Application of other Fire Systems Components

In addition to detectors, there are other elements that form part of a fire detection system.


Manual call points are devices, usually in the form of break glass units, used to raise an alarm manually. They are an important part of any fire detection and alarm system as they allow people in a building to raise an alarm and people are sometimes better placed to notice a fire than automatic detectors. Manual call points should be sited so that someone discovering a fire can always operate a call point before leaving the building or, in the case of buildings with more than one storey, the floor they are on. This means that manual call points should be sited at all exits to open air and on stairway landings at each level. They should also 'stand out' from the background and, where they will be viewed from the side for example in a corridor, they should not be flush mounted. Standards normally recommend the maximum distance that anyone should have to travel to reach a call point.

Sounders are devices used to produce an audible indication of an alarm. Audible alarm signals need to be provided to warn the occupants of a building that there is a fire. However, this depends to some extent on the purpose of the system. It may be that not all of the occupants need to be warned. For example, in hospitals, it is only staff who need to be alerted, not the patients. Systems intended for property protection may only need to alert key personnel in order to ensure that fire fighting action is taken. Fire detection standards normally specify a minimum sound pressure level that must be achieved. This will depend on whether the people are awake or asleep.

To find out more, visit the Sounders page

Beacons are devices used to give a visual indication of an alarm and have been developed as a supplement to sounders in situations where there is a risk that sounders will not be heard. This could be where there is high background noise, for example in a workshop or machine room or in a music room in a school. It might also be because the occupants are deaf or hard of hearing so that a beacon is needed in public buildings or public accesss areas and workplaces. Beacons can also be used to give a 'staff alarm' where the use of sounders is undesirable. This could be in TV or radio studios, cinemas or theatres or in hospitals and care homes.

To find out more, visit the Beacon page

Interfaces are designed to enable connection of various inputs and outputs to an analogue addressable loop. These inputs and outputs will all be associated with the fire alarm systems ie they could be conventional detection devices such as beam detectors, flame detectors or heat cables. On the output side they could be sounder circuits, extinguishing systems, plant shutdowns, fire doors or sending alarm signals to other forms of control equipment.

To find out more, visit the Interfaces page

Isolators are not addressable devices although they are used on addressable systems. They are designed specifically to isolate sections of the loop wiring or individual devices in the event of a short-circuit fault. If isolators were not fitted, then a single short-circuit would disable an entire loop of devices.

Control panels are apparatus used to control a fire proctection system and can be thought of as its 'brain'. The control panel can automatically process information from detection devices and manual call points on the system. It can then operate outputs, such as sounders and bells, or signal to the Fire Brigade automatically. Control panels are mains operated with a battery back-up. They are usually situated near the reception or security areas or entrance/exit doors.