User manual

4 LST700 SERIES USER MANUAL • Approved Document No. DFU7001003 Rev 4
LST700 SERIES FIRE ALARM PANEL
The primary purpose of a fire alarm system is to provide early warning of a fire so that building
occupants can be evacuated and action taken to stop the fire as soon as possible - all according
to a predetermined plan.
Alarms may be raised automatically, by smoke or heat detectors, or manually by a person operating
a manual call point.
To ensure an alarm is dealt with in an orderly manner, it is important to know where the alarm is
coming from. To aid this function, fire alarm systems are usually split into zones, each covering a
different area of a building.
When an alarm has been raised, the fire alarm panel responds by indicating the zone in which the
alarm
has occurred and activating all relevant sounders, bells and other alarm outputs to provide a
warning of the fire.
Additional alarm outputs available on this fire alarm panel (which may or may
not be used depending on the requirements of the site) are:-
■ A Remote Output: this output is automatically activated whenever the fire panel is in alarm and
is returned to normal when the alarm sounders are silenced.
■ An Auxiliary Output: this output is activated when the panel is in alarm and is returned to
normal when the panel is reset. It may be used to signal an alarm condition to other parts
of the fire alarm system. If used, its function will be declared on the System Set-up Data
Chart on page 13 of this user manual. This output may be disabled if required.
The building’s fire management plan should always be executed when the fire alarm panel goes into
alarm. See user responsibilities section on page 5 for further details.
Fault monitoring
For obvious reasons, the reliability of the fire alarm system is paramount. To this end, the fire
alarm panel continuously monitors all connections between detectors, manual call points and
sounders and also checks its own power supply and back-up batteries for faults.
If a fault is detected anywhere on the system, the panel responds by illuminating one or more of
the fault light(s) located on the front of its enclosure and sounding its internal fault buzzer. The
panel’s fault output is also activated, sending notification of the fault (if connected) to a remote
manned monitoring centre or other electronic equipment, as required.
Delays
Certain zones on a fire alarm system can be prone to conditions that lead to frequent and una-
voidable false alarms, a common example being a waiting room filled with cigarette smoke. In
areas such as these, it may be acceptable to delay the activation
of the alarm sounders and other
outputs to give a responsible person time to investigate the cause of the alarm. If the cause is found
to be a true fire hazard, the delay can be overridden. In the event of a false alarm, the panel can be
reset. Should the delay period expire without any user intervention, the alarm sounders will automati-
cally sound to evacuate the premises. To ascertain if any delays have been programmed into the
panel,
refer to the System Set-up Data Chart on page 13.
Disablements
In abnormal conditions, certain parts of the fire alarm system can be temporarily turned off (disa-
bled) to suit prevailing conditions. For example, if there is a risk of a false alarm occurring in a
zone, say from vehicle exhaust smoke in a loading bay, it is possible to disable that zone during
the risk period, then enable it again afterwards. Another example is the disablement of outputs
during a routine test or temporary fault.
Coincidence
This feature should only be used where it is acceptable to the Authority Having Jurisdiction. The
function is intended to control the effects of a false alarm but only when this is likely to have a
significant impact, such as the activation of fire suppression systems.
FIRE ALARM SYSTEMS - AN OVERVIEW