Spectrex 20/20MU - Mini Flame Detector - Manual (Page 23)

Spectrex Inc. - SharpEye TM ML & MU Flame Detector Manual – TM 767100, Rev. A, April 2005
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4.2.1 Optional latching
The detector has an optional latched alarm output capability, which operates
according to the programmable function. If selected, upon the detection of a fire,
the detection signal is latched until manually reset (disconnecting the power supply
or performing a manual BIT). Latching affects the ALARM RELAY, 4-20mA output,
the ALARM LED.
4.2.2 Built-In-Test
When the programmable function “Alarm BIT” at YES, successful Manual BIT will
activate the alarm relay for 3 sec. and the 4-20mA output will provide 20mA for 3
sec.
4.3 Detector Mode Setup
4.3.1 Detector setting
See Section 4.3.3 for default factory settings
The 20/20ML and 20/20MU incorporates several functions that can be set by the
customer using Spectrex Host software, which will be supplied for each detector
shipment
The Host software enables you to change functions as described in 4.3.2. Refer to
manual TM 784050 for programming instructions.
4.3.2 Detector’s various functions
a. Sensitivity Ranges
The detector offers two (2) sensitivity settings. The settings refer to the
gasoline fire of 1ft
2
from
b. Alarm Delay
The detector is equipped with an Alarm Delay option, which provides
programmable time delays of 0 to 30 seconds with eight (8) fixed settings:
0, anti-flare, 3, 5, 10, 15, 20, and 30 seconds.
The Alarm delay option will affect the alarm relay and the 4-20mA output
When an Alarm (Detection) level condition is encountered, the detector
delays the execution of the Alarm output relay by the specified period of
time. The detector will then evaluate the condition for 3 seconds. If the
Alarm level is still present, the Alarm outputs will be activated. If this
condition no longer exists, the detector will return to its standby state.. The
LED will indicate warning level during the delay time only if the fire condition
exists.