Det-Tronics C7051B, C UV Flame Detector - Manual (Page 22)

TESTING OF DETECTOR MODULE RESPONSE TO
UV RADIATION (COUNT MODE TEST)
1. Place keylock switch in TEST position.
2. SYSTEM STATUS displays the number “1”.
3. ZONE display shows the zone that is electrically
positioned for testing.
4. Press and release SELECT and TEST/ACCEPT but-
tons simultaneously.
5. SYSTEM STATUS display changes to an “8”.
6. Press and hold TEST/ACCEPT button.
7. UV source tube (in detector housing of the module
under test) turns on.
8. Upper displays indicate the discharge rate of the
sensor under test (in cps). If FIRE LOGIC LEDs
turn on, multiply displayed count by 10. Count
rate should be between 50 and 300 cps. If not,
clean the window (fire detector module) and the
metal
oi reflector ring. If count rate does not fall
within the 50 to 300 cps range after cleaning,
and the oi ring shows no signs of deterioration,
replace the sensor tube module. Record count
reading in the Recommended Test Form (inside
back cover).
9. Release TEST/ACCEPT button.
10. Upper displays now indicate quiescent state of
detector tube. Count should be between 00 and
05. If higher, place an obstruction over the detec-
tor window. If the count rate returns to the 00 to 05
range, the detector has been responding to exter-
nal radiation. Check area for external source of UV
radiation, and either remove it or shield the detec-
tor from it. If none can be found, use cardboard to
cover the windows of the detectors in the zone
being tested. If the high count rate continues after
the detector window is covered, this indicates a
faulty module, and it must be replaced. If other
detectors in the vicinity exhibit similar symptoms,
the presence of x-rays or gamma radiation is indi-
cated.
11. To test the next detector, press and release the
SELECT button.
12. ZONE display shows zone just tested.
13. Press and release the SELECT button again.
14. Controller cycles to next lower zone pair (controller
cycles through the detectors selected on rocker
switches 1-1 to 1-4). (See “Theory of Operation.”)
15. Repeat steps 6 through 14 until all detectors have
been checked. At the completion of the sequence,
each detector will have been tested for the follow-
ing conditions:
A. Influence of background radiation, if any.
B. UV transmission capability of all optical surfaces
(where applicable).
C. Calibration of UV source/UV detector (these ele-
ments are factory adjusted, but are subject to
influences that may affect the calibration).
D. If the system is to be tested for response to an
actual fire, the exact response of each detector
can be measured. If any improvements in system
layout are needed, they will be revealed in this
way.
16. After completion of all tests, return keylock switch
to NORMAL position. System resets and both dig-
ital displays should become blank.
NOTE
The Automatic oi system continuously monitors
the operation of the R7404 but does not monitor
external relays or equipment that may be operat-
ed from the fire signal outputs, the alarm signal
output or the fault signal output. It is important
that the system be manually checked using the
Normal Mode Checkout Procedure on a regular
basis. The whole system (including external
equipment) should be checked periodically using
the W8066 UV Test Lamp or an equivalent UV
source to simulate a fire.
MANUAL CHECK IN NORMAL MODE
The whole system should be periodically checked with
the W8066 UV Test Lamp or an equivalent UV source to
make sure that the detectors are not obstructed, that the
area “seen” by the detector has not changed, and that
there is no fault in the
oi circuit.
CAUTION
Secure output loads (remove power from valves,
relays, igniters or other devices which would nor-
mally be actuated by the UV system) before per-
forming the following test.
20