NXA-VAV-02 Variable Air Volume Controller ... - Johnson Controls

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NXA-VAV-02 Variable Air Volume Controller
General Information
®
The Johnson Controls NexSys product
line is a complete family of electronic
distributed controllers designed
around Echelon , s LONWORKS ® control
networking technology. The NexSys family
of products is designed for LONMARK ®
certification (certified where applicable)
and designed to support interoperability
between multiple vendors. A LONMARK
compliant NexSys controller can reside on
the same network as another vendor , s
lighting controller, power monitor, and/or
variable speed controller. In addition,
through UNITY a range of Original
Vendor Systems (OVS) such as those
manufactured by Honeywell, Trane,
Johnson Controls, EST, Siemens, and CSI
can exist on the same system. When
provided as a UNITY subsystem, NexSys
provides UNITY users with the significant
benefits of a LONWORKS control networking
architecture along with increased flexibility
in the future development and management
of their facilities.
Application
The NXA-VAV-02 variable air volume
controller is part of a family of LONWORKS
based application specific controllers
manufactured by Johnson Controls.
The NXA-VAV-02 is an Echelon
microprocessor based electronic
controller which provides precise control
of a single VAV terminal unit. This
controller utilizes an integrated air flow
sensor, surface mount circuitry, microprocessor
technology, and pre-engineered
control sequences to provide for standard
VAV control strategies. The integrated
damper actuator is designed to minimize
field installation time for retrofit applications.
The controller accepts several
temperature sensor options and provides
triac outputs for external reheat or valve
actuators. This controller supports standalone
operation, but is best utilized in
conjunction with network communications.
PRODUCT DATA
Features
• Designed around Echelon , s LONWORKS
Control Networking Technology for
Interoperability with other Manufacturers
, systems
• Supports both Pressure Independent
and Pressure Dependent Modes Using
most Standard Tri-state Type Damper
Actuators
• Accepts several NexSys Temperature
inputs:
• Sensor Only
• Sensor with Override Button
• Temperature/Setpoint/Override STAT
• Intelligent STAT with Digital LCD
Display
• Use of Pre-engineered Control
Strategies Minimizes System Design,
Installation, and Commissioning Time
• Downloadable Firmware
www.johnsoncontrols.com
• Integrated Actuator for Simpler
Installation
• Capable of Stand-alone and Network
Operations
• Extensive Library of VAV Control
Sequences including Smoke Control
and Indoor Air Quality Routines
• Communicates with NexSys Workstation
and other Controllers via a
LONWORKS Control Network Using
Free-topology Transceivers
• Can be Commissioned via Laptop PC
or Intelligent STAT with LCD
• Extensive Diagnostic, Engineering,
and Support Tools Available with
Johnson Controls NexSys
Workstation Software
PUBL-3348

Processor
Echelon 3150
Memory
RAM: 8K
Flash: 64K
Physical Description
Dimensions: 7.5" L x 6.0" W x 2.5" H (190mm x 153mm
x 49mm)
Enclosure: Meets UL94-5V UL flammability for
Plenum applications
Power Requirements: 24 VAC, +/- 10% 50/60 Hz @ 5.0 VA plus
external load
Operating Environment
Temperature: 32° to 120° F (0° - 49° C)
Humidity: 5% - 85% RH non-condensing
Network Communications Requirements
Echelon Free Topology Transceiver (FTT-10)
Network Wiring Requirements
Local Operating Network Length: 8850 feet maximum
(2700 meters maximum)
Cable Supported:
Unshielded Twisted Pair
Belden 85102 or equivalent
NOTE: Refer to LIT-EB-N0015 for specific wiring information.
Inputs
Accuracy:
10-bit. +/- 1% error
Space Sensor: Thermistor 10K Ohm, Type II/CP
Accuracy: 0.5° F (0.28° C)
ESUSA STAT: Supports Intelligent STAT or TSO STAT
Accuracy: 0.5° F (0.28° C)
Velocity Pressure Input:
Operating Range: 0.011 to 1.5" of W.C.
Tubing Connections: Barb fittings for 0.170" (4.3mm) I.D.
FRPE polyethylene tubing
Tubing Length: 4ft (1.2m) maximum each tube
Outputs
3 Low voltage Triac: 24 VAC @ 0.5A maximum (voltage sinking)
Actuator
Manual Override:
Motor clutch is released via a push
button for manual setting of damper
Stroke: Push button adjustable from 0 to 90
degrees of travel
Torque Rating: 53 lb/in
Timing: 2 sec/deg rotation at 60 Hz @ 24
VAC visual indication of position
provided
Damper Mounting Linkage: Fits standard 1/2" damper shafts
extending 1" from box. An optional
adaptor for 3/8" shaft is available.
Terminations
Terminal Blocks: Non-removable screw terminal connectors
GENERAL SPECIFICATIONS
Indicators
LEDs: Digital Outputs, Microprocessor Check, Service Pin
Agency Approvals
FCC Part 15
UL 916 Energy Management Equipment
CUL 24KM Open Energy Management Equipment
LONMARK Certification: Program ID 80 00 21 50 0A 0A 04 80
Guide Specifications
General: Each terminal unit shall have a factory mounted
LONWORKS based DDC controller designed to provide the
specified sequences. The VAV controller shall be LONMARK
certified, shall store all specific control sequences in non-volatile
memory, and shall be provided with a multi-function, microprocessor-based
room sensor. The room sensor shall provide
override functions, be password protected, and shall provide full
access to all controller parameters.
Each controller shall communicate with the local operating
network utilizing free-topology transceivers over a twisted pair
cable. The network may be configured as a bus, star, or loop
arrangement, but cable lengths in excess of 8,850 feet will not be
allowed.
All pressure independent VAV terminals shall have integral
pressure transducers complete with an automatic calibration
routine to ensure accuracy and eliminate any sensor drift.
Pressure independent units shall include an algorithm to
automatically revert to pressure dependent mode should the
pressure transducer fail.
The temperature control algorithm shall control to minimum and
maximum damper position with a room temperature PID loop and
a CFM PID loop.
Units that control tri-state actuators shall be applicable to
dampers with any rotation up to 90 o and shall automatically
calibrate each terminal unit to show this rotation as 0 to 100%.
Thus, a terminal unit with maximum damper travel of 60 o or 90 o
will register the respective unitís travel as 0 to 100%. Minimum
and maximum travel as a percent of this maximum travel shall be
programmable from the central workstation as well as with a
hand-held service tool connected to the local room sensor.
Damper position shall be based on calculated position provided
the controller has an algorithm to automatically recalibrate the
position calculation and is adjustable for different speed
actuators if the actuator is not integral to the controller.
Each VAV controller shall provide for fan control, not less than 3
stages of heat or floating valve control, and I/O to support an
additional discharge air sensor.
Pressure independent units shall include a control algorithm to
allow the balancing contractor to program in separate noninterfering
adjustment factors to tune both the minimum and
maximum airflow readings to match as installed conditions.
Controllers with fewer than two separate adjustment factors will
not be accepted.
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For more information on Johnson Controls products and services contact your local Johnson Controls office or call (800) 765-7773.
www.johnsoncontrols.com
©2002 Johnson Controls, Inc. Johnson Controls reserves the right to update specifications when appropriate.
Printed in U.S.A
Information contained in this document is based on specifications believed to be correct at the time of publication.
Honeywell ® , Echelon ® , Siemens ® , CSI ® , EST ® , and Trane ® are registered trade marks and service marks of companies other than Johnson Controls. Johnson Controls
products and services are not sponsored or approved by those companies, and Johnson Controls has used those marks without the authorization of those companies.