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Trane Tracer ZN521 Installation And Operation Manual

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Tracer
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CNT-SVX07C-EN

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Summary of Contents for Trane Tracer ZN521

  • Page 1: Installation And Operation

    Installation and Operation Tracer ZN521 ™ Zone Controller CNT-SVX07C-EN...
  • Page 3 Installation and Operation Tracer ZN521 ™ Zone Controller CNT-SVX07C-EN April 2005...
  • Page 4 CNT-SVX07C-EN...
  • Page 5 Although Trane has tested the hardware and software described in this guide, no guarantee is offered that the hardware and software are error free. Trane reserves the right to revise this publication at any time and to make changes to its content without obligation to notify any per- son of such revision or change.
  • Page 6 NOTICE: Warnings and Cautions appear at appropriate sections throughout this manual. Read these carefully: WARNING Indicates a potentially hazardous situation, which, if not avoided, could result in death or serious injury. CAUTION Indicates a potentially hazardous situation, which, if not avoided, may result in minor or moderate injury. It may also be used to alert against unsafe practices.

  • Page 7: Table Of Contents

    Contents Chapter 1 Overview and specifications ....1 Product description ......... . 1 Storage environment .
  • Page 8 Contents Analog inputs ..........16 GND: Ground terminals .
  • Page 9 Contents Modulating outdoor/return air dampers......43 ASHRAE Cycle 1 conformance ......45 ASHRAE Cycle 2 conformance .
  • Page 10 Contents Chapter 7 Troubleshooting ......63 Index ........69 CNT-SVX07C-EN...

  • Page 11: Chapter 1 Overview And Specifications

    Overview and specifications This guide provides installation and configuration information for the Tracer ZN521 zone controller, as well as a description of its operations. The overview includes a product description, specifications, and descrip- tions of ancillary products that may be necessary.

  • Page 12: Storage Environment

    Chapter 1 Overview and specifications Storage environment If a Tracer ZN521 zone controller is to be stored for a substantial amount of time, store it in an indoor environment that meets the following requirements: • Temperature: –40° to 185°F (–40° to 85°C) •...
  • Page 13 Clearances Figure 1. Plastic-cover model dimensions and clearances 1 in (25 mm) 4 in 4 in. (102 mm) (102 mm) 4 in (102 mm) 5.625 in. 6.875 in 6.31 (143 mm) (175 mm) (160 mm) 5.625 in (143 mm) 2 in. (51 mm) 1 in (25 mm) Figure 2.

  • Page 14: Agency Listing/Compliance

    Power transformer Use a UL-listed Class 2 power transformer supplying a nominal 24 Vac (19–30 Vac) to power both the Tracer ZN521 zone controller (14 VA) and its associated output devices, including relays and actuators, to a maxi- mum of 12 VA per output utilized.

  • Page 15: Damper Actuators

    Zone humidity sensor For measurement of relative humidity (RH), the Tracer ZN521 requires a zone humidity sensor with a 4–20 mA output, where 4 mA is 0% RH and 20 mA is 100% RH. The controller provides 20 Vdc to power the zone humidity sensor.
  • Page 16 Chapter 1 Overview and specifications CNT-SVX07C-EN...

  • Page 17: Chapter 2 General Wiring Information

    Chapter 2 General wiring information This chapter provides specifications and general information about wir- ing the Tracer ZN521 zone controller. The controller requires wiring for: Input/output terminals • AC power to the controller • Communication-link wiring, if the controller is to communicate with a •...
  • Page 18 Do not share 24 Vac between controllers. All wiring must comply with National Electrical Code and local codes. The ac-power connections are in the top left corner of the Tracer ZN521 zone controller (see Figure 3). Figure 3. Connecting ac-power wires to the controller...

  • Page 19: Communication-Link Wiring And Addressing

    Communication-link wiring and addressing Communication-link wiring and addressing The Tracer ZN521 zone controller communicates with the BAS and with other LonTalk controllers by means of a LonTalk communication link. IMPORTANT For important instructions on network wiring, refer to the Tracer Sum- mit Hardware and Software Installation guide (BMTX-SVN01A-EN).
  • Page 20 Chapter 2 General wiring information CNT-SVX07C-EN...

  • Page 21: Chapter 3 Mounting The Controller

    The controller can often be mounted inside the wiring enclosure of the associated mechanical equipment. Operating environment requirements Operate a Tracer ZN521 zone controller in an indoor environment that meets the following requirements: • Temperature: from 32°F to 140°F (from 0°C to 60°C) •...

  • Page 22: Mounting Recommendations

    Mounting recommendations are as follows: CAUTION Mount the Tracer ZN521 zone controller with the cover on to avoid the possibility of damaging the circuit board during installation. Mount the controller in any position, other than with the front of the •...

  • Page 23: Chapter 4 Input/Output Functions And Wiring For Typical

    This chapter provides information about the function of inputs and out- puts and examples of wiring for typical applications. Applications sup- ported by the Tracer ZN521 zone controller are shown in Table 2. Table 2. Typical applications for the Tracer ZN521 zone controller...

  • Page 24: Binary Inputs

    If BI2 is wired to a condensate overflow switch and the level of condensate reaches the trip point, the Tracer ZN521 will detect the condition and generate a Condensate Overflow diagnostic.

  • Page 25: Bi3: Occupancy Or Generic Binary Input

    BI3 is the only binary input that can be configured as generic. If config- ured as a generic binary input, it can be monitored by a BAS and has no direct effect on Tracer ZN521 operation. BI4: Fan status The fan status input provides feedback to the controller regarding the fan’s operating status.

  • Page 26: Analog Inputs

    The ZN analog input functions as the local (hard-wired) zone temperature input. The controller receives the temperature as a resistance signal from a 10 kΩ thermistor in a standard Trane zone sensor wired to analog input ZN. A zone temperature value communicated by means of a LonTalk link can also be used for controllers operating on a BAS.

  • Page 27: Set: Local Setpoint

    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.

  • Page 28: Ai2: Discharge Air Temperature

    The AI2 analog input functions as the local discharge air temperature input. IMPORTANT The Tracer ZN521 cannot operate without a valid discharge air tempera- ture value. The controller receives the temperature as a resistance signal from a 10 kΩ thermistor wired to analog input AI2. The thermistor is typically located downstream from all unit heating and cooling coils at the unit dis- charge area.

  • Page 29: Ai4: Universal 4-20 Ma

    Analog inputs Economizing (free cooling) is a function whereby outdoor air is used as a source of cooling before hydronic or DX cooling is used. The Tracer ZN521 uses the outdoor air temperature value to determine whether economiz- ing is feasible. Economizing is not possible without a valid outdoor air temperature.
  • Page 30 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 CO Sensor Failure diagnostic.

  • Page 31: Binary Outputs

    Binary output 10 is the only output that can be configured as a generic binary output. When configured as a generic binary output, it can be con- trolled only by a BAS, and has no direct effect on Tracer ZN521 operation. CNT-SVX07C-EN...

  • Page 32: Overriding Binary Outputs

    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”...
  • Page 33 Wiring requirements and options Figure 7. Two-pipe hydronic-cooling unit † 24 V Fan, high speed † 24 V Exhaust (or fan, medium speed) † 24 V Fan, low speed Fan status (closed=on)* † 24 V Cooling valve Occupancy (open=occupied)* † 24 V Electric heat, stage 1 (optional) †...
  • Page 34 Chapter 4 Input/output functions and wiring for typical applications Figure 8. Two-pipe hydronic-heating unit † 24 V Fan, high speed † 24 V Exhaust (or fan, medium speed) † 24 V Fan, low speed Fan status (closed=on)* 24 V † Occupancy (open=occupied)* Heating valve Condensate overflow (closed=normal)*...
  • Page 35 Wiring requirements and options Figure 9. Two-pipe hydronic heating/cooling unit with auto changeover † 24 V Fan, high speed † 24 V Exhaust (or fan, medium speed) † 24 V Fan, low speed Fan status (closed=on) † 24 V Heating/cooling changeover valve Occupancy (open=occupied)* †...
  • Page 36 Chapter 4 Input/output functions and wiring for typical applications Figure 10. Four-pipe hydronic heating/cooling unit † 24 V Fan, high speed 24 V † Exhaust (or fan, medium speed) † 24 V Fan, low speed Fan status (closed=on)* † 24 V Occupancy (open=occupied)* Cooling valve †...
  • Page 37 Wiring requirements and options Figure 11. Four-pipe heating/cooling unit with auto changeover † 24 V Fan, high speed † 24 V Exhaust (or fan, medium speed) † 24 V Fan, low speed Fan status (closed=on)* 24 V † Occupancy (open=occupied)* Heating/cooling changeover valve †...
  • Page 38 Chapter 4 Input/output functions and wiring for typical applications Figure 12. Two-pipe heating unit with DX cooling † 24 V Fan, high speed † 24 V Exhaust (or fan, medium speed) † 24 V Fan, low speed Fan status (closed=on)* †...
  • Page 39 Wiring requirements and options Figure 13. Electric heat unit with DX cooling † 24 V Fan, high speed 24 V † Exhaust Fan status (closed=on)* † 24 V DX cooling Occupancy (open=occupied)* † 24 V Electric heat, stage 1 (optional) 24 V †...
  • Page 40 Chapter 4 Input/output functions and wiring for typical applications Figure 14. Electric heat unit † 24 V Fan, high speed † 24 V Exhaust Fan status (closed=on)* Occupancy (open=occupied)* † 24 V Electric heat, stage 1 † 24 V Condensate overflow (closed=normal)* Electric heat, stage 2 †...
  • Page 41 Wiring requirements and options Figure 15. Two-pipe heating unit with face-and-bypass damper † 24 V Fan, high speed † 24 V Exhaust (or fan, medium speed) † 24 V Fan, low speed Fan status (closed=on)* † 24 V Face & bypass damper actuator Occupancy (open=occupied)* Condensate overflow (closed=normal)* †...
  • Page 42 Chapter 4 Input/output functions and wiring for typical applications Figure 16. Two-pipe heating/cooling unit with face-and-bypass damper † 24 V Fan, high speed † 24 V Exhaust (or fan, medium speed) † 24 V Fan status (closed=on)* Fan, low speed 24 V †...
  • Page 43 Wiring requirements and options Figure 17. Four-pipe heating/cooling unit with face-and-bypass damper 24 V † † 24 V Fan, high speed Exhaust (or fan, medium speed) † 24 V Fan, low speed † 24 V Fan status (closed=on)* Cooling isolation valve, open/close †...
  • Page 44 Chapter 4 Input/output functions and wiring for typical applications CNT-SVX07C-EN...

  • Page 45: Chapter 5 Sequence Of Operations

    Power-up sequence When 24 Vac power is initially applied to the Tracer ZN521 zone control- ler, the following sequence occurs: 1. The green status indicator LED turns on (see “Interpreting LEDs” on page 56).

  • Page 46: Occupancy Modes

    The state of the local (hard-wired) occupancy binary input BI3 (see • “BI3: Occupancy or generic binary input” on page 15) A timed override request from a Trane zone sensor (see “Timed over- • ride control” on page 37) A communicated signal from a peer device (see “Peer-to-peer commu- •...

  • Page 47: Occupied Bypass Mode

    Trane zone sensor is pressed or the controller receives a com- municated occupied bypass signal from a BAS. In occupied bypass mode, the controller maintains the zone temperature based on the occupied heating or cooling setpoints.

  • Page 48: Zone Temperature Control

    Chapter 5 Sequence of operations Zone temperature control The Tracer ZN521 zone controller uses two methods of zone temperature control: Cascade zone control—used in the occupied, occupied bypass, and • occupied standby modes Simplified zone control—used in the unoccupied mode •...

  • Page 49: Discharge Air Tempering

    Discharge air tempering Discharge air tempering If the controller is in cooling mode, cascade zone control initiates a dis- charge air tempering function when the discharge air temperature falls below the Discharge Air Control Point Low Limit (configurable using the Rover service tool) and all cooling capacity is at a minimum.

  • Page 50: Entering Water Temperature Sampling Function

    Fan operation The Tracer ZN521 supports up to three fan speeds. Every time the fan is enabled, the fan will begin operation and run on high speed for a period of time (0.5 seconds for fan coils and 3 seconds for unit ventilators and blower coils) before changing to any other speed.

  • Page 51: Exhaust Control

    If both a communicated and hard-wired value (fan- speed switch) is present, the communicated value has priority. Note: In occupied mode, The Tracer ZN521 zone controller requires continuous fan operation because of cascade zone control. In unoccupied mode, the fan cycles.

  • Page 52: Valve Operation

    Calibration of modulating valves is done automatically. During normal operation, the controller overdrives the actuator (135% of the stroke time) whenever a position of 0% or 100% is requested. as part of Tracer ZN521 normal operation. At power-up or after a power outage, the controller first drives all modulating valves (and dampers) to the closed position.

  • Page 53: Two-Position Valve Operation

    Modulating outdoor/return air dampers Two-position valve operation The Tracer ZN521 supports two-position valves with a single binary out- put for each valve. Controllers used for two-pipe applications support heating, cooling, or heat/cool changeover with a single valve/coil. Control- ler used for four-pipe applications support cooling or heat/cool changeover with a main valve/coil, and heating only with an auxiliary valve/coil.
  • Page 54 Chapter 5 Sequence of operations low-speed fan operation. A controller can also receive a BAS-communi- cated outdoor air damper minimum position. A BAS-communicated minimum position setpoint has priority over all locally configured setpoints. When a communicated minimum position setpoint is not present, the controller uses the configured minimum posi- tion for low fan speed whenever the fan is running at low speed, regard- less of the occupancy state.

  • Page 55: Ashrae Cycle 1 Conformance

    100% open during occupied periods. If the zone temperature drops 3°F (1.7°C) below the active zone temperature set- point, the Tracer ZN521 closes the outdoor air damper regardless of the minimum position setpoint. ASHRAE Cycle 2 conformance Tracer ZN521 controller applications with modulating outside air damper support ASHRAE Cycle 2 conformance.

  • Page 56: Two-Position Control Of A Modulating Outdoor Air Damper

    Chapter 5 Sequence of operations Two-position control of a modulating outdoor air damper The Tracer ZN521 does not support a two-position outdoor air damper actuator. However, a modulating outdoor/return air damper actuator can be used for two-position control. Two-position control can be accomplished...

  • Page 57: Electric Heat Operation

    Electric heat operation Electric heat operation The Tracer ZN521 supports both single-stage and two-stage electric heat. Electric heat is cycled on and off to maintain the discharge air tempera- ture at the active heating setpoint. Two-pipe changeover units with elec- tric heat use the electric heat only when hot water is not available.

  • Page 58: Peer-To-Peer Communication

    Chapter 5 Sequence of operations Peer-to-peer communication Tracer ZN521 zone controllers have the ability to share data with other LonTalk-based controllers. Multiple controllers can be bound as peers, using the Rover service tool, to share: • Setpoint Zone temperature •...

  • Page 59: Smart Reset

    Unit protection strategies Smart reset The Tracer ZN521 will automatically restart a unit that is locked-out as a result of a Low Coil Temp Detection (BI1) diagnostic. Referred to as “smart reset,” this automatic restart will occur 30 minutes after the diag- nostic occurs.

  • Page 60: Filter-Maintenance Timer

    Chapter 5 Sequence of operations Filter-maintenance timer The filter-maintenance timer tracks the amount of time (in hours) that the fan is enabled. The Maintenance Required Timer Setpoint (config- urable using the Rover service tool) is used to set the amount of time until maintenance (typically, a filter change) is needed.

  • Page 61: Communication

    The Test button is used to perform the manual output test (see “Manual output test” on page 52), which verifies that the controller output devices are operating properly. It is located on the Tracer ZN521 circuit board as shown in Figure 19. You must remove the cover to access the Test button.

  • Page 62: Manual Output Test

    Chapter 6 Status indicators for operation and communication Manual output test The manual output test sequentially turns on and off all binary outputs to verify their operation. The test overrides normal operation of the con- troller, which is suspended while the test is being performed. Use the manual output test to: Verify output wiring and operation •...
  • Page 63 Manual output test heat 2)Baseboard 1)Generic close damper, Outdoor open damper, Outdoor stage heat, 2)Electric close valve, 1)Heating stage heat, 3)Electric valve heat 2)Two-position open valve, 1)Heating close valve, Cooling/changeover compressor 3)DX valve changeover cooling/ 2)Two-position open valve, 1)Cooling/changeover 2)Exhaust medium 1)Fan high...
  • Page 64 Chapter 6 Status indicators for operation and communication heat 2)Baseboard 1)Generic close damper, Outdoor open damper, Outdoor stage heat, 2)Electric close valve, 1)Heating stage heat, 3)Electric valve heat 2)Two-position open valve, 1)Heating close valve, Cooling/changeover compressor 3)DX valve changeover cooling/ 2)Two-position open valve,...
  • Page 65 Manual output test Table 12. Manual output test sequence for face-and-bypass configurations (two-position isolation valves only) Step Result BOP1 BOP2 BOP3 BOP4 BOP5 BOP6 BOP7 BOP8 BOP9 Begins test On/Close On/Close mode On/High On/Open Fan high 1) On/Med On/Open medium 2) Off On/Low On/Open...

  • Page 66: Service Pin Button

    (see Table 14 on page 57 and “Setting the Auto-wink option” in EMTX-SVX01A-EN) Interpreting LEDs The red (service) LED on the Tracer ZN521 controller (see Figure 19 on page 51) indicates whether the controller is capable of operating normally (see Table 13).
  • Page 67 Interpreting LEDs The green (status) LED on the Tracer ZN521 controller (see Figure 19 on page 51) indicates whether the controller has power applied to it and if the controller is in manual test mode (see Table 14). Table 14. Green LED: Status indicator...

  • Page 68: Diagnostics

    Chapter 6 Status indicators for operation and communication Diagnostics Diagnostics are informational messages that indicate the operational sta- tus of the controller. In response to most diagnostics, the controller attempts to protect the equipment by enabling or disabling, or opening or closing, specific outputs.

  • Page 69: Smart Reset Diagnostics

    “Manual (latching) diag- nostics.” Table of diagnostics Table 16 The tables present each diagnostic that can be generated by the Tracer ZN521, its effect on outputs (consequences), and its type. Note: The generic binary output is unaffected by diagnostics. Table 16. Diagnostics...
  • Page 70 Chapter 6 Status indicators for operation and communication Table 16. Diagnostics (Continued) Diagnostic Diagnostic Probable cause Consequences type Space Temperature Failure Invalid or missing value Fan off Automatic for zone temperature Valves closed Outdoor air damper closed Face and bypass damper bypass DX/electric heat off Baseboard heat off Entering Water Temp Failure...
  • Page 71 Diagnostics Table 16. Diagnostics (Continued) Diagnostic Diagnostic Probable cause Consequences type Generic AIP Failure Invalid or missing value Fan unaffected Informational for generic analog input Valves unaffected Outdoor air damper unaffected Face and bypass damper unaffected DX cooling/electric heat unaffected Baseboard heat unaffected Local Fan Mode Failure Invalid or missing fan-...
  • Page 72 Chapter 6 Status indicators for operation and communication CNT-SVX07C-EN...

  • Page 73: Chapter 7 Troubleshooting

    No power to the con- If the controller does not have power, the unit fan does not operate. For the Tracer ZN521 troller controller to operate normally, it must have an input voltage of 24 Vac. If the green LED is off continuously, the controller does not have sufficient power or has failed.
  • Page 74 Chapter 7 Troubleshooting Table 17. Fan does not energize (Continued) Probable cause Explanation Cycling fan operation/ The controller operates the fan continuously when in the occupied, occupied standby, or continuous occupied bypass mode. When the controller is in the unoccupied mode, the fan is cycled between high speed and off with capacity.
  • Page 75 No power to the If the controller does not have power, heat outputs do not operate. For the Tracer ZN521 controller controller to operate normally, you must apply an input voltage of 24 Vac. If the green LED is off continuously, the controller does not have sufficient power or has failed.
  • Page 76 If the controller does not have power, the outdoor air damper does not operate. For the controller Tracer ZN521 controller to operate normally, you must apply an input voltage of 24 Vac. If the green LED is off continuously, the controller does not have sufficient power or has failed.
  • Page 77 Troubleshooting Table 22. Outdoor air damper remains open (Continued) Probable cause Explanation Normal The controller opens and closes the outdoor air damper based on the controller’s occu- operation pancy mode and fan status. Normally, the outdoor air damper is open during occupied mode when the fan is running and closed during unoccupied mode.
  • Page 78 Chapter 7 Troubleshooting CNT-SVX07C-EN...

  • Page 79: Index

    Index Numerics 24 Vac wiring, 7 BAS communication, 1, 9 Baseboard heat Operation, 47 Supported application, 21 Binary inputs, 14–15 AC-power wiring, 7 BI1 (Low-coil-temperature Actuators detection), 14 Damper, 5, 46 BI2 (Condensate overflow), 14 Valve, 4 BI3 (Occupancy or generic), 15 Additional application-dependent BI3 configuration options, 15 components, 4–5...
  • Page 80 Index Electric heat, 1 Zone Temp Failure, 59 Face-and-bypass dampers, 1 Dimensional diagram, 3 Generic Outdoor/return air dampers, 1 Dimensions, 2 Binary input, 15 Rover service tool, 1 Discharge air temperature Binary output, 59 Tri-state modulating dampers, 1 Failure diagnostic, 60 Temperature input, 18 Tri-state modulating valves, 1 Low limit diagnostic, 60...
  • Page 81 Index Low-coil-temperature detection Overriding binary outputs, 22 Fan status, 49 Diagnostic, 14, 59 General, 52 Filter-maintenance timer, 50 Input, 14 Four-pipe operation, 43 Freeze avoidance, 50 Freeze protection, 50 Heating/cooling mode, 39 Peer-to-peer communication, 48 Isolation valve, 46 Manual output test, 52 Power transformers, 4, 7 Modulating-valve calibration, 42 Modulating outdoor/return air...
  • Page 82 Index Switching devices Condensate overflow, 4, 14 Valves Zone humidity Current sensing, 4 Actuators, 4 Sensor, 5 Fan status, 4 Calibration of modulating, 42 Freeze protection, 4, 14 Zone temperature Four-pipe operation, 43 Low-coil-temperature, 4 Input, 16 General operation, 42 Occupancy, 4, 15 Sensors, 4 Isolation-valve operation, 43...
  • Page 84 For more information contact your local Trane Trane has a policy of continuous product and product data improvement and reserves the right to office or e-mail us at comfort@trane.com change design and specifications without notice. Only qualified technicians should perform the installa-...

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