Fire Alarms
Basic Guide to Fire Alarm Installation
Introduction to BS5839 Part 1, 2002 BS5839 part 1 is a code of practice for Fire Alarm system design, installation and servicing for fire detection for general buildings. The standards have been revised and are effective from mid July 2003.
A fire alarm system is generally required to be installed as part of fire certificate required by the Fire Precautions Act or the workplace regulations after an audit of a fire risk assessment.
Planning the Fire Alarm System
The decision of whether a fire alarm system is required or the type of category should not normally be the responsibility of the designer, customer/installer. The local authorities should take these decisions for enforcing legislation in buildings. With all fire alarm systems there should be an exchange of information and decision process a typical example would be.
- Building control officers
- Fire authorities
- Statuary and insurance requirements
When sufficient information and level of category has been obtained then the fire alarm system can be designed.
System Design
Process/Decision and exchange of information
- Purchaser specifies the category of fire alarm system, this would have been provided by the local authorities, if required the designer can propose a category.
- System to be designed
- Consultation
- Any variation of the British Standards to be agreed.
- System proposal to be approved by all parties.
There are different categories of protection within BS5839 Part 1, 2002
Property Protection
(Objective: To summon the fire brigade in the early stages of a fire)
Type P1: Property protection, automatic detection installed throughout the protected building.
Type P2: Property protection, automatic detection in designated areas.
Life Protection
(Objective: To protect people from loss of life or injury)
Type M: Manual system (call points).
Type L5: Life safety generally when specific fire engineering solutions or where PI insurance is required.
Type L4: Life safety system, same as a manual system plus smoke detection on escape route.
Type L3: Life safety system, same as a manual system plus smoke detection on escape route and heat or smoke detection in adjacent rooms.
Type L2: Life safety system, same as L3 but detection in fire hazard/risk of ignition i.e. kitchens, sleeping areas and other specified areas.
Type L1: Life safety system, similar to P1 but the audibility is more critical.
Call Points
- Call points should be fitted in conspicuous and easily accessible points on escape routes, mounted at 1.4 metres +/- 0.2m above floor level.
- Call points should be located at the exits to the open air and all storey exits on each floor.
- You should not have to travel more than 45 metres to operate a call point or 25 metres in any special hazards or high-risk areas. Zoning
- The floor area of a single zone should not exceed 2,000m2.