CTI GG-CO2 Manuel utilisateur
Installation and Operation Manual
GG-CO2
CARBON DIOXIDE GAS SENSOR
2GG-CO2
Warning
Use this product only in the manner described in this manual.
If the equipment is used in a manner not specied by Calibration
Technologies, the protection provided by the equipment may be impaired.
This equipment should be installed by qualied personnel.
GG-CO2 3
Table of Contents
For technical support, contact:
Calibration Technologies
920 N Tradewinds Pkwy
Columbia, MO 65201
866-394-5861
www.ctiengineering.com
General description .....................4
Installation .............................4
Locating the sensor ...................4
Installation guidelines .................5
Wiring ..............................6
Operation ..............................7
Start-up .............................7
Calibration mode .....................7
Maintenance ...........................9
Specications ..........................10
Warranty ..............................11
4GG-CO2
General Description Installation
The GG-CO2 sensor is a +24 VDC, three-wire, 4/20
mA sensor for carbon dioxide which utilizes proven
infrared sensor technology for accurate and reliable
leak detection. The 0-3% (0-30,000ppm) detection
range of the GG-CO2 provides real-time continuous
monitoring of ambient carbon dioxide concentrations.
0-1% and 0-5% ranges are also available.
The GG-CO2 provides an industry standard linear 4/20
mA output signal compatible with most gas detection
systems and PLCs. The output signal is not aected
by drastic temperature and moisture variations that
occur during washdown, defrost cycles, etc.
The circuit board is sealed in potting compound,
completely protecting sensitive electronic components
and copper tracing from corrosion. The specially
vented chemical-resistant polycarbonate enclosure
protects the sensor from accidental damage, weather
and direct hose-hits from cleaning crews.
Locating the sensor
One of the most important considerations when
installing GG-CO2 sensors is that they must be easily
accessible for calibration and maintenance.
For optimum personnel protection (representative
concentration reading that an employee would be
exposed to), mount the sensor at a height in the
breathing zone of the employees. It would typically
be about ve feet o the ground, which also allows
easy access. As a general rule of thumb, try to mount
sensors within 30 feet of potential leak sources.
5
GG-CO2
Installation Guidelines:
• Always mount the sensor vertically.
• Must be easily accessible for calibration and
maintenance.
• Mount the sensor close to the potential leak source.
• For optimum personnel protection, mount sensor
in the “breathing zone” (4’ – 5’ above oor).
• Take air movement and ventilation patterns into
account.
• To prevent electrical interference, keep sensor and
wire runs away from mercury vapor lights, variable
speed drives, and radio repeaters.
• Protect sensor from physical damage(forklifts, etc.).
• If mounting on a wall with studs, the mounting
screws should be screwed into the studs.
• Mount sensor enclosures through the mounting
holes as shown in Figure 1. Use the supplied
self-tapping screws for mounting on sheet metal
surfaces.
• Even though the sensor comes from the factory
calibrated, it is always a good idea to calibrate the
sensor to the environment in which it is installed.
This will compensate for any inaccuracies caused by
a change is temperature, altitude, etc.
2.0"
6.5"
6.8"7.75"
Figure 1: Mounting Dimensions
6GG-CO2
Wiring
Electrical wiring must comply with all applicable codes.
Electrical Power: 24 VDC regulated, 350 mA.
Output: Linear 4/20 mA output. Monitoring
equipment may have a maximum input impedance of
700 ohms.
Cable Recommendation: 20/3 shielded cable
(General Cable C2525A or equivalent). Length of cable
to sensor should be no greater than 1,500 feet.
Monitoring: Monitoring equipment must be
congured to indicate a fault if the signal is below 1
mA. All signals over 20 mA must be considered high
gas concentrations. Alarm setpoints should not be
lower than 10% of full-scale range.
Wiring Guidelines:
• Always use three conductor, insulated, stranded,
shielded copper cable.
• Do not pull sensor wiring with AC power cables.
This can cause electrical interference.
• If cable runs cannot be made without a splice, all
splice connections should be soldered.
• Ground the shield at the main control panel.
Connect the shield wire in the sensor terminal
block labeled SHLD.
• Always disconnect power at the controller before
performing any wiring at the sensor.
• To maintain NEMA/IP rating of the enclosure,
conduit ttings of the same rating or better must
be used.
To signal input of monitoring equipment
To +24V terminal of power supply
To ground terminal of power supply
To case (earth) ground of monitoring equipment
Terminal Block Plug (Field Wiring):
SHLD: To case (earth) ground of monitoring equipment
GND: To ground terminal of power supply
+24V: To +24V terminal of power supply
SIG: To signal input of monitoring equipment
7
GG-CO2
Operation
Start-up
Before applying power, make a nal check of all wiring
for continuity, shorts, grounds, etc. After power-up,
allow at least 2 hours for the system to stabilize before
testing the sensors. Because sensors are normally
located at a distance from the main unit, the test
time required and accuracy of the response checks
will be improved if two people perform the start-up
procedures and use radio contact.
Start-Up Test:
1) One person exposes each sensor to calibration gas.
(breathing on the sensor can also produce a signicant
signal rise)
2) The second person stays at the control unit to
determine that each sensor, when exposed to
carbon dioxide, is connected to the proper input and
responds, causing appropriate alarm functions.
Calibration
The GG-CO2 Sensor comes factory calibrated and
should require only minimal adjustments after
installation. There are two pots on the preamp that
are used for calibration.
Note: Never measure sensor output in mA.
Always use mVDC (or VDC) voltmeter settings.
Zero Calibration: After the unit is installed and has
been powered up for a minimum of 2 hours, the unit
can be zero calibrated by the following:
• Apply 500 ppm CO2gas at 0.5 to 0.8 L/min.
• Adjust the zero pot until the voltmeter reads the
following mVdc on the test points [-] to [+] (see
Figure 2).
• 0-1% CO2range sensor = 48.0 mVdc
• 0-3% CO2range sensor = 42.7 mVdc
• 0-5% CO2range sensor = 41.6 mVdc
Span Calibration: If span adjustment is required, the
following procedure will span the unit:
• Perform zero calibration prior to spanning.
• Connect tubing to the calibration port of the
infrared tube. (see Figure 2)
• Apply span gas at 0.5 to 0.8 L/min.
• Sensor should react to gas within 10 seconds.
• Once the output signal has peaked (or two minutes
maximum) adjust the span pot until the correct
output is achieved with full-scale span gas, the
calculated span value will be 200 mVdc.
Note: The adjustment response is dampened. Make
slight adjustments (no more than ½ turn of the
potentiometer) and wait for output response.
If the correct output cannot be achieved, contact
Calibration Technologies for technical help.
8GG-CO2
Figure 2: Sensor output and zero/span adjustments
Span and Zero
adjustments
40-200 mV
mVDC
Black Red
-+
Calibration Gas Port
9
GG-CO2
Maintenance
The GG-CO2 was designed for long life and minimal
maintenance. For proper operation it is essential
that the test and calibration schedule be adhered to.
Calibration Technologies recommends the following
maintenance schedule
Maintenance Guidelines:
• The sensor is shipped with a factory calibration.
Sensor should be calibrated 6 months from
purchase date.
• Calibrate the detector at least once every 6 months.
• Calibration should be performed with certied
calibration gas. Calibration kits and replacement
cylinders are available from Calibration
Technologies.
• All tests and calibrations must be logged.
• Always disconnect power at the controller before
performing any wiring at the sensor.
Sensor Life: Typical sensor life of the GG-CO2 is ve
to seven years. Failure of the infrared sensor happens
normally when the infrared source opens or breaks,
similar to an incandescent light bulb lament. If this
occurs, the sensor will produce a continuous fault
indication signal of 0.5 mA and the fault LED will be
lit. Contact Calibration Technologies for a sensor
replacement.
10 GG-CO2
Specications
Input Power: +24 VDC, 350 mA
Detection Principle: Infrared
Detection Method: Diusion
Gases: Carbon dioxide (CO2)
Ranges:
0-1% (0-10,000ppm)
0-3% (0-30,000ppm) (standard range)
0-5% (0-50,000ppm)
Output Signal:
Linear 4/20 mA (max input impedance: 700 Ohms)
Response Time:
T50 = less than 30 seconds
T90 = less than 60 seconds
Accuracy: +/- 2% of full-scale
Zero Drift: Less than 0.5% of full-scale per month,
non-cumulative
Span Drift: Less than 1% per month, non-cumulative
Linearity: +/- 0.5% of full-scale
Repeatability: +/- 1% of full-scale
Wiring Connections: 3-conductor, shielded,
stranded, ≥ 20 AWG cable (General Cable C2525A or
equivalent) up to 1500 ft.
Terminal Block Plug (Field Wiring): 26-12 AWG,
torque 4.5 lbs-in.
Enclosure: Injection-molded, NEMA 3RX washdown-
duty, polycarbonate sensor housing with hinged lid
and captive screw. For non-classied areas. Optional
18 GA, NEMA 3RX washdown-duty stainless steel
enclosure with hinged lid and captive screw. For non-
classied areas.
Temperature Range: -60°F to +120°F (-51°C to +49°C)
Humidity Range: 5% to 100% condensing
Dimensions: 7.7” high x 6.7” wide x 3.8” deep
Weight: 3 lbs
Certication:
ETL Listed:
Conforms to UL 61010-1
Certied to CSA C22.2 No. 61010-1
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