12
3.2.7
Alternate connection to alarm panel
In this application (
3.2.7 Alternate connection to alarm panel
) the Fan or primary relay is used as a low-level alarm relay. The Alarm or
secondary relay is used as a supervisory relay when utilized in the normally closed configuration. The CD-6”x” monitors all critical
functions of the unit through software diagnostics that continually test and verify its operations. If a problem is found, the unit will switch
to a fail-safe/error mode or trouble condition. In this error mode the Fan* and Alarm relays will be activated indicating the trouble condition
at panel and the CD-6”x display will flash the error. *See the
Trouble Fan Setting
Option.
3.3
Power Up
The CD-6”x” cycles through an internal self-test cycle for the first minute that it is powered. The unit will execute the test cycle any time
power is de-energized and re-energized (i.e. power failure). During the self-test cycle the unit will display the firmware version number,
then
count down from 60 to 0 (if the display setting is “On”) and finally go into normal operation. The alarm relay will be activated for 10
seconds and the fan relay for 60 seconds during the power-up cycle unless the “Power Up Test” (PUt) option is OFF. The indicator light
(LED) will flash green during the self-test cycle. At the end of the 1-minute cycle, the unit will take its first sample of the air and the
indicator light will turn solid green.
3.4
Operation
1.
With the display function turned “On”, the CD-6”x” will show the current concentration of CO
2
ppm in the air. Normal
outdoor concentration ranges between 350-450 ppm. When the CO
2
concentration reaches the Fan Relay setting
(2000ppm, for example) the display will flash back and forth between “FAn” and “2000”. With the display function
turned “Off”, the display does not show the CO
2
concentration, but will show “FAn” as long as the fan relay is
activated.
2.
With the display function turned “On” and the CO
2
concentration reaching the Alarm Relay setting, (4000 ppm, for
example) the display will flash back and forth between “ALr” and “4000”. The buzzer will sound indicating “Alarm” if
the buzzer is turned “On”. With the display function turned off the display does not show the CO
2
concentration, but
will show “ALr” when the Alarm relay is activated.
3.
With the 4-20 mA function turned “On” and the CO
2
concentration climbing, the 4-20 mA signal will ramp up
corresponding to the concentration (0-5000 ppm, for example). The display will show “FAn” and “ALr” and sound as
outlined above.