Trane Tracer Unit Ventilator, ZN.520 Freeze Protection, Fan Failure, Space Temperature Failure

Page 57

Troubleshooting

Safeties

Freeze Protection

The Tracer ZN.520 controller has two methods of freeze protection.

1.An optional binary freezestat that is wired to a binary input. The freezestat is a capillary tube type and is factory set to 35 °F. When this device opens, a “Low Coil Temp Detect” diagnostic is generated.

2.Using the discharge air tem- perature sensor, if the dis- charge air temperature falls below the discharge air low limit, the controller increases the heating capacity to temper the air. If the discharge air temperature remains below the discharge air low limit for 3 minutes, the controller gen- erates a “Low Coil Temp Detect” diagnostic.

Fan Failure

A “Low Air Flow—Fan Failure” di- agnostic is generated when a fan status device is present and fails to close after 1 minute of unit start-up or when it opens for more than 1 minute during normal unit opera- tion.

Space Temperature

Failure

If the Tracer ZN.520 has validated a space temperature input and then the input becomes invalid, a space temperature failure diag- nostic occurs.

Entering Water

Temperature Failure

If the Tracer ZN.520 has validated an entering water temperature in- put and then the input becomes in- valid, an entering water temp- erature failure diagnostic occurs.

Discharge Air

Temperature Limit

When the discharge air exceeds the high or low limit setpoint and the unit can not correct it by alter- ing capacity, a “Discharge Air Temp Limit” diagnostic is generat- ed.

Outdoor Air Temperature

Failure

If the Tracer ZN.520 has validated an outdoor air temperature input and then the input becomes in- valid, an outdoor air temperature failure diagnostic occurs.

Humidity Input Failure

If the Tracer ZN.520 has validated a relative humidity input and then the input becomes invalid, a hu- midity input failure diagnostic oc- curs.

CO Sensor Failure

2

If the Tracer ZN.520 has validated a CO2 input and then the input be- comes invalid, a CO input failure

2

diagnostic occurs.

Generic AIP Failure

If the Tracer ZN.520 has validated a generic analog input and then the input becomes invalid, a ge- neric analog input failure diagnos- tic occurs.

Defrosting-Compressor

Lockout

The defrost stat used with Tracer ZN.520 on DX units is wired in se- ries with the condensing unit.

When it opens to indicate a frost condition, the Tracer ZN.520 sens- es the open circuit and de-energiz- es the condensing unit output. A defrosting diagnostic is generated at this point.

Maintenance Required

Note: If power to the unit is cycled or discontinued for any reason, all maintenance timers are automatically reset.

The “Maintenance Required” di- agnostic is generated when the fan run-time exceeds the configurable limit. This diagnostic is useful for filter change notification.

Local Fan Mode Failure

If the hardwired fan mode input to the Tracer ZN.520 controller is present and then becomes invalid, a local fan mode failure diagnostic is generated.

Local Setpoint Failure

If the hardwired setpoint input to the Tracer ZN.520 controller is present and then becomes invalid, a local setpoint failure diagnostic is generated.

Generic Temperature

Failure

If the Tracer ZN.520 has validated a generic temperature input and then the input becomes invalid, a generic temperature input failure diagnostic occurs.

Invalid Unit

Configuration

If the Tracer ZN.520 has been con- figured improperly or loses its configuration, an invalid unit con- figuration diagnostic is generated. The unit must be re-configured with a valid configuration to cor- rect this problem.

UV-SVP01A-EN

51

Image 57
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 Characteristic End Device SpecificationsStandard End Devices DescriptionStandard 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 Configurable parameters ConfigurationCooling source Heating sourceBinary Outputs1 Binary Inputs1 Binary input summary ConfigurationAnalog Inputs1 Analog input summaryEnd Device Configurations Fan ConfigurationFan configuration ranges DefaultDischarge air limit ranges Default Valid range Setpoint defaults Default Valid rangeSetpoints Discharge Air LimitsOccupied Bypass Timer Power-Up Control WaitMaintenance Timers Location Identifier Unit Identification TagWinking Unit Operation Power-UpHeating And Cooling Changeover Logic OccupancyHeat/Cool Changeover logic Cooling Operation Fan Off DelayHeating Operation Fan OperationFace-and-Bypass Damper Operation Valve OperationExhaust fan/damper operation Modulating ValvesWater assumption chart Entering Water Temperature SamplingUnit Configuration Temperature Assumed1DX Operation Economizer OperationElectric Heat Operation Baseboard Heat OperationOutput Overrides Filter Status/ Maintenance TimerFan Status Other ModesSimple 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 Red Service LED TroubleshootingBlack Service Push Button Yellow Comm LEDExit6 Test ProcedureTroubleshooting Entering Water Temperature Failure Space Temperature FailureDischarge Air Temperature Limit Outdoor Air Temperature FailureDiagnostics 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 ReplacementFan Switch Resistance Values Hardwired Setpoint AdjustmentHardwired Thermistor Values AppendixBinary Configuration Appendix-Binary ConfigurationBinary configuration details Binary input or output FunctionEffective heat/ cool mode output nvoHeatCool Heat/cool mode input NviHeatCoolAppendix-Unit Operation Unit Operation Based On The Effective HEAT/COOL OutputAppendix-Unit Operation Appendix-Data Lists Configuration properties1Data Lists Input/output listing1Appendix-Timeclock Setting the Time ClockSet the Time and Day Set the ProgramOverride Program Manual Operation Review and Change ProgramsAppendix-Timeclock Appendix-Location Identifier Location Identifier Location Identifier Location Identifier Trane Company