Fire detection systems

Fire detection systems | General aspects

A fire detection and warning system is a protective installation designed to detect and signal the occurrence of a fire start in protected areas as soon as possible and to alert staff, and any other category of people in the area who can help to extinguish the fire and limit its effects.

Fire detection systems | General composition

  • One or more fire detectors
  • Control and signaling equipment
  • Fire alarm devices
  • One or more manual alarm triggering
  • A fire alarm transmission device
  • Fire alarm station
  • Control system for automatic fire protection systems
  • Fire protection equipment
  • Defective signal transmission device
  • Bad signal reception station
  • Power supply equipment
  • Connector elements
  • One or more autonomous smoke alarm devices

Fire detection systems are determined according to the fire category, building type, building importance and parameters to be monitored such as room temperature, smoke, hazardous or explosive flame.

Fire detection systems | Alarm system components

The detection system consists of fire detection devices (manual triggers or automatic gas, smoke, heat, flame detectors).

Composition of control and signalling equipment

Control and signalling equipment (E.C.S.) is a structure whereby other components can be powered and controlled. Its role is complex:

  1. Reception of detector signals and their analysis to determine whether or not they correspond to alarm conditions, audible and visible signalling of these alarm conditions, and indication of the location of the hazard, as well as the recording if any of this information is possible.
  2. Monitoring the correct operation of the system, audible and visible warning of any defect (IE: short circuit, line break or power failure).

Fire-alarm systems shall ensure:

  • detection of fires both on the roads for the normal functioning of the buildings, especially in the spaces and the auxiliary rooms, as well as in those rooms where the fire could unfold uninterruptedly without being observed in a timely manner
  • fire announcement at the permanent surveillance point, automatic and / or manual alarms and indoor telephones, as well as, where appropriate, the fire brigade (fire service)
  • the operational alarm of service personnel who must organize and ensure first intervention and evacuation of users in accordance with established action plans
  • warning the occupants (users) of the building about the fire hazard and sending instructions (messages) to avoid panic.

Fire detection and alarm systems are conventional and addressable

  • Conventional systems are those systems for small spaces.
  • Addressable systems are complex systems for large spaces, allow for accurate identification of the alarm element with multiple interconnected functions and extinguishing installations so that they can automatically trigger the extinguishing system (with sprinklers, foam, or gas).

The component of a basic fire detection system is shown in the diagram below and contains:

  • Heat, smoke and flame detectors designed to transmit the detected signal as a result of the onset of fire
  • Warning button that can be manually operated if there is a risk of fire
  • The siren that warns all occupants that they have to evacuate the building
  • Multifunctional power plant
  • The software calculator can record and store any event produced

The signalling plant is the basic component of a fire alarm system that can be used, as appropriate, for:

  • to receive signals from the connected detectors;
  • determine whether these signals correspond to an alarm condition;
  • indicate an acoustic and optical alarm condition;
  • indicate the location of the fire outbreak;
  • start the extinguishing system;
  • record any of this above mentioned information.

Fire detection systems | Stages of installing such a system

Design of detection and alarm systems

The design phase is one of the critical parts of a fire alarm system. If this phase is not properly developed, false alarms may occur, and in the worst-case scenario, a potentially life-threatening system that does not detect correctly or does not detect everything.

European Standard EN54 dedicated to alarm and fire alarm systems.

The installation of the fire alarm system must be in accordance with the standard

It is the responsibility of the key person to ensure that the contractor or the installer has the necessary competence to install by authorizing the firm. The engineer must ensure that the alarm system is in accordance with the specifications of the design plan.

It is the responsibility of the key person to ensure that the contractor or the installer has the necessary competence to install by authorizing the firm. The engineer must ensure that the alarm system is in accordance with the specifications of the design plan.

Commissioning / Testing

The final stage and perhaps the most important in installing the detection and alarm system is commissioning, where the inspected person checks the entire functionality of the system and validates it as safe and appropriate to achieve the purpose.

In the first phase it is checked whether the system complies with design specifications and sketches, and the wiring conforms to the regulations and is safe to use.

Maintenance

Any fire detection and alarm system must be maintained by an authorized person or firm. According to the regulations, the system should be checked once every 6 months or more frequently if the risk class is very high or if there is a danger of vandalism on the system.