3.3.3
Fail Safe
Switches #1 through #4 control the fail-safe operation for each of the four alarm relays. Each switch must
be turned "ON" to be fail-safe (refer to FIGURE 3.0). In the fail-safe mode, the normal or non-alarm state
of each of the four (4) alarm relays is energized. When an alarm signal is generated, the respective relay
for the alarm is de-energized. This would be the same relay state (de-energized) that would be achieved
if the power source (AC, DC, or Battery) were interrupted. The factory default setting for switches #1
through #4 is "OFF" (normal operation or non fail-safe).
Please remember that when Fail Safe
Behavior is selected for the relays, the drain from the optional NiMH battery back-up is
approximately doubled, and the analyzer operating time is approximately halved.
3.3.4
Manual Clear / Auto Clear
There are two possible conditions that effect the way the instrument will respond to alarm cancellation.
One is Auto-Clear operation and the other is Manual Clear. The mode of operation is determined by the
setting switch #6 of SW6.
When switch 6 of DIP Switch 6 is placed in the “Off” or ‘”Manually Clear Al arms” position, the user is
required to manually clear the alarm indication from the analyzer even if the original alarm condition has
returned to a non-alarm level. When the switch is in the “On” or “Auto-Clear Alarms” position, the analyzer
will automatically clear the three (3) alarm indications (LED, Audible Alarm, and Relay) when the original
alarm condition returns to a non-alarm level.
3.3.4.1 Manual Clear Operation
In the Manual Clear mode (SW6, switch #6 is "OFF), the analyzer will not automatically clear the three (3)
alarm indicators. The user must first cancel the audible alarm by pushing the appropriate alarm button.
Only after the audible alarm has been canceled can the user clear the alarm condition by again pushing
the appropriate alarm button. If the set-point is to remain the same, simply push the appropriate alarm
button a third time.
Note:
If the audible alarm is activated, pressing any alarm button that is not associated with an alarm
condition will temporarily quiet the audible alarm. Upon exiting the alarm set condition or if the monitor
times out because of no user input, the audible alarm will resume awaiting a manual clear operation as
described above
3.3.4.2 Auto Clear Operation
In the Auto Clear mode (SW6, switch #6 is ON), the Series 9510 Carbon Dioxide Analyzer will
automatically reset the 3 alarm indications mentioned above when the alarm condition clears. Under
Auto-Clear operation, the silenced audible alarm may automatically come back on if the CO
2
reading
should go out of alarm range and then back into alarm condition. Also, after silencing the audible alarm, all
alarms must be cleared to re-enable the audible alarm.
3.3.5
Setting the Alarm Levels
Assuming that no alarms are currently activated (no LEDs are lit), press the desired alarm switch on the
front panel, "Alarm 1", "Alarm 2", or "Alarm 3" . The numerical value in the LCD is the existing alarm value
associated with that alarm channel. When the alarm switch is pressed, the LED directly above the switch
will light indicating that channel is in the alarm set mode. Any of the three CO
2
Alarms can be changed
from low to high level or vice versa by pressing the UP and DOWN arrows simultaneously. To set the
CO
2
alarm values, press the DOWN arrow to lower the CO
2
alarm value or the UP arrow to increase the
value. The longer either arrow is held down, the more rapidly the alarm values will scroll in the display.
When the value in the display is close to the desired CO
2
set point value, it is recommended that pressure
be released from the switch. To obtain the final value, apply momentary pressure to the switch to change
values in small increments. When finished setting the alarm, press the associated alarm switch. The LED
ALPHA OMEGA INSTRUMENTS CORP.
SERIES 9510 CARBON DIOXIDE ANALYZER INSTRUCTION MANUAL
16
