Trane CNT-SVX07C-EN, Zone Controller Wiring requirements and options, Overriding binary outputs

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Chapter 4 Input/output functions and wiring for typical applications

Overriding binary outputs

The Tracer ZN521 controller includes a manual output test and a water valve override feature. Use the manual output test to manually control the outputs in a defined sequence. For information, see “Manual output test” on page 52.

The water valve override feature is a procedure used for water balancing.

Using the Rover service tool or a BAS, a user can specify that a Tracer

ZN521 override the state of water valves to:

•Open all valves

•Close all valves

The controller resets itself to normal operation after two hours.

Wiring requirements and options

Table 7 shows required controller inputs for minimal proper operation of all applications.

Table 7. Required controller inputs for proper operation

	Function	Input source	For more information,
	Function	Input source	see:
			see:

	24 Vac power	Terminals: GND, 24 V	“AC-power wiring” on
			page 7

	Zone temperature	Terminals: ZN, GND	“ZN: Zone tempera-
		or communicated	ture” on page 16

	Discharge air temperature	Terminals: AI2	“AI2: Discharge air tem-
			perature” on page 18

	Entering water tempera-	Terminal: AI1	“AI1: Entering water
	ture—required only for	or communicated	temperature” on
	units with auto		page 17
	changeover

	Outdoor air temperature—	Terminals: AI3 or	“AI3: Outdoor air tem-
	required only for econo-	communicated	perature or generic
	mizing		temperature” on
			page 18

	Relative humidity—	Terminals: AI4	“AI4: Universal 4–
	required only for dehu-		20 mA” on page 19
	midification

Figure 7 on page 23 through Figure 17 on page 33 show typical applica- tions that include all required and all optional components.

22	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 descriptionClearances DimensionsStorage environment Plastic-cover model dimensions and clearances Agency listing/compliance Additional componentsTracer zone temperature sensor options Damper actuatorsZone humidity sensor 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 controllerTypical applications for the Tracer ZN521 zone controller Application SpeedfanMultiple DehumidificationControlValve Economizing HeatElectricBI1 Low-coil-temperature detection Binary inputsBI2 Condensate overflow Binary inputsBI3 Occupancy or generic binary input BI4 Fan statusZN Zone temperature Analog inputsGND Ground terminals Analog inputsSET Local setpoint FAN Fan mode inputAI1 Entering water temperature AI2 Discharge air temperature AI3 Outdoor air temperature or generic temperatureAI4 Universal 4-20 mA AI4 configuration options and associated measurement rangesConfiguration Measurement range AI4 terminal wiring CO2 measurement Binary outputs Generic binary outputBinary output functions Binary output FunctionsWiring requirements and options Overriding binary outputsRequired controller inputs for proper operation 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 mode Unoccupied modeOccupied standby mode Occupancy modesOccupied bypass mode Timed override controlSimplified zone control Zone temperature controlCascade zone control Heating or cooling mode Discharge air temperingMorning warm-up Morning cool-downEntering water temperature sampling function Fan operationExhaust control Exhaust controlValve operation Modulating valve operationModulating valve calibration Valve control optionsModulating outdoor/return air dampers Two-position valve operationIsolation-valve operation Two-pipe operationModulating outdoor air damper position Economizing free cooling Ashrae Cycle 1 conformanceAshrae Cycle 2 conformance Two-position control of a modulating outdoor air damper Face-and-bypass damper operationDX cooling operation Face-and-bypass, isolation-valve operationDehumidification Electric heat operationBaseboard heat operation Peer-to-peer communication Unit protection strategiesSmart reset Low-coil-temperature protectionFan off delay Condensate overflowFreeze avoidance Filter-maintenance timerFreeze protection discharge air temperature low limit 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 BOP9Service pin button Red LED Service indicatorInterpreting LEDs LED activity ExplanationGreen LED Status indicator Yellow LED Communications indicatorDiagnostics Types of diagnosticsTable of diagnostics DiagnosticsDiagnostic Probable cause Consequences Type 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