Installation and Operation Tracer™ ZN521 Zone Controller CNT-SVX07C-EN
Installation and Operation Tracer™ ZN521 Zone Controller CNT-SVX07C-EN April 2005
CNT-SVX07C-EN
Tracer ZN521 Zone Controller Installation and Operation This guide and the information in it are the property of American Standard Inc. and may not be used or reproduced in whole or in part, without the written permission of American Standard Inc. Trane, a business of American Standard, Inc., has a policy of continuous product and product data improvement and reserves the right to change design and specification without notice.
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. CAUTION Indicates a situation that may result in equipment damage or property damage.
Contents Chapter 1 Overview and specifications . . . . . . . . . . . . . . . . . . 1 Product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Storage environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents Analog inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 GND: Ground terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 ZN: Zone temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 SET: Local setpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 FAN: Fan mode input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contents Modulating outdoor/return air dampers. . . . . . . . . . . . . . . . . . . . . . . . . 43 ASHRAE Cycle 1 conformance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 ASHRAE Cycle 2 conformance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Economizing (free cooling) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Two-position control of a modulating outdoor air damper . . . . . . . . . 46 Face-and-bypass damper operation . . . . . . . . . . . . . . . .
Contents Chapter 7 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 1 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 descriptions of ancillary products that may be necessary. Product description The Tracer ZN521 is an application-specific controller that provides direct-digital zone temperature control.
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) Relative humidity: 5–95%, noncondensing Dimensions Plastic-cover model dimensions For complete dimensional drawing, see Figure 1 on page 3. • • • Height: 5.375 in. (137 mm) Width: 6.875 in. (175 mm) Depth: 2 in.
Clearances Figure 1. Plastic-cover model dimensions and clearances 1 in (25 mm) 4 in (102 mm) 4 in. (102 mm) 5.625 in. (143 mm) 6.31 (160 mm) 4 in (102 mm) 6.875 in (175 mm) 5.625 in (143 mm) 2 in. (51 mm) 1 in (25 mm) Figure 2. Metal-cover model dimensions and clearances 1 in. (25 mm) 1.875 in. (48 mm) 6.5 in. (165 mm) 0.28 in. (7 mm) 9 in. (229 mm) 9 in. (229 mm) 7 in. (178 mm) 2 in. (51 mm) 2 in. (51 mm) 24 in. (610 mm) 10.37 in.
Chapter 1 Overview and specifications Agency listing/compliance CE—Immunity: EN 50082-1:1997; EN 50082-2:1995 CE—Emissions: EN 50081-1:1992 (CISPR 22) Class B UL and C-UL 916 listed: Energy management system UL 94-5V (UL flammability rating for plenum use) FCC Part 15, Class A ASHRAE Cycle 1 & Cycle 2 control sequences Additional components The Tracer ZN521 zone controller requires the use of additional components for monitoring and proper control of the associated equipment.
Additional components Table 1.
Chapter 1 Overview and specifications 6 CNT-SVX07C-EN
Chapter 2 General wiring information This chapter provides specifications and general information about wiring the Tracer ZN521 zone controller.
Chapter 2 General wiring information CAUTION Complete input/output wiring before applying power to the Tracer ZN521 zone controller. Failure to do so may cause damage to the controller or power transformer due to inadvertent connections to power circuits. IMPORTANT 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.
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 Summit Hardware and Software Installation guide (BMTX-SVN01A-EN).
Chapter 2 General wiring information 10 CNT-SVX07C-EN
Chapter 3 Mounting the controller This chapter gives recommendations and requirements for mounting a Tracer ZN521 zone controller.
Chapter 3 Mounting the controller 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 cover facing downward. Mount using the two 3/16 in. (4.8 mm) radius mounting holes provided (see Figure 4). Mounting fasteners are not included.
Chapter 4 Input/output functions and wiring for typical applications This chapter provides information about the function of inputs and outputs and examples of wiring for typical applications. Applications supported by the Tracer ZN521 zone controller are shown in Table 2.
Chapter 4 Input/output functions and wiring for typical applications Binary inputs The Tracer ZN521 controller includes four binary inputs. Each binary input associates an input signal of 0 Vac with open contacts and 24 Vac with closed contacts. You can use the Rover service tool to configure each of the inputs as normally open or normally closed. If an application does not warrant the use of a particular input, configure the input as Not Used.
Binary inputs BI3: Occupancy or generic binary input The BI3 binary input can function as either: • • The occupancy input A generic binary input The function of occupancy is to save energy by spreading zone setpoints when the zone is unoccupied. As the occupancy input, BI3 can be used for two related functions. For stand-alone controllers, BI3 can be hard-wired to a binary switch or timeclock to determine the occupancy mode—either occupied or unoccupied.
Chapter 4 Input/output functions and wiring for typical applications Analog inputs The Tracer ZN521 controller includes seven analog inputs. Table 4 describes their functions. Each function is explained in the following paragraphs. For an explanation of the diagnostics generated by each analog input, see “Diagnostics” on page 58. For more information about how the controller operates, see Chapter 5, “Sequence of operations” Table 4.
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 temperature 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.
Chapter 4 Input/output functions and wiring for typical applications For units not configured as changeover units, the entering water temperature value is used for information and troubleshooting only and does not affect the operation of the controller. Note: AI1 is not polarity sensitive; you can connect either terminal to either sensor lead. AI2: Discharge air temperature The AI2 analog input functions as the local discharge air temperature input.
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 economizing is feasible. Economizing is not possible without a valid outdoor air temperature. (For more information, see “Economizing (free cooling)” on page 45.) The outdoor air temperature value is also used for the freeze avoidance function.
Chapter 4 Input/output functions and wiring for typical applications is established and then is no longer present, the controller generates a Generic AIP Failure diagnostic. For the CO2 measurement configuration, a 4–20 mA sensor must be hardwired to the 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.
Binary outputs Binary outputs The ZN521 zone controller supports fan coil, blower coil, and unit ventilator applications that may include the following components: • • • • • • • Supply fan with up to three speeds Hydronic cooling and/or heating coils with two-position or tri-state modulating control valve DX cooling (single stage) Electric heat (single stage or two stage) Baseboard heat (single stage) Tri-state modulating outdoor/return air damper Tri-state modulating face-and-bypass damper The Tracer Z
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.
Wiring requirements and options Figure 7.
Chapter 4 Input/output functions and wiring for typical applications Figure 8.
Wiring requirements and options Figure 9.
Chapter 4 Input/output functions and wiring for typical applications Figure 10.
Wiring requirements and options Figure 11.
Chapter 4 Input/output functions and wiring for typical applications Figure 12.
Wiring requirements and options Figure 13.
Chapter 4 Input/output functions and wiring for typical applications Figure 14.
Wiring requirements and options Figure 15.
Chapter 4 Input/output functions and wiring for typical applications Figure 16.
Wiring requirements and options Figure 17.
Chapter 4 Input/output functions and wiring for typical applications 34 CNT-SVX07C-EN
Chapter 5 Sequence of operations The Tracer ZN521 zone controller will operate to maintain the zone temperature setpoint. This chapter discusses many of the operational sequences used by the controller to accomplish this goal. Power-up sequence When 24 Vac power is initially applied to the Tracer ZN521 zone controller, the following sequence occurs: 1. The green status indicator LED turns on (see “Interpreting LEDs” on page 56). 2. All outputs are controlled off.
Chapter 5 Sequence of operations Occupancy modes Occupancy modes can be controlled by any of the following: • • • • 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 override control” on page 37) A communicated signal from a peer device (see “Peer-to-peer communication” on page 48) A communicated signal from a BAS A communicated request, either from a BAS or a peer control
Timed override control The fan will run as configured (continuous or cycling) for occupied mode. The controller always uses the stored default setpoint values (configurable using the Rover service tool), regardless of hard-wired or communicated setpoint values. In addition, the outdoor air damper uses the Economizer Occupied Standby Minimum Position setpoint to reduce the ventilation rate.
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 Cascade zone control Cascade zone control maintains zone temperature by controlling the discharge air temperature to control the zone temperature.
Discharge air tempering Discharge air tempering If the controller is in cooling mode, cascade zone control initiates a discharge 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.
Chapter 5 Sequence of operations In heating and cooling mode, the controller maintains the zone temperature based on the active heating setpoint and the active cooling setpoint, respectively. The active heating and cooling setpoints are determined by the occupancy mode of the controller. For two-pipe and four-pipe changeover units, normal heat/cool operation will not begin until the ability to conduct the desired heating or cooling operation is verified.
Exhaust control fan configuration. The controller can be configured to auto, to a specific fan speed, or to off. If both a communicated and hard-wired value (fanspeed 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.
Chapter 5 Sequence of operations • • The exhaust output is de-energized if the outdoor air damper position drops 10% below the Exhaust Fan/Damper Enable Setpoint. If the Exhaust Fan/Damper Enable Setpoint is less than 10%, the exhaust output is energized if the outdoor air damper position is at the setpoint and de-energized at 0. Valve operation The Tracer ZN521 zone controller supports one or two tri-state modulating or two-position valves, depending on the application (see Table 8).
Modulating outdoor/return air dampers Two-position valve operation The Tracer ZN521 supports two-position valves with a single binary output for each valve. Controllers used for two-pipe applications support heating, cooling, or heat/cool changeover with a single valve/coil. Controller used for four-pipe applications support cooling or heat/cool changeover with a main valve/coil, and heating only with an auxiliary valve/coil. Isolation-valve operation See “Face-and-bypass damper operation” on page 46.
Chapter 5 Sequence of operations low-speed fan operation. A controller can also receive a BAS-communicated 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 position for low fan speed whenever the fan is running at low speed, regardless of the occupancy state.
Modulating outdoor/return air dampers ASHRAE Cycle 1 conformance Tracer ZN521 applications with an outside air damper support ASHRAE Cycle 1 conformance. ASHRAE Cycle 1 operation admits 100% outdoor air at all times except during a warm-up cycle. A tri-state modulating damper actuator is required for this operation. For Tracer ZN521 ASHRAE Cycle 1 conformance, configure the minimum position of the economizer setpoint to 100% open during occupied periods. If the zone temperature drops 3°F (1.
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.
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 temperature at the active heating setpoint. Two-pipe changeover units with electric heat use the electric heat only when hot water is not available. The use of both electric and hydronic heat is not supported. Baseboard heat operation When configured for baseboard heat output, the controller turns on baseboard heat at 2.
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 Heating/cooling mode Fan status Unit capacity control Shared data is communicated from one controller to any other controller that is bound to it as a peer.
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 diagnostic occurs. If the unit is successfully restarted, the diagnostic is cleared. If the unit undergoes another Low Coil Temp Detection diagnostic within a 24-hour period, the unit will be locked out until it is manually reset.
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 (configurable using the Rover service tool) is used to set the amount of time until maintenance (typically, a filter change) is needed. If the setpoint is configured to zero, the filter-maintenance timer is disabled. The controller compares the fan-run time to Maintenance Required Timer Setpoint.
Chapter 6 Status indicators for operation and communication This chapter describes the operation and communication status indicators on the Tracer ZN521 controller, including: • • A description of the location and function of the Test button and Service pin button and the light-emitting diodes (LEDs) located on the controller A complete list of the diagnostics that can occur, their effect on controller outputs, and an explanation of how diagnostics are cleared and the device restored to normal operation
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 controller, which is suspended while the test is being performed.
CNT-SVX07C-EN Begins test mode1 Fan high2 Fan medium3 Fan low4 Main open, DX on Main close, DX off, aux open, EH1 on Aux open, EH1 on, exhaust fan5 Aux close, EH1 off, EH2 on, damper open Damper close Generic/ baseboard heat energized6 2 3 4 5 6 7 8 9 10 Result 1 Number of times Test button is pressed Step On/High On/High On/High On/High On/High On/High Off Off Off 1) Off 2) On Off Off Off 1) On/Med 2) Off Off Off Off On/High Off Off Off Off Off Off On/Low Of
6 5 4 3 2 1 Result BOP7 1)Heating valve, close 2)Electric heat, stage 2 BOP6 1)Heating valve, open 2)Two-position heat valve 3)Electric heat, stage 1 BOP5 Cooling/changeover valve, close BOP4 1)Cooling/changeover valve, open 2)Two-position cooling/ changeover valve 3)DX compressor BOP3 Fan low BOP2 1)Fan medium 2)Exhaust BOP1 BOP9 BOP8 Outdoor air damper, open Fan high BOP10 The controller turns off all fan and electric heat outputs and drives all dampers and valves closed.
Manual output test BOP5 BOP6 BOP7 Two-position heat valve Face and bypass damper, close (bypass) BOP8 BOP9 Outdoor air damper, close BOP4 Outdoor air damper, open BOP3 BO Begins test mode1 Off Off Off Off Off Off On/Close Off On/Close Off 2 Fan high2 On/High Off Off Off On/Open Off Off Off Off Off 3 Fan medium3 Off 1) On/Med 2) Off Off Off On/Open Off Off Off Off Off 4 Fan low4 Off Off On/Low Off On/Open Off Off Off Off Off 5 Main open, DX on On/H
Chapter 6 Status indicators for operation and communication Service pin button The Service pin button is located as shown in Figure 19 on page 51.
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 LED activity Explanation LED is on continuously. Power is on (normal operation). LED blinks (one recurring blink). Manual output test mode is being performed and no diagnostics are present. LED blinks (blinks twice as a recurring sequence).
Chapter 6 Status indicators for operation and communication Diagnostics Diagnostics are informational messages that indicate the operational status 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. Other diagnostics provide information about the status of the controller, but have no effect on outputs. Diagnostics are reported in the order in which they occur.
Diagnostics Smart reset diagnostics After the controller detects the first smart reset diagnostic, the unit waits 30 minutes before initiating the smart reset function. If another diagnostic of this type occurs again within 24 hours after an automatic clearing, you must clear the diagnostic manually by using any of the ways shown for “Manual (latching) diagnostics.” Informational diagnostics Informational diagnostics provide information about the status of the controller.
Chapter 6 Status indicators for operation and communication Table 16.
Diagnostics Table 16.
Chapter 6 Status indicators for operation and communication 62 CNT-SVX07C-EN
Chapter 7 Troubleshooting Use Table 17 through Table 22 to assist you in diagnosing any of the following operational problems that you might encounter with the Tracer ZN521 zone controller: • • • • • • • Fan does not energize (Table 17) Valves remain closed (Table 18 on page 64) Valves remain open (Table 19 on page 65) Compressors are not running (Table 20 on page 65) Electric heat does not energize (Table 20 on page 65) An outdoor air damper stays closed (Table 21 on page 66) An outdoor air damper stays
Chapter 7 Troubleshooting Table 17. Fan does not energize (Continued) Probable cause Explanation Cycling fan operation/ continuous The controller operates the fan continuously when in the occupied, occupied standby, or occupied bypass mode. When the controller is in the unoccupied mode, the fan is cycled between high speed and off with capacity. Unoccupied operation Even if the controller is configured for continuous fan operation, the fan normally cycles with capacity during unoccupied mode.
Troubleshooting Table 19. Valves remain open Probable cause Explanation Unit wiring The wiring between the controller outputs and the valve(s) must be present and correct for normal valve operation. Refer to applicable wiring diagram. Failed end device The valves must be checked to ensure proper operations. Normal operation The controller opens and closes the valves to meet the unit capacity requirements.
Chapter 7 Troubleshooting Table 20. DX or electric heat does not energize (Continued) Probable cause Explanation Requested mode off You can communicate a desired operating mode (such as off, heat, and cool) to the controller. If off is communicated to the controller, the unit shuts off the compressor or electric heat.
Troubleshooting Table 22. Outdoor air damper remains open (Continued) Probable cause Explanation Normal operation The controller opens and closes the outdoor air damper based on the controller’s occupancy mode and fan status. Normally, the outdoor air damper is open during occupied mode when the fan is running and closed during unoccupied mode. (See “Modulating outdoor/return air dampers” on page 43.
Chapter 7 Troubleshooting 68 CNT-SVX07C-EN
Index Numerics B 24 Vac wiring, 7 BAS communication, 1, 9 A Baseboard heat Operation, 47 Supported application, 21 AC-power wiring, 7 Actuators Damper, 5, 46 Valve, 4 Additional application-dependent components, 4–5 Addressing LonTalk communication, 9 Neuron IDs, 9 Agency listing/compliance, 3 Analog inputs, 16–20 AI1 (Entering water temperature), 17 AI2 (Discharge air temperature), 18 AI3 (Outdoor air temperature), 18 AI3 configuration options, 18 AI4 (Universal 4–20 mA), 19 AI4 configuration options
Index Electric heat, 1 Face-and-bypass dampers, 1 Outdoor/return air dampers, 1 Rover service tool, 1 Tri-state modulating dampers, 1 Tri-state modulating valves, 1 Two-position valves, 1 Current-sensing switches, 4 D Dampers Actuators, 5 Exhaust, 41 Face-and-bypass, 1, 21, 46 Modulating outdoor/return air, 43, 46 Outdoor/return air, 1, 21, 41, 43 Supported applications, 1, 21 Tri-state modulating, 1 Two-position control, 46 Data sharing, 48 Dehumidification, 47 Device addressing for BAS communication, 9
Index Low-coil-temperature detection Diagnostic, 14, 59 Input, 14 M Overriding binary outputs, 22 General, 52 P Peer-to-peer communication, 48 Manual output test, 52 Power transformers, 4, 7 Modulating outdoor/return air dampers, 43 Power wiring, 7 Modulating valves Calibration, 42 Operation, 42 Morning cool-down, 39 Power-up sequence, 35 Product description, 1 Protection strategies, see Unit protection strategies Morning warm-up, 39 Mounting Cover, 12 Diagram, 12 Location, 11 Operating environme
Index Switching devices Condensate overflow, 4, 14 Current sensing, 4 Fan status, 4 Freeze protection, 4, 14 Low-coil-temperature, 4 Occupancy, 4, 15 T Temperature sensors Table of options, 5 Water and duct, 4 Zone, 4 Termination resistors, 9 V Z Valves Actuators, 4 Calibration of modulating, 42 Four-pipe operation, 43 General operation, 42 Isolation-valve operation, 43 Operation of modulating, 42 Operation of two-position, 43 Supported applications, 1, 21, 42 Tri-state modulating, 1, 21, 42 Troublesho
Trane A business of American Standard Companies www.trane.com For more information contact your local Trane office or e-mail us at comfort@trane.com Literature Order Number CNT-SVX07C-EN File Number SV-ES-BAS-CNT-SVX-07C-EN 0405 Supersedes CNT-SVX07B-EN October 2001 Stocking Location Inland Trane has a policy of continuous product and product data improvement and reserves the right to change design and specifications without notice.
