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Application Guide 505-011

VAV Series Terminal Unit ControllerSelf-Contained Interoperable Controller Model CM2

SUPERSEDES: November 17, 2010 EFFECTIVE: March 16, 2011

Table of Contents

VAV Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Purpose of This Guide . . . . . . . . . . . . . . . . . . . . . . . . . 3

Representations and Warranties . . . . . . . . . . . . . . . . . 4

Applicable Documentation . . . . . . . . . . . . . . . . . . . . . . 4

Installation Instructions . . . . . . . . . . . . . . . . . . . . . . . . . 5Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Static Electricity . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5FCC Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Before Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6About this Document . . . . . . . . . . . . . . . . . . . . . . . . 6Inspecting the Equipment . . . . . . . . . . . . . . . . . . . . 6What is Not Included with this Equipment . . . . . . . . 6Equipment Location . . . . . . . . . . . . . . . . . . . . . . . . . 6Selecting a Power Source . . . . . . . . . . . . . . . . . . . . 6

Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6Mounting the Device . . . . . . . . . . . . . . . . . . . . . . . . 7Routing Cabling to the Device . . . . . . . . . . . . . . . . . 8Grounding the Device . . . . . . . . . . . . . . . . . . . . . . . 9

Wiring Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Connecting Input Devices . . . . . . . . . . . . . . . . . . . . 9Connecting Output Devices . . . . . . . . . . . . . . . . . . 10Other Connections . . . . . . . . . . . . . . . . . . . . . . . . . 10

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Electrical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Mechanical . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Application Description. . . . . . . . . . . . . . . . . . . . . . . . 12

Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . 13Operational Mode . . . . . . . . . . . . . . . . . . . . . . . . . 13Occupancy Mode. . . . . . . . . . . . . . . . . . . . . . . . . . 14Setpoint Calculations . . . . . . . . . . . . . . . . . . . . . . . 14Damper Control . . . . . . . . . . . . . . . . . . . . . . . . . . . 17Local Heating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19Parallel Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21Series Fan Operation. . . . . . . . . . . . . . . . . . . . . . . 23Indoor Air Quality (IAQ) . . . . . . . . . . . . . . . . . . . . . 23Stand-Alone Mode. . . . . . . . . . . . . . . . . . . . . . . . . 23Heating Failed . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Thermostat. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24Precon III Thermistor, Space Temperature . . . . . . 24Local Backup Schedule . . . . . . . . . . . . . . . . . . . . . 24Runtime Accumulations . . . . . . . . . . . . . . . . . . . . . 24Alarm and Events . . . . . . . . . . . . . . . . . . . . . . . . . 25Manual Overrides . . . . . . . . . . . . . . . . . . . . . . . . . 25Communication with Associated Devices . . . . . . . 25Automatic Configuration . . . . . . . . . . . . . . . . . . . . 26

Controller Identification . . . . . . . . . . . . . . . . . . . . . . . 27Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32Diagnostic LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . 32Troubleshooting Tips . . . . . . . . . . . . . . . . . . . . . . . 32

© 2011 Taco Electronic Solutions, Inc. 1

iWorx® VAV Series

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2 505-011, Effective: March 16, 2011 © 2011 Taco Electronic Solutions, Inc.

iWorx® VAV Series

VAV SERIESThe VAV Series terminal units are stand alone microprocessor based controllers for either pressure independent (VAVI) or pressure dependent (VAVD) terminal box applications.

OverviewA digital input is provided for an indoor air quality alarm. Analog inputs are provided for discharge air temperature and primary air temperature sensing. A two-wire serial interface is provided for the thermostat. The controller incorporates digital outputs in the form of triacs for fan start/stop and two heating stages or heating valve open/close.

The controller is based on LONWORKS® networking technology. It can be networked to a higher-level control system for monitoring and control applications.

Features• On-board air-flow sensor (VAVI)• Integral damper actuator• Optional indoor air quality (IAQ) alarm input (contact closure)• Optional discharge air temperature (DAT) monitoring• Two stages of electric reheat or floating point or modulating 0-10V setpoint hot water reheat valves• Option to use auxiliary local heat sources for first stage of heating• Parallel or series fan• Pressure dependent or pressure independent flow control• Individual temperature setpoints for occupied/unoccupied heating• Networked operation using LONWORKS Technology• Thermostat with space temperature, setpoint adjust, occupancy override• Integrates with Multiplex Package Unit controller (MPU2)• Integrates with Variable Air Volume Package Unit controller (VPU2)• “Stand Alone Mode” for independent operation• Indoor air quality compensation• Selection between thermostat types: TS30x and 10K Precon type III thermistor• Optional normally open dry contact occupancy sensor input• Optional Primary Air Temperature sensor for use in "Stand Alone Mode"• Automatic configuration with the Local Control Interface (LCI)• Alarm/Event reporting

PURPOSE OF THIS GUIDEThe iWorx® VAV Series Application Guide provides application information for the VAV Series Controller.

The reader should understand basic HVAC concepts, intelligent environmental control automation, and basic LON-WORKS networking and communications. This Application Guide is written for:

• Users who engineer control logic• Users who set up hardware configuration• Users who change hardware or control logic• Technicians and field engineers of Taco Electronic Solutions, Inc.

505-011, Effective: March 16, 2011 3 © 2011 Taco Electronic Solutions, Inc.

iWorx® VAV Series

REPRESENTATIONS AND WARRANTIESThis Document is subject to change from time to time at the sole discretion of Taco Electronic Solutions, Inc. All updates to the Document are available at www.taco-hvac.com. When installing this product, it is the reader’s responsi-bility to ensure that the latest version of the Document is being used.

iWorx® products shall only be used for the applications identified in the product specifications and for no other pur-poses. For example, iWorx® products are not intended for use to support fire suppression systems, life support sys-tems, critical care applications, commercial aviation, nuclear facilities or any other applications where product failure could lead to injury to person, loss of life, or catastrophic property damage and should not be used for such purposes.

Taco Electronic Solutions, Inc. will not be responsible for any product or part not installed or operated in conformity with the Document and instructions or which has been subject to accident, disaster, neglect, misuse, misapplication, inade-quate operating environment, repair, attempted repair, modification or alteration, or other abuse. For further informa-tion, please refer to the last page of this Document for the company’s Limited Warranty Statement, which is also issued with the product or available at www.taco-hvac.com.

APPLICABLE DOCUMENTATIONSee the table below for additional documentation that may be applicable to this controller.

Description Audience PurposeiWorx® LCI2 Application Guide, Doc-ument No. 505-002

– Application Engineers– Installers– Service Personnel– Start-up Technicians– End user

Provides instructions for setting up and using the iWorx® Local Control Interface.

iWorx® VPU2 Application Guide, Document No. 505-010


Provides instructions for setting up and using the iWorx® VPU controller.

iWorx® MPU2 Application Guide, Document No. 505-009


Provides instructions for setting up and using the iWorx® MPU controller.

iWorx® TS100 Series Installation Guide, Document No. 502-015


Provides instructions for installing and using the iWorx® TS100 Series sensors.

iWorx® TS300 Series Installation Guide, Document No. 502-017


Provides instructions for installing and using the iWorx® TS300 Series sensors.

http://iWorxWizard.taco-hvac.com – Application Engineers– Wholesalers– Contractors

An on-line configuration and submittal package generator based on user input. Automatically generates bill of materials, sequence of opera-tions, flow diagrams, wiring diagrams, points and specifications.

Additional Documentation

LonWorks FTT-10A Free Topology Transceiver User’s Guide, published by Echelon Corpo-ration. It provides specifications and user instructions for the FTT-10A Free Topology Trans-ceiver. See also: www.echelon.com/support/documentation/manuals/transceivers.


iWorx® VAV Series

INSTALLATION INSTRUCTIONS

Precautions

GeneralThis symbol is intended to alert the user to the presence of important installation and maintenance (servic-ing) instructions in the literature accompanying the equipment.

WARNING: Electrical shock hazard. Disconnect ALL power sources when installing or servicing this equipment to prevent electrical shock or equipment damage.

Make all wiring connections in accordance with these instructions and in accordance with pertinent national and local electrical codes. Use only copper conductors.

Static ElectricityStatic charges produce voltages that can damage this equipment. Follow these static electricity precautions when han-dling this equipment.

• Work in a static free area.• Touch a known, securely grounded object to discharge any charge you may have accumulated.• Use a wrist strap when handling printed circuit boards. The strap must be secured to earth ground.

LocationAvoid locations where corrosive fumes, excessive moisture, vibration or explosive vapors are present.

Avoid electrical noise interference. Do not install near large contactors, electrical machinery, or welding equipment.

This equipment is suitable for indoor or outdoor use. Preferably, or as required by National Electrical Code, the unit is intended to be installed within an electrical control enclosure. Operate where ambient temperatures do not exceed 122 °F (50 °C) or fall below 32 °F (0 °C) and relative humidity does not exceed 90%, non-condensing.

FCC ComplianceThis equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference. This equip-ment can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a par-ticular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.• Increase the separation between the equipment and the receiver.• Connect the equipment to a power source different from that to which the receiver is connected.• Consult the equipment supplier or an experienced radio/TV technician for help.

You are cautioned that any changes or modifications to this equipment not expressly approved in these instructions could void your authority to operate this equipment in the United States.


iWorx® VAV Series

BEFORE INSTALLING

About this DocumentThe instructions in this manual are for the Terminal Unit Controller controllers.

Inspecting the EquipmentInspect the shipping carton for damage. If damaged, notify the carrier immediately. Inspect the equipment for damage. Return damaged equipment to the supplier.

What is Not Included with this Equipment• A power source for the equipment electronics and peripheral devices.• Tools necessary to install, troubleshoot and service the equipment.• The screws or DIN rail needed to mount the device.• Peripheral devices, such as sensors, actuators, etc.• Cabling, cabling raceway, and fittings necessary to connect this equipment to the power source, FTT-10A network

and peripheral devices.

Equipment LocationAbide by all warnings regarding equipment location provided earlier in this document.

Optimally, the equipment should be installed within a secure enclosure.

If the equipment is to be installed outdoors, it must be contained within a protective enclosure. The enclosure must maintain internal temperature and humidity within the ranges specified for this equipment.

The equipment must be installed within 500 feet of all input peripherals (smoke detectors, sensors, etc.) that will be connected to the equipment.

Selecting a Power SourceThis equipment requires a UL recognized Class 2 external power source (not supplied) to operate. The controller power input requires a voltage of 24 Volts AC.

To calculate power source current requirements, add the power consumption of all peripheral devices to that of the controller.

The controller and triac output loads can use the same power source. If both are using the same power source, the loads must have EMF protection. This protection can be integral to the load, or installed in the 24 VAC wiring across the load’s coil.

To provide necessary RFI and transient protection, the controller’s ground (GND) pin (T10) must be con-nected to earth ground or the earth ground of the packaged unit’s enclosure ground. Failure to properly ground the controller may cause it to exceed FCC limits. Excessive noise could also produce inaccurate sensor data. The power source must be capable of operating with this connection to ground.

INSTALLATIONWarning: Electrical shock hazard. To prevent electrical shock or equipment damage, disconnect ALL power sources to controllers and loads before installing or servicing this equipment or modifying any wir-ing.


iWorx® VAV Series

Mounting the Device1.Open the damper halfway.2.Press the black motor release on the motor housing and rotate the actuator so that its flat edge is parallel to the

edge of the housing as shown in Figure ?.3.Slide the controller down over the damper shaft so that the shaft goes through the round opening above the actu-

ator motor.4.Tighten the retaining nuts to secure the actuator to the damper shaft.5.Remove tape that secures the mounting screw to the mounting tab at the left of the controller.6.Drive the mounting screw through the hole in the mounting tab and into the metal of the damper box.7.Set the motor stops to prevent the actuator motor from over driving the damper.

a.Rotate the damper shaft until the damper is completely closed.b.Loosen the screw that holds the low stop, and slide it around until it rests against the actuator.c.Tighten the screw to secure the low stop.d.Rotate the damper until it is completely open, and set the high stop.

8.Attach the differential pressure sensor tubes from the duct to the inputs at the top of the controller. Make sure to attach the “Low” and “High” tubes to the “Low” and “High” attachment points on the controller.

9.Wire the controller (see “Wiring Information” below).


iWorx® VAV Series

Figure 1: Mounting Dimensions

Routing Cabling to the DeviceCabling used to connect the power source and cabling used to connect the FTT-10A network must remain separated within the control enclosure and wiring conduit.


iWorx® VAV Series

Grounding the DeviceThe ground terminal (T10) must be securely connected to earth ground, and T9 must be connected to T10 using a jumper wire. Failure to properly ground this equipment may increase the risk of electrical shock and the possibility of interference to radio/TV reception, and will decrease the reliability of the device’s sen-sor readings.

Connecting the device commons (COM) to earth ground will also connect the power source to earth ground.

WIRING INFORMATIONWARNING: Terminals 9, 14, 17, and 20 are connected internally on all Terminal Unit Controller controllers. Disconnect ALL power sources when installing or servicing this equipment to prevent electrical shock or equipment damage.

Figure 2: VAV Series Terminal Connections

Connecting Input Devices

Thermostat (STAT)Connect one wire of a TS300 Series sensor to the STAT (T15) terminal. Connect the other wire to the adjacent com-mon (T14).

Discharge Air Temperature (DAT)To connect the discharge air thermistor to the unit, attach one wire from the thermistor to DAT (T16) and the other wire to the adjacent common (T17). The thermistor used must be 10K Precon Type III.


iWorx® VAV Series

Indoor Air Quality (IAQ)To connect the digital CO2 level sensor to the unit, attach one wire from the sensor to IAQ (T18) and the other wire to the adjacent common (T17). The sensor must provide a contact closure when the CO2 limit is exceeded.

Primary Air Temperature (PAT)To connect the primary air temperature to the unit, attach one wire from the thermistor to PAT (T19) and the other wire to the adjacent common (T20). The thermistor used must be 10K Precon Type III.

Occupancy Sensor (OCC) To connect the digital occupancy sensor to the unit, attach one wire of the sensor to OCC (T21) and the other to the adjacent common (T20). The sensor must provide a contact closure when the occupancy button is pressed.

Connecting Output Devices

Heating Stages 2 (H1, H2)The heating stage outputs must be connected to 24 VAC pilot relays with EMF protection. Connect Heat Stage 1 to T5 and the adjacent common on T6. Connect Heat Stage 2 To T4 and the adjacent common on T3. See Figure ? for details.

Fan Start/Stop (FAN)The fan outputs must be connected to a 24 VAC pilot relay with EMF protection. Connect the Fan to T7 and the adja-cent common on T6. See Figure ? for details. If the controller is being used with auxiliary heat sources, this output is used as the auxiliary heat output.

Analog Reheat Valve (AO1) To connect the reheat valve output, attach one wire to AO1 (T13) and the other wire to the adjacent common (T14).

Other Connections

Network (LON)Network wiring must be twisted pair. One network wire must be connected to terminal NETA (T11) and the other net-work wire must be connected to terminal NETB (T12). Polarity is not an issue since an FTT-10A network is used for communications. Terminals T9 and T10 must be jumpered together.

Power (PWR)Connect one output wire from a 24 VAC power supply to PWR (T8) and the other output wire from the power supply to the adjacent common terminal (T9).

Ground (GND)Terminal GND (T10) must be connected to earth ground. Failure to properly ground this equipment will result in improper operation. Improper grounding may also increase the risk of electrical shock, and may increase the possibility of interference with radio and TV reception.


iWorx® VAV Series

SPECIFICATIONS

Electrical

Inputs• Cabling: twisted shielded pair, 18 AWG recommended—500 feet max. (152 meters)• Resolution: 10 bit

Thermostat Network• 12 Volt nominal, internally limited to 0.04 A

Primary Air Temperature, Discharge Air Temperature Sensors• Precon Type III 10K thermistor

Indoor Air Quality• Dry Contact• Normally open• 5 Volts DC max

Outputs Fan Start/Stop, Heating Stages 1 & 2 or Heating Valve Open & Close

• 20 to 28 Volts AC• 0.7A maximum each

PowerPower Requirements

• 24 VAC nominal, 100VA max (requires an external class 2 supply)Power Consumption

• 15VA with no external loads, maximum limited by the class 2 supply rating

Recommended Sensor Wire

FTT-10A Network• Speed: 78KBPS• Cabling: Maximum node-to-node distance: 1312 feet (400 meters)• Maximum total distance: 1640 feet (500 meters)

For detailed specifications, refer to the FTT-10A Free-Topology Transceiver User’s Guide published by Echelon Corpo-ration (www.echelon.com/support/documentation/manuals/transceivers).

Mechanical

Housing• Dimensions: 5.25" (13.34 cm) high, 8.87" (22.53 cm) wide, 2.75" (6.99 cm) deep

Cable Type Pairs Details Taco Catalog No.18AWG 1 Stranded Twisted Shielded Pair, Plenum WIR-018

Cable Type Pairs Details Taco Catalog No.Level 4 22AWG (0.65mm) 1 Unshielded, Plenum, U.L. Type CMP WIR-022


iWorx® VAV Series

• ABS Polycarbonate

Weight• Controller weight: 29 ounces (0.82 kilograms)• Shipping weight: 40 ounces (1.1 kilograms)

Electronics• Processor: 3150 Neuron 10 MHz• Flash: 48 Kilobytes • SRAM: 8 Kilobytes • Termination: 0.197” (5.0 mm) Pluggable Terminal Blocks, 14-22 AWG

Actuator• Angle of rotation: 95° (adjustable)• Torque: 35 in-lb [4 Nm] nominal

Environmental• Temperature: 32 °F to 122 °F (0 °C to 50 °C)• Humidity: 0 to 90%, non-condensing

Agency Listings• UL Listed for US and Canada, Energy Management Equipment PAZX and PAZX7.

Agency Compliances• FCC Part 15 Class A

APPLICATION DESCRIPTIONThe controller can operate in a Pressure Independent (VAVI) or Pressure Dependent (VAVD) mode of operation.

Throughout the descriptions in this document, you will notice references to a flow setpoint this is a common term used when describing the Pressure Independent mode of operation. When the references refer to a damper position it is referring to the Pressure Dependent mode of operation.

The controller maintains the temperature of a space to a user-defined setpoint. Control is achieved by modulating the amount of airflow through the primary damper. In addition, the controller can control a series or parallel fan, floating point, modulating 0-10v or electric reheat.

The controller controls airflow by modulating the primary damper. The controller monitors the air temperature in the space using an attached digital thermostat module or thermistor. The algorithm is based on the space temperature input, cooling setpoint, heating setpoint, minimum airflow & maximum airflow (Pressure Independent mode) or mini-mum position and maximum position (Pressure Dependent mode).

The controller operates in the cooling mode when the primary air source is providing cooled air and the supply air tem-perature is below the current space temperature. The controller modulates the damper to provide the required amount of cooling to the space. When the space temperature is below the cooling setpoint, the controller closes the damper to maintain the minimum airflow setpoint or minimum damper position. As the zone temperature rises above the cooling setpoint the airflow setpoint is regulated between the minimum and maximum airflow setpoints or the minimum and maximum damper positions.


iWorx® VAV Series

If the space temperature drops below the heating setpoint during the primary cooling mode, local reheating can be acti-vated to heat the space. The reheat may be accomplished via electric reheat or floating setpoint, or modulating 0-10v reheat valves. The controller can modulate a floating setpoint hot water valve actuator based on its full stroke travel time and calculated desired position. The desired position is calculated by a Proportional + Integral (PI) control algo-rithm based on the zone temperature and a heating setpoint. The heating stages are sequenced on and off with a time proportioned control algorithm to minimize excessive cycling.

The controller operates in the primary heating mode when the primary air source is providing heated air and the supply air temperature is above the current space temperature. When the space temperature is above the heating setpoint, the controller closes the damper to maintain the minimum airflow setpoint or damper position. As the zone temperature drops below the heating setpoint the airflow setpoint is regulated between the minimum and maximum airflow setpoint or damper position. The damper is modulated to provide the required amount of heating to the space.

The controller operates in the ventilation mode when the primary air source is not providing heated or cooled air. In this mode, the damper is modulated to 55% of the total of the minimum flow plus the maximum flow or minimum damper position plus maximum damper position.

The controller operates in one of two occupancy states: occupied or unoccupied. The active occupancy state is deter-mined by the LCI. During the occupied period, the controller maintains the comfort level to a user defined heating and cooling setpoints. During the unoccupied period, the heating setpoint is set back and the cooling setpoint is set up by a user defined amount.

The series fan is energized during the occupied periods. It is off during unoccupied periods, unless the control calls for heating or cooling.

During occupied periods, the parallel fan is energized when air flow drops below a programmable setpoint, or when the zone temperature drops below the heating setpoint. During standby and warm-up periods, the fan is temperature con-trolled. The parallel fan is always off during unoccupied periods.

The fan will always be used as the first stage of reheat.

A local CO2 sensor connected directly to the controller can be used to monitor the Indoor Air Quality (IAQ). In addition, the controller can participate in system wide IAQ operation initiated by the primary air source controller (MPU2 or VPU2). When a local IAQ alarm condition exists, the controller reports the condition to the primary air source controller. The primary air source controller provides fresh air to the zone by turning on the system fan and modulating the econ-omizer. The primary air source controller signals the VAV Series to begin IAQ alarm operation.

During IAQ alarm operation, the VAV Series opens the damper to the maximum flow setpoint or maximum damper position. The temperature setpoints are reset to allow the space temperature to rise or drop a configurable limit from setpoint. This permits fresh airflow into the zone even if the temperature setpoints are exceeded. If the IAQ sensor is connected directly, an IAQ alarm is reported to the LCI.

In stand alone mode, the controller functions independently from the central HVAC system and is not associated with any master device. It assumes that only cool air is being provided by the central HVAC system, and provides local heat-ing as necessary without communicating a demand to any master controller.

When a heating failed alarm is received from the primary air controller, the VAV Series modulates its damper to the maximum airflow position or maximum damper position.

If the space temperature exceeds a programmable limit a high limit alarm is reported to the LCI. If the space tempera-ture drops below a programmable limit, a low limit alarm is reported to the LCI. When the space temperature returns to the proper range a return to normal message is generated.

SEQUENCE OF OPERATIONThis section describes the detailed sequence of operation for the controller’s control algorithms.

Operational ModeThe VAV Series operates in four operating modes: primary heating, primary cooling, primary fan only, and primary off.


iWorx® VAV Series

The controller operates as a stand alone unit until it is grouped under a primary source device at the LCI. In stand alone mode, the controller functions independently from the central HVAC system and is not associated with any master device. The controller uses the Primary Air Temperature (PAT) sensor to determine the operating mode of heating or cooling. The operating mode is heating when the PAT is above 90 degrees F. When the operating mode is heating, the PAT must drop below 80 degrees F to enter the cooling mode. A one-minute cycle time will be enforced before chang-ing the operating modes. If the PAT sensor is not connected, the PAT temperature input will read -30 degrees F and the operational mode will be cooling. To use the standalone mode of operation, the standalone option must be set to 'On' in the 'System Options' of the VAV Series controller.

Once the controller is grouped under a master device that controls the primary air source HVAC equipment, the master device determines the current operating mode. The operational mode information is periodically transferred to the con-troller over the communications network. The following information is transferred to the VAV Series controller from the primary air source controller:

• Operational Mode (primary cool, primary heat, primary off, primary fan only)• Alarm Conditions (IAQ Mode, Heat Failed On)• Occupancy Mode (occupied, unoccupied)• Supply Air Temperature

The primary air source device determines the operational mode based on the zone demand information supplied by each of the VAV Series zone controllers. Each VAV Series periodically transfers its zone demand information to the pri-mary air source controller over the communications network. The following information is transferred to the primary air source controller:

• Space Temperature• Calculated Heating Setpoint• Calculated Cooling Setpoint• IAQ Sensor Status (normal, alarm)• Local Alarm (VAV Series shutdown)• Occupancy Mode (occupied, unoccupied, occupied extension)• Supplemental Heat Status (on, off)

Occupancy ModeA remote device on the network normally provides the current occupancy mode. There are two modes of occupancy: occupied and unoccupied. A push-button on the local digital thermostat module (TS300 series) can be used to force the occupancy mode from unoccupied to occupied.

Setpoint CalculationsThe heating and cooling setpoint for both occupied and unoccupied periods are programmable values. The effective setpoint is a calculated value based on the programmed heating setpoint, cooling setpoint and current occupancy mode (i.e. occupied or unoccupied).

The effective setpoint is derived by first calculating the zero energy band (zeb) for the current occupancy state. The zero energy band is then added to the appropriate heating setpoint.

The space setpoint is displayed at the thermostat and the LCI's controllers list.


iWorx® VAV Series

The zero energy band is calculated as follows:

OCCUPIED MODE:

UNOCCUPIED MODE:

Figure 3:

- Occupied HeatingSetpoint

+ Occupied CoolingSetpointSpace

Setpoint

Zero Energy Band(Zeb)

1/2 zeb

Effective Setpoint Calculation

The thermostat setpoint offset is used to increase or decrease the effective setpoint from the local thermostat. The off-set value is limited to plus or minus the programmed setpoint adjustment.

ZebOcc OccupiedCoolSp OccupiedHeatSp–=

EffectiveSp OccupiedHeatSp ZebOcc2

--------------------+=

ZebUnocc UnoccupiedCoolSp UnoccupiedHeatSp–=

EffectiveSp UnoccupiedHeatSp ZebUnocc2

---------------------------+=


iWorx® VAV Series

The setpoint offset also affects the calculated heating and calculated cooling setpoints by an equal amount. The set-point offset only applies in the occupied period. It has no affect in the unoccupied period. Note that the actual pro-grammed heating and cooling setpoints are not changed. The offset is simply added to the programmed setpoints to derive the calculated values.

OCCUPIED MODE WITH USER ADJUST:

UNOCCUPIED MODE WITH USER ADJUST:

Figure 4:

- Occupied HeatingSetpoint

+ Occupied CoolingSetpoint

SpaceSetpoint

Zero Energy Band(zeb)

70°F (21.1°C)

71°F (21.7°C)

72°F (22.2°C)

Thermostat Offset = 0°F (0.0°C)


Thermostat Offset = +2°F (+1.1°C)

- Occupied Heating Setpoint

72°F (22.2°C)

+ Occupied Cooling Setpoint

74°F (23.3°C)Space Setpoint73°F (22.8°C)


Thermostat Offset = -2°F (-1.1°C)

- Occupied Heating Setpoint

68°F (20.0°C)

+ Occupied Cooling Setpoint

70°F (21.1°C)Space Setpoint69°F (20.6°C)

Setpoint Adjustment Examples

CalcCoolingSp OccupiedCoolingSp UserAdjust±=

CalcHeatingSp OccupiedHeatingSp UserAdjust±=

EffectiveSp EffectiveSp SpOffset±=

CalcCoolingSp UnoccupiedCoolingSp=

CalcHeatingSp UnoccupiedHeatingSp=


iWorx® VAV Series

Damper ControlThe primary air damper actuator is controlled based on the current operating mode, space demand and occupancy mode. During the occupied period when the primary air source is cooling, the damper will operate in the primary cool-ing mode. When the primary air source is heating, the damper will operate in the primary heating mode. During ventila-tion mode, the damper follows a special rule; see “Ventilation Mode Operation” on page 18.

Zone overheating and overcooling are prevented by keeping the damper closed until the supply air temperature is at least 4 °F (2.22 °C) degrees below the current zone temperature (for cooling mode) or 4 °F (2.22 °C) degrees above the current zone temperature (for heating mode).

During the unoccupied period, the calculated heating and cooling setpoints are set to their unoccupied values. The damper control is the same as the occupied mode. However, when the space temperature is between the calculated cooling and heating setpoints and the zone demand has been satisfied, the damper will be fully closed.

Figure 5: Occupied Damper Control

Figure 6: Unoccupied Damper Control


iWorx® VAV Series

Primary Cooling Damper Operation During primary cooling mode the primary air source will supply cool air to the zones. A control loop is used to calculate a required airflow setpoint to satisfy the space demands. The calculation is based on the space temperature and calcu-lated heating setpoint (space demand). The damper is then modulated to maintain the calculated airflow setpoint or damper position. In the pressure dependent mode the damper is calculated using the following formula:

Position = (spacetemp - coolingSP) * (MaxPosition - MinPosition) / ControlBand

As the space temperature rises above the calculated cooling setpoint, the controller enters the cooling mode. The con-trol loop regulates the calculated airflow setpoint or damper position over a range defined by the damper control band. When the space temperature is above the damper control band, the control loop will maintain the maximum flow set-point or damper position.

When the space temperature is at or below the calculated cooling setpoint, the control loop will maintain the minimum flow setpoint or damper position. The minimum flow or damper position will be maintained as long as the space temper-ature remains between the calculated cooling and heating setpoints.

As the space temperature drops below the calculated heating setpoint, the controller enters the local heating mode. If local reheat has been configured and a reheat flow setpoint or damper position has been defined, the control will main-tain the reheat flow setpoint or damper position.

During unoccupied periods, the minimum flow setpoint and damper position are set to zero. This allows the damper to close completely when the space demand has been satisfied.

Primary Heating Damper OperationDuring primary heating mode the primary air source will supply warm air to the zones. A control loop is used to calcu-late a required airflow setpoint or damper position to satisfy the space demands. The calculation is based on the space temperature and calculated heating setpoint (space demand). The damper is then modulated to maintain the calcu-lated airflow setpoint or damper position.

As the space temperature drops below the calculated heating setpoint, the controller enters the heating mode. The control loop regulates the calculated airflow setpoint or damper position over a range defined by the damper control band. When the space temperature is below the damper control band, the control loop will maintain the maximum flow setpoint or damper position.

When the space temperature is at or above the calculated heating setpoint or damper position, the control loop will maintain the minimum flow setpoint or damper position.

During unoccupied periods, the minimum flow setpoint and damper position are set to zero. This allows the damper to close completely when the space demand has been satisfied.

Ventilation Mode OperationWhen the primary source controller is in “Primary Fan Only” or “Primary Off” modes, the damper maintains air flow for ventilation purposes. The VAV Series will enter ventilation mode if the primary air source controller is in “Primary Fan Only” mode and the VAV Series is in local heating mode. The primary air source controller can also override ventilation mode by placing the VAV Series into Indoor Air Quality (IAQ) mode.

In ventilation mode, the damper will be modulated according to the following equation:

For instance in the pressure independent mode, if the minimum flow is zero, and the maximum flow is 500 CFM, 55% of 500 is 275, so the damper is modulated to provide 275 CFM or airflow.

For instance in the pressure dependent mode, if the minimum position is 0%, and the maximum position is 100%, 55% of 100 is 55%, so the damper is modulated to 55%.

In order to reduce overheating and overcooling of the zone, the damper does not open for ventilation mode until the supply air temperature is between 65 and 80 °F (18.33 and 26.66 °C).

Flow PressureIndependent( ) 0.55 MinimumFlow MaximumFlow+( )×=

Position PressureDependent( ) 0.55 MinDamperPosition MaxDamperPosition+( )×=


iWorx® VAV Series

Damper Actuator ControlThe controller supports integral floating-setpoint actuator for controlling the damper position. The actuator has a con-tact for opening the damper and a contact for closing the damper. The controller will modulate the floating-setpoint damper actuator to maintain the calculated flow setpoint. An integral flow transducer on the controller measures the pri-mary airflow when configured for pressure independent operation. When configured for pressure dependent operation the integral flow transducer is ignored.

In the pressure independent mode; when the primary airflow is below the calculated flow setpoint, the damper open contact will be closed and the damper close contact will be open. When the primary airflow is above the calculated flow setpoint, the damper close output will be closed and the damper open contact will be open. Both contacts will be open when the primary airflow equals the calculated flow setpoint. A dead band is provided around the calculated flow set-point to prevent unnecessary movement of the damper due to minor flow fluctuations. When the calculated flow set-point is zero, the control will drive the damper closed for the actuator travel time to ensure that the damper has closed completely.

In the pressure dependent mode; when the damper position is below the calculated damper position, the damper open contact will be closed and the damper close contact will be open. When the damper position is above the calculated damper position, the damper close output will be closed and the damper open contact will be open. Both contacts will be open when the damper position equals the calculated damper position. A dead band is provided around the calcu-lated damper position to prevent unnecessary movement of the damper due to minor calculation fluctuations. When the calculated damper position is zero, the control will drive the damper closed for the actuator travel time to ensure that the damper has closed completely.

Figure 7:

MaximumAirflowSetpoint

CalculatedAirflowSetpoint

MinimumAirflowSetpoint

FlowDeadband

Close

Open

Damper Actuator Control (Pressure Independent)

Local Heating The heating stages are controlled based on the space temperature, calculated heating setpoint, heating control band and operational mode. The controller provides the following heating options:

• None• 1 stage electric• 2 stage electric• Floating point and modulating valve


iWorx® VAV Series

Heating can be reheat, supplemental heat, or auxiliary heating. Reheat is when the operational mode is cooling, the supply air is cool and the space needs heating. Supplemental heat is a way to provide additional heat when the opera-tional mode is heating and supply air is warm. Auxiliary heating uses local auxiliary heat sources as first stage heating without communicating a heating demand to the central HVAC system.

Electric Heating StagesDuring primary cooling mode, when the space temperature drops below the calculated heating setpoint, the controller enters reheat mode. If the space temperature drops below the heating control band for a predefined period of time, the first stage is turned on. If the space temperature remains below the heating control band for an additional period of time, the second stage is turned on. As the space temperature rises above the calculated heating setpoint for a pre-defined period of time, the second stage is turned off. If the space temperature remains above the calculated heating setpoint for an additional period of time, the first stage is turned off. When the zone temperature rises above the zone setpoint all of the heating stages will immediately turn off. During local heating, the damper will modulate to the reheat flow setpoint or damper position. Reheat is interlocked with the parallel fan operation if it has been configured. The par-allel fan will act as the first stage of heating. Therefore, the reheat stages will wait one time interval so that the fan can provide heat to the space first.

During primary heating mode, when the space temperature drops below the calculated heating setpoint and the pri-mary airflow is at its maximum, the VAV Series enters supplemental heating mode if it is enabled. The heating is cycled on in the same manner as reheat. The parallel fan is not available as the first stage of heat during supplemental heating operation.

During primary off and primary fan only modes the local heating is disabled.

Figure 8: Electric Reheat

T1 = Stage Cycle Time

Calculated Heating Setpoint

Heating Control Band

T2 = Stage Cycle Time x 2

Space Setpoint

Stage 2 On

Stage 1 On

Stage 2 Off

Stage 1 Off

T1 T2T1T2

Modulated Hot Water Valve ReheatThe hot water valve is modulated based on zone temperature. During primary cooling mode, when the zone tempera-ture is above the heating setpoint the reheat valve will be closed. As the zone temperature drops below the heating set-point a reverse acting control loop modulates the valve position. The position is calculated over a band equal to the heating control band. When the zone temperature is below the heating control band, the valve will be at the maximum reheat position.

During primary heating mode, when the space temperature drops below the calculated heating setpoint and the pri-mary airflow is at its maximum, the controller enters supplemental heating mode if enabled. The heating valve is modu-lated in the same manner as reheat. The parallel fan is not available as the first stage of heat during supplemental heating operation.


iWorx® VAV Series

During primary off and primary fan only modes the local heating is disabled.

Figure 9: Modulated Reheat Valve

Modulated Hot Water Valve Reheat (0 - 10 VDC Analog Output)The modulating reheat (AO1) runs in parallel with the floating setpoint control logic and is disabled when the heating control band is zero. The valve output will be zero when any of the following conditions are met:

• The space temperature is greater than the heating setpoint• When there is no flow (VAVI)• When the operating mode is off• When the operating mode is fan only• Operating mode is heating and the supplemental heating is not enabled

The valve output will be 100% when the space temperature is less than the heating setpoint minus the heating control band.

The reheat setpoint will be proportionally calculated when the space temperature is within the control band by the fol-lowing formula:

Reheat Setpoint = ((HeatingSetpoint - SpaceTemp) * 100%) / ControlBand

Auxiliary Heating ModeThe controller can use auxiliary heat such as radiant floor heat or fin tube as first stage heating without communicating a heating demand to the central HVAC system. In this mode, the controller's parallel fan output is used as the auxiliary heat output. (The controller’s Fan Type must be set to “Temperature Controlled Parallel”.) If additional heating is needed, second-stage demand is communicated to the central system as described under “Electric Heating Stages” on page 20.

Parallel FanThere are two programmable modes of operation for the parallel fan terminal units; flow controlled and temperature controlled. In flow controlled operation, the fan will energize if the air flow drops below a programmable setpoint during occupied periods. During standby periods and occupied temperature controlled operation, the fan will turn on if the zone temperature drops below the heating setpoint during unoccupied periods, the fan will not energize.


iWorx® VAV Series

Temperature Controlled Parallel Fan OperationDuring occupied periods when the operational mode is primary cooling, the parallel fan will act as the first stage of heating when the zone requires heat. When the space temperature drops below the heating control band the parallel fan will energize. The fan will remain energized until the space temperature rises above the calculated heating setpoint.

The fan operation during unoccupied periods is same as in the occupied period. In this case the calculated heating set-point will have been setback to the unoccupied value.

The parallel fan is disabled when the operational mode is primary heating, primary off and primary fan only. The fan is also disabled during supplemental local heating.

Figure 10: Temperature Controlled Parallel Fan Operation

Flow Controlled Parallel Fan OperationDuring occupied periods when the operational mode is primary cooling, the parallel fan will act as the first stage of heating when the airflow drops below the fan flow setpoint. When the space temperature drops below the heating con-trol band the parallel fan will energize. The fan will remain energized until the space temperature rises above the calcu-lated heating setpoint.

During unoccupied periods, the fan is temperature controlled. The fan operation during unoccupied periods is same as the temperature controlled fan. In this case the calculated heating setpoint will have been setback to the unoccupied value.

The parallel fan is disabled when the operational mode is primary heating, primary off and primary fan only. The fan is also disabled during supplemental local heating.

Figure 11: Flow Controlled Parallel Fan Operation


iWorx® VAV Series

Series Fan OperationDuring occupied periods, the series fan will always run. During unoccupied periods, the series fan remains off unless there is a call for heating or cooling and the calculated flow setpoint is not zero. Since a call for zero airflow will close the damper completely, the controller will shut off the series fan if the calculated flow setpoint is zero.

During primary off and primary fan only modes, the series fan is disabled.

Indoor Air Quality (IAQ)The IAQ feature allows the VAV Series to interface with the primary air source controller to maintain the quality of indoor air within the zone acceptable limits. The IAQ sensing device can be defined as local or system wide IAQ. Local IAQ is defined as a VAV Series with an IAQ sensor attached. System wide IAQ consists of an IAQ sensor attached to the primary air source controller. In this case the IAQ would be mounted in the return air duct.

When an IAQ alarm condition is sensed by the VAV Series in local IAQ mode, only the damper of the VAV Series with the active alarm condition will be able to enter the IAQ mode of operation. The VAV Series will signal the primary air source controller indicating that a local IAQ alarm condition exists in the zone. The primary air source controller will energize the supply air fan in an attempt to provide additional fresh air to the zone. After a configurable delay, the pri-mary air source controller will open the economizer and signal the VAV Series that IAQ mode has been entered. The VAV Series will modulate the damper to maintain the programmed maximum airflow setpoint or damper position. When the IAQ alarm condition ceases to exist, the VAV Series will signal the primary air source controller and resume normal control of the damper.

The VAV Series has a temperature reset function of IAQ alarm operation. The temperature reset function allows the space temperature to rise above or drop below the calculated control setpoints by a configurable amount. This feature allows time for the indoor air quality to improve. During IAQ alarm operation, if the space temperature rises above or drops below the temperature reset limit, the VAV Series will resume normal damper control to maintain comfort within the zone. Once the space temperature is brought within the calculated control setpoints and an IAQ alarm condition still exists, the VAV Series will ensure the IAQ mode of operation.

The VAV Series has an alarm delay function that configures how long it waits before signaling an IAQ alarm condition.

The VAV Series can optionally participate in system wide IAQ alarm operation. In this case, the primary air source con-troller signals the VAV Series indicating IAQ mode of operation is active.

Stand-Alone ModeIn this mode, the controller functions independently from the central HVAC system and is not grouped under a primary source device. The VAV Series uses the Primary Air Temperature (PAT) sensor to determine the operating mode of heating or cooling. The operating mode is heating when the PAT is above 90 °F. When the operating mode is heating, the PAT must drop below 80 °F to enter the cooling mode. A one-minute cycle time will be enforced before changing the operating modes.

If the PAT sensor is not connected, the PAT temperature input will read -30 °F and the operating mode will be cooling.

The VAV Series operates in stand-alone mode until it is grouped under a primary source device at the LCI. To place the controller back into stand-alone mode after it has been grouped, remove it from the master controller's group, and set the Stand Alone Mode system option to “On.”

Heating FailedThe controller receives information about the state of the HVAC heating equipment from the primary air source control-ler. A signal will be sent to the VAV Series when the HVAC heating has failed to turn off. To help prevent overheating of the equipment, the VAV Series will override the calculating airflow setpoint or damper position and position the damper to maintain the maximum airflow setpoint or damper position.


iWorx® VAV Series

Thermostat The STAT input is a bi-directional serial data link between the VAV Series and the TS300 Series thermostat. The space temperature value setpoint adjustment and occupancy override request are monitored by the TS300 and sent to the VAV Series over the serial link. The current space temperature reading, current setpoint value control occupancy mode, fan status and override time are sent back to the thermostat. The VAV Series periodically sends configuration information indicating valid modes, sensors, setpoints, limits and icons to the thermostat module.

The setpoint adjustment is performed using the increment and decrement buttons on the thermostat when the incre-ment push-button is pressed, the setpoint will begin incrementing. When the decrement button is pressed, the setpoint will begin decrementing. In both cases, the increment or decrement function will stop when the button is released. The adjusted setpoint will be sent to the VAV Series through the serial interface. Once the adjustment is complete, the dis-play will revert to the current space temperature reading. The range of the adjustment is a configuration parameter.

A push-button is provided on the thermostat for the occupancy extension request feature. When the button is pressed, the extension timer will be armed with the configured occupancy extension time. The request will switch the operating mode to OCCUPIED if the current mode is UNOCCUPIED and the extension timer has not expired. The occupancy extension LED on the thermostat will be on when the controller is in the extended occupancy mode. The mode will automatically switch back to UNOCCUPIED and the LED will turn off once the extension time has expired.

The VAV Series sends the current control mode to the thermostat. When the heating mode is enabled, the heating icon will be displayed. In the cooling mode, the cooling icon will be displayed. Neither icon will be displayed when the control is off.

The VAV Series will automatically detect a failure of the thermostat. When the thermostat fails, the damper will close, local heating will be disabled and the fan will turn off.

Precon III Thermistor, Space TemperatureThe installer has an option to use the TS300 thermostat or Precon Type III thermistor for reading the space tempera-ture. If using the Precon Type III thermistor, the W1 jumper must be placed in the 'T' position to enable the hardware support. When using the Precon Type III thermistor option, there is no user thermostat adjustment and the effective set-point will be halfway between the cooling and heating setpoints.

In addition to the jumper configuration, the installer must also change the Thermostat type to Precon III, under the Thermostat section of the VAV Series configuration.

Local Backup ScheduleThe LCI normally determines the operating mode. You can define a local backup schedule for situations when the LCI is not available. When the controller detects that the LCI is not available (after 10 minutes without communications), it resorts to the local backup schedule that has been configured. If the local backup schedule is disabled, the controller defaults to the occupied mode.

You configure the occupied and unoccupied times that are used in determining the current operating mode of the con-troller when it is running the backup schedule. By default, both the unoccupied and occupied times are set to zero, which disables the local backup schedule. This causes the controller to default to the occupied mode of operation when communications are lost to the LCI for 10 minutes or longer.

Runtime AccumulationsThe total runtime is accumulated for the local heating outputs. The runtime can be used to indicate that maintenance is required on the equipment controlled by these outputs. The runtime can be reset by an operator or maintenance per-son once service has been performed.


iWorx® VAV Series

Alarm and EventsThe controller detects certain alarm conditions and sends them to the LCI. Before this can occur, the controller must be communicating on the LCI's LON network. The controller generates alarms for the following events:

Thermostat FailureThe controller automatically detects the presence of the local thermostat and monitors its status. If the thermostat fails to communicate with the controller, a Thermostat Failed alarm is generated and the controller's status LED turns red. If the space temperature is overridden by a host controller, this alarm is disabled.

Maintenance AlarmThe controller provides programmable run limit for generating runtime Maintenance alarms. When the heating runtime limit is exceeded, a Maintenance alarm is sent to the LCI.

Space Temperature AlarmsThe controller generates high and low limit alarms for the space temperature. You can configure a programmable space temperature alarm limit offset. The temperature limits are calculated based on the control setpoints, alarm limit offset and control band.

When the measured space temperature exceeds the high limit, a high limit alarm (Space Temperature High Limitalarm) is generated. When the space temperature drops below the low limit, a low limit alarm is generated (Space Tem-perature Low Limit alarm). A return to normal alarm is generated when the space temperature is between the high and low limit (Space Temperature Return to Normal).

When the controller switches between the unoccupied and occupied modes of operation, no space temperature alarms are reported for 30 minutes. This helps eliminate nuisance alarms.

Indoor Air Quality (IAQ) AlarmThe VAV Series monitors the status of the IAQ digital input and generates an “indoor air quality alarm” when the contact closes.

Starved Box AlarmIf the controller detects that it is not receiving sufficient airflow from the central HVAC system to meet its airflow setpoint even though the damper is at 100%, a “Starved Box Alarm” is sent to the LCI. This alarm can be disabled via the Starved Box Alarm system configuration option.

Manual OverridesManual override of the damper control is provided for use during installation and air balancing of the zone. The override will permit the installer/balancer to override the damper in the following manner:

1.Control flow to a user defined value2.Fully open the damper3.Fully close the damper4.Damper Position5.Control flow to the minimum value6.Control flow to the maximum value.

Communication with Associated DevicesThe controller is capable of communicating and sharing information with other controllers on the network.

HighLimit CalcColingSp CoolBand AlarmLimitOffset+ +=

LowLimit CalcHeatingSp HeatBand– AlarmLimitOffset–=


iWorx® VAV Series

Communication with MPU or VPUThe communication between MPU or VPU and VAV Series is configured by the LCI. In the individual controller screen for the MPU or VPU, you can see a button labeled Zone Member. Press this button to make an association between the MPU or VPU and a VAV Series. The MPU or VPU acts as the master and the VAV Series acts as a slave. Up to 32 VAV controllers can be associated to a single MPU2 and up to 60 VAV controllers can be associated to a single VPU2. There can be multiple VPU2 and/or MPU2 controllers with associations on the same network as long as the total num-ber of controllers does not exceed the maximum node number of 63.

During the association process, the MPU or VPU receives a configuration message from the LCI containing the neuron id for the VAV Series. Once associated, the MPU or VPU starts exchanging messages with the VAV Series. To disasso-ciate VAVs from a VPU2/MPU2, deselect the desired controller from the list of members until the field is gray and the text message displays the words “not associated.” Press the Save button to activate the selection and sent the mes-sage to the controllers in question.

Automatic ConfigurationThe VAV Series and iWorx® Local Control Interface (LCI) use a self-configuring network management scheme requir-ing no external tools, binding, or LONWORKS knowledge. The LCI recognizes and configures the VAV Series when the controller’s service pin is pressed. The controller’s status light flashes green until the controller is configured, and will be solid green after the controller is configured. Once the service pin has been pressed, no further action is required by the user; the controller is fully accessible to the LCI. Users may bind to SNVTs on the VAV Series with LNS or other LONWORKS tools if they wish.

The LCI also provides network supervision of the VAV Series. The LCI periodically sends a "ping" message to the VAV Series, which elicits a response. If the response fails, an alarm is displayed on the LCI. The LCI also uses the "ping" message to refresh the occupancy mode and other system wide data.


iWorx® VAV Series

CONTROLLER IDENTIFICATIONOnce the VAV Series is properly installed and recognized by the Local Control Interface (LCI), the LCI can be used to configure the settings of the controller. This section describes the commands available on the LCI for configuration of the VAV Series, and the meanings and default values for controller parameters. For more information on using the LCI, see the iWorX LCI Application Guide.

InputsThe Inputs screen displays the current values of the controller’s inputs. These values cannot be changed.

OutputsThis screen displays the current values of the controller’s outputs. These values cannot be changed.

Setting Range DescriptionOutside Temp -29 to 230 °F (-34.4 to 110 °C) The outside air temperature com-

municated through the LCI from the ASM controller.

Space Temperature -29 to 230 °F (-34.4 to 110 °C) The space temperature reported from the SLink or thermistor.

Indoor Air Qual Normal, Alarm

Status of the indoor air quality sen-sor when defined as Digital.

Occupancy Sensor Off, On Status of the occupancy sensor when a thermistor is used for space temperature.

Occupancy Mode Occupied,Unoccupied,Bypass

Occupancy mode of the controller.

Discharge Temp -29 to 230 °F (-34.4 to 110 °C) Temperature of the supply air duct.Primary Air Temp -29 to 230 °F (-34.4 to 110 °C) Temperature of the primary air

duct.

Setting Range DescriptionMode Off,

On,Heat,Cool,Fan,Bypass

Operating mode.

Heat Output 0.00% to 100.00% Current state of the heating output.Cool Output 0.00% to 100.00% Current state of the cooling output.Reheat Output 0.00% to 100.0% Current state of the reheat output.

Fan Output 0.00% or 100.00% Current state of the fan output.Box Flow 0 to 10000 CFM

(0 to 4720 L/s)Current box flow.

Damper Position 0.00% to 100.00% Current position of the damper.In Alarm On,

OffAlarm indication.


iWorx® VAV Series

ConfigurationOnce the controller is properly installed and recognized by the LCI, the LCI can be used to configure the settings of the controller. This section describes the commands available on the LCI for configuration of the controller and the descrip-tions and defaulted values for the controller parameters.

All SettingsDisplays all of the controller's settings and provides access to edit all parameters from a single screen. Some parame-ters (defaulted as Structure) will be described in individual tables below.

Commissioning Displays all of the controller‘s editable settings for this category and provides access to edit these parameters from a single screen.

Setting Range Default DescriptionCommissioning Structure N/A Commissioning settingsSystem Options Structure N/A System option settingsOccup. Temp Setpts Structure N/A Setpoint settingsPress Independent Structure N/A Pressure Independent settingsPress Dependent Structure N/A Pressure Dependent settingsThermostat Structure N/A Thermostat settingsIndoor Air Quality Structure N/A IAQ settingsLocal Reheat Structure N/A Local Reheat settingsDamp Ctl Band 0 to 20.0 F (0 to 11.12 C) 4.0 F (C) Value added to calculate the cool-

ing setpoint or subtract from the calculated heating setpoint to from the damper modulation range.

Fan Type Disabled, Series Fan,Parallel (Temp),Parallel (Flow)

Disabled Type of fan controlled by the VAV Series. Set to “Parallel (Temp)” if running the VAV Series in Auxiliary Heating mode.

Backup Occ Time Structure N/A Backup schedule settingsBackup Unocc Time Structure N/A Backup schedule settings

Setting Range Default DescriptionOverride Mode Off,

Damper Position,Flow Value, Dmp Fully Open, Dmp Fully Closed, Dmp Minimum, Dmp Maximum

Off Set to any value besides “Off” to place the controller into that over-ride mode.

Damper Position 0.00 to 100.00% 0.00% Position to use when the controller is placed in “Damper Position” override mode.

Flow Value 0 to 10001 CFM(0 to 4720 L/s)

0 CFM Flow rate to use when the control-ler is placed in “Flow Value” over-ride mode.


iWorx® VAV Series

System Options Displays all of the controller‘s editable settings for this category and provides access to edit these parameters from a single screen.

Occupied Temp SetptsDisplays all of the controller‘s editable settings for this category and provides access to edit these parameters from a single screen.

Pressure Independent Displays all of the controller‘s editable settings for this category and provides access to edit these parameters from a single screen.

Setting Range Default DescriptionLocal IAQ Alarm? Off, On Off Set to “On” to enable IAQ features

using input from the local IAQ sen-sor.

Global IAQ Alarm? Off, On Off Set to “On” to enable IAQ features using input from the master air handler’s IAQ sensor.

Supplemental Heat? Off, On Off Enables supplemental heating, see “Local Heating” on page 19.

Reverse Damper? Off, On Off Reverse direction of the damper actuator.

Starved Box Alarm Off, On On Set to “On” to enable reporting of “Starved Box” conditions.

Stand Alone Mode Off, On On Set to “On” to place controller in stand-alone mode regardless of grouping.

Aux Heating Mode Off, On Off Set to “On” to use auxiliary heating as first stage of heating. See “Aux-iliary Heating Mode” on page 21.

Display IAQ Alarm Off, On Off Set to “On” to enable reporting of the IAQ alarm.

Setpoint Range Default DescriptionOccupied Cool 50 to 95 °F (10 to 35 °C) 72.0 °F (22.2 °C) Cooling setpoint for occupied time periods.Unoccupied Cool 50 to 95 °F (10 to 35 °C) 82.0 °F (27.7 °C) Cooling setpoint for unoccupied time peri-

ods.Occupied Heat 50 to 95 °F (10 to 35 °C) 70.0 °F (21.1 °C) Heating setpoint for occupied time periods.Unoccupied Heat 50 to 95 °F (10 to 35 °C) 59.5 °F (15.5 °C) Heating setpoint for unoccupied time peri-

ods.

Setting Range Default DescriptionK Factor 0 to 10001 CFM

(0 to 4720 L/s)0 CFM K factor for the terminal box in use.

Min Flow 0 to 10001 CFM(0 to 4720 L/s)

100 CFM(47.2 L/s)

Minimum desired airflow through the termi-nal box.


iWorx® VAV Series

Pressure Dependent Displays all of the controller‘s editable settings for this category and provides access to edit these parameters from a single screen.

ThermostatDisplays all of the controller‘s editable settings for this category and provides access to edit these parameters from a single screen.

Indoor Air QualityDisplays all of the controller‘s editable settings for this category and provides access to edit these parameters from a single screen.

Max Flow 0 to 10001 CFM(0 to 4720 L/s)

500 CFM(236.0 L/s)

Maximum desired airflow through the termi-nal box.

Reheat Flow Setpoint 0 to 10001 CFM(0 to 4720 L/s)

0 CFM Airflow setpoint used if local reheat is active; must be set above the minimum airflow.

Fan Flow Setpoint 0 to 10001 CFM(0 to 4720 L/s)

0 CFM Airflow setpoint used when parallel flow is selected.

Setting Range Default DescriptionMin Position 0.0 to 100.0% 20.00% Minimum desired position of the terminal

box damper.Max Position 0.0 to 100.0% 100.00% Maximum desired position of the terminal

box damper.Reheat Position 0.0 to 100.0% 50.00% Desired position used if local reheat is

active; must be set above the minimum posi-tion.

Fan Damper Position 0.0 to 100.0% 50.00% Desired position used when parallel flow is selected.

Setting Range Default DescriptionType SLink,

Precon IIISLink Type of space sensor. Note: Use “SLink” for

TS300 Series sensor.Setpoint Adjustment 0 to 10 °F (0 to 5.56 °C) 2.0 °F (1.1 °C) Maximum amount of setpoint adjustment

allowable from the SLink.Occ. Extend Time 0 to 1000 minutes 60 minutes Allowable occupancy extension time.Space Temp Limit 0 to 14.9 °F (0 to 8.28 °C) 5 °F (2.78 °C) Offset subtracted from the heating control

setpoint to determine the temperature below which an alarm should be generated, or added to the cooling setpoint to determine the temperature above which an alarm should be generated.

Setting Range Default DescriptionIAQ Delay Time 0 to 1000 min 5 min Delay time before reporting a local IAQ

alarm.Temp Reset Limit 0 to 14.9 °F (0 to 8.28 °C) 5 °F (2.78 °C) Space temperature reset limit for IAQ alarm

operation.

Setting Range Default Description


iWorx® VAV Series

Local ReheatDisplays all of the controller‘s editable settings for this category and provides access to edit these parameters from a single screen.

Backup Occ / Unocc TimeDisplays all of the VAV Series‘ setpoints and editable settings and provides access to edit all VAV Series parameters from a single screen.

Alarms

Setting Range Default DescriptionLocal Heating Type Disabled,

Float. Mod. Vlv, 1 stg, 2 Vlv, 2 stg.

Disabled Type of reheat to be controlled by the VAV Series.

Control Band 0 to 10 °F (0 to 5.56 °C) 0 °F (0 °C) Value to subtract from the calculated heating setpoint to form the temperature range in which local heating is enabled.

Valve Travel Time 0 to 65535 sec 300 sec The rate at which heating stages are sequenced or the full stroke time of the valve.

Runtime Limit 0 to 65535 hr 1000 hr Runtime limit for the heating stages after which a maintenance alarm is generated.

Valve AO Min 0.0 to 10.0 V 0.0 V Minimum output voltage when the analog valve is used.

Valve AO Max 0.0 to 10.0 V 10.0 V Maximum output voltage when the analog valve is used.

Setting Range Default DescriptionHour 0 to 23 0 Hour to start occupied/unoccupied times.Minute 0 to 59 0 Minute to start occupied/unoccupied times.

Alarm Range Alarm Trigger Alarm ResetThermostat Failure Normal, Alarm The thermostat fails to communi-

cate with the controller.Communication between thermostat and controller is re-established.

Maintenance Alarm Normal, Alarm When the Heating Runtime exceeds the limit set.

Button Reset Runtimes gets pressed after servicing the equipment.

Space Temperature High Normal, Alarm SpaceTemp > (CalcCoolingSp + Coolband + AlarmLimitOffset)

Space Temp goes back below High Limit.

Space Temperature Low Normal, Alarm SpaceTemp < (CalcHeatingSp -Heatband -AlarmLimitOffset)

Space Temp goes back above Low Limit.

Indoor Air Quality (IAQ) Normal, Alarm The controller receives a signal from the connected CO2 Unit in form of a contact closure.

The contact opens again.

Starved Box Normal, Alarm Insufficient Airflow even when the damper position is at 100%. Can be configured for enabled and dis-abled.

Airflow setpoint is reached.


iWorx® VAV Series

TROUBLESHOOTING

Diagnostic LEDsThe controller has 4 LED indicators. These indicators can aid in troubleshooting equipment operation problems. The following table lists the functions of the controller’s LEDs in the order they appear from left to right on the unit.

Figure 12: Terminal Unit Controller Controller LEDs

Service (SRV)

Status (RUN)

Network (WNK)

Fault (FLT)

Troubleshooting TipsThe following table provides tips on resolving common issues.

LED IndicationStatus – Solid green when running and configured by an LCI

– Flashing green when running and NOT configured by an LCINetwork – Yellow while the controller is transmitting data onto the FTT-10A network

– Green when there is network activity– Off when there is no network activity

Fault – Solid red when a fault condition existsService – Illuminated when the service pin is pushed

Problem SolutionController is not running and Status LED is not illuminated.

No power to controller. Verify the voltage on the controller’s power connector (24 VAC).

How do I reset the controller? The controller can be reset by the LCI, or you can cycle power to the controller. Refer to the LCI documentation for more information on resetting the controller using the LCI.

I am using a TS303 thermostat and cannot force the fan ON.

On the VAV Series controller, the Fan Override button is disabled. Model TS303 is not recommended for use with VAV Series controllers.

On other iWorx® controllers, the sta-tus LED will turn Red when the con-troller has entered a fault mode that requires a reset. Are there any such modes on the VAV Series?

Yes, but it doesn't require a reset. As with any of the controllers, if the controller detects that no TS300 series sensor is present, an alarm is issued, the controller enters fault mode, and the LED is turned red. However, this type of failure doesn't require a manual reset.

Can VAV Series controllers have independent schedules?

Yes, each VAV Series controller on the network can be part of a different LCI group con-taining a different schedule. Remember the LCI is limited to 16 groups and 16 sched-ules.


iWorx® VAV Series

Getting HelpComponents within an iWorx® VAV Series controller cannot be field repaired. If there is a problem with a controller, fol-low the steps below before contacting your local TES representative or TES technical service.

1.Make sure controllers are connected and communicating to desired devices.2.Record precise hardware setup indicating the following:

Version numbers of applications software.

Controller firmware version number.

A complete description of difficulties encountered.

Notes:

What is the maximum number of VAV Series controllers that the LCI can support?

Since VAV Series controllers require either a VPU2 or MPU2 controlling the air-handling unit, the LCI can support up to 32 VAVD controllers per MPU2 and up to 60 VAVI con-trollers per VPU2. Remember the LCI can only support a maximum of 63 controllers.

When will the damper be controlled to the minimum flow value?

The damper will be controlled to the minimum flow value when the space temperature is satisfied.

Is there any provision for an air bal-ancer to override the VAV box damper?

Yes, using the LCI there is a mode that an air balancer can manipulate the damper or set it to maintain a specified flow.

My VAV Series boxes are not enter-ing heating or cooling mode.

Have the controllers been grouped with an VPU2 or MPU2? Have you sent the group-ing information to the controllers?

My temperature and flow readings are fluctuating rapidly.

Verify that the VAV Series is properly grounded. There must be a wire jumper between terminals T9 and T10.

Controller is not in stand alone mode, even though it has been ungrouped.

The VAV Series does not automatically re-enter stand alone mode when it is deleted from a VPU2 or MPU2’s group. Manually place the VAV Series in stand alone mode from the “System Options” screen of the LCI, and reset the controller.

Controller is operating as if in stand alone mode, even though it is grouped.

If the VAV Series has been manually switched to stand alone mode, it does not auto-matically exit stand alone mode when it is added to a VPU2 or MPU2’s group. Switch “Stand Alone Mode” to “Off” on the “System Options” screen of the LCI, and reset the controller.

Changes to system options are not taking effect.

To prevent inadvertent changes to the functionality of the VAV Series, the controller must be reset after any changes on the “System Options” screen of the LCI.

Problem Solution


iWorx® VAV Series

Printed in the USA iWorx® and iView® are registered trademarks of Taco Electronic Solutions, Inc. © 2011 Taco Electronic Solutions, Inc. LON, LONWORKS, & LONMARK are trademarks of Echelon Corporation

CONTROLS MADE EASY®

Taco Electronic Solutions, Inc., 1160 Cranston Street, Cranston, RI 02920 Telephone: (401) 942-8000 FAX: (401) 942-2360.

Taco (Canada), Ltd., 8450 Lawson Road, Unit #3, Milton, Ontario L9T 0J8. Telephone: 905/564-9422. FAX: 905/564-9436.

Taco Electronic Solutions, Inc. is a subsidiary of Taco, Inc. Visit our web site at: http://www.taco-hvac.com

Taco Electronic Solutions, Inc. (TES) will repair or replace without charge (at the company's option) any product or part which is proven defective under normal use within one (1) year from the date of start-up or one (1) year and six (6) months from date of shipment (whichever occurs first).

In order to obtain service under this warranty, it is the responsibility of the purchaser to promptly notify the local TES stocking distribu-tor or TES in writing and promptly deliver the subject product or part, delivery prepaid, to the stocking distributor. For assistance on war-ranty returns, the purchaser may either contact the local TES stocking distributor or TES. If the subject product or part contains no defect as covered in this warranty, the purchaser will be billed for parts and labor charges in effect at time of factory examination and repair.

Any TES product or part not installed or oper-ated in conformity with TES instructions or which has been subject to accident, disaster, neglect, misuse, misapplication, inadequate operating environment, repair, attempted repair, modification or alteration, or other abuse, will not be covered by this warranty.

TES products are not intended for use to sup-port fire suppression systems, life support sys-tems, critical care applications, commercial aviation, nuclear facilities or any other applica-tions where product failure could lead to injury to person, loss of life, or catastrophic property damage and should not be sold for such pur-poses.

If in doubt as to whether a particular product is suitable for use with a TES product or part, or for any application restrictions, consult the applicable TES instruction sheets or in the U.S. contact TES at 401-942-8000 and in Canada contact Taco (Canada) Limited at 905-564-9422.

TES reserves the right to provide replacement products and parts which are substantially simi-lar in design and functionally equivalent to the defective product or part. TES reserves the right to make changes in details of design, con-struction, or arrangement of materials of its products without notification.

TES OFFERS THIS WARRANTY IN LIEU OF ALL OTHER EXPRESS WARRANTIES. ANY WARRANTY IMPLIED BY LAW INCLUDING

WARRANTIES OF MERCHANTABILITY OR FITNESS IS IN EFFECT ONLY FOR THE DURATION OF THE EXPRESS WARRANTY SET FORTH IN THE FIRST PARAGRAPH ABOVE.

THE ABOVE WARRANTIES ARE IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR STATUTORY, OR ANY OTHER WARRANTY OBLIGATION ON THE PART OF TES.

TES WILL NOT BE LIABLE FOR ANY SPE-CIAL, INCIDENTAL, INDIRECT OR CONSE-QUENTIAL DAMAGES RESULTING FROM THE USE OF ITS PRODUCTS OR ANY INCI-DENTAL COSTS OF REMOVING OR REPLACING DEFECTIVE PRODUCTS.

This warranty gives the purchaser specific rights, and the purchaser may have other rights which vary from state to state. Some states do not allow limitations on how long an implied warranty lasts or on the exclusion of incidental or consequential damages, so these limitations or exclusions may not apply to you.

LIMITED WARRANTY STATEMENT

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