Det-Tronics C7050 A, C, G, P UV Flame Detector - Manual (Page 6)

tem. The main loop of the operating program continu-
ously cycles through the Automatic Optical Integrity test,
checking each detector and its wiring. At the same time,
the microprocessor can be interrupted by any one of
several status changes, such as a fault, a “fire” signal
from one of the detection zones, or a change in the set-
ting of the keylock switch. In the event of a status
change, the microprocessor will take the appropriate
action.
NOTE
The R7404 is available with various optional oper-
ating programs (STAR Logic, Remote Surveillance,
etc.). This manual covers the operation of the
R7404 with the standard program. Always refer to
the manual supplied with any special purpose con-
trollers when operating or installing the equipment.
Fire Response
When the controller receives a “fire” signal from any
detector in the system, it is compared to the stored infor-
mation of the program. If the signal frequency is lower
than the programmed setting for sensitivity, the lower
display on the front panel of the controller responds with
a “3” and the upper display identifies the first zone
affected. If the signal frequency is greater than the pro-
grammed sensitivity setting for a period greater than the
preset time delay, the following actions take place:
1. The appropriate solid state zone output(s) is ener-
gized. One zone output is available for each of the
eight zones.
2. The solid state alarm output is energized. The alarm
output is activated when any zone detects a fire.
3. The ZONE display identifies the first responding
zone. The DETECTOR display is blank.
4. The SYSTEM STATUS display shows a “6”, indicat-
ing fire.
5. One or more ZONE LEDs turn on (blinking), indicat-
ing the zone(s) detecting UV radiation.
6. If the selected “voting” criteria has been satisfied,
the appropriate Fire Logic output is energized, and
the corresponding LED is on.
NOTE
When a fire signal is no longer present, the ZONE
LED(s) and the display indication will latch until
manually reset (ZONE LED emits steady light).
The display latch feature is useful in post-fire analy-
sis as a means of determining fire origin.
The Alarm output is typically used to actuate an external
audible alarm when a fire signal is received from one or
more detectors. Since these alarms can be disruptive to
personnel who are responding to the fire emergency, a
means for alarm silencing has been provided. The
R7404 is equipped with a TEST/ACCEPT button, which
will de-activate the alarm circuit without interrupting the
Zone and Fire Logic outputs. The alarm can also be
silenced by an optional external silence switch (see
“Typical Applications” section).
NOTE
If the system is going to be put out of service for
periods of time, use the Test/accept to bypass the
alarm contacts instead of shutting down the sys-
tem. This will provide optimum performance when
reconnected.
Digital Displays
The upper digital display on the R7404 panel identifies
both the detector and zone involved in any “System
Status” occurrence. For example, with the keylock
switch in the TEST position, and a “1” digit showing on
the lower display, the upper display shows which detec-
tor and zone is electrically positioned for a manual
oi
test.
Voting Logic
The R7404 permits two groups of four zones each to
“vote” separately, or eight zones to “vote” together. This
means that the controller can be programmed to require
more than one detector to be actuated before the Fire
Logic A and/or B outputs are energized. The Det-
Tronics “voting” principle allows combinations of detec-
E0235
RED LEDS
RED LEDS
KEYLOCK SWITCH
LAMP TEST
TEST/ACCEPT
AMBER LED
DETECTOR SELECTION
AMBER LED
GREEN LED
Figure 2—Front Panel of R7404
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