Honeywell W7752D Zone Control Options, Output Configuration Options, Input Configuration Options

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EXCEL 10 FCU CONTROLLER LNS PLUG-INS USER GUIDE

APPENDIX B: CONFIGURING FOR MASTER/SLAVE OPERATION

More than one Excel 10 FCU Controller may be used to control the temperature of a room. In this situation one controller must be identified as the master unit which will perform the temperature control algorithm. The other FCU Controllers in the room are designated as slave units, and their control algorithms are disabled. The slave units receive heating, cooling, and fan output information from the master controller via network variables sent across the LonWorks network. There can be a maximum of one wall module active in the room, and it must be wired directly to the master controller. If a slave controller has a wall module connected to it, the wall module will be ignored.

If a fan is used in the slave units, all fan control settings must be the same as in the master controller.

All heating and cooling stage switching levels should be identical to those of the master controller.

Zone Control Options

All zone temperature control options including PID settings and miscellaneous settings are used only by the master controller and are ignored in the slave units.

Configuration of the master controller is the same as for any controller operating alone in a room. Configuration of the slave controllers must follow the rules described in this section. The following sections correspond to the screens in the LNS tool used for configuring Excel 10 FCU Controllers. An additional section discusses binding of network variables to support master/slave configurations.

Output Configuration Options

Slave devices must have their outputs configured identically with the master controller. The same system type and actuator types must be used. Valve run-times, cycle times, and PWM zero and full position configuration options must be the same as well. If the master controller has a reheat output, the slave units must have one; and both must be configured the same. Fan control in the slave units is via network command from the master unit.

IMPORTANT

The fan minimum on-time must be configured to zero in the slave controllers so that the fans in both master and slave units switch ON at the same time.

Input Configuration Options

Slave controllers may have wall modules connected to them, but they must be deactivated while the controllers are operating as slave units. They must be configured for no temperature sensor and no fan speed switch. The digital input may be used on the slave units for window open/closed or air flow (fan fail) detection and must be configured as such. In the case of window sensing, the window status network variable must be mapped to the master controller as the slave controller does not execute the control algorithm.

Network Variable Binding

In a master/slave configuration, the control algorithm is executed in the master controller only. Heating and cooling output as calculated by the control algorithm is then sent via the network to the slave controllers. The master controller output variables nvoHeatOutput and nvoCoolOutput must be bound to the slave input variables nviManHeat and nviManCool respectively.

For a master/slave system using heat/cool changeover, the master controller output variable must be bound to the slave controllers’ input NV nviApplicMode unless a changeover contact is connected to the slave devices. The binding of these two NVs is also required in applications where heat/cool energy is not always available.

The T7780 wall module must be connected to the master controller. The master controller output variable nvoFanSpeed must be bound to the slave controllers’ input variable nviFanSpeedCmd

IMPORTANT

The OFF position of the fan speed switch on the wall module turns OFF heating and cooling control functions as well as the fan, so the network variable binding described above for fan speed must still be performed as described.

For applications with reheat, the master controller output variable nvoReheat must be bound to the slaves’ input variable nviReheatRelay.

Equipment Control Options

Valve action and fan interlock settings must be the same as for the master controller. Output staging hysteresis, minimum stage OFF times, and reheat switching and hysteresis should be the same as in the master controller.

EN2B-0285GE51 R0909

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Contents Excel Appendix a Using An LNS tool to Commission a Fan Coil Unit Appendix B Configuring for Master/Slave OperationAppendix C LON Interface Revision History Description of Devices Typical system overviewProducts Covered Organization of ManualApplicable Literature Product NamesControl Application Control ProvidedSetpoints Setpoint KnobSetpoint Limits Setpoint from NetworkZEB Energy-Saving Features BypassOccupancy Status Safety Features Operating ModesConstruction Excel 10 W7752 FCU ControllersExcel 10 W7754 FCU Controllers Electrical Shock Hazard180 Controller Performance Specifications Configurations GeneralFan Type Type of Heating and Cooling Equipment Reheat Output Digital InputCommon Temperature Control Master/Slave Controllers Excel 10 Wall Module OptionsAbbreviations and Definitions Overview Plan the SystemDetermine Other Bus Devices Required Step No DescriptionLay Out Communications and Power Wiring Lonworks LayoutPrepare Wiring Diagrams Power WiringGeneral Considerations Wiring PowerVendor wire type PlenumLOW 230 ONW Orks Termination XAL-TermOrder Equipment Excel 10 Wall ModulesExcel 10 Sensors Echelon-Based Components and PartsConfigure Controllers Using Plug-InsOutput Input Equipment Control FanSwitching Levels Zone OptionsMiscellaneous Troubleshooting Troubleshooting Excel 10 FCU Controllers and Wall ModulesAlarms CommissioningFCU Alarms ReturntonormalBroadcasting the Service Message Manual ModeTemperature Sensor Calibration ProcedureOutput Configuration Options Input Configuration OptionsZone Control Options Network Variable BindingAppendix C LON Interface Page NV name Continuous Automode To 100% For the reheat output EN2B-0285GE51 R0909 Noswitch Byte NtcnonlinearizeNtcnonlinearized Byte FivepositionByte Dinotused DiwindowclosedDioccupiedsensor DiairflowByte Floating OnestageTwostage ThreestageByte Reheat FreeuseRelnotused Fourpipe TwopipeUword Offset AbsolutemiddleBypassunoccupie NobuttonTable C3. Input Variables for Excel 10 FCU Controllers Modeenable Unsuppressalarms ModedisableSuppressalarms OcnulRqnormal Rqupdatestatus Rqupdatealarm Rqreportmask OFF NULInvalid Byte Normalhcmode OFF1OFF2ON1OFF2 OFF1ON2Byte Normalfanmode Ledoff LedonNowindow ClosedOpen Table C4. Output Variables for Excel 10 FCU Controllers Rtncomfailtempreset AlarmnotifydisabledRtncomfailsetptoffs RtncomfailschedoccAlmcomfailmanheat Almcomfailmancool Almhwswmismatch OFF NotassignedOcbypass Ocstandby OFF Nofanspeedsw Ubyte FieldeffectoccFieldhwoverride FieldschedoccCtlfanswitchoff CtldisabledOcunoccupied Ocbypass Ocstandby Ocunoccupied Ocbypass Ocstandby OcnulNot Actice Active FanoffafteroncmdFanruns ExternalnotacticeStoff StonInvalid Uword OFF Noreheat NotpressedPressed Contactopen Contactclosed UwordStlow Stmed Sthigh Invalid Byte InitialEnabled DisabledNoalarm InalarmAlarm Suppressalarms Alarmnotifydisabled Open NowindowBugver Nodetype Table C5. Unused Variables for Excel 10 FCU Controllers WordAutomation and Control Solutions

W7752D specifications

The Honeywell W7752D is a versatile and advanced electronic gas combination control designed primarily for use in commercial heating systems. This product stands out for its ability to manage both gas ignition and safety functions, which are critical for maintaining the efficiency and safety of heating appliances. Its robust construction and advanced features make it a popular choice for HVAC professionals and service technicians.

One of the main features of the W7752D is its integration of multiple functions in a single device. It serves as both an automatic gas ignition control and a safety shut-off valve, which simplifies installation and reduces the need for additional components. This integrated design not only enhances reliability but also streamlines maintenance procedures.

Another notable technology utilized in the W7752D is its microprocessor-based control logic. This advanced technology allows for precise management of the ignition sequence, improving the overall efficiency of the heating system. The microprocessor enables the control to adapt to varying operating conditions, ensuring optimal performance even under changing demands.

The W7752D is equipped with features that enhance user-interface and diagnostics capabilities. It includes LED indicators that provide clear information about the operational status and any potential issues. This diagnostics capability facilitates easier troubleshooting, saving time and reducing the likelihood of extended downtimes.

Safety is a primary concern in gas appliances, and the W7752D addresses this with built-in safety mechanisms, including flame detection technologies. These features ensure that the appliance operates safely, automatically shutting down in case of any irregularities during operation. This emphasis on safety not only protects property but also provides peace of mind for users.

In terms of compatibility, the Honeywell W7752D is designed to work with a wide range of gas heating appliances. Its flexibility allows it to be used in various applications, making it suitable for different types of commercial environments. Additionally, the control complies with relevant safety and performance standards, ensuring reliable operation.

In summary, the Honeywell W7752D combines advanced technology with essential safety features, making it a top choice for commercial heating applications. Its integrated design, microprocessor-based control, user-friendly diagnostics, and robust safety mechanisms make it an essential component for efficient and safe gas heating systems. Whether it is for new installations or replacements, the W7752D provides HVAC professionals with the reliability and ease of use they demand.
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