Spectrex 20/20SH - Hydrogen Flame Detector - Manual (Page 21)

Spectrex Inc. - SharpEye TM Hydrogen (SH) Flame Detector Manual – TM 784600, Rev. A, May 2005
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4.3.3 Alarm Delay
The detector is equipped with an Alarm Delay option, which provides
programmable time delays of 0 to 30 sec. with eight (8) fixed settings at: 0, anti-
flare, 3, 5, 10, 15, 20, and 30 sec. When an Alarm (Detection) level condition is
encountered, the detector delays the execution of the Alarm output’s relay by the
specified period of time. The detector will then evaluate the condition for 3 sec. 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 Alarm delay
option will affect the output relay and the 4-20mA. The LEDS will indicate warning
level during the delay time only if the fire condition exists.
ANTI FLARE
Anti Flare mode is selected to prevent false alarm in locations where fast flares
may be present. The Time delay for fire alarm in this mode is from 2.5 to 15 sec.
(mostly less than 10 sec.).
Table 8: Time delay
Delay (sec.)
0
A* -- anti-flare
3
5
10
15
20
30
* Default
Note: The new FM approval from January 2003 does not allow using 20 and 30
second delay.
4.3.4 Addresses Setup
Refer to TM784050 for instructions for defining the addresses of the detectors.
The detector provides up to 247 addresses that can be used with RS-485
communication link.