Honeywell W7761A specifications VA Rating, Nema class 2 transformer voltage output limits

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EXCEL 10 W7761A INPUT/OUTPUT DEVICE

No installation should be designed where the line loss is greater than two volts to allow for nominal operation if the primary voltage drops to 102 Vac (120 Vac minus 15 percent).

To meet the National Electrical Manufacturers Association (NEMA) standards, a transformer must stay within the NEMA limits. The chart in Fig. 11 shows the required limits at various loads.

With 100 percent load, the transformer secondary must supply between 23 and 25 volts to meet the NEMA standard. When a purchased transformer meets the NEMA standard DC20-1986, the transformer voltage-regulating ability can be considered reliable. Compliance with the NEMA standard is voluntary.

The following Honeywell transformers meet this NEMA standard:

Transformer Type	VA Rating
AT20A	20
AT40A	40
AT72D	40
AT87A	50
AK3310 Assembly	100

SECONDARY VOLTAGE

27

26

25

24

23

22

21

20

19

18

17

16

15

14

050100150200

% OF LOAD

M993

Fig. 11. NEMA class 2 transformer voltage output limits.

Attach earth ground to W7761 Device terminal 1. See Fig. 12, 13 and 14, 16 through 20.

TRIAC`

COMMON

TRANSFORMER

TRIAC LINES` TO ACTUATORS` AND CONTACTORS

W7761A

CONNECT POWER TO `

TERMINALS 24 AND 25

25 24 22 20

	1
	EARTH`	M10089
	GROUND	M10089
	GROUND

Fig. 12. Power wiring details for one Excel 10 per transformer.

22

74-2699

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Contents Excel 10 W7761A Remote Input/Output Device List of Tables AppendicesDescription of Devices Typical system overviewProducts Covered Control ApplicationControl Provided Organization of ManualProduct Names Agency Listings Abbreviations and DefinitionsExcel 10 W7761A INPUT/OUTPUT Device Construction ControllersExcel 10 W7761A Remote I/O Device W7761A construction in in. mm Performance Specifications Power List Of Available Points W7761AShipping Temperature Specified Space Temperature Sensing RangeEnvironmental Operating Temperature Memory CapacityReturn Air Temperature Discharge Air TemperatureOutdoor Air Temperature Mixed Air TemperatureWall Modules 5585Configurations T7780 construction, subbase dimensions in in. mmWindow Open/Closed Digital Input Mixed-Output-Type ControlOccupancy Sensor Wall Module OptionsPlan The System OverviewApplication Steps Step No Description Determine Other Bus Devices Required Lay Out Communications and Power WiringBus Layout 750,1$ Power Wiring Power Budget Calculation ExampleVA Ratings For Transformer Sizing Device Description Line LossVA Rating Nema class 2 transformer voltage output limitsLine VOLTAGE` GREATER` Than 150 VAC General Considerations Prepare Wiring DiagramsW7761A Devices W7761A I/O Description Terminal Number DescriptionTemperature Sensor DE V IC E Window Contact Contact Closed = Occupancy Sensor Occupied Valve Actuator Bus Termination Module Typical Pneumatic transducer Series 60 Floating to W7761ASee for E-Bus termination wiring options +$672 T7770 Wall Modules Order EquipmentExcel 10 W7750 Controllers SensorsAccessories Echelon Based Components and PartsCabling Temperature Degrees Excel 10 Alarms Broadcasting the Service MessageW7761A Device Status LED T7780 Ddwm Bypass Pushbutton LED StatesAppendix A. Using E-Vision to Commission a W7761 Device Adding Analog Inputs Enthalpy 4 to 20 mAAdding Other VOLTAGE/CURRENT Sensors Adding Digital Inputs Appendix B. Sequences of Operation Room Temperature Sensor RmTempCommon Operations Series 60 Modulating Control Window Sensor StatusWndwDirty Filter Monitor Pulse Width Modulating PWM ControlAir Flow Temperature Relative HumidityRelative CO 2 ConcentrationDefault Table C1. Input/Output Points LeftTable C1. Input/Output Points Right Excel 10 W7761A INPUT/OUTPUT Device Values that can be assigned to any output channels English Metric or User Address DI3Sel1Type Refer to the description for DI1Sel1Type Stoff Stnul Stlow Stmed Sthigh Ston DO2Type Excel 10 W7761A INPUT/OUTPUT Device SrcDigIn2Sts Refer to the description for SrcDigIn1Sts Table C2. Control Parameters Left Table C2. Control Parameters Right SH MA DA EV HW MN TSNoalarm Table C3. Status Points LeftTable C3. Status Points Right RIO1 Software version NvoStatus InOverride SH MA DA EV HW MN TS Table C4. Configuration Parameters Left Table C4. Configuration Parameters Right DO0 Higher than the value specified for AILowLimit DO4 Seconds = 25.6 seconds DO6PWMPeriod Refer to the description for DO1PWMPeriod Table C5. Direct Access And Special Points Left Table C5. Direct Access And Special Points RightApproximate Memory Size Estimating Procedure Fig. D-1. Point capacity estimate for Zone ManagerSensor Type Appendix E. Sensor Data for CalibrationResistance Sensors Sensor Use1956.79 Table E-4. Sensor Voltage Versus Humidity Voltage/Current SensorsHumidity Percentage Sensor Voltage C7600C1008 4 to 20 mA C7600C output current vs. humidity Sensor Type Fig. E-6. Graph of Sensor Current versus Enthalpy volts CO 2 Concentration PPM Sensor Voltage Table E-9. Sensor Voltage Versus CO 2 ConcentrationTable E-10. Sensor Voltage Versus Input Voltage To A/D Table E-11. Sensor Voltage Vdc Versus Pressure Inw Voltage to A/D Sensor VoltagePressure Inw kPa Sensor Voltage Vdc 3ODD