Omega GSTA User guide

SERIES GSTA & GSTC | CARBON MONOXIDE/NITROGEN DIOXIDE

®

GAS TRANSMITTER

WallmountwithLCD WallmountwithoutLCD Ductmount

BENEFITS/FEATURES

•Easyeldmaintenancewithindustrialgradereplaceablesensors

•Reducedinventoryofunitswitheldselectableoutputs

•Simpliedsetupfornon-LCDunitsusingtheset-updisplaytool

DESCRIPTIONAPPLICATIONS

• Garage or loading dock ventilation

• Mechanical room monitoring

The Series GSTA and GSTC Carbon Monoxide/Nitrogen Dioxide Transmitter monitors gas concentration
in underground parking garages and loading docks. The carbon monoxide transmitter is used to measure the
exhaust of gasoline engines, while the nitrogen dioxide transmitter is used for diesel engines. The Series GSTA

has eld selectable current and voltage output, and the Series GSTC is compatible with either BACnet or Modbus®

communication protocol, allowing the transmitters to be used with almost any building management controller.

To maximize the accuracy of the transmitters, the sensors can be eld-calibrated using the A-449 remote LCD

display. When the sensor reaches the end of its life, the display will indicate that the sensor needs to be replaced.

SPECIFICATIONS

Sensor Field replaceable electrochemical, 4 years typical lifespan.

Range NO

OutputDrift <5% per year in air.

CoverageArea 5000 to 7500 sq ft typical.

Accuracy

Resolution CO: 1 PPM; NO

TemperatureLimits -4 to 122°F (-20 to 50°C).

StorageTemperature For best sensor life, 32 to 68°F (0 to 20°C).

HumidityLimits 15 to 90% RH constant; 0 to 99% RH intermittent.

ResponseTime <45 s to 90% CO, <25 s to 90% NO

SpanandZeroAdjustments Via onboard push-buttons or using optional A-449 display; GSTC models: Zero only via BACnet or Modbus

Housing UV resistant glass lled polycarbonate.

OutputSignals GSTA: Switch selectable 4-20 mA (loop powered), 0-5 V @ 5 mA, or 0-10 V @ 5 mA; Switch selectable 0-5 V/1-5 V

PowerRequirements GSTA: Current output: 10-35 VDC, Voltage output: 15-35 VDC or 15-29 VAC; GSTC: 10-36 VDC or isolated

ElectricalConnection Removable terminal block, knockouts for conduit tting.

Calibration Via onboard push-buttons (LCD model only) or using optional A-449 display. Span gas concentration is eld

EnclosureRating IP64.

Weight 1 lb (0.45 kg).

AgencyApprovals CE.

2: 10 PPM; GSTA CO: Switch selectable 200 or 500 PPM; GSTC CO: 500 PPM.

CO: 2% FS, NO

communication protocol.

and 0-10 V/2-10 V; Switch selectable normal or reverse output; GSTC: BACnet MS/TP, Modbus
ASCII (switch selectable) communication protocol.

21.6-33 VAC, 5.7 mA @ 24 VDC.

selectable.

2: 3% FS, at the time of calibration.
2: 0.1 PPM.

2.

®

®

RTU, or Modbus®

DIMENSIONS WIRING DIAGRAM

3-23/64

TO

PWRCOM A[-] B[+]

TO

NEXT

PWRCOM A[-] B[+]

RECEIVER

I OUT WIRING

RECEIVER

V OUT WIRING

2

1

3

4

+

+

3-45/64

[94.06]

3-1/8

[107.95]

2-15/64

[56.75]

[85]

2-55/64

[73]

2-15/64

[57]

POWER
SUPPLY

2

1

3

4

POWER
SUPPLY

-

-

-

+

-

+

4-17/32
[115.09]

5-7/64

[129.78]

3-59/64

[100]

HOW TO ORDER

Use the bold characters from the chart below to construct a product code.

GSTA -N -LCD

SERIES

GSTA: Field selectable analog outputs
GSTC: Field selectable BACnet or Modbus

communication protocol

GAS SENSED

-C: CO, carbon monoxide

-N: NO

2, nitrogen dioxide

OPTIONS

BLANK: Wall mount without options

-D: Duct mount

-LCD: Wall mount with integral LCD

®

GSTAcurrentoutput

PREVIOUS

DEVICE

B[+]
A[-]
PWR

COM

PREVIOUS

DEVICE

B[+]
A[-]

COM

GSTAvoltageoutput

1234

ATTA CH SHIELDS
TOGETHER W/WIRE NUT

GSTCcommonpowersupply

1234

TO NEXT

DEVICE

B[+]
A[-]
PWR

COM

TO

DEVICE

B[+]
A[-]
COM

-+

ATTA CH SHIELDS
TOGETHER W/WIRE NUT

GSTClocalpowersupply

ACCESSORIES

Model Description
A-449
A-505
A-506
A-507
A-GSTA-SE
GCK-200CO-2000CO2

©Copyright 2021 Dwyer Instruments, Inc.
Printed in U.S.A. 6/21 DS-GSTA-GSTC Rev. 2

Important Notice: Dwyer Instruments, Inc. reserves the right to make changes to or discontinue any product or service identied in this publication without notice. Dwyer advises its customers to obtain the
latest version of the relevant information to verify, before placing any orders, that the information being relied upon is current.

Remote LCD display
CO replacement sensor
NO

2 replacement sensor

Calibration adaptor

Security enclosure

Calibration gas

GCK-200CO-2000CO2

A-449A-GSTA-SE A-505 A-506

Modbus® is a registered trademark of Schneider Automation, Inc.

DWYER INSTRUMENTS, INC.

A-507