Det-Tronics U7652B, C Unitized UV/IR Flame Detector - Manual (Page 4)

oi FEATURE
Both sensors are equipped with the Optical Integrity
(
oi ) test feature to assure proper operation of the
detector by checking the cleanliness of the optical
surfaces, sensitivity of the sensors, and proper func-
tioning of the electronic circuitry. No testing with an
external test lamp is required. The detector automati-
cally performs the same test that a maintenance per-
son with a test lamp would perform — once every
minute, 60 times per hour. A successful automatic
oi
test does not produce an alarm condition.
The U7652 can be programmed (using a jumper
plug) for automatic and/or manually initiated
oi test-
ing. Use of automatic oi is highly recommended.
Automatic oi
With automatic oi selected, the oi test is automatical-
ly performed on each sensor once every minute. If a
fault is detected, the normally energized Fault relay is
de-energized and the LEDs on the faulty sensor stop
blinking. When automatic
oi is selected, the detector
can also be tested using the manual oi test.
Manual oi
The detector also incorporates a manual oi feature
that provides the same test as the automatic oi , and
in addition actuates the Alarm relay to verify output
operation. The manual
oi feature is available in all
models and can be performed at any time. This test
requires bypass of all extinguishing devices to
avoid release resulting from a successful test.
RELAYS AND OUTPUTS
All U7652 Models
All U7652 Models are furnished with two standard
output relays that are rated for 5 amperes (resistive)
at 30 vdc.
Fire relay has SPDT (normally open/normally closed)
contacts:
— Normally de-energized (no fire).
— Energizes upon detection of fire.
— Field programmable for either latching or non-
latching operation.
Fault relay has SPST (normally open) contacts:
— Normally energized (no fault).
— De-energizes when fault is detected.
— Non-latching operation (automatically resets when
fault is corrected).
U7652C Model
The U7652C is furnished with either an auxiliary relay
or a 4 to 20 ma output in addition to the standard out-
puts. The U7652C with auxiliary relay requires the
presence of radiation at only one sensor for relay
actuation-rated for 1 ampere at 30 vdc. (Not recom-
mended for uncontrolled locations.)
Auxiliary relay has SPST (normally open) contacts.
— Field selectable for actuation when “UV radiation
only” or “any UV or IR radiation” is detected.
(Factory-shipped with the field selectable jumper
plug in the “UV only” position.)
— Normally de-energized (selected radiation not
detected).
— Energizes upon detection of selected radiation.
— Non-latching when responding to UV only or IR
only condition.
— Latches in response to UV and IR radiation at
background levels (fire threshold not exceeded).
Table 1—Detector Status Chart
2
Status UV LEDs IR LEDs Fire Relay Fault Relay
Normal Blinking Blinking De-energized Energized
UV Fault Off Blinking De-energized De-energized
IR Fault Blinking Off De-energized De-energized
General Fault Off Off De-energized De-energized
Background UV On Off* De-energized Energized
Background IR Off* On De-energized Energized
Fire On On Energized Energized
Manual oi Test On On Energized Energized
During normal operation when automatic oi is selected, LEDs blink once
every 5 seconds. During normal operation when manual oi is selected, UV
and IR sides blink alternately every 5 seconds.
*Some earlier models will blink under these conditions.