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.

Application Guide

2.6 MAINTENANCE OF FIRE DE TECTORS

Caution: Prior to carrying out any mai ntenance or testing

on a ﬁre alarm system, the relevant authorit ies and staff

should be notiﬁed.

Over time, the sensitivity of a smoke detec tor can change

owing to a build-up of dirt in the detector cha mber. In most

modern detectors this effec t is slowed by the inclusion of drift

compensation functions, however the build u p can still lead to

a risk of false alarms or change in the detect or sensitivity.

The frequency of maintenance requireme nts on a detector will

depend on site conditions, obviously the di rtier the site the

more frequent maintenance will be require d. The optimum

frequency for a given site should be determin ed over a period

of time after the commissioning of the ﬁre sys tem.

All System Sensor detectors ( smoke, heat, or multi-criteria )

are designed such that they can be easily disman tled for

maintenance. Instructions are give n for maintenance in the

instruction manual supplied with each de tector. Normally it

is sufﬁcient to use compressed air or a vac uum cleaner to

remove dust from the detector chamber.

Once maintenance on a ﬁre detection sys tem has been

completed, it should be re-tested.

2.7 ROUTINE FUNCTIONAL TE STING OF FIRE DETECTORS

BS5839 Part 1: 2002 give s a range of recommendations

regarding routine testing of a ﬁre detec tion system.

A weekly test should be carried out on a ﬁre de tection system

by activating a manual call point to ensure tha t all ﬁre alarm

signals operate correctly, and that the ap propriate alarm

signals are clearly received. This test sho uld be carried out at

approximately the same time each week, using a dif ferent call

point in rotation.

In order to comply with BS5839 Pa rt 1: 2002, periodic

inspections, servicing and funct ional tests of the ﬁre alarm

system should be carried out at inter vals determined by

an assessment of the site and type of sy stem installed, not

normally greater than six months.

It is recommended to perform regular f unctional tests on all

ﬁre detectors annually. These annual tes ts may be carried

out over the course of two or more servic e visits during the

twelve-month period.

System Sensor detectors include va rious means of testing the

system without using smoke, dependent on the de tector range

being tested, including magnet switches and la ser test tools.

Codes and standards (in the UK B S5839 Part 1:20 02, Section

6) now require functional tests t o introduce smoke through

the smoke detector vents and into the sensi ng chamber. It also

calls for heat detectors to be tested b y means of a suitable

heat source, and not by a live ﬂame. CO ﬁre detect ors now

also need to be functionally tested by a met hod that conﬁrms

that carbon monoxide can enter the chambe r.

Many installers use a set of equipment tha t consists of a

complete range of test tools that locat e on the end of the pole

such as those available from No Climb Produc ts Ltd. (www.

noclimb.com) in order to aid compliance wit h codes. Tools

exist for testing smoke, heat, and CO ﬁre de tectors, whilst

also enabling them to be accessed and removed at heig hts up

to 9 meters from the ground.

Using functional test equipment, alo ng with those

maintenance tools available from Syste m Sensor, should

ensure that the system remains at its opt imum operation for

many years.