bs5839 fire alarm systems

7/15/2019 BS5839 Fire Alarm Systems

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BS and Alarm systems for Buildings-Code of practice for system design, installation and servicing

BS 1:2002 Fire detection and Alarm systems forBuildings-

Code of practice for system design, installation and servicing

Due to the on going and continued advances in Fire Alarm System

Technology

and the changes in Building Design and Construction the previous

British Standard 5839:Part 1:1988 had become out of date.

Consequently the Standard taking into account these

advances/changes

made over the years has been revised.

1. GENERAL

BS 5839:Part 1:2002 like its predecessor provides guidance by

recommendations fromthe initial Planning Stage, through the Design, Installation,

Commissioning and

Final Maintenance of Fire Alarm Systems in and around buildings

other than

Domestic Dwellings, these being covered by Part 6 of the Standard.

It should be noted that the Standard does not recommend or identify

whether a

Fire Alarm System need be or should be installed within any given

premises. This

should/must be subject to, in the respect of new buildings, Fire

Precautions Act (1971)

and Building Regulations.



Existing Buildings consequently are subject to the Workplace

Regulations and the

subsequent Risk Assessment.

It should be noted that the Standard does not cover Extinguishing/Fire Control Systems,

Voice Alarms (BS5839:Part 8), 999 Public Emergency Call

Systems,

Audible/Visual Way Guidance Systems, Critical Electronic Systems

(BS 6266) or

Fire Alarm Systems covered under NHS Estates Publication HTM

82.

NHS Estates Publication HTM 82 generally calls for the

recommendations of

BS 5839:Part 1 but also contains its own requirements which may

be in variance from

the Standard.

With regard to existing Fire Alarm Systems the new Standard

generally applies toExtensions and Alterations of these system, at least in respects of the

Planning, Design,

Installation, Commissioning, Maintenance and Certification of the

new works. Albeit that

the extended/altered system might not, overall, comply with the

recommendations of the

Standard.

2. CATEGORIES OF SYSTEMBS 5839:Part 1:2002 like the 1988 Standard Categorises Fire Alarm

Systems to satisfy

one, or both, of two principle objectives…

The Protection of Life and The Protection of Property.



The 1988 Standard sub-categorized these objectives into the

following levels of

protection;

Life

L1:Automatic Protection Throughout the Premises.

L2:Automatic Protection as L3, but also including Defined areas

of High Risk.

L3:Automatic Protection along Escape Routes and all Rooms

opening onto these

Escape Routes.

M:Manual. (Manual Call Point)

Property

P1:Automatic Protection Throughout the Premises.

P2:Automatic Protection in Defined Areas of High Risk.

The new 2002 Standard has recognized and consequently identified

the need to expand

these categorises further and now include both L4 and L5 in the Lifecategory.

L4:Automatic Protection along Escape Routes.

L5:Automatic Protection in Defined Areas only.

I t should be noted that a very comprehensive and recorded record

of

Risk Assessment should be made if a system is to be designed and

categorized as L5 due to the implication and ramifications of a Fire Alarm

System being installed

for the protection of life with Automatic Detection ONLY

COVERING

DEFINED AREAS!



P1: All areas covered by Automatic Fire Detection.

If Manual Call Points are installed, i.e. Giving the

implication, that at times

the building will/may be occupied consideration must be

given to the provisionof adequate Audible Fire Alarm Sounders to warn the

occupants of an

activation of the Fire Alarm System.

All Systems installed for the Protection of Property must

have means of

remote indicating that the Fire Alarm System has activated.

Usually achievedby means of a Digital Communicator or the alike.

P2: Defined Areas of High Risk covered by Automatic

Fire Detection.

Like a P1 System if Manual Call Points are installed, the

provision of adequate

Audible Fire Alarm Sounders to warn the occupants of an

activation of the

Fire Alarm System must be installed. Plus the provision of remote signalling.

L1: All areas covered by Automatic Fire Detection.

L2: As an L3 System.

i.e. Automatic Fire Detection on Escape Route, Rooms

opening onto

Escape Routes, and including Defined Areas of High Risk.

L3: Automatic Fire Detection on Escape Routes, Rooms

opening

onto Escape Routes.



L4: Automatic Fire Detection on Escape Routes.

As well as only covering Escape Routes an L4 System does

not exclude

other Areas of Defined High Risk

L5: Automatic Fire Detection covering only defined

areas of High Risk.

As previously stated a Life System to this category must be

subject to a very

comprehensive and detailed and recorded Risk Assessment

due to the possible

ramifications of this type of system.

M or Manual.

These systems purely rely on possibly the most reliable and

effective

Fire Detection device for the protection of life in existence!

i.e. A Human Being.

Consequently this type of system requires the need of

Manual Call Point

“Break Glass” Units.

3. POSITIONING OF EQUIPMENT

There have been no discernable changes in the new standard

regarding the spacing and

coverage of Automatic Fire Detectors.

Smoke Detectors still can cover an overall area of 100 square

metres. Heat Detectors

like wise with an overall coverage of 50 square metres.

The standard it should be noted now recognizes the use of the newly

developed

CO (Carbon Monoxide) Detectors which it must be said can reduce

the causes of false



alarms, however like wise they may not detect a real fire condition,

thus it is

recommended that they are not used on their own but installed

interleaved with

optical detection.

The only major changes in recommendations for manual call points

is the change

of distance between call points to 45m. A further recommendation

concerns call points

located on stairways or landings. To aid in locating the possible area

of activation the

standards suggest that the call points can either located on theroutes/exits leading to the

Stairways/landings or on the landings. With either method it is

recommended that

the units are always connected to the same detection zone of

adjacent storey.

i.e.

0



4. AUDIBLE ALARM SIGNALS

The 1988 Standard called for a Minimum Alarm Sound Level of

65dB. The revised2002 Standard appreciates that a Sound Pressure Level difference of

2 to 3 dB is

only just perceivable by the human ear. Consequently the new

standard now calls for a

general level of 65dB in open areas with a minimum of 60dB at

specific points of limited

extent within the area.

A level of 60dB is now also acceptable in small enclosed spaces

such as Cellular Offices,

Stairways etc.

The requirement of 75dB at a bed-head is required if the intention is

to rouse a person

from sleep.

The new recommended minimum alarm sound levels must still takeinto account any

background noise which is in excess of 60dB with the requirement

that the Fire Alarm

Audibility Level should be at least 5dB above the Background

Noise.

The maximum Level of 120dB at any normally accessible point

should still not beexceed. If this is not attainable the recommendations require that

any Alarm Sounders

be supplemented with Visual Alarm Signals, such us Xenon

Beacons.



Should the protected premise be used for either Public

Entertainment, Retail or Similar

in which any background noise may be caused by Music etc. that is

greater than 80dB,

the new 2002 Standard recommends that in the event of a Alarm

Activation the Music

and alike be automatically muted by the Fire Alarm System.

Both the New and Old Standards recommend that there be at least 2

off individual

Alarm Sounder Circuits within the protected premises, even if only

1 sounder was on

the second circuit. This recommendation allows that in the event of

a Sounder Circuit

Failure that at least an alarm sounder would operate to draw theattention of the building

occupants to a Fire Condition.

Recommendations in the new standard in particular to larger areas

accessible to the



general public (typically areas of 4000sq m or more) or where in

excess of

500 members of the public are present that the Fire Alarm Sounders

within these

areas are distributed or interleaved across 2 or more sounder circuits. These individual

circuits not being contained within the same common cable sheath.

( i.e. Precluding the use of 4 Core Cable)

5. CONTROL EQUIPMENT

BS5839:Part 1:2002 recommends that the Control and Indicating

Equipment used for Fire Alarm Systems, including their associated power supplies

should confirm to the

requirements of EN54 Parts 2 and 4.

(Partly due to some recommendation included within the new



BS5839 Standard,

both parts 2 and 4 of EN54 are under review.)

A fundamental requirement with regard to Fire Alarm Control and

Indicating Equipmentconforming to EN54 is to limit the number of Automatic Devices

(Fire Detectors,

Manual Call Points, Interface Units etc.) controlled by a single

Micro-Processor within

the Control Panel to a Maximum of 512 Devices.

This generally limits Single Conventional non-addressable Fire

Alarm Panels to 16 Zones(larger panels are generally however made up of one or more

interlinking mother boards).

This application however, with regards to Addressable Panels limits

most single control

Panels to 4 Detection Loops.

This limitation can be over come with use of “Networked”Indicator Control Panels

distributing the Fire Alarm system amongst a number of “Sub-

Panels”, these sub-panels

usually being located remote from each other.

The practical use of this type of networked system may reduce the

cabling for the entire

system as the remote panels can be located within specific areas of

the buildings, particularly adjacent to the areas to which the connected detection

loops are protecting.

However there may be some instances, particularly in larger

addressable systems



here the use of Networked Systems may not be practical to achieve

the desired/required

number of detection loops.

BS5839:Part 1:2002 being only a guidance document therefore doesnot preclude the use

of Panels that do not confirm with the requirements of EN54.

Therefore Multi-Loop Panels

manufactured to confirm to the previous standard for panels

BS5839:Part 4:1988

can still be used if desired, subject to agreement between the Client

and the Designer. This

agreed variation must be recorded and noted on the DesignersDesign Certificate for the

system.

A major revision to the standard is the requirement for standby

power supplies. The

1988 standard related standby capacity to the type and occupancy of

the premises protected.

The 2002 standard recommends that sufficient backup capacity can

now be met by:

L Category Systems 24 Hours plus 30 minutes in alarm

should suffice.

P Category Systems should provide for any unoccupied

time of the protected

premise plus 24 hours up to a maximum of 72 hours plus

30 minutes inalarm. Should the 72 hour period expire and fault signal

should be sent to

the connected remote monitoring centre.



6. CABLING

Unlike the earlier standard where the use of Non-Fire Rated Cabling

would have been

acceptable for the Detection Circuits and Fire Rated Cables used for

theAlarm Circuits. The 2002 standard recommends the use of Fire

Rated Cables for Critical

Signal Paths, this includes both the Detection and Alarm Circuits.

Even though the

Indicating and Control Equipment is provided with means of a

“Standby Supply”

(i.e. Battery Backup) the normal Electrical Mains Supply to the

equipment is nowconsidered as a Critical Circuit and consequently should be

adequately protected from the

effects of fire.

Cabling for Critical Signal Paths are now categorized to two

standards;

Standard Grade Fire Resisting Cables, generally of the Soft Skinned type,

FP200/Firetuf and

the similar.

Enhanced Grade

Until recently only M.I.C.C. Cable, but now includes both

FP200 Plus

& Firetuf Plus Soft Skinned cables

Standard Cabling in most instances will usually be adequate for a

great majority of installations.

Detection, Alarm Circuits etc.



Apart form the previously mentioned FP200 and FireTuf, Fire Rated

Steel Wired

Armoured cable would also be acceptable particularly for external

applications.

Where a buildings Fire Alarm System incorporates a four or more

phased evacuation

procedure, or the building is greater than 30metres in height, or

being identified by a

Fire Risk Assessment or as part of a Fire Engineered solution which

compensates for

shortfalls in building construction than the use of Enhanced cabling

should be used.

The standard recommends the use of Enhanced Grade cabling for

Network

Communication Cables between networked Panels.

However if all the following criteria can be met standard Grade and

Communications

Cables (i.e. Beldon Type Cables etc.) would be acceptable;

1. The Network is configured as a loop; and

2. There is diverse routing of both the incoming and out

going circuits of the

Network Loop; and

3. There will be no loss of communication to any sub-panel

in the event of asingle open or short circuit on the Network Loop.



7. REMOTE MONITORING

BS 5839:Part 1:2002 has identified possible inherent faults with the

current methods

of providing Fire Alarm Activations to Remote Monitoring Centres

by means of

Digital Communicators and consequently provides the

recommendations to alleviate theshort comings of current equipment;

All interconnections including the telephone line should be

monitored (usually only

achievable by means of BT Redcare or similar).

Interconnecting cables to be run through areas of low Fire Risk.

Digital communicator Unit located within area of low Fire Risk or

protected by means

of Automatic Fire Detection.

Standby Capacity of any communicator should match that as of the



Fire Alarm System

and should be a minimum of 24 hours. Which would preclude the

use of

security Digital Communicators which only usually have a backup

capacity of 8 hours.

8. FIRE ALARM SYSTEM DESIGN

BS5839:Part 1:2002 has identified, in particular for new Fire Alarm

Systems the need to

manage and limit the numbers of false alarms.

Consequently the revised/updated standard recommends and

emphasizes for a moredetailed roll and resultant responsibility for the designer of new Fire

Alarm System.

The standard as previously stated does not identify the need for a

fire alarm system. This

is the responsibility of the purchaser, be they a Developer or Final

User of a building. This

process will evolve consultation with the Fire Authorities, Building

Control Officers and Insurers.

The decision/consultation process for new buildings would progress

through and with

reference to general compliance to;

FIRE PRECAUTIONS ACT (1971)

BUILDING REGULATION

Which would identify and provide solutions to enable the building

to be issued with the

necessary resultant Fire Certificate.

From this point and for existing buildings this decision/consultation



process would

continue with reference to the "WORK PLACE REGULATIONS"

and the resultant

RISK ASSESSMENT would identify the need (if any) for the

provision of aFire Alarm System.

Upon completion of the decision process the purchaser should be in procession of all

the necessary information to identify the need and category for a fire

alarm system. This

information should then be passed to the Designer whom, with

regard to the

identified Risk and Category of System, provide a suitable design

inline with the

recommendation of the new standard.

The ultimate responsibility for the need and category of the system

solely rest with the

purchaser. However the designer can propose a category should the

situation arise. But



the final decision must be taken by the client/purchaser.

The proposed new Fire Alarm System must take into account all the

findings of the

provided Risk Assessment which has identified the category of thenew system. Vital

importance in the design is the need to identify and

resolve/eliminate any potential causes

of false alarms.

Any variations from the standard should be agreed between the

Designer and the

Purchaser. These if agreed variations should be documented.

Upon completion of the design a signed DESIGN CERTIFICATE

would be submitted

detailing all aspects of the final design including any agreed

variations from the standard.

This Certificate will form an integral part of the proposed system

and must be forwarded

through the entire process from the installation, commissioning andfinal acceptance by

the purchaser.

9. INSTALLATION

BS 5839:Part 1:2002 in keeping with the recommendation about

responsibilities for both

the Purchaser/Client/User as well as the system Designer has also

identified the need for

the Competency and subsequent responsibilities for both theInstallation and

Commissioning Engineers.

The installation engineer(s) responsibility extends to ensuring that

they, as well as any



sub-contracts they use carry out the installation in compliance to

both the new standard

and the designers design.

They also have a responsibility to make the designer aware of any building features that

the designer was not or could not have known which would effect

the design. They

should not however alter the design with out written confirmation

from the designer.

The installers responsibility also extends to ensuring compliance for

installed componentsto both manufactures and the British Standards recommendations.

Consequently any installer engaged in the installation of fire alarm

systems should be fully

conversant with BS 5839:part 1:2002.

The installation and in particular the cabling should be installed to

the requirements of BS 7671 (Wiring Regulations)

Fixing of cables should be as per the manufactures requirement,

generally ensuring that

Metal Fixings are used where necessary (i.e. Stainless Steel Cable

ties when securing

below steel cable trays). Particular attention should be made to the

use of metal fixing

within PVC Trunking, where the trunking forms the only means of support for the Fire

Alarm Cabling installed within.

Cabling installed should meet either Standard or Enhanced Grade

dependent on both the



designers specification and the probable intended routing of the

cables as well as any

system and cabling requirements regarding Earth/Screening

continuity as required by the

manufacture.

As with any electrical or mechanical installation protection and fire

stopping should always be

considered.

As per BS 7671 (Wiring Regulations) all the cabling should be

tested for

insulation resistance. BS 5839:Part 1:2002 recommends that thesetest should always be

carried out to prevent damage to equipment with all equipment

disconnect.

Also it is recommended (which may be at variance with the wiring

regulations) that thes

test be carried out using a Test Instrument set at 500v.

The standard also calls for the mains supply to the Indicator andControl Equipment and

any other relevant supplies associated with the Fire Alarm System

should be tested for

both Earth Continuity and Earth Fault Loop Impedance.

The field wiring and most particularly Loop Wiring to be tested for

Circuit Resistance.

All these test must be recorded for the system final documentation

plus a copy of the

results must also be forwarded to the commissioning engineer.



Once the installation and test are completed the installation engineer

would sign of the

system and provide the next Certificate for the system, the

Installation Certificate.

10. COMMISSIONING

Once the Fire Alarm System has been installed the system should be

set-up and

functionally tested, the commission.

Like the installer the Commissioning Engineer should be competent

with a good

knowledge of Fire Alarm Design, False Alarms and their Avoidanceand

Fire Alarm Installation. The engineer should be able to deal directly

with the

purchaser/client and other interested parties.

To facilitate the commissioning all documentation for the Fire

Alarm System,

System Specification, Design Documents (including a copy of the

Final Design Certificate),consultation documents, Original and the Installers “As Fitted”

Drawings and the installers

Test Records must be made available to the Commission Engineer.

Apart from carrying out any programming of any addressable Fire

Alarm Panels, the

commissioning engineer must ensure that the system is fully

functionally tested.

Call points, Automatic Detectors, Interfaces etc. operate and

indicate correctly, audibility

levels should be measured for sounders and where Voice Alarms are

installed their



intelligibility is satisfactory. Signals required to be transmitted to

“Alarm Receiving Centres” are correctly received. Cause and

Effects of the system

are functionally checked and operate as per the specification. They

should also note anychanges to the building since the original design that may effect the

design and

performance of the system. The engineer would also check that the

installed components,

Manual Call Points, Detectors, Control and Indicating Equipment,

Visual Alarms are

suitable and correctly sited and consequently acceptable to the

relevant clauses of theBritish Standard.

Also recommend by the standard and to be checked by the

Commission Engineer is that

a suitable Zone Plan is displayed.

During the commission the engineer would also inspect and check

the suitability of theMains Supply, Standby Power (i.e. Battery Backup) functions

correctly both on and off

load and has sufficient backup capacity. There is also a

recommendation that the batteries

are labelled with the date of installation.

The engineer would also check that the correct/specified cable has

been installed

(as as far as it is reasonably practical to ascertain), as well as theworkmanship of the

installation.

As far as reasonably practical to ascertain the engineer would also

check for immunity to



false alarms.

Any non-compliances with the design should be noted and the

designer informed.

Upon satisfactory completion of the system commissioning

following a " SOAK TEST"

(during which time the system would be deemed as not operational)

the system would

be signed off by the engineer and a Commissioning Certificate

submitted.

Like both the Design and Installation Certificates all details pursuantto the Design

including any agreed variations from the new standard would be

noted on the

Commission Certificate, all of which should be consistent through

all the Certificates.

11. FIRE ALARM SYSTEM ACCEPTANCE

The final stage of the installation process, not taking into account

the necessary ongoingmaintenance of the system would be the handover of the system to

the

purchaser/client/user.

Arrangements for the handover should include for full training to the

"Users Responsible Person" on the operation of the system and the

provision of

full documentation for the system. Including all the originalconsultation documents,

design documentation, “As Fitted” installation drawings, a system

Log Book,

Maintenance Instructions and the Design, Installation and

Commissioning Certificates to



be handed to the purchaser/client/user.

Once the purchaser/client/user has formally accepted the Fire Alarm

System they will sign

the Final Acceptance Certificate as evidence of their satisfaction of the system.

It should be noted that the new standard has a strong

recommendation that a minimum

and this duration may/should be increased for larger systems that the

new system be

left on a “Soak Test” for at least a week before the system is

certified as being functionaland can consequently be formally handed over to the

purchaser/client/user.

12. FIRE ALARM SYSTEM MAINTENANCE

BS 5839:Part 1:2002 provides recommendations and consequently

suggested

procedures regarding the Maintenance/Servicing of Fire Alarm

Systems.

The new Standard recognizes that modern Fire Alarm Systems may

incorporate a high

degree of monitoring, so that any faults that develop are indicated

automatically, usually

on the Control and Indicating Equipment. These fault indications are

only effective if they

are identified and appropriate action taken.

Consequently a need has been identified that the monitoring of these

systems should be

carried out by the Fire Alarm System Users nominated Responsible

Person, this person



should be some one whom is normally employed within the

protected premises.

The Responsible Person shall ensure that Routine Tests of the Fire

Alarm Systemare carried out. Every week, a Manual Call Point should be operated

during normal

working hours, it should be confirmed that the Control Equipment

functions correctly,

Alarm Sounders Sound and should a link to a Remote Monitoring

Centre be connected

that a signal is correctly received. The weekly test should be carried

out at approximatelythe same time each week with the alarm sounders not operating for

longer than 1 minute.

A different Call point should be tested each week so over a period

all points are tested.

(i.e. 80 Call Points would take 80weeks to test)

Premises provided with means of Standby Power Supplies

(Generator) should be test

Monthly by simulating failure of the normal power supply.

As previous identified provision of a Fire Alarm System both new

buildings would be

subject to a consultation process with reference to:

Fire Precaution Act

Building Regulations

and as well for both new and existing buildings:

Work Place Regulations

resultant Risk Assessment



The Fire Precautions (Workplace) Regulations require that any

equipment and devices

provided in respect of the regulations SHALL be subject to a

suitable system of

maintenance and be maintained in an efficient state, in efficientworking order and in good

repair. Failure to provide this may warrant the user liable for

prosecution.

The Health & Safety (Safety Signs & Signals) Regulations 1996

requires that

Fire Alarm warning system must be provided with a guaranteed

emergency supply inevent of interruption of the normal mains supply, unless the hazard

has thereby been

eliminated. Consequently systems not having a standby power

supply

(i.e. Battery Backup) are no longer legal!

BS5839:Part 1:2002 recommends that maintenance of Fire Alarm

Systems be carriedout by Competent Persons (i.e. Maintenance Organisations).

A Periodic Service Inspections of a period not exceeding six

months, subject to a

Risk Assessment and agreement between all interested parties this

period may be

reduced.

Tests and Checks should include operation of one Manual Call Point

or Detector oneach Circuit, changes that may effect the operation of the system,

signals if connected

to Remote Monitoring Centre.

An annual inspection (over a 12month period) to include a complete



function and

operational test of all equipment connected and interfaced to the Fire

Alarm System,

including all “Cause and Effects”.

Upon satisfactory completion of the Inspection;

All Devices operated correctly

Transmission to Remote Monitoring Centre correctly received

Analogue Levels on Addressable Equipment within acceptable

range

Radio Signal Strength for Radio Equipment within acceptable

rangeCause & Effect programme proved

Standby Power Supply Capacity Satisfactory

a Inspection and Service Certificate would be issued with any

recommendations noted.

During the annual inspection confirmation of the number of false

alarms would be checkedin the Log Book to see if within acceptable limits.

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