Trane Zone Controller, N512, CNT-SVX07C-EN manual AI4 terminal wiring CO2 measurement

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Chapter 4 Input/output functions and wiring for typical applications

is established and then is no longer present, the controller generates a Generic AIP Failure diagnostic.

For the CO2 measurement configuration, a 4–20 mA sensor must be hard- wired to the AI4 terminal as shown in Figure 5. The sensor will transmit a 0–2000 ppm value to the BAS. This configuration has no direct effect on Tracer ZN521 operation. If a valid value is established and then is no longer present, the controller generates a CO2 Sensor Failure diagnostic.

Figure 5. AI4 terminal wiring: CO2 measurement

Tracer ZN521

24 Vac

CO2 sensor (Trane 5010 0828 shown)

24 Vac

GND Signal

For the RH measurement configuration, either a hard-wired 4–20 mA zone humidity sensor (see Figure 6) must provide a value to the controller or a BAS communicates a value to the controller. The controller uses this value to support the dehumidification function. (For more information, see “Dehumidification” on page 47.) If a valid hard-wired or communi- cated relative humidity value is established and then is no longer present, the controller generates a Humidity Input Failure diagnostic and disables the dehumidification function.

Figure 6. AI4 terminal wiring: RH measurement

Tracer ZN521

RH sensor

20	CNT-SVX07C-EN

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Contents Installation and Operation Tracer ZN521 Zone Controller Page CNT-SVX07C-EN April CNT-SVX07C-EN Tracer ZN521 Zone Controller Installation and Operation CNT-SVX07C-EN Contents Sequence of operations Status indicators for operation and communication Troubleshooting Index Overview and specifications Product descriptionDimensions Storage environmentClearances Plastic-cover model dimensions and clearances Agency listing/compliance Additional componentsZone humidity sensor Tracer zone temperature sensor optionsDamper actuators CO2 sensorOverview and specifications Input/output terminal wiring AC-power wiringGeneral wiring information Communication-link wiring and addressing General wiring information Location recommendations Operating environment requirementsMounting recommendations Mounting the Tracer ZN521 zone controllerControlValve Economizing Typical applications for the Tracer ZN521 zone controllerApplication SpeedfanMultiple Dehumidification HeatElectricBI2 Condensate overflow BI1 Low-coil-temperature detectionBinary inputs Binary inputsBI3 Occupancy or generic binary input BI4 Fan statusGND Ground terminals ZN Zone temperatureAnalog inputs Analog inputs FAN Fan mode input AI1 Entering water temperature SET Local setpoint AI2 Discharge air temperature AI3 Outdoor air temperature or generic temperatureAI4 configuration options and associated measurement ranges Configuration Measurement rangeAI4 Universal 4-20 mA AI4 terminal wiring CO2 measurement Binary output functions Binary outputsGeneric binary output Binary output FunctionsRequired controller inputs for proper operation Wiring requirements and optionsOverriding binary outputs Function Input source For more information SeeTwo-pipe hydronic-cooling unit Two-pipe hydronic-heating unit Two-pipe hydronic heating/cooling unit with auto changeover Four-pipe hydronic heating/cooling unit Four-pipe heating/cooling unit with auto changeover Two-pipe heating unit with DX cooling Electric heat unit with DX cooling Electric heat unit Two-pipe heating unit with face-and-bypass damper Two-pipe heating/cooling unit with face-and-bypass damper Four-pipe heating/cooling unit with face-and-bypass damper Input/output functions and wiring for typical applications Power-up sequence Random startOccupied standby mode Occupied modeUnoccupied mode Occupancy modesOccupied bypass mode Timed override controlZone temperature control Cascade zone controlSimplified zone control Morning warm-up Heating or cooling modeDischarge air tempering Morning cool-downEntering water temperature sampling function Fan operationExhaust control Exhaust controlModulating valve calibration Valve operationModulating valve operation Valve control optionsIsolation-valve operation Modulating outdoor/return air dampersTwo-position valve operation Two-pipe operationModulating outdoor air damper position Ashrae Cycle 1 conformance Ashrae Cycle 2 conformanceEconomizing free cooling DX cooling operation Two-position control of a modulating outdoor air damperFace-and-bypass damper operation Face-and-bypass, isolation-valve operationElectric heat operation Baseboard heat operationDehumidification Peer-to-peer communication Unit protection strategiesFan off delay Smart resetLow-coil-temperature protection Condensate overflowFilter-maintenance timer Freeze protection discharge air temperature low limitFreeze avoidance Test button Tracer ZN521 zone controller circuit boardManual output test For non OutputClose damper, air Outdoor Open damper, air Outdoor Step Result BOP1 BOP2 BOP3 BOP4 BOP5 BOP6 BOP7 BOP8 BOP9Interpreting LEDs Service pin buttonRed LED Service indicator LED activity ExplanationGreen LED Status indicator Yellow LED Communications indicatorDiagnostics Types of diagnosticsDiagnostic Probable cause Consequences Type Table of diagnosticsDiagnostics Fan unaffectedValved unaffected PositionDamper unaffected Status indicators for operation and communication Fan does not energize Probable cause ExplanationTroubleshooting Valves remain closedValves remain open DX or electric heat does not energizeOutdoor air damper remains closed Outdoor air damper remains openOutdoor air damper remains open Troubleshooting Index NumericsIndex Index Index Page Trane