Deciding Catagory Of Fire Alarm

[Adi]

BS5839 tells you what category, give us a minute ill find the page number.

Just had a look and part 1 has some guidance which could be used page 115. Not as good as Part 6 thats more informative. Gives you more ammo if installing in flats, b&bs ect...

Part 1's guidance seems more in favour of P systems but i rarely get asked to install a fire system because of insurance reasons, more for life saftey. So i usually quote an L system at category L3 as minimum, if regs or risk assessment says otherwise then obviously up the ladder we go.

Another thing, Are L5 systems supposed to be designed or agreed with technical fire engineers or something.

Just had a look and part 1 has some guidance which could be used page 115. Not as good as Part 6 thats more informative. Gives you more ammo if installing in flats, b&bs ect...

Part 1's guidance seems more in favour of P systems but i rarely get asked to install a fire system because of insurance reasons, more for life saftey. So i usually quote an L system at category L3 as minimum, if regs or risk assessment says otherwise then obviously up the ladder we go.

Another thing, Are L5 systems supposed to be designed or agreed with technical fire engineers or something.

Page 17 of part 1 is quite informative, so mix and match that with annex A and a risk assessment you will be on the right side of the regs, the law and your conciense(however you spell it) no funny remarks with I T.

[Guest Thunderfingers]

Just so as all can reference from the horses mouth!

5.1.1 Introduction

Fire alarm systems may be installed in buildings to satisfy one, or both, of two principal objectives, namely protection of life and protection of property. The objectives may differ in time or place. Other possible objectives exist, such as protection against business interruption and protection of the environment; these are likely to be satisfied by the recommendations in this standard for protection of property.

Because of the great variety of applications for systems covered by this part of BS 5839, systems are divided into a number of different Categories, as described in 5.1.2, 5.1.3 and 5.1.4.

5.1.2 Category M Systems

Category M systems are manual systems and, therefore, incorporate no automatic fire detectors.

5.1.3 Category L Systems

Category L systems are automatic fire detection systems intended for the protection of life. They are further subdivided into:

a) Category L1: systems installed throughout all areas of the building.

The objective of a Category L1 system is to offer the earliest possible warning of fire, so as to achieve the longest available time for escape;

b) Category L2: systems installed only in defined parts of the building.

A Category L2 system should include the coverage necessary to satisfy the recommendations of this standard for a Category L3 system; the objective of a Category L2 system is identical to that of a Category L3 system, with the additional objective of affording early warning of fire in specified areas of high fire hazard level and/or high fire risk;

c) Category L3: systems designed to give a warning of fire at an early enough stage to enable all occupants, other than possibly those in the room of fire origin, to escape safely, before the escape routes are impassable owing to the presence of fire, smoke or toxic gases;

NOTE To achieve the above objective it will normally be necessary to install detectors in rooms which open onto an escape route

(see 8.2).

d) Category L4: systems installed within those parts of the escape routes comprising circulation areas and circulation spaces, such as corridors and stairways.

The objective of a Category L4 system is to enhance the safety of occupants by providing warning of smoke within escape routes;

NOTE The installation of detectors in additional areas is not precluded, and the system could then still be regarded as a Category L4 system.

e) Category L5: systems in which the protected area(s) and/or the location of detectors is designed to satisfy a specific fire safety objective (other than that of a Category L1, L2, L3 or L4 system).

Often the design is based on a fire risk assessment or forms part of a fire engineering solution. Protection may be provided to compensate for some departure from normal guidance elsewhere or as a part of the operating system for a fire protection system. Such a system could be as simple as one that incorporates a single automatic fire detector in one room (in which outbreak of fire would create undue risk to occupants, either in the room or elsewhere in the building), but the system could comprise comprehensive detection throughout large areas of a building in which, for example, structural fire resistance is less than that normally specified for buildings of that type;

NOTE The protection afforded by a Category L5 system might, or might not, incorporate that provided by a Category L2, L3 or L4 system.

5.1.4 Category P systems

Category P systems are automatic fire detection systems intended for the protection of property. They are further subdivided into:

a) Category P1: systems installed throughout all areas of the building.

The objective of a Category P1 system is to offer the earliest possible warning of fire so as to minimize the time between ignition and the arrival of fire-fighters;

B) Category P2: systems installed only in defined parts of the building.

The objective of a Category P2 system is to provide early warning of fire in areas of high fire hazard level, or areas in which the risk to property or business continuity from fire is high.

5.1.5 Selection of category

Even in buildings with comprehensive fire detection, the provision of manual call points will still normally be of great value; people in the vicinity of a fire will normally be aware of the fire, and able to raise the alarm by use of a manual call point, before it is detected automatically.

If a system is intended to fulfil the objectives of more than one Category of system, then the system needs to comply with the recommendations for each of the Categories. For example, a system whose sole purpose is to provide property protection throughout the building (a Category P1 system) might not need to give an alarm

signal of sufficient audibility to rouse all occupants who might sleep in the building. If, however, the system were also installed for the purpose of life safety (a Category L system), sufficient fire alarm sounders to rouse sleeping occupants would be necessary.

This part of BS 5839 does not recommend which Category of system needs to be installed in any given premises. The various system Categories need to be regarded as a

[Adi]

From this then I would take it that the design engineer is capable of specifying a category for the particular risk involved if the customer has asked for a fire alarm system - you tell them that you see it as at least an L3 (for life protection) or P2 (property) and if they think thats OTT then ask them to read up and specify it themselves (or use another third party willing to stick their name to it).

I agree, only put your name on something your happy with.

[Cubit]

TF

you're above posts explaining the various categories and types is very informative and most useful.

Many thanks

[esp-protocol]

4.2 Recommendations

The following recommendations are applicable.

a) Where there is uncertainty regarding the need for a fire alarm system, or the Category of system that

should be used (see Clause 5) reference should be made, by the developer, potential purchaser or user, to

one or more of the following:

1) relevant part of BS 5588;

2) guidance documents that support fire safety legislation;

3) any authority responsible for enforcing fire safety legislation that applies to the premises;

4) the property insurer;

5) any relevant fire risk assessment.

B) The purchaser or user should ensure that the designer of a fire detection and alarm system is

adequately appraised of the objectives of the system and any relevant requirements of enforcing

authorities and insurers.

Still down to the purchaser to make the final decision as to the category required though, not a fire alarm engineer who isn't qualified to do a fire risk assessment...............!

The designer's job is simply to interpret the category and the objective and create a system around the specified requirements.

[Guest Thunderfingers]

4.2 Recommendations

The following recommendations are applicable.

a) Where there is uncertainty regarding the need for a fire alarm system, or the Category of system that

should be used (see Clause 5) reference should be made, by the developer, potential purchaser or user, to

one or more of the following:

1) relevant part of BS 5588;

2) guidance documents that support fire safety legislation;

3) any authority responsible for enforcing fire safety legislation that applies to the premises;

4) the property insurer;

5) any relevant fire risk assessment.

B) The purchaser or user should ensure that the designer of a fire detection and alarm system is

adequately appraised of the objectives of the system and any relevant requirements of enforcing

authorities and insurers.

Still down to the purchaser to make the final decision as to the category required though, not a fire alarm engineer who isn't qualified to do a fire risk assessment...............!

The designer's job is simply to interpret the category and the objective and create a system around the specified requirements.

"The various system Categories need to be regarded as a

[esp-protocol]

"The various system Categories need to be regarded as a

[Guest Thunderfingers]

and then there's the RRFSO..... also says the user is responsible for the RA and specifying the level of detection.....

Tis a bit of a minefiled....!!

RRFSO????Ahh,another of those part P type things that doesn't apply over here!

[Chorlton]

RRFSO????Ahh,another of those part P type things that doesn't apply over here!

QFA but we've got the Fire (scotland) act 2005 which is pretty similar to the RRFSO.

What you got and is it similar too?

c.

[Guest Thunderfingers]

QFA but we've got the Fire (scotland) act 2005 which is pretty similar to the RRFSO.

What you got and is it similar too?

c.

The Fire and Rescue Services (Northern Ireland) Order 2006 - Here for Details

Not too many taking notice of it as I think that it has still to go through the joke we call our assembly.