Spectrex 20/20SH - Hydrogen Flame Detector - Manual (Page 18)

Spectrex Inc. - SharpEye TM Hydrogen (SH) Flame Detector Manual – TM 784600, Rev. A, May 2005
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4 The alarm outputs will be activated as long as the alarm conditions are present
and will stop approximately 5 seconds after the fire is no longer detected.
4.2.1 Optional latching
The detector includes a latched alarm output capability, which operates according
to the programmable function. 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 (the
Accessory Relay will be latched only when the function “Alarm Latch” at YES (see
table 6)).
4.2.2 Built-In-Test (BIT)
Successful Manual BIT will activate the following outputs according to
programmable function (see table 6).
Alarm BIT at Yes
• The Alarm Relay will be activated for 3 sec.
• The 4-20mA output will provide 15mA for 3 sec.
Alarm BIT and Accessory
BIT at Yes
• The Accessory & Alarm Relays will be activated
for 3 sec.
• The 4-20mA output will provide 15mA for 3 sec.
Accessory BIT at Yes
Alarm BIT at No
• The Accessory Relay will be activated for 3 sec.
• The 4-20mA output will provide 10mA for 3 sec.
4.2.3 Accessory Relay as EOL
The accessory relay is used as End of Line relay. In this case, the accessory relay
is active as long as the detector is not in its FAULT state.