BS 5839-1:2017

BSI Standards Publication

Fire detection and fire alarm systems for

buildings

Part 1: Code of practice for design, installation, commissioning

and maintenance of systems in non-domestic premises
BS 5839-1:2017 BRITISH STANDARD

Publishing and copyright information

The BSI copyright notice displayed in this document indicates when the document was last issued.

© The British Standards Institution 2017

Published by BSI Standards Limited 2017

ISBN 978 0 580 93402 5

ICS 13.220.20; 13.320

The following BSI references relate to the work on this document:

Committee reference FSH/12/1
Draft for comment 16/30337833 DC

Amendments/corrigenda issued since publication

Date Text affected

© THE BRITISH STANDARDS INSTITUTION 2017 – ALL RIGHTS RESERVED

BRITISH STANDARD BS 5839-1:2017

Contents Page

Foreword iv
Section 1 General 1
1 Scope1
2 Normative references 2
3 Terms and definitions 3
4 Need for a fire detection and fire alarm system and type of system 10
5 Categories of system 11
6 Exchange of information and definition of responsibilities 13
7 Variations from the recommendations of this standard 15
Section 2: Design considerations 17
8 Relationship between system category and protected areas 17
9 Actuation of other fire protection systems or safety facilities 20
10 Systems in explosive gas or dust atmospheres 21
11 System components 21
12 Monitoring, integrity and reliability of circuits external to control equipment 23
Figure 1 – Sounder circuits 27
13 Detection zones 28
Figure 2 – Examples of search distances in an open area [see 13.2.3b)] 30
14 Alarm zones 30
Figure 3 – Alarm zones [see 14.2d)] 31
15 Communication with the fire and rescue service 32
16 Audible alarm signals 35
Figure 4 – Sound pressure levels [see 16.2.1a)] 39
17 Visual alarm signals 39
18 Fire alarm warnings for people who are Deaf and hard of hearing 40
19 Staged fire alarms 43
Figure 5 – Typical staff alarm arrangement 46
20 Manual call points 47
Figure 6 – Manual call points on escape routes [see 20.2d)] 49
21 Types of fire detector and their selection 49
22 Spacing and siting of automatic fire detectors 56
Figure 7 – Smoke detectors in pitched roofs [see 22.3d)] 61
Figure 8 – Detectors in top 10% of a void [see 22.3g)] 62
Figure 9 – Proximity of detectors to ceiling fittings [see 22.3i)] 62
Figure 10 – Partitions or storage on racks 63
Figure 11 – Ceilings 63
Figure 12 – Detector on perforated ceiling [see 22.3o)] 64
Figure 13 – Clear space around a detector [see 22.3p)] 65
Figure 14 – Spacing and siting of detectors on honeycomb and similar ceilings 65
Table 1 – Spacing and siting of detectors on honeycomb and similar ceilings 66
Figure 15 – Spacing and siting of detectors on ceilings with closely spaced structural beams or joists 66
Table 2 – Spacing and siting of detectors on ceilings with closely spaced structural beams or joists 67
Figure 16 – Siting optical beam detectors 69
Table 3 – Limits of ceiling height 71

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BS 5839-1:2017 BRITISH STANDARD

23 Control and indicating equipment 72

24 Networked systems 74
25 Power supplies 76
26 Cables, wiring and other interconnections 80
Figure 17 – Example of a networked fire alarm system 84
27 Radio-linked systems 85
28 Electromagnetic compatibility 87
29 Electrical earthing 89
Section 3: Limitation of false alarms and unwanted fire alarm signals 91
30 Responsibility for limitation of false alarms and unwanted fire alarm signals 91
31 Categories of false alarms 93
32 Acceptable rate of false alarms 94
33 Causes of false alarms 95
34 Design process for limitation of false alarms and unwanted fire alarm signals 96
35 Measures to limit false alarms and prevent unwanted fire alarm signals 97
Section 4: Installation 104
36 Responsibility of installer 104
37 Installation practices and workmanship 105
Figure 18 – Examples of screen connections for continuity 107
38 Inspection and testing of wiring 107
Section 5: Commissioning and handover 109
39 Commissioning 109
40 Documentation 111
41 Certification 113
42 Acceptance 114
43 Verification 115
Section 6: Maintenance 117
44 Routine testing 117
45 Inspection and servicing 118
46 Non-routine attention 123
Section 7: User’s responsibilities 128
47 Premises management 128
48 Logbook 129
Annex A (informative) Choice of appropriate category of fire detection and fire alarm system 130
Table A.1 – Choice of appropriate category of a fire detection and fire alarm system 130
Annex B (informative) Typical noise levels in buildings 132
Table B.1 – Typical occupational noise levels (Lp) 132
Annex C (normative) Control and transmission equipment for tactile alarm devices provided
 134
Annex D (normative) Method for calculating standby battery capacity 136
Annex E (informative) The selection and application of fire detectors 137
Figure E.1 – Flow chart for the selection of detector and application verification 138
Table E.1 – Detector selection 139
Table E.2 – Example fire risks 142
Table E.3 – Example avoiding false alarms 143

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BRITISH STANDARD BS 5839-1:2017

Annex F (informative) Model format for system logbook 144

Annex G (informative) Model certificates 157
Bibliography 158

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BS 5839-1:2017 BRITISH STANDARD

Foreword
Publishing information
This part of BS 5839 is published by BSI Standards Limited, under licence from The British Standards
Institution, and came into effect on 31 August 2017. It was prepared by Technical Subcommittee
FSH/12/1, Installation and servicing, under the authority of Technical Committee FSH/12, Fire
detection and fire alarm systems. A list of organizations represented on these committees can be
obtained on request to their secretary.

Supersession
This part of BS 5839 supersedes BS 5839:2013, which is withdrawn.

Information about this document

This is a full revision of the standard, and introduces the following principal changes:
a) In Clause 2:
1) BS 8591, Remote centres receiving signals from alarm systems – Code of practice replaces the
reference to BS 5979, which has been withdrawn; and
2) references have been added to:
• BS EN 54-21, Fire detection and fire alarm systems – Part 21: Alarm transmission and
fault warning routing equipment;
• BS EN 54-29, Fire detection and fire alarm systems – Multi-sensor fire detectors – Point
detectors using a combination of smoke and heat sensors;
• BS EN 54-30, Fire detection and fire alarm systems – Multi-sensor fire detectors – Point
detectors using a combination of carbon monoxide and heat sensors; and
• BS EN 54-31, Fire detection and fire alarm system – Part 31: Multi-sensor fire detectors
– Point detectors using a combination of smoke, carbon monoxide and optionally heat
sensors.
b) In Clause 3, the definition of “critical signal path” has been expanded to include transmission
equipment for the routing signals to alarm receiving centres and the definition of “false alarm”
has been changed to refer to “environmental false alarms”.
c) In Section 3 a new definition of “unwanted fire signal (UwFS)” has been added, taking into
account the effect on the fire and rescue service.
d) In 8.2 the multi-sensor detectors are now considered as one of the detection options for
Categories L3 and L4 systems and in escape routes for Category L1 systems. An informative note
explains the process of designing Category L2 systems.
e) In 11.2 and 20.2b), it is now recommended that a protective cover is fitted to a Type A manual
call point to help prevent false alarms.
f) 11.2 now recommends that alarm transmission and fault warning routing equipment should
conform to the requirements specified in BS EN 54-21.
g) 15.2 now recommends that alarm receiving centres to which fire alarm signals are relayed
should conform to BS 8591 and have in place an agreement with the appropriate fire and rescue
service to pass on fire signals from fire alarm systems at the monitored property.

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BRITISH STANDARD BS 5839-1:2017

h) 15.2 also includes a new recommendation that, where fire alarm signals are routed via the
routing equipment of an intruder alarm system, the standby power supplies for the routing
equipment should conform to 25.4.
i) In 19.2.2, it is acknowledged that, in premises, other than residential care homes, that generate
a high number of unwanted fire alarm signals, automatic transmission of a signal to an alarm
receiving centre may be delayed pending investigation of alarm signals from these devices.
j) A new subclause, 21.1.7 has been introduced specifically addressing video fire detectors,
re-grouping text which was in different subclauses in the 2013 edition of the code.
k) New text in 21.1.8 commentary explains detection principle choices involving single sensor
detectors and multi-sensor detectors.
l) Attention is drawn in Clause 22 to the need to consider field testing of hard-to-access detectors
when designing the system.
m) In 22.9 and Table 3, it is now recommended that the limits specified for ceiling heights should
only be used as guidance for vertical or flue-like structures, such as lift shafts and stairwells.
n) In 25.2, the recommendation to provide double pole isolation has been replaced with a
recommendation to provide local safe isolation. An informative note explains what is meant by
“special tool”.
o) In 26.2, the recommendations for cables, wiring and other interconnections have been
updated to reflect the currently available standards: BS EN 60702-1, BS EN 60702-2,
BS 7629-1 and BS 7846. In addition, the duration of survival of cables has been referred to the
tests in BS EN 50200 and BS 8434-2.
p) The heading of Clause 29, “Electrical safety”, has been replaced by the new heading “Electrical
Earthing”.
q) Section 3 has been expanded and introduces the concept of “unwanted fire alarm signals”. To
minimize the risk of false alarms and unwanted fire alarm signals, it recommends that manual
call points should be fitted with protective covers and that systems that incorporate connection
to an alarm receiving centre should have this connection disabled during the soak period.
r) In Clause 45, recommendations have been added for:
1) measuring the battery voltage;
2) testing of multi-sensor fire detectors;
3) for using different types of devices when carrying system tests; and
4) checking whether a suitable zone plan has been provided.
s) There is a new Annex E (informative), which gives advice regarding selection and application of
fire detectors.
t) Annex F in the 2013 edition, which gave guidance on visual alarm device illumination
characteristics, has been removed as it duplicated the information in the referenced code:
LPS CoP 0001 [1].
National building regulations [2, 3, 4] require fire detection and fire alarm systems to be installed in
many buildings at the time of construction. In addition, legislation requires that, where necessary
to safeguard relevant persons in case of fire, existing premises are equipped with “appropriate fire
detection and fire alarm systems”.
Although this standard makes recommendations for the provision of fire detection and fire alarm
systems in a wide variety of premises, reference to particular types of premises in Annex A does not

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BS 5839-1:2017 BRITISH STANDARD

necessarily mean that all such premises are required by law to have such systems installed. In certain
small premises, word of mouth or mechanical devices, such as rotary gongs, might constitute an
adequate means of giving warning to occupants in the event of fire. The need for a fire detection and
fire alarm system, and the nature of the system, is often determined by a fire risk assessment.
The fire and rescue authority can advise on the fire legislation that applies to any building. If a
fire detection and fire alarm system is to be installed, or modified, to satisfy the requirements of
legislation, early consultation with the authority or authorities responsible for enforcement of the
legislation might be appropriate.
The protection of property with a fire detection and fire alarm system could result in an insurance
company being prepared to offer a reduced premium, provided that the system is acceptable. Early
consultation with the insurer is thus advisable.
Fire protection is not to be confused with fire prevention or other fire precautions, and the provision
of a fire detection and fire alarm system can never be regarded as giving complete protection against
fire. A fire detection and fire alarm system is, however, likely to form an important component in
defence against fire, and can form part of a fire engineering solution. Advice on the likely need for
a fire detection and fire alarm system in certain premises is given in BS 9999. For advice on fire
engineering solutions, reference can be made to BS 7974 and PD 7974-4.
It has been assumed in the preparation of this British Standard that the execution of its provisions
will be entrusted to appropriately qualified and competent people, for whose use it has been
produced.

Use of this document

As a code of practice, this British Standard takes the form of guidance and recommendations.
It should not be quoted as if it were a specification and particular care should be taken to ensure that
claims of compliance are not misleading.
Any user claiming compliance with this British Standard is expected to be able to justify any course of
action that deviates from its recommendations.

Presentational conventions
The provisions of this standard are presented in roman (i.e. upright) type. Its recommendations are
expressed in sentences in which the principal auxiliary verb is “should”.
Commentary, explanation and general informative material is presented in smaller italic type, and does
not constitute a normative element.
Where words have alternative spellings, the preferred spelling of the Shorter Oxford English
Dictionary is used (e.g. “organization” rather than “organisation”).
The word “should” is used to express recommendations of this standard. The word “may” is used in
the text to express permissibility, e.g. as an alternative to the primary recommendation of the clause.
The word “can” is used to express possibility, e.g. a consequence of an action or an event.
Notes and commentaries are provided throughout the text of this standard. Notes give references
and additional information that are important but do not form part of the recommendations.
Commentaries give background information.

Contractual and legal considerations

This publication does not purport to include all the necessary provisions of a contract. Users are
responsible for its correct application.
Compliance with a British Standard cannot confer immunity from legal obligations.

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BRITISH STANDARD BS 5839-1:2017

Section 1: General

1 Scope
This part of BS 5839 provides recommendations for the planning, design, installation, commissioning
and maintenance of fire detection and fire alarm systems in and around buildings, other than
domestic premises. It does not recommend whether or not a fire detection and fire alarm system
should be installed in any given premises. Recommendations for fire detection and fire alarm systems
in domestic premises are given in BS 5839-6.
The term fire detection and fire alarm systems, in the context of this part of BS 5839, includes
systems that range from those comprising only one or two manual call points and sounders to
complex networked systems that incorporate a large number of automatic fire detectors, manual call
points and sounders, connected to numerous inter-communicating control and indicating panels.
The term also includes systems that are capable of providing signals to initiate the operation of other
fire protection systems and equipment (such as fire extinguishing systems, smoke control systems or
automatic door release equipment) or safety measures (such as shutdown of air handling systems,
closing of oil or gas valves or grounding of lifts). It does not apply to the other systems and equipment
themselves, or the ancillary circuits to interface with them. Recommendations for the planning,
installation and servicing of facilities for operation of certain fire protection systems by the systems
addressed within this part of BS 5839 are given in BS 7273 (all parts).
This part of BS 5839 does not cover systems whose primary function is to extinguish or control fire,
such as sprinkler or automatic extinguishing systems, even though they might have a secondary
alarm function; it does, however, cover the use of a signal from an automatic extinguishing system as
one initiating element of a fire alarm system (e.g. by use of a pressure or flow switch).
This part of BS 5839 does not cover voice alarm systems. Recommendations for voice alarm systems
and voice sounders are given in BS 5839-8.
This part of BS 5839 does not cover systems combining fire alarm functions with other non-fire
related functions. Recommendations for such integrated systems are given in DD CLC/TS 50398.
This part of BS 5839 does not cover the 999 (or 112) public emergency call system, or manually or
mechanically operated sounders.
This part of BS 5839 does not cover audible or visual way-guidance systems which are designed to
complement fire alarm systems.
Recommendations for fire detection and fire alarm systems in electronic data processing
installations and similar critical electronic equipment rooms are given in BS 6266, which provides
recommendations over and above those given in this part of BS 5839.
Recommendations for fire detection and fire alarm systems in hospitals are given in the NHS Estates
publications HTM 05-03 Part B [N1] (in England and Wales) or SHTM 82 [N2] (in Scotland).
This part of BS 5839 applies to extensions and alterations to existing systems, at least in respect of
the design, installation, commissioning and certification of the new work, albeit that the extended or
altered system might not, overall, conform to the recommendations of this standard.

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