Trane Tracer Unit Ventilator, ZN.520 manual DX/Electric Heat, Outside Air Damper

Page 63

Troubleshooting

Table 31: Valves stay open

Probable cause

Possible Explanation

 

 

 

When the fan is off with no demand for capacity (0%) and the outdoor air temperature is below the

Freeze avoidance

freeze avoidance setpoint, the controller opens the water valves (100%) to prevent coil freezing. This

 

includes unoccupied mode when there is no call for capacity or any other time the fan is off.

Normal operation

The controller opens and closes the valves to meet the unit capacity requirements.

DX/Electric Heat

Table 32: DX or electric output(s) does not energize

Probable cause

Possible Explanation

 

 

 

 

Unit wiring

The wiring between the controller outputs and the end devices must be present and correct for normal

operation.

 

 

 

Unit configuration

The controller must be properly configured based on the actual installed end devices and application.

When the unit configuration does not match the actual end devices, the unit may not work correctly.

 

 

 

Diagnostic present

A specific list of diagnostics affect compressor and electric heat operation. For more information see,

Tracerâ„¢ ZN.520 Unit Controller diagnostics, on page 52 for more information.)

 

 

 

 

The controller includes a manual output test sequence you can use to verify output operation and

Manual output test

associated output wiring. However, based on the current step in the test sequence, the DX or electric

 

outputs may be OFF. For more information see, Manual Output Test, on page 48 for more information.)

 

 

 

When the fan is OFF with no demand for capacity (0%) and the outdoor air temperature is below the

Freeze avoidance

freeze avoidance setpoint, the controller disables compressors and electric heat outputs. This includes

 

UNOCCUPIED mode when there is no call for capacity or any other time the fan is OFF.

 

 

Normal operation

The controller energizes the outputs only as needed to meet the unit capacity requirements.

 

 

Outside Air Damper

Table 33: Outdoor air damper stays closed

Probable cause

 

Explanation

 

 

 

 

Unit wiring

The wiring between the controller outputs and the outdoor air damper must be present and correct for

normal damper operation.

 

 

 

 

The controller must be properly configured based on the actual installed end devices and application.

Unit configuration

When the unit configuration does not match the actual end devices, the damper may not work

 

correctly.

 

 

Random-start observed

After power-up, the controller always observes a random-start from 5 to 30 seconds. The controller

remains OFF until the random-start time expires.

 

 

 

 

When power-up control wait is enabled (non-zero time), the controller remains OFF until one of two

 

conditions occurs:

Power-up control wait

1.

The controller exits power-up control wait once it receives communicated information.

 

 

2.

The controller exits power-up control wait once the power-up control wait time expires.

 

 

Diagnostic present

A specific list of diagnostics affects outdoor air operation. For more information see, Tracerâ„¢ ZN.520

Unit Controller diagnostics, on page 52 for more information.)

 

 

 

 

The controller includes a manual output test sequence you can use to verify output operation and

Manual output test

associated output wiring. However, based on the current step in the test sequence, the unit damper

 

may not be open. For more information see, Manual Output Test, on page 48 for more information.)

 

 

Fan mode OFF

When a local fan mode switch (provided on the Trane zone sensor) determines the fan operation, the

OFF position controls the unit OFF and damper to close.

 

UV-SVP01A-EN

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Image 63
Contents Tracer ZN.520 for Classroom Unit Ventilator Installation Owner DiagnosticsInstallation of New Units Start-up ProceduresPower Up Sequence Tracer ZN.520 Overview General InformationGeneral Information Tracer ZN.520 unit controller circuit board Controller Circuit Board FeaturesController Features ServiceTypical Components Communication Configurations Peer-to-Peer CommunicationsIntegrated Comfort System Stand-Alone Communication InterfaceInteroperability Description End Device SpecificationsCharacteristic Standard End DevicesStandard End Devices Way Control Valve Time clock Zone sensor Dpdt Control Transformer Specifications Installation and WiringBinary Inputs Generic/baseboard Heat Binary Output Binary OutputsAnalog inputs Analog InputsMounting Vertical classroom unit ventilator end pocket Power WiringProper zone sensor placement Installing the Wall- Mounted Zone Sensor OptionalHumidity and CO2 Sensors Typical Wiring Diagram-Wall Mounted Zone Sensor Typical Wiring Diagram-Unit Mounted Zone Sensor Typical Wiring Diagram-Unit Input and output summary Input/Output SummaryInput/Output Summary Heating source ConfigurationConfigurable parameters Cooling sourceBinary Outputs1 Analog input summary Binary input summary ConfigurationBinary Inputs1 Analog Inputs1Default Fan ConfigurationEnd Device Configurations Fan configuration rangesDischarge Air Limits Setpoint defaults Default Valid rangeDischarge air limit ranges Default Valid range SetpointsOccupied Bypass Timer Power-Up Control WaitMaintenance Timers Location Identifier Unit Identification TagWinking Occupancy Power-UpUnit Operation Heating And Cooling Changeover LogicHeat/Cool Changeover logic Fan Operation Fan Off DelayCooling Operation Heating OperationModulating Valves Valve OperationFace-and-Bypass Damper Operation Exhaust fan/damper operationTemperature Assumed1 Entering Water Temperature SamplingWater assumption chart Unit ConfigurationBaseboard Heat Operation Economizer OperationDX Operation Electric Heat OperationOther Modes Filter Status/ Maintenance TimerOutput Overrides Fan StatusSimple data sharing application Data Sharing-LonWorksMore complex data sharing application Heating And Cooling Changeover Logic Heat/Cool Changeover logic Cooling Operation Valve Operation Entering Water Temperature Sampling Economizer Operation Output Overrides Data Sharing-LonWorks More complex data sharing application Yellow Comm LED TroubleshootingRed Service LED Black Service Push ButtonExit6 Test ProcedureTroubleshooting Outdoor Air Temperature Failure Space Temperature FailureEntering Water Temperature Failure Discharge Air Temperature LimitDiagnostics Troubleshooting Translating Multiple Diagnostics Fans Rover service toolValves Valves stay closed Probable cause Possible ExplanationValves stay open Probable cause Possible Explanation DX/Electric Heat Outside Air DamperOutdoor air damper stays closed Probable cause Explanation Probable Cause Explanation Outdoor air damper stays openReplacing Circuit Boards Tracer ZN.520 Unit Controller ReplacementAppendix Hardwired Setpoint AdjustmentFan Switch Resistance Values Hardwired Thermistor ValuesFunction Appendix-Binary ConfigurationBinary Configuration Binary configuration details Binary input or outputUnit Operation Based On The Effective HEAT/COOL Output Heat/cool mode input NviHeatCoolEffective heat/ cool mode output nvoHeatCool Appendix-Unit OperationAppendix-Unit Operation Input/output listing1 Configuration properties1Appendix-Data Lists Data ListsSet the Program Setting the Time ClockAppendix-Timeclock Set the Time and DayOverride Program Manual Operation Review and Change ProgramsAppendix-Timeclock Appendix-Location Identifier Location Identifier Location Identifier Location Identifier Trane Company