Honeywell W7750A Remote Setpoint RmtStptPot, Setpoint Limits LoSetptLim and HiSetptLim

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EXCEL 10 W7750A,B,C CONSTANT VOLUME AHU CONTROLLER

than Intermittent Fan (see Fan Operation in this Appendix), and the mode is Occupied when the RmTemp value becomes invalid, the fan continues to run.

REMOTE SETPOINT (RmtStptPot)

This is the Setpoint Potentiometer contained in the T7770 or the T7560A,B Wall Module. When configured, this occupant value is set to calculate the actual cooling or heating Occupied Setpoint. There are two options for how to calculate the actual setpoint to be used by the temperature control algorithm: (Offset) and (Absolute Middle). When SetPtKnob is set to Offset, the Wall Module setpoint knob represents a number from -9° to +9°F (-5° to +5°C) which is added to the software occupied setpoints for the heat and the cool modes (CoolOccSpt and HeatOccSpt). When SetPtKnob is set to Absolute Middle, the setpoint knob becomes the center of the Zero Energy Band (ZEB) between the cooling and heating occupied setpoints. The size of the ZEB is found by taking the difference between the software heating and cooling occupied setpoints; therefore, for Absolute Middle, the actual setpoints are found as follows:

ActualCoolSpt = RmtStptPot + (CoolOccSpt - HeatOccSpt) / 2

ActualHeatSpt = RmtStptPot - (CoolOccSpt - HeatOccSpt) / 2

During Standby and Unoccupied times, the remote setpoint pot is not referenced, and the software setpoints for those modes are used instead.

SETPOINT LIMITS (LoSetptLim AND HiSetptLim)

Remote setpoint pot limits are provided by LoSetptLim and HiSetptLim. The occupied setpoints used in the control algorithms are limited by these parameters. When the setpoint knob is configured to be of type Absolute Middle, the lowest actual setpoint allowed is equal to LoSetptLim, and the highest actual setpoint allowed is equal to HiSetptLim. When the setpoint knob is configured to be an Offset type, the lowest actual setpoint allowed is equal to HeatOccSpt - LoSetptLim, and the highest allowed is equal to CoolOccSpt + HiSetptLim.

BYPASS MODE (StatusOvrd AND StatusLed)

During Unoccupied periods, the facility occupant can request that Occupied temperature control setpoints be observed by depressing the Bypass pushbutton on the wall module. When activated, the controller remains in Bypass mode until:

1.Bypass Duration Setting has timed out (BypTime), or

2.User again presses the Wall Module pushbutton to switch off Bypass mode, or

3.Occupancy schedule (DestSchedOcc network input or TimeClckOcc digital input) switches the mode to Occupied.

4.User sets the DestManOcc network point to Not

Assigned.

The LED on the T7770 Wall Module (Override LED) indicates the current bypass mode status (see the T7770C,D Wall Module Bypass Pushbutton and Override LED section). The LCD on the T7560 Digital Wall Module indicates the current bypass mode status (see the T7560A,B Digital Wall Module Bypass Pushbutton and LCD Occupancy Symbols section).

BypassTime

BypassTime is the time between the pressing of the override button at the wall module (or initiating OC_BYPASS via nviManOcc) and the return to the original occupancy state. When the bypass state has been activated, the bypass timer is set to BypassTime (default of 180 minutes).

OverrideType

OverrideType specifies the behavior of the override button on the wall module. There are three possible states that have the following meanings:

NONE disables the override button.

NORMAL causes the override button to set the OverRide state to OC_BYPASS for BypassTime (default 180 minutes), when the override button has been pressed for approximately 1 to 4 seconds, or to set the OverRide state to UNOCC when the button has been pressed for approximately 4 to 7 seconds. When the button is pressed longer than approximately 7 seconds, then the OverRide state is set to OC_NUL (no manual override is active).

BYPASS_ONLY causes the override button to set the OverRide state to OC_BYPASS for BypassTime (default 180 minutes), on the first press (1 to 7 seconds). On the next press, the OverRide state is set to OC_NUL (no manual over ride is active).

OverridePriority

OverridePriority configures the override arbitration between nviManOcc, nviBypass.state, and the wall module override button. There are two possible states which have the following meanings:

LAST specifies that the last command received from either the wall module or nviManOcc determines the effective override state.

NET specifies that when nviManOcc is not OC_NUL, then the effective occupancy is nviManOcc regardless of the wall module override state.

CYCLES PER HOUR (ubHeatCph AND ubCoolCph)

ubHeatCph specifies the mid-load number of on / off cycles per hour (default is 6), when the mode is HEAT. ubCoolCph specifies the mid-load number of on / off cycles per hour (default is 3), when the mode is COOL. This is to protect the mechanical equipment against short cycling causing excessive wear. In addition the cycle rate specifies the minimum on and off time according to Table 17.

T7770C,D OR T7560A,B WALL MODULE BYPASS PUSHBUTTON OPERATION

The Wall Module Bypass pushbutton is located on both the T7770C,D or the T7560A,B Wall Modules, see Fig. 43 and 44. The bypass pushbutton can change the controller into various occupancy modes, see Table 16.

Table 16. Bypass Pushbutton Operation.

 

 

 

If the pushbutton is

But for not

 

held down for

more than

The resulting mode is

 

 

 

Less than 1 second

—

No Override is active

 

 

 

1 second

4 seconds

Bypass (a timed Occupied

 

 

Override)

 

 

 

4 seconds

7 seconds

Continuous Unoccupied

 

 

Override

 

 

 

NOTES: If the pushbutton is held down for longer than seven seconds, the controller reverts back to No Override and repeats the cycle above. See Fig. 45.

Continuous Occupied override mode can only be initiated remotely; that is, over the LONWORKS Bus network.

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Contents Excel Appendices General Considerations W7750 Controllers72-2958 74-2958 List of Figures74-2958 Setpoint ramping parameters with ramp rate calculationList of Tables Typical system overview Description of DevicesControl Provided Control ApplicationForm No Title Products CoveredOrganization of Manual Applicable LiteratureAgency Listings Product NamesAbbreviations and Definitions Controllers ConstructionDI-1 W7750APower Performance SpecificationsSpecial Note for the W7750B,C Unit CPU Specified Space Temperature Sensing RangeMemory Capacity Excel 10 W7750C Constant Volume AHU Controller Jack Lonmark Functional Profile DIN rail adaptersAnalog Inputs Inputs/OutputsTriac Outputs on the W7750B,C Models only Digital InputsDigital Outputs T7770C Wall ModulesDuct Sensor T7770A1006T7560A,B construction in in. mm General ConfigurationsConfiguration Options Summary For W7750A,B,C Controllers Modulating HEATING/COOLING Control Allowable Heating and Cooling Equipment ConfigurationsStaged HEATING/COOLING Control Heat Pump ControlPneumatic Actuator Control Economizer ControlMIXED-OUTPUT-TYPE Control Occupancy SensorWindow Open/Closed Digital Input Wall Module OptionsSmoke Control Modes of OperationDirty Filter Monitor Indoor Air Quality IAQ OverrideAssigned OFF ModeDisabled NotStep No Description OverviewPlan the System Determine Other Bus Devices RequiredLonworks Bus Layout Lay Out Communications and Power WiringExcel VAV Cvahu Power Budget Calculation Example Power WiringDeviceVA Information Obtained from Line Loss VA Ratings For Transformer Sizing Device DescriptionML6161A/B Damper Actuator, 35 lb-in R8242A Contactor ML7984B PWM Valve ActuatorNema 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 optionsHoneywell Logo T7770D1018 T7770 and T7560 Wall ModulesSensor with Bypass/LED and Lonworks Jack Accessories Accessories SensorsEchelon Based Components and Parts Cabling Configure ControllersTroubleshooting Troubleshooting Excel 10 Controllers and Wall ModulesExcel 10 Alarms AlarmsResistance Value ohms W7750 Controller Status LED Broadcasting the Service MessageSensor Calibration Appendix A. Using E-Vision to Commission a W7750 ControllerSetting the Pid Parameters T7770C,D Wall Module Bypass Pushbutton and Override LEDAppendix B. Sequences of Operation Common Operations IAQ Option Room Temperature Sensor RmTempHeating EconomizerBypassTime Bypass Mode StatusOvrd and StatusLedRemote Setpoint RmtStptPot Setpoint Limits LoSetptLim and HiSetptLimBypass Occupied Continuous Unoccupied ModeOccupancy Mode and Manual Override Arbitration Not AssignedSetpoint Ramping Recovery Ramping for Heat Pump SystemsTime Clock OccTimeClock Schedule Master SchedMasterDemand Limit Control DLC Window Sensor StatusWndwSmoke Control FAN OperationSee for a diagram of a typical W7750 Unit Temperature Control OperationsDirty Filter Monitor Three Stages Staged Cooling ControlONE Stage TWO StagesOutdoor AIR Lockout of HEATING/COOLING Cascade Control of Modulating COOLING/HEATINGSeries 60 Modulating Control Pulse Width Modulating PWM ControlDischarge AIR LOW Limit Control Economizer ENABLE/DISABLE ControlIndoor AIR Quality IAQ Override Freeze StatStatus Points Address Input Output Points AddressControl Parameters Address Energy Management Points AddressMappable User Addresses and Table Number Enthalpy Relative TemperatureAir Flow CO2 ConcentrationEnumerated values are shown Application reset therefore, these points canPlaced in manual mode through a menu Valid states and the correspondingComments DefaultInput/Output Points NvName Field NameOccsensor Unuseddi NciIoSelect DigitalIn1Occsensor Shcedmasterin 255 NciIoSelect DigitalIn2COOLSTAGE4 COOLSTAGE1COOLSTAGE2 COOLSTAGE3Siinvalid SixtyfiftyFalse PPM SiinvalidTrue OccSensr NvoIO EconEnSw NvoIO EconEnableInPosition when poor indoor air quality is detected StatusDI3 NvoIO UbDigitalInNvName Default CommentsControl Parameters MaxClRamp, OdTempMaxClRamp, OdEnthalpyEnableMaxClRamp NciAux1SetPt UbMaxClRampS0 Degrees F/Hr MinClRamp NciAux1SetPt UbMinClRampS0 Degrees F/HrPPM GainHeatProp NciAux2SetPt UbKpHeatS2 Degrees F Degrees C Discharge air temperature cascade control loopGainCoolProp NciAux2SetPt UbKpCoolS2 Degrees F Degrees C Gain for the cooling control loopEnergy Management Points Network variable input fails Refer to WSHPEnable.valueNviFree1 Value Auxiliary functions. nviFree1 controls the FREE1OUT255 SrcTimeClkCt NvoTimeClk Value NviTimeClk ValueDestTimeClk NviTimeClk State Refer to nviTimeClk.valueStatus Points Bit Offset = InvalidSetPtAlrm Alarmbit1Bit Offset = SensorFailAlrm Bit Offset = FrostProtectAlrmUpdateallfields NoalarmNodedisabled SmokealarmCool DisabledmodeStartupwait HeatStatusManOcc NvoData1 NetManOcc StatusEconEn NvoData1 EconEnableAir flow switch is configured NciAux1SetPts.ubOdEnthalpyEnableS2For both heating or cooling HeatStgsOn NvoData1 HeatStagesOnAuxiliary heating stages are turned on CoolStgsOn NvoData1 CoolStagesOnMonitorSw NvoData1 MonSwitch Is 1, the algorithm controls as per the settings foundNciConfig.SmokeControl Controller mode is switched to FreezeprotectDischargetempfield BypasstimerfieldTempcontrolptfield SpacetempfieldUbinvalid Bit Offset = Temperature SetPtError NvoError Errorbit0 StatusError NvoError Errorbit0SpaceTempError NvoError Errorbit0Bit Offset = SpaceCO2Error NvoError Errorbit1 NvoError Errorbit1Bit Offset = RtnEnthalpyError NvoError Errorbit1 Are disabled as if the sensor was not configuredBit Offset = NvByPassError NvoError Errorbit3 Bit Offset = NvWindowError NvoError Errorbit2Bit Offset = NvDlcShedError NvoError Errorbit2 Bit Offset = NvTodEventError NvoError Errorbit3Calibration Points CfglocalCfgexternal CfgnulConfiguration Parameters False True UseRaTempCtl NciConfig DisMinHtTime NciConfig DisableHeatMinTimeDisMinClTime NciConfig DisableCoolMinTime CascCntrl NciConfig CascadeControlBypassonly Last NETOffset Absolutemiddle None NormalLonmark /Open System Points Hvacoff HvacautoHvacheat Hvacmrngwrmup Hvacprecool Hvaccool Hvacnightpurge HvacnulSrcRmTemp NvoSpaceTemp Degrees F 74-2958 100DestRmTemp NviSpaceTemp Degrees F SNVTtempp 14 toHvacmrngwrmup Hvacauto HvacnulHvactest Alarmnotifydisabled NvoStatus Unabletomeasure NvoStatus Electricalfault103 NvoStatus Inalarm 255 Not configured 74-2958Swon SrcEconEnCt NvoEcon Value On other nodes. If the economizer function is configured byCorresponding economizer function is not enabled because SrcEconEnable NvoEcon StateDirect Access And Special Points OFF Data Share Points Mapped points = number of mapped points per Excel Approximate Memory Size Estimating Procedure=using One-to-Many and not using points = including mapped points and others forSensor Use Sensor Resistance Versus Temperature Resistance OhmsResistance Sensors Sensor TypeAbove and Below Setpoint Resistance Ohms Offset Setpoint TemperatureDirect Setpoint Temperature T7770B,C 10K ohm setpoint potentiometer RelativeSensor Voltage Versus Humidity Humidity Percentage Voltage/Current SensorsSensor Voltage Versus Humidity Relative Humidity Percentage 113 74-2958 Sensor Current Versus Enthalpy volts Enthalpy mA74-2958 114 T7242 or equivalentMAmAmAmA AmA mA mA Sensor Voltage Versus Input Voltage To A/D Voltage to A/D 50.0.13 Sensor Voltage Vdc Versus Pressure InwPressure Inw kPa Sensor Voltage Vdc Inw
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