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The optional relay output is on the N.O. RELAY terminals as shown in Figure 8. The relay output is completely
isolated and has a Normally Open (NO) signal. This signal can be used to directly control an alarm or
ventilation fan. See specifications for contact ratings.
The optional override switch is a two-wire dry contact normally open switch contact as shown in Figure 9.
The two-wire temperature sensor output is available with various RTDs and thermistors to suit all control
applications and is available on the TEMP terminals as shown in Figure 10.
START-UP MODE
Verify the device is properly wired and connections are tight. Ensure the V/I switch is set for the correct
signal type. Apply power and the LCD will indicate the software version number, the output signal type,
the relay setpoint (if installed), the CO
2
measurement range and then the sensor will begin reading the
CO2 level, output the correct analog signal and display the value on the LCD.
OUTPUT SIGNAL
The CO
2
output is scaled such that 4-20 mA (or 0-5/0-10 Vdc) equals 0 to Out_High. Depending on the
model, the factory default is 0-20,000 ppm. Out_High can be changed in the Setup Menu and the output
is scaled accordingly. If using voltage output type, the default is 0-5 Vdc (0-10 can be selected in the
menu).
OPERATION
The output signal is available on the CO
2
terminal and is connected to the BAS analog input which reads
the signal and calculates the CO
2
ppm value using correct scaling for the range and signal type. The CO
2
value is used to control output ventilation devices or initiate alarms. The CO
2
value is also displayed locally
on the optional LCD.
If a relay is installed it can control a small fan or alarm by setting the trip value and hysteresis to appropriate
values.
If a temperature sensor is installed it will be wired to an analog input of the BAS that is set for the specific
resistance type. This could be a 10 KΩ thermistor, a 1000Ω RTD or other sensor values. The BAS reads the
resistance signal and converts it to a temperature value.
The override switch provides a dry contact closure to a digital input of the BAS.
SETUP MENU
The menu has several items shown below. Some items change depending on the hardware
configuration and the CO
2
sensor. To enter the menu, press and release the <MENU> key while in normal
operation. This will enter SETUP menu step 1, pressing the <MENU> key
again advances to step 2. Each press of <MENU> advances the menu
item. No values are saved or changed by using <MENU>. The <ROLL> key
is used to make changes to program variables by scrolling through the
available options. When a value is changed, use the <SAVE> key to save it
to memory and advance to the next menu item as shown is Figure 11.
<MENU>
Press and release the <MENU> key to enter the Setup Menu
Out High
20000 PPM
The default CO2 range is 0-20,000 ppm. The span can be changed from 2000 to
20,000 ppm in increments of 500. Use the <ROLL> key to change the value and
<SAVE> to save. The factory default is 20,000 ppm.
<MENU>
Press to advance to next menu item
1. CO
2
RANGE
ROLL
SAVE
MENU
Figure 11
Copyright © Greystone Energy Systems, Inc. All Rights Reserved Phone: +1 506 853 3057 Web: www.greystoneenergy.com
IN-GE-CDD4B1XXX-01 05/20
