Dwyer Instruments GSTC Series Installation And Operating Instruction Manual

Wall Mount
With LCD
The Series GSTC Carbon Monoxide/Nitrogen Dioxide Gas Transmitter
monitors the 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 GSTC is compatible with either BACnet or MODBUS
protocol, allowing the transmitter to be used with almost any building management
controller. The GSTC output is communicated over an RS-485 wire via BACnet or
MODBUS communication protocol. To maximize the accuracy of the Series GSTC,
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the sensor can be field-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.
BACnet and MODBUS communication protocol recommend limiting the number of
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nodes in any segment to 32. Therefore, the transceiver may be rated at one unit
load. Fractional loads are also acceptable. The Series GSTC accounts as an
eighth of a load on the MSTP network.
WARNING Disconnect power supply before installation to prevent electrical
shock and equipment damage. Make sure all connections are in
accordance with the job wiring diagram and in accordance with national and local
electrical codes. Use copper conductors only.
NOTICE
Use electrostatic discharge precautions (e.g., use of wrist
straps) during installation and wiring to prevent equipment
damage.
NOTICE Avoid locations where severe shock or vibration, excessive
moisture, or corrosive fumes are present.
NOTICE Do not exceed ratings of this device, permanent damage not
covered by warranty may result.
NOTICE The electrochemical sensors should be stored in an
environment with a minimum humidity level of 20% RH. If the
sensor dries out, replacements will not be covered under warranty, but they can be
revived by allowing them to stabilize in an environment above 40% RH for 10 days.
Once revived, they need to be recalibrated before use.
INSTALLATION
NOTICE These are general guidelines. Local laws or ordinances will take
precedence.
• The transmitter should be mounted at normal breathing height, approximately 5
to 6 ft above the floor.
• The unit may be mounted in the horizontal or vertical position. It should be
mounted in an area that is shielded from direct contact with the elements or direct
sunlight.
• Mount in an area that will prevent the sensor from having any direct contact with
water.
• The unit should be placed in an area that will give an average of the air quality.
Do not place the unit so it will receive direct engine exhaust. Prolonged exposure
to direct engine exhaust may damage the sensor.
DWYER INSTRUMENTS, INC.
P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.
Series GSTC Carbon Monoxide/Nitrogen Dioxide Gas Transmitter
Specifications - Installation and Operating Instructions
Wall Mount
Without LCD
communication
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Duct Mount
SPECIFICATIONS
Sensor: Field replaceable
electrochemical, 4 years typical
lifespan.
Range: CO: 0 to 500 PPM, NO
PPM.
Output Drift: <5% per year in air.
Coverage Area: 5000 to 7500 sq ft
typical.
Accuracy: CO: 2% FS, NO : 3% FS,
2
at the time of calibration.
Resolution: CO: 1 PPM; NO
PPM.
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 .
2
Figure 1 shows the location of the wiring terminal, 8 position DIP Switch SW1, used
for configuring the RS-485 address, the 4 position DIP Switch SW2, used for
configuring hardware and software options, sensor, span and zero adjustments,
and status LEDs.
The device provides three LEDs to indicate status and activity. The LEDs are
located to the right of DIP Switch SW1. The yellow LED indicates that the unit is
sending a BACnet or MODBUS
the unit is receiving a BACnet or MODBUS
this specific device. The red LED will flash once periodically if the BACnet or
MODBUS communication protocol address is set incorrectly or the red LED will
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flash twice periodically if the auto serial configuration is in progress.
Span
Sensor
DIP Switch
SW2
Wiring
Terminal
Phone: 219/879-8000
Fax: 219/872-9057
Bulletin AQ-GSTC
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Wall Mount Duct Mount
Span and Zero Adjustment: Via
pushbutton, using optional A-449
display. Zero only via BACnet or
MODBUS communication protocol.
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: 10 Housing: UV resistant glass filled
2
polycarbonate.
Output Signals: BACnet MS/TP or
MODBUS RTU (switch selectable)
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communication protocol.
Power Requirements: 10 to 36 VDC
or isolated 21.6 to 33 VAC.
: 0.1 Electrical Connection: Removable
2
terminal block, knock outs for conduit
fitting.
Calibration: Via pushbuttons using A-
449 auxiliary display. Span gas
concentration is field selectable.
Enclosure Rating: IP64.
Weight: 1 lb (0.45 kg).
Agency Approvals: CE.
communication protocol. The green LED indicates
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communication protocol addressed to
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Zero
DIP Switch
SW1
Status
LEDs
Figure 1
www.dwyer-inst.com
e-mail: info@dwyermail.com
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