of Modulating COOLING/HEATING Series 60 Modulating ControlPulse Width Modulating PWM Control Outdoor AIR Lockout of HEATING/COOLINGEconomizer ENABLE/DISABLE Control Indoor AIR Quality IAQ OverrideFreeze Stat Discharge AIR LOW Limit ControlInput Output Points Address Control Parameters AddressEnergy Management Points Address Status Points AddressMappable User Addresses and Table Number Relative Temperature Air FlowCO2 Concentration EnthalpyApplication reset therefore, these points can Placed in manual mode through a menuValid states and the corresponding Enumerated values are shownDefault Input/Output PointsNvName Field Name CommentsNciIoSelect DigitalIn1 Occsensor Shcedmasterin255 NciIoSelect DigitalIn2 Occsensor UnuseddiCOOLSTAGE1 COOLSTAGE2COOLSTAGE3 COOLSTAGE4Sixtyfifty SiinvalidTrue PPM SiinvalidFalse EconEnSw NvoIO EconEnableIn Position when poor indoor air quality is detectedStatusDI3 NvoIO UbDigitalIn OccSensr NvoIODefault Comments NvNameControl Parameters OdEnthalpyEnable MaxClRamp NciAux1SetPt UbMaxClRampS0 Degrees F/HrMinClRamp NciAux1SetPt UbMinClRampS0 Degrees F/Hr MaxClRamp, OdTempMaxClRamp,PPM Discharge air temperature cascade control loop GainCoolProp NciAux2SetPt UbKpCoolS2 Degrees F Degrees CGain for the cooling control loop GainHeatProp NciAux2SetPt UbKpHeatS2 Degrees F Degrees CEnergy Management Points Refer to WSHPEnable.value NviFree1 ValueAuxiliary functions. nviFree1 controls the FREE1OUT Network variable input failsNviTimeClk Value DestTimeClk NviTimeClk StateRefer to nviTimeClk.value 255 SrcTimeClkCt NvoTimeClk ValueStatus Points Alarmbit1 Bit Offset = SensorFailAlrmBit Offset = FrostProtectAlrm Bit Offset = InvalidSetPtAlrmNoalarm NodedisabledSmokealarm UpdateallfieldsDisabledmode StartupwaitHeat CoolStatusEconEn NvoData1 EconEnable Air flow switch is configuredNciAux1SetPts.ubOdEnthalpyEnableS2 StatusManOcc NvoData1 NetManOccHeatStgsOn NvoData1 HeatStagesOn Auxiliary heating stages are turned onCoolStgsOn NvoData1 CoolStagesOn For both heating or coolingIs 1, the algorithm controls as per the settings found NciConfig.SmokeControlController mode is switched to Freezeprotect MonitorSw NvoData1 MonSwitchBypasstimerfield TempcontrolptfieldSpacetempfield DischargetempfieldUbinvalid StatusError NvoError Errorbit0 SpaceTempErrorNvoError Errorbit0 Bit Offset = Temperature SetPtError NvoError Errorbit0NvoError Errorbit1 Bit Offset = RtnEnthalpyError NvoError Errorbit1Are disabled as if the sensor was not configured Bit Offset = SpaceCO2Error NvoError Errorbit1Bit Offset = NvWindowError NvoError Errorbit2 Bit Offset = NvDlcShedError NvoError Errorbit2Bit Offset = NvTodEventError NvoError Errorbit3 Bit Offset = NvByPassError NvoError Errorbit3Cfglocal CfgexternalCfgnul Calibration PointsConfiguration Parameters False True DisMinHtTime NciConfig DisableHeatMinTime DisMinClTime NciConfig DisableCoolMinTimeCascCntrl NciConfig CascadeControl UseRaTempCtl NciConfigLast NET Offset AbsolutemiddleNone Normal BypassonlyLonmark /Open System Points Hvacauto HvacheatHvacmrngwrmup Hvacprecool Hvaccool Hvacnightpurge Hvacnul Hvacoff74-2958 100 DestRmTemp NviSpaceTemp Degrees FSNVTtempp 14 to SrcRmTemp NvoSpaceTemp Degrees FHvactest Hvacauto HvacnulHvacmrngwrmup Alarmnotifydisabled NvoStatus Electricalfault 103 NvoStatus Inalarm255 Not configured 74-2958 NvoStatus UnabletomeasureSwon On other nodes. If the economizer function is configured by Corresponding economizer function is not enabled becauseSrcEconEnable NvoEcon State SrcEconEnCt NvoEcon ValueDirect Access And Special Points OFF Data Share Points Approximate Memory Size Estimating Procedure =using One-to-Many and not using points= including mapped points and others for Mapped points = number of mapped points per ExcelSensor Resistance Versus Temperature Resistance Ohms Resistance SensorsSensor Type Sensor UseOffset Setpoint Temperature Direct Setpoint TemperatureT7770B,C 10K ohm setpoint potentiometer Relative Above and Below Setpoint Resistance OhmsSensor Voltage Versus Humidity Relative Humidity Percentage Voltage/Current SensorsSensor Voltage Versus Humidity Humidity Percentage Sensor Current Versus Enthalpy volts Enthalpy mA 113 74-2958MAmAmAmA AmA mA mA T7242 or equivalent74-2958 114 Sensor Voltage Versus Input Voltage To A/D Voltage to A/D Sensor Voltage Vdc Versus Pressure Inw Pressure Inw kPa Sensor Voltage VdcInw 50.0.13