Honeywell W7752D specifications Bypass, Energy-Saving Features

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EXCEL 10 FCU CONTROLLER LNS PLUG-INS USER GUIDE

Bypass

Bypass Mode

When the Excel 10 FCU Controller is in the "unoccupied" mode, the Excel 10 wall module's bypass push-button may be used to force the Excel 10 FCU Controller into the "occupied" mode. The Excel 10 FCU Controller can also be forced into the "occupied" mode by means of a LONWORKS network command (when nviManOccCmd is set to OC_BYPASS). The controller will then remain in "bypass" mode until:

1.The bypass timer has timed out, or

2.The user again presses the Excel 10 wall module's bypass push-button, thus cancelling the "bypass" mode, or

3.The occupancy schedule (nviTodEvent) switches the mode to "occupied".

4.nviManOccCmd is set to OC_NUL.

The Excel 10 wall module indicates the current bypass mode status (see Excel 10 wall module literature for further information).

Bypass Timer

When the "bypass" mode has been activated, the bypass timer is set to BypTime (default of 180 minutes), at the end of which the mode will revert to its original state (see Excel 10 wall module literature for further information).

Continuous "Unoccupied" Mode

The continuous "unoccupied" mode is entered when an Excel

10 wall module is configured to allow it and if:

•(in the case of the T7460) the bypass button is pressed for four to seven seconds (until the LED blinks),

•(in the case of the T7560) the bypass button is pressed for more than five seconds (until the flashing moon appears).

The Excel 10 FCU Controller can also be forced into the con- tinuous "unoccupied" mode by means of a LONWORKS net- work command (when nviManOccCmd is set to OC_UNOCCUPIED). The Excel 10 FCU Controller will then remain in this mode indefinitely, or until the bypass button is pressed to exit the mode or a network command is sent to clear the mode.

Bypass Push-Button

Excel 10 FCU Controllers may be hardwired to an Excel 10 wall module equipped with a bypass push-button. The bypass push-button has three possible configurations (see Table 17 for further information):

•NONE

•BYPASS_UNOCCUPIED

•BYPASS_ONLY

Override Priority

Excel 10 FCU Controllers can be configured to arbitrate overrides coming from the bypass push-button and the network. There are two possible configurations, having the following meanings:

•LAST_WINS specifies that the last command received from either the wall module or nviManOccCmd determines the effective override state.

•NETWORK_WINS specifies that, regardless of the wall module override state, the effective occupancy mode is

determined by nviManOccCmd (provided it has not been set to OC_NUL).

LED/LCD

LED Override

The wall module’s LED indicates that the FCU Controller is being overridden by either the bypass button or the LONWORKS network.

•LED ON ⇒ "override bypass"

•One flash per second ⇒ "override unoccupied"

•Two flashes per second ⇒ "override standby" or "occupied"

•LED OFF ⇒ no override

•Four flashes per second ⇒ The controller is responding to a LONWORKS network management wink command.

LED Occupancy

The wall module’s LED indicates the effective occupancy mode.

•LED ON ⇒ effective "occupied" or effective "bypass"

•One flash per second ⇒ effective "standby"

•LED OFF ⇒ effective "unoccupied"

•Four flashes per second ⇒ The controller is responding to a LONWORKS network management wink command.

LCD Display

This mode is used only for T7560 Wall Modules. The occupancy mode is represented by the following symbols:

⇒ effective "occupied" or effective "bypass"

⇒ effective "standby"

⇒ effective "unoccupied"

⇒ Controller is OFF

and ⇒ Controller is OFF, frost protection is enabled.

Flashing symbols indicate the "override" mode: ⇒ override "occupied" or override "bypass"

⇒ override "standby"

⇒ override "unoccupied"

⇒The controller is responding to a LONWORKS network

management wink command.

Energy-Saving Features

The "Standby" Mode

The digital input for reading input from an occupancy sensor (usually a motion detector) provides the Excel 10 FCU Con- troller with a means to enter an energy-saving standby mode whenever there are no people in the room. The "standby" mode occurs when the scheduled occupancy mode is "occupied" but the occupancy sensor indicates that the room is nevertheless currently unoccupied. If no occupancy sensor is directly connected to the Excel 10 FCU Controller, an occupancy sensor from another node may be bound to the network input nviSensorOCC. The Excel 10 FCU Controller can also be forced into the "standby" mode by means of a LONWORKS network command (when nviManOccCmd is set to OC_STANDBY). When in the "standby" mode, the Excel 10 FCU Controller uses the "standby" setpoints configured for the heating and the cooling modes.

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Contents Excel Appendix C LON Interface Revision History Appendix a Using An LNS tool to Commission a Fan Coil UnitAppendix B Configuring for Master/Slave Operation 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 Fan Type ConfigurationsGeneral 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 LayoutGeneral Considerations Prepare Wiring DiagramsPower Wiring 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 FanMiscellaneous Switching LevelsZone Options 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 ThreestageRelnotused Byte ReheatFreeuse Fourpipe TwopipeUword Offset AbsolutemiddleBypassunoccupie NobuttonTable C3. Input Variables for Excel 10 FCU Controllers Modeenable Unsuppressalarms ModedisableSuppressalarms OcnulInvalid Rqnormal Rqupdatestatus Rqupdatealarm RqreportmaskOFF NUL Byte Normalhcmode OFF1OFF2ON1OFF2 OFF1ON2Byte Normalfanmode Ledoff LedonOpen NowindowClosed Table C4. Output Variables for Excel 10 FCU Controllers Rtncomfailtempreset AlarmnotifydisabledRtncomfailsetptoffs RtncomfailschedoccOcbypass Ocstandby Almcomfailmanheat Almcomfailmancool AlmhwswmismatchOFF Notassigned OFF Nofanspeedsw Ubyte FieldeffectoccFieldhwoverride FieldschedoccCtlfanswitchoff CtldisabledOcunoccupied Ocbypass Ocstandby Ocunoccupied Ocbypass Ocstandby OcnulNot Actice Active FanoffafteroncmdFanruns ExternalnotacticeInvalid Uword StoffSton 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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