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OPERATION
The output signal is available on one of the CO2 terminals and is connected to the BAS analog input
which reads the signal and calculates the CO2 ppm value using correct scaling for the range and signal
type. The CO2 value is used to control output ventilation devices or initiate alarms.
If an optional temperature sensor is installed it will be wired to an analog input of the BAS that is set for
the specic resistance type. This could be a 10K thermistor, a 1000 ohm RTD or other sensor values. The
BAS reads the resistance signal and converts it to a temperature value.
The device includes a red LED on the PCB to indicate correct operation. In warm-up mode (the rst 1
minute after power is applied), the LED blinks at 2 times per second. After the warm-up period the LED
will blink once every 4 seconds to indicate normal operation. If the CO2 level is above the maximum
scale (over-range), then the LED will blink once per second.
When activated for the rst time a period of minimum 7 days is needed so that the algorithm can nd its
initial parameter set for Self Calibration. The sensor has to be exposed to fresh air for at least 1 hour every
day. Also during that period, the sensor may not be disconnected from the power supply, otherwise the
procedure to nd calibration parameters is aborted and has to be restarted from the beginning
CALIBRATION
Every sensor is factory calibrated and will achieve stable long term operation due to using dual IR
detectors and proprietary signal processing technology. The duct CO2 sensor is designed for simple
integration into any BAS system and for long term trouble free operation. As such, eld calibration is not
available or recommended on the product.
OUTPUT SIGNAL
The CO2 output is scaled such that 4-20 mA or 0-5 Vdc or 0-10 Vdc equals 0 to 2000 ppm.
For 4-20 mA output type, connect the mA output terminal to the controller analog input. The COMMON
terminal is the signal reference. Typically, this type of input would have a 250 ohm input impedance.
If using voltage output type, connect the VOLT output terminal to the controller analog input. The
COMMON terminal is the signal reference. Typically, this type of input would have a high impedance
> 10 Kohms. The VOLT output signal can be scaled as 0-5 or 0-10 Vdc by changing the jumper position on
the PCB.
SPECIFICATIONS
SENSOR
CO2 Sensor ...................................... Dual channel non-dispersive infrared (NDIR)
Range................................................. 0-2000 ppm
Accuracy ........................................... ± (30 ppm + 3% of reading)
Response Time ............................... 20 seconds (T63)
Sensor Life Span............................. >15 years
OUTPUT
Output Signals ..................................4-20 mA, 0-5 Vdc, 0-10 Vdc (eld selectable)
Drive Capability................................Current: 600 max @ 24 Vdc
Voltage: 10K min
POWER SUPPLY
Power Supply.....................................24 Vac/dc ± 20% (non-isolated half-wave rectied)
Consumption.....................................80 mA max @ 24 Vdc, 160 mA max @ 24 Vac
Protection............................................Reverse voltage and transient protected
OPTIONS
Optional Temperature Sensor....Various RTDs or thermistors as a 2-wire resistance output
GENERAL
Probe.....................................................152 mm L x 21.6 mm Diameter (6" x 0.85")
Enclosure Material...........................Polycarbonate, UL94-V0, IP65 (NEMA 4X)
Enclosure Dimensions...................112 mm W x 117 mm H x 53 mm D (4.4" x 4.6" x 2.1")
Warm-up Time...................................1 minute
Temperature Dependency......... ±2.5 ppm/°C
Operating Conditions....................0 to 50°C (32 to 122°F), 0-90 %RH non-condensing
Storage Conditions.........................-40 to 70°C (-40 to 158°F), 0-85 %RH non-condensing
Wiring Connections........................Screw terminal block (14-22 AWG)
Approvals.............................................CE, RoHS
Country of Origin..............................Canada
IN-GE-CEDTXXX-03 Copyright © Greystone Energy Systems, Inc. All Rights Reserved Phone: +1 506 853 3057 Web: www.greystoneenergy.com
