Detcon 10C - Manual (Page 7)

Model 10C
A typical application of an Energized relay could be the use of the Fault Relay in a Fail-Safe Fault Circuit. The
loss of functionality of the Controller would cause the coil to De-Energize, thus creating a Fault output to the
receiving equipment, for instance: if power is lost to the 10C Controller, or if the 10C module is unplugged
from the live chassis.
1.2.3 Ascending or Descending
Alarm 1, and Alarm 2 can be programmed for whether the alarm condition is triggered by an increasing
concentration (Ascending) or a decreasing concentration (Descending) through a set-point. The descending
feature, although mainly used for oxygen deficiency, can be useful for setting the trigger of alarms when there
is lack of gas concentration. When set for ascending, the associated alarms will trigger when the gas
concentration goes above the preset set-point. When set for descending, the associated alarms will trigger
when the gas concentration falls below the preset set-point.
1.2.4 Silenceable or Non-silenceable (Alarm Acknowledge)
The terminology “to acknowledge alarms” is synonymous with the terminology “to silence an alarm”. All
Alarms (Alarm 1, Alarm 2, and Fault) can be programmed as Silenceable or Non-silenceable. When an alarm
is programmed as Silenceable, the setting allows the alarm(s) to be silenced even during an alarm state. To
silence an alarm the 10C controller’s alarm must be programmed as Silenceable. When an alarm occurs, the
Silenceable alarm can be silenced by pressing the “SLNC” pushbutton, followed by acknowledging the
“Silence Alarms?” scrolling display by pressing the “ENT” pushbutton. An instance where this feature might
be used is a Strobe device connected to Alarm 1 and a Horn device connected to Alarm 2. In the event of an
alarm, where both the Strobe and Horn were activated, the Horn could be silenced while the Strobe would
remain activated. The silenced state is reset when and if the alarm condition clears and then exceeds alarm set-
point again. The Horn would be reactivated upon the return of the alarm condition.
The “Remote Reset” signal that resets latched alarms also functions as a signal to silence active Silenceable
Alarms.
NOTE: There is a minimum alarm time before acknowledge. When a silenceable alarm
triggers, a minimum-time timer starts. Whenever a silenceable alarm is attempted to be
silenced, the alarm will not silence unless/until the minimum-time timer has timed out. This
guarantees that the alarm has a minimum activity time.
1.2.5 Alarm Reset
An alarm “RESET” pushbutton key-switch is located on the front panel of the 10C Controller. This switch is
used to reset alarms that have been programmed as latching. Once alarm conditions clear, alarms that have
been set as latching can be reset by use of this switch. If cleared latched alarms are pending, pressing the
“RESET” pushbutton will cause the display to scroll the text: “Reset Alarms?” Pressing the “ENT”
pushbutton will reset the alarms which is apparent with the displayed text: “Reset DONE”. The “Remote
Reset” signal, activated from an optional external switch, can be momentarily operated to reset the latched
relays.
The “Remote Reset” signal needs to be operated only once and without an acknowledge sequence, to reset all
pending latched alarms. The text “Ext Alm Rst” scrolls across the 10C Controller front panel display when the
“Remote Reset” signal is sensed.
10C Control Module Instruction Manual Rev. 0.B Page 3 of 25