Trane Zone Controller SET Local setpoint, FAN Fan mode input, AI1 Entering water temperature

Page 27

Analog inputs

SET: Local setpoint

The SET analog input functions as the local (hard-wired) temperature setpoint input for applications utilizing a Trane zone sensor with a tem- perature setpoint thumbwheel. The local setpoint input is configurable (as enabled or disabled) using the Rover service tool. A setpoint value communicated by means of a LonTalk link can also be used for controllers operating on a BAS. If both hard-wired and communicated setpoint val- ues are present, the controller uses the communicated value. If neither a hard-wired nor a communicated setpoint value is present, the controller uses the stored default setpoints (configurable using the Rover service tool). If a valid hard-wired or communicated setpoint value is established and then is no longer present, the controller generates a Setpoint Failure diagnostic.

FAN: Fan mode input

The FAN analog input functions as the local (hard-wired) fan mode switch input for applications using the Trane zone sensor with a fan mode switch option. The various fan mode switch positions (off, low, medium, high, auto) provide different resistances that are interpreted by the Tracer ZN521. The local fan mode switch input is configurable (as enabled or disabled) using the Rover service tool. A communicated fan mode request via the LonTalk communications link can also be used for controllers operating on a BAS. If both hard-wired and communicated fan mode values are present, the controller uses the communicated value. If neither a hard-wired nor a communicated fan mode value is present, the controller recognizes the fan mode value as auto and operates according to the default configuration. If a valid hard-wired or communicated fan mode value is established and then is no longer present, the controller generates a Fan Mode Failure diagnostic.

AI1: Entering water temperature

The AI1 analog input functions as the local (hard-wired) entering water temperature input. An entering water temperature communicated via the LonTalk communications link can also be used for controllers operating on a BAS. If both hard-wired and communicated entering water tempera- ture values are present, the controller uses the communicated value. If a valid hard-wired or communicated entering water temperature value is established and then is no longer present, the controller generates an Entering Water Temp Failure diagnostic.

For units configured as 2-pipe or 4-pipe changeover units, the entering water temperature is used to make heating/cooling operation decisions. If neither a hard-wired nor a communicated entering water temperature value is present on changeover units, the controller will always operate in heating mode.

CNT-SVX07C-EN

17

Image 27
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 Product description Overview and specificationsDimensions Storage environmentClearances Plastic-cover model dimensions and clearances Additional components Agency listing/complianceCO2 sensor Tracer zone temperature sensor optionsDamper actuators Zone humidity sensorOverview and specifications AC-power wiring Input/output terminal wiringGeneral wiring information Communication-link wiring and addressing General wiring information Operating environment requirements Location recommendationsMounting the Tracer ZN521 zone controller Mounting recommendationsHeatElectric Typical applications for the Tracer ZN521 zone controllerApplication SpeedfanMultiple Dehumidification ControlValve EconomizingBinary inputs BI1 Low-coil-temperature detectionBinary inputs BI2 Condensate overflowBI4 Fan status BI3 Occupancy or generic binary inputAnalog inputs ZN Zone temperatureAnalog inputs GND Ground terminalsFAN Fan mode input AI1 Entering water temperatureSET Local setpoint AI3 Outdoor air temperature or generic temperature AI2 Discharge air 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 functionsFunction Input source For more information See Wiring requirements and optionsOverriding binary outputs Required controller inputs for proper operationTwo-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 Random start Power-up sequenceOccupancy modes Occupied modeUnoccupied mode Occupied standby modeTimed override control Occupied bypass modeZone temperature control Cascade zone controlSimplified zone control Morning cool-down Heating or cooling modeDischarge air tempering Morning warm-upFan operation Entering water temperature sampling functionExhaust control Exhaust controlValve control options Valve operationModulating valve operation Modulating valve calibrationTwo-pipe operation Modulating outdoor/return air dampersTwo-position valve operation Isolation-valve operationModulating outdoor air damper position Ashrae Cycle 1 conformance Ashrae Cycle 2 conformanceEconomizing free cooling Face-and-bypass, isolation-valve operation Two-position control of a modulating outdoor air damperFace-and-bypass damper operation DX cooling operationElectric heat operation Baseboard heat operationDehumidification Unit protection strategies Peer-to-peer communicationCondensate overflow Smart resetLow-coil-temperature protection Fan off delayFilter-maintenance timer Freeze protection discharge air temperature low limitFreeze avoidance Tracer ZN521 zone controller circuit board Test buttonManual output test Output For nonClose damper, air Outdoor Open damper, air Outdoor BOP1 BOP2 BOP3 BOP4 BOP5 BOP6 BOP7 BOP8 BOP9 Step ResultLED activity Explanation Service pin buttonRed LED Service indicator Interpreting LEDsYellow LED Communications indicator Green LED Status indicatorTypes of diagnostics DiagnosticsFan unaffected Table of diagnosticsDiagnostics Diagnostic Probable cause Consequences TypePosition Valved unaffectedDamper unaffected Status indicators for operation and communication Probable cause Explanation Fan does not energizeValves remain closed TroubleshootingDX or electric heat does not energize Valves remain openOutdoor air damper remains open Outdoor air damper remains closedOutdoor air damper remains open Troubleshooting Numerics IndexIndex Index Index Page Trane