Honeywell W7750A Time Clock OccTimeClock, Schedule Master SchedMaster, Setpoint Ramping

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EXCEL 10 W7750A,B,C CONSTANT VOLUME AHU CONTROLLER

DestBypass - Has possible states: Bypass On, Bypass Off or Not Assigned (not active). This input places the controller in an untimed bypass state or turns off the bypass mode. This source is second in priority to DestManOcc under the same arbitration schemes mentioned above.

Override Button -The wall module Override pushbutton can command status of Bypass, Continuous Unoccupied and Not Assigned. This source has the lowest priority status in the above mentioned schemes. The above mention sources of override must be either Not Assigned or Off before the Override pushbutton affects the manual override status in the Network Wins scheme. All actions, in this case, taken from the Override pushbutton are locked out.

Bypass status is a controller-timed event whose duration is set in BypTime. Upon expiration of the timer, the status returns to Not Assigned. The status of this input can be overridden with the receipt of Not Assigned from DestManOcc. This, in effect, cancels a timed bypass or a continuous unoccupied mode.

The Override pushbutton can be configured as Normal (all of the above mentioned states are possible), Bypass Only (Bypass and Not Assigned only) or None (effectively Disabling the Override pushbutton).

TIME CLOCK (Occ_Time_Clock)

OccTimeClock is the state of the digital input configured and wired to a time clock. When the digital input is detected to be Closed (Occupied), the scheduled occupancy will be OC_OCCUPIED. If the detected state of the digital input is Open (Unoccupied), then the scheduled occupancy will be OC_UNOCCUPIED. If the Occ_Time_Clock is not configured, then either the DestSchedOcc network input received from a central control or the time clock that is broadcast from a Sched_Master configured W7750, controls the occupied mode.

SCHEDULE MASTER (Sched_Master)

Sched_Master is the state of a digital input that is configured and wired to the W7750. If the Sched_Master input is closed (input shorted), the node is the schedule master and the state of the locally connected time clock will be broadcast out over the LONWORKS Bus to the other W7750 controllers. If the Sched_Master input is open, then the node is not a schedule master and the local time clock will not be sent out over the LONWORKS Bus even if the time clock input is configured. However, the DestSchedOcc network input received from a central control has a higher priority than the local time clock, and therefore overrides the local time clock. The W7750 controllers automatically bind without the need for a configuration tool.

SETPOINT RAMPING

The W7750 Controller incorporates a ramping feature that gradually changes the space setpoints between occupancy modes. This feature is only operational if the network variable inputs DestSchedOcc, TodEventNext, and Time Until Next Change Of State (TUNCOS) are being used to change the W7750 Occupancy mode. The applicable Setpoints are OaTempMinHtRamp, OaTempMaxHtRamp, MinHtRamp and MaxHtRamp (for HEAT mode operation), and OaTempMinClRamp, OaTempMaxClRamp, MinClRamp and MaxClRamp (for the COOL mode operation). See Fig. 46 for a pictorial representation of how these setpoints interact.

During recovery operation, the setpoint changes at a rate in degrees per hour depending on the outdoor air temperature. If there is no outdoor air temperature sensor available, then MinHtRamp is used as the recovery rate.

HEAT RECOVERY

 

RAMP RATE

 

(DEGREES/HOUR)

 

MaxHtRam

 

MinHtRam

 

 

OUTDOOR AIR

 

TEMPERATURE

OaTempMinHtRa

OaTempMaxHtRam

 

M10109

Fig. 46. Setpoint ramping parameters with ramp rate

calculation.

NOTE: Recovery ramping applies between scheduled heating or cooling setpoint changes from UNOCCUPIED to STANDBY, UNOCCUPIED to OCCUPIED, and STANDBY to OCCUPIED. Scheduled setpoint changes from OCCUPIED to UNOCCUPIED or OCCUPIED to STANDBY do not use a ramped setpoint but instead use a step change in setpoint. Recovery ramps begin before the next scheduled occupancy time and are ramped from the setpoint for the existing scheduled occupancy state to the setpoint for the next occupancy state.

RECOVERY RAMPING FOR HEAT PUMP SYSTEMS

When the node is controlling heat pump equipment, during the recovery ramps, the heating setpoint is split into a heat pump setpoint (for compressors) and an auxiliary heat setpoint (for auxiliary heat stages). The heat pump setpoint is a step change at the recovery time prior to the OCCUPIED time. Recovery time is computed from the configured heat recovery ramp rate. The recovery time is calculated:

Recovery time = (OCC setpoint - current setpoint)/ramp rate

See Fig. 47 for the various setpoints.

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Contents Excel General Considerations W7750 Controllers Appendices72-2958 74-2958 List of Figures74-2958 Setpoint ramping parameters with ramp rate calculationList of Tables Typical system overview Description of DevicesControl Provided Control ApplicationOrganization of Manual Products CoveredApplicable Literature Form No TitleAgency Listings Product NamesAbbreviations and Definitions Controllers ConstructionDI-1 W7750APerformance Specifications PowerSpecial Note for the W7750B,C Unit Specified Space Temperature Sensing Range CPUMemory Capacity Excel 10 W7750C Constant Volume AHU Controller Jack Lonmark Functional Profile DIN rail adaptersAnalog Inputs Inputs/OutputsDigital Inputs Triac Outputs on the W7750B,C Models onlyDigital Outputs Duct Sensor Wall ModulesT7770A1006 T7770CT7560A,B construction in in. mm General ConfigurationsConfiguration Options Summary For W7750A,B,C Controllers Staged HEATING/COOLING Control Allowable Heating and Cooling Equipment ConfigurationsHeat Pump Control Modulating HEATING/COOLING ControlPneumatic Actuator Control Economizer ControlWindow Open/Closed Digital Input Occupancy SensorWall Module Options MIXED-OUTPUT-TYPE ControlDirty Filter Monitor Modes of OperationIndoor Air Quality IAQ Override Smoke ControlDisabled OFF ModeNot AssignedPlan the System OverviewDetermine Other Bus Devices Required Step No DescriptionLonworks Bus Layout Lay Out Communications and Power WiringExcel VAV Cvahu Power Wiring Power Budget Calculation ExampleDeviceVA Information Obtained from ML6161A/B Damper Actuator, 35 lb-in R8242A Contactor VA Ratings For Transformer Sizing Device DescriptionML7984B PWM Valve Actuator Line LossNema class 2 transformer voltage output limits Power wiring details for one Excel 10 per TransformerGeneral Considerations Prepare Wiring DiagramsW7750 Controllers Terminal Terminal Number Description Factory Default Digital OutputsConstant Volume AHU Controller ML6161 Floating Actuator COM CCW Load Controller Power Heat Wall Economizer Damper PWM Actuator Power Signal W7750C Constant Pneumatic transducer to W7750B,C Shown, see triangle note Lonworks Bus Termination ModuleBrown Orange Order Equipment Lonworks Bus termination wiring optionsT7770 and T7560 Wall Modules Honeywell Logo T7770D1018Sensor with Bypass/LED and Lonworks Jack Accessories Sensors AccessoriesEchelon Based Components and Parts Troubleshooting Configure ControllersTroubleshooting Excel 10 Controllers and Wall Modules CablingAlarms Excel 10 AlarmsResistance Value ohms W7750 Controller Status LED Broadcasting the Service MessageSetting the Pid Parameters Appendix A. Using E-Vision to Commission a W7750 ControllerT7770C,D Wall Module Bypass Pushbutton and Override LED Sensor CalibrationAppendix B. Sequences of Operation Common Operations Heating Room Temperature Sensor RmTempEconomizer IAQ OptionRemote Setpoint RmtStptPot Bypass Mode StatusOvrd and StatusLedSetpoint Limits LoSetptLim and HiSetptLim BypassTimeOccupancy Mode and Manual Override Arbitration Continuous Unoccupied ModeNot Assigned Bypass OccupiedTime Clock OccTimeClock Recovery Ramping for Heat Pump SystemsSchedule Master SchedMaster Setpoint RampingSmoke Control Window Sensor StatusWndwFAN Operation Demand Limit Control DLCTemperature Control Operations See for a diagram of a typical W7750 UnitDirty Filter Monitor ONE Stage Staged Cooling ControlTWO Stages Three StagesSeries 60 Modulating Control Cascade Control of Modulating COOLING/HEATINGPulse Width Modulating PWM Control Outdoor AIR Lockout of HEATING/COOLINGIndoor AIR Quality IAQ Override Economizer ENABLE/DISABLE ControlFreeze Stat Discharge AIR LOW Limit ControlControl Parameters Address Input Output Points AddressEnergy Management Points Address Status Points AddressMappable User Addresses and Table Number Air Flow Relative TemperatureCO2 Concentration EnthalpyPlaced in manual mode through a menu Application reset therefore, these points canValid states and the corresponding Enumerated values are shownInput/Output Points DefaultNvName Field Name CommentsOccsensor Shcedmasterin NciIoSelect DigitalIn1255 NciIoSelect DigitalIn2 Occsensor UnuseddiCOOLSTAGE2 COOLSTAGE1COOLSTAGE3 COOLSTAGE4Siinvalid SixtyfiftyPPM Siinvalid FalseTrue Position when poor indoor air quality is detected EconEnSw NvoIO EconEnableInStatusDI3 NvoIO UbDigitalIn OccSensr NvoIONvName Default CommentsControl Parameters MaxClRamp NciAux1SetPt UbMaxClRampS0 Degrees F/Hr OdEnthalpyEnableMinClRamp NciAux1SetPt UbMinClRampS0 Degrees F/Hr MaxClRamp, OdTempMaxClRamp,PPM GainCoolProp NciAux2SetPt UbKpCoolS2 Degrees F Degrees C Discharge air temperature cascade control loopGain for the cooling control loop GainHeatProp NciAux2SetPt UbKpHeatS2 Degrees F Degrees CEnergy Management Points NviFree1 Value Refer to WSHPEnable.valueAuxiliary functions. nviFree1 controls the FREE1OUT Network variable input failsDestTimeClk NviTimeClk State NviTimeClk ValueRefer to nviTimeClk.value 255 SrcTimeClkCt NvoTimeClk ValueStatus Points Bit Offset = SensorFailAlrm Alarmbit1Bit Offset = FrostProtectAlrm Bit Offset = InvalidSetPtAlrmNodedisabled NoalarmSmokealarm UpdateallfieldsStartupwait DisabledmodeHeat CoolAir flow switch is configured StatusEconEn NvoData1 EconEnableNciAux1SetPts.ubOdEnthalpyEnableS2 StatusManOcc NvoData1 NetManOccAuxiliary heating stages are turned on HeatStgsOn NvoData1 HeatStagesOnCoolStgsOn NvoData1 CoolStagesOn For both heating or coolingNciConfig.SmokeControl Is 1, the algorithm controls as per the settings foundController mode is switched to Freezeprotect MonitorSw NvoData1 MonSwitchTempcontrolptfield BypasstimerfieldSpacetempfield DischargetempfieldUbinvalid SpaceTempError StatusError NvoError Errorbit0NvoError Errorbit0 Bit Offset = Temperature SetPtError NvoError Errorbit0Bit Offset = RtnEnthalpyError NvoError Errorbit1 NvoError Errorbit1Are disabled as if the sensor was not configured Bit Offset = SpaceCO2Error NvoError Errorbit1Bit Offset = NvDlcShedError NvoError Errorbit2 Bit Offset = NvWindowError NvoError Errorbit2Bit Offset = NvTodEventError NvoError Errorbit3 Bit Offset = NvByPassError NvoError Errorbit3Cfgexternal CfglocalCfgnul Calibration PointsConfiguration Parameters False True DisMinClTime NciConfig DisableCoolMinTime DisMinHtTime NciConfig DisableHeatMinTimeCascCntrl NciConfig CascadeControl UseRaTempCtl NciConfigOffset Absolutemiddle Last NETNone Normal BypassonlyLonmark /Open System Points Hvacheat HvacautoHvacmrngwrmup Hvacprecool Hvaccool Hvacnightpurge Hvacnul HvacoffDestRmTemp NviSpaceTemp Degrees F 74-2958 100SNVTtempp 14 to SrcRmTemp NvoSpaceTemp Degrees FHvacauto Hvacnul HvacmrngwrmupHvactest Alarmnotifydisabled 103 NvoStatus Inalarm NvoStatus Electricalfault255 Not configured 74-2958 NvoStatus UnabletomeasureSwon Corresponding economizer function is not enabled because On other nodes. If the economizer function is configured bySrcEconEnable NvoEcon State SrcEconEnCt NvoEcon ValueDirect Access And Special Points OFF Data Share Points =using One-to-Many and not using points Approximate Memory Size Estimating Procedure= including mapped points and others for Mapped points = number of mapped points per ExcelResistance Sensors Sensor Resistance Versus Temperature Resistance OhmsSensor Type Sensor UseDirect Setpoint Temperature Offset Setpoint TemperatureT7770B,C 10K ohm setpoint potentiometer Relative Above and Below Setpoint Resistance OhmsVoltage/Current Sensors Sensor Voltage Versus Humidity Humidity PercentageSensor Voltage Versus Humidity Relative Humidity Percentage 113 74-2958 Sensor Current Versus Enthalpy volts Enthalpy mAT7242 or equivalent 74-2958 114MAmAmAmA AmA mA mA Sensor Voltage Versus Input Voltage To A/D Voltage to A/D Pressure Inw kPa Sensor Voltage Vdc Sensor Voltage Vdc Versus Pressure InwInw 50.0.13
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