System Sensor BS5839

Note: This document is based on the recommendatio ns of BS5839 Part 1: 2002. I t is intended only as a guide to the ap plication of ﬁre detection systems.

Reference must be made to relevant national and local stan dards.

Intelligent Fire Alarm Systems

1.10. REMOTE LEDS

Most system smoke detectors are equi pped with a terminal to

allow the connection of a remote LED. Remote L EDs are often

used outside bedroom doors in hotels s o that in case of a ﬁre,

it is easy for the ﬁre brigade to identif y the location of the ﬁre

without the need to enter every room in th e building. They

may also be used where a detector is concealed i n loft space,

for example, to provide a visual indication tha t the detector is

in an alarm state.

1.11. INTERFACE MODULES

Input and Output modules can be used to pr ovide an interface

between a ﬁre loop and a variety of ty pes of electrical

equipment. Output or control module s can be used to operate

sounders or shut down electrical equipme nt by command

from the panel in case of a ﬁre. Input or monit or modules are

used to monitor volt-free switch contac ts, for example from a

sprinkler supervisory switch o r an existing conventional ﬁre

panel. Conventional zone monitor modules ar e also available,

providing an interface between a zone o f conventional

detectors and an analogue ﬁre detec tion loop, and are often

used when existing conventional systems ar e upgraded.

1.12. PROGRAMMING OF INTELLIGENT FIRE AL ARM

PANELS

Most small intelligent systems can be prog rammed with

ease without the need for any specialised e quipment. The

control panel has an alphanumeric keypad, w hich is used to

enter data into the system. Typically a passwor d is required

to set the panel to ‘engineering mode’, allowing the panel to

be programmed. Many control panels have an ‘au to-learn’

facility, whereby the control panel polls ever y address on the

system, and detects which addresses h ave been used, and

what type of detector or module has bee n connected to each

address. As a default, the panel will usu ally programme all

the devices on the loop into the same zone. The use r can

then customise the system by entering how th e zones are

conﬁgured. The panel may give the user an opti on of how

modules are to be conﬁgured - for example whet her an input

module should trigger an alarm or a fault when ope rated and

whether the wiring is to be monitored for ope n circuit faults.

Other optional features may also be prog rammed using the

keypad. The sensitivity of each detec tor on the system can

be conﬁgured for high sensitivity i f the detector is installed

in a clean smoke-free area, or for low sensiti vity if the area

is subject to cigarette smoke, for example. T he pre-alarm

facility may be enabled or disabled.

Complex intelligent systems offer many u ser-programmable

features that can be time-consuming to en ter manually

using the keypad. In this case, many panels have the fa cility

to connect a portable PC by means of a ser ial data link.

The user is supplied with a specialised piece of s oftware,

which enables the entire conﬁguration o f the system to be

programmed into the PC, away from site if nec essary. It is

then a simple matter of temporarily conne cting the PC to the

control panel and downloading the system co nﬁguration to

the panel. Once the information has been dow nloaded, it is

permanently stored in the control pa nel, and the PC can be

removed.

1.13. ADVANTAGES OF INTELLIGENT SYSTEMS

• The wiring cost of a system c an be reduced by the use

of a single pair of wires for up to 198 devices includi ng

smoke and heat detectors, call point s, beam detectors,

input and output modules.

• Intelligent Systems allow t he location of a ﬁre to be

precisely located from the cont rol panel

• The use of looped wiring allows th e system to function

normally even with an open circuit in the loop wi ring

• The use of short circuit i solators allows correct

operation of most, if not all of the sys tem even with a

short circuit in the loop wiring

• Detectors are cons tantly monitored for correc t

operation

• The use of a ‘pre-alarm’ fea ture alerts staff to chec k

whether a ﬁre condition exists be fore the alarm is raised

• Different dete ctor sensitivities can be used f or diverse

applications

• The use of addressable loop -powered sounders allows

the same wiring to be used for sensors, call p oints and

sounders

• The use of monitor modules allow s contacts from

sprinkler switches, existing ﬁre alar m systems, ﬁre

dampers etc. to be monitored using det ector loop wiring

• The use of control module s allows sounder lines, air

conditioning systems, lifts et c. to be controlled or shut

down using detector loop wiring