Smoke Alarm User Manual

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Note: This document is based on the recommendations of BS5839 Part 1: 2002. It is intended only as a guide to the application of fire detection systems.
Reference must be made to relevant national and local standards.
Intelligent Fire Alarm Systems
1.10. REMOTE LEDS
Most system smoke detectors are equipped with a terminal to
allow the connection of a remote LED. Remote LEDs are often
used outside bedroom doors in hotels so that in case of a fire,
it is easy for the fire brigade to identify the location of the fire
without the need to enter every room in the building. They
may also be used where a detector is concealed in loft space,
for example, to provide a visual indication that the detector is
in an alarm state.
1.11. INTERFACE MODULES
Input and Output modules can be used to provide an interface
between a fire loop and a variety of types of electrical
equipment. Output or control modules can be used to operate
sounders or shut down electrical equipment by command
from the panel in case of a fire. Input or monitor modules are
used to monitor volt-free switch contacts, for example from a
sprinkler supervisory switch or an existing conventional fire
panel. Conventional zone monitor modules are also available,
providing an interface between a zone of conventional
detectors and an analogue fire detection loop, and are often
used when existing conventional systems are upgraded.
1.12. PROGRAMMING OF INTELLIGENT FIRE ALARM
PANELS
Most small intelligent systems can be programmed with
ease without the need for any specialised equipment. The
control panel has an alphanumeric keypad, which is used to
enter data into the system. Typically a password is required
to set the panel to ‘engineering mode’, allowing the panel to
be programmed. Many control panels have an ‘auto-learn’
facility, whereby the control panel polls every address on the
system, and detects which addresses have been used, and
what type of detector or module has been connected to each
address. As a default, the panel will usually programme all
the devices on the loop into the same zone. The user can
then customise the system by entering how the zones are
configured. The panel may give the user an option of how
modules are to be configured - for example whether an input
module should trigger an alarm or a fault when operated and
whether the wiring is to be monitored for open circuit faults.
Other optional features may also be programmed using the
keypad. The sensitivity of each detector on the system can
be configured for high sensitivity if the detector is installed
in a clean smoke-free area, or for low sensitivity if the area
is subject to cigarette smoke, for example. The pre-alarm
facility may be enabled or disabled.
Complex intelligent systems offer many user-programmable
features that can be time-consuming to enter manually
using the keypad. In this case, many panels have the facility
to connect a portable PC by means of a serial data link.
The user is supplied with a specialised piece of software,
which enables the entire configuration of the system to be
programmed into the PC, away from site if necessary. It is
then a simple matter of temporarily connecting the PC to the
control panel and downloading the system configuration to
the panel. Once the information has been downloaded, it is
permanently stored in the control panel, and the PC can be
removed.
1.13. ADVANTAGES OF INTELLIGENT SYSTEMS
• The wiring cost of a system can be reduced by the use
of a single pair of wires for up to 198 devices including
smoke and heat detectors, call points, beam detectors,
input and output modules.
• Intelligent Systems allow the location of a fire to be
precisely located from the control panel
• The use of looped wiring allows the system to function
normally even with an open circuit in the loop wiring
• The use of short circuit isolators allows correct
operation of most, if not all of the system even with a
short circuit in the loop wiring
• Detectors are constantly monitored for correct
operation
• The use of a ‘pre-alarm’ feature alerts staff to check
whether a fire condition exists before the alarm is raised
• Different detector sensitivities can be used for diverse
applications
• The use of addressable loop-powered sounders allows
the same wiring to be used for sensors, call points and
sounders
• The use of monitor modules allows contacts from
sprinkler switches, existing fire alarm systems, fire
dampers etc. to be monitored using detector loop wiring
• The use of control modules allows sounder lines, air
conditioning systems, lifts etc. to be controlled or shut
down using detector loop wiring