MSA FlameGard 5 UV/IR-E Instruction Manual page 8

COPM Circuitry
A self-testing feature called Continuous Optical Path Monitoring (COPM) checks the optical
path, the detector(s), and the related electronic circuitry once every minute. If foreign
material impairs the optical path of the UV detector tube or infrared detector for two
consecutive checks, the unit will indicate FAULT. The optical FAULT outputs are,
depending on the version, a 2.0 mA signal or de-energizing of the FAULT relay. The
FAULT status is available via the RS-485 serial communications port. (see Section 3-6
Terminal Connections). After a COPM FAULT, a COPM check is performed every ten
seconds until the obstruction is removed. Then the COPM check will resume checking
once per minute check.
WARNING – Dirty or partially blocked windows can significantly reduce the detector's field
of view and detection distance.
NOTE: Since the optical path is checked once per minute and it requires two check failures
to produce a FAULT, it may take up to two minutes for the unit to detect an obstruction.
Alarm Test
The FlameGard 5 UV/IR-E have a built-in Alarm Test feature. This test may be activated
via the serial communications port (see Section 3-6 Terminal Connections).
The Flame Detectors will immediately go into WARN and then into time delayed ALARM.
After two to ten seconds the Flame Detectors will activate the ALARM. A latching WARN
and/or ALARM will remain latched until reset.
Visual Indicators
Two light emitting diodes (LEDs) are visible through the IR window. LEDs are provided for
a visual indication that corresponds with the detector's outputs. The following blinking
sequence indicates the operating condition:
•
Timeout (10 seconds when the unit is first powered) – Green and red LEDs blinking
alternately.
•
Ready – Green LED that flashes off 1 second, every 5 seconds.
•
WARNING – Slow blinking red LED.
•
ALARM – Fast blinking red LED.
•
COPM FAULT – Slow blinking green LED.
•
Low Voltage FAULT – Fast blinking green LED.
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FlameGard 5 UV/IR-E