The Benefits of Wireless Fire Alarm Systems

Radio or wireless fire alarm systems first became available in the early 1980’s. In these early days of radio, the early radio or wireless fire alarm systems began to gain a poor reputation for reliability, mainly related to the radio transmissions and battery life of the devices and poor fire alarm design.  However over time the technology involved in these fire systems has steadily advanced to where we are today.  Today’s Radio or Wireless Fire Alarm Systems are light years ahead of their early 80’s ancestors.  Interestingly the advance in technology with the radio fire alarm systems has occurred as a bi-product of major advances in technology in the computer, battery and mobile phone industries.  Radio Fire Alarm System designers and engineers have embraced and harnessed this new technology to create and manufacture a new generation of radio fire alarm systems that are much more sophisticated in terms of performance, fault monitoring and reliability.  These new systems are fully compliant to BS5839 and EN54 and are fully monitored.

One of the main benefits of A Radio Fire Alarm System is that they reduce the needs to install cabling to each individual device on the fire alarm system.  Modern radio fire alarm systems will only need cables to be installed to the control and signal booster panel positions to provide a mains supply.  This benefit of radio fire alarm systems means that have been ideally suited to listed type buildings.  It allows the installation of a fully functioning fire alarm system within the building while not ‘running’ cables where it is impractical to do so.  Examples of installations of this type are in Windsor Castle and The Ritz Hotel, both of which have radio fire alarm systems installed.  In some instances conservation bodies would also prohibit the installation of cables within protected buildings and radio fire alarm systems may be the only solution to allow the building to comply with current regulations and standards.

Fire alarm monitoring and reliability cont.

Note that duplication of fire alarm sounder circuits throughout a building is not generally necessary and can even fail to achieve the objective outlined in the previous blog. In this case, if fire damages one circuit, it is also likely to damage any other circuit in the same area. However, in a large building with multiple sounder circuits, each serving a different area of the building, the above objective is satisfied. In a smaller building, which could, otherwise, be served by a single sounder circuit, additional measures will be necessary to ensure that, if this single circuit fails during a fire, at least one sounder (e.g. on a second circuit) continues to operate.

However, in buildings designed to accommodate the general public in large numbers, typically within a single space, the threat to life in the event of a fire may be such that additional fire alarm device circuits,
over and above those described above, is justified; this then addresses the remote possibility of failure or impairment of a single circuit serving a large public space at the time of a fire. Frequently, such buildings are served by a voice alarm system interfaced to the fire alarm system. In the case of such fire systems, BS 5839-8 recommends additional loudspeaker circuits in large, un-compartmented public spaces of public buildings such as transport
terminals, shopping malls, places of entertainment, large department stores and leisure centres. The size of the un-compartmented public space above which additional loudspeaker circuits are recommended by BS 5839-8 is entirely arbitrary but, for consistency, if such a large public space is protected by audible fire alarm devices, duplicated and evenly distributed fire alarm device circuits need to be installed within the space; such duplication is, however, not necessary in other parts of the building.

A Fire alarm system design needs to be arranged to limit the extent of impairments, whether as a result of faults or work on the Fire alarm system. A fault (but not fire) signal needs to be given at the control and indicating equipment in the event of any failure in the critical signal path (see 3.13).
Care needs to be taken in the use of multi-core cable for the wiring of more than one circuit. It needs to be
assumed that any fault that affects a multi-core cable affects all conductors of the cable; this precludes the
use of multi-core cable for certain applications in which the failure of more than one circuit as a result of a
single fault is precluded by the recommendations of this standard.

Fire alarm monitoring of external circuits

12.Fire alarm Monitoring, integrity and reliability of circuits external to control equipment
12.1 Commentary
External circuits external to the fire alarm control equipment, need to be arranged such that the probability of faults that could prevent the fire system from giving a fire warning is minimized. Such faults will, however, occur occasionally. Work on the fire alarm system, for
the purpose of modification, repair or routine fire alarm maintenance, may also cause an impairment of the fire alarm system to operate as designed in the event of fire.

Measures are incorporated within this code of practice to limit the probability of impairments, whether as a result of faults or work on the fire system, and to limit the duration of any impairment. The wiring of all critical signal paths is protected against mechanical damage and damage by fire. Critical signal paths are monitored, so that faults will be identified quickly. Compliance with the recommendations for fire alarm maintenance arrangements ensures that any such fault is quickly repaired. The probability that a fault will exist at the
time of a fire is, therefore, considered to be extremely low. In the event of fire, fire damage to wiring during the period required for evacuation is unlikely to occur in view of the recommendations of this code of practice for the fire resistance of cables.
As a result of the above considerations, duplication of, or redundancy in, external circuits is not normally necessary. However, in the case of circuits serving fire alarm devices, special measures need to be taken to ensure that, during, or following, evacuation, damage to any wiring, with resultant loss of the evacuation signal, does not imply to occupants of the building that it is safe to remain in, or re-occupy, the building.
This can be achieved by ensuring that, in the event of a short circuit developing on any fire alarm device circuit during a fire (e.g. at a cable termination), a minimum of one audible fire alarm device continues to
sound as a reminder that the system has not been silenced or reset. Normally, this sounder is located close to the control and indicating equipment, as this equipment will be sited in a suitable area (e.g. a reception area, security control room or main entrance foyer) at which the reminder needs to be given.

Fire alarm design recommendations

11.2 Recommendations
The following recommendations are applicable.
a) Fire alarm manual call points should conform to the requirements of BS EN 54-11 for Type A (“single action”) manual call points.
b) Fire alarm detection in the form of point heat detectors should conform to the requirements of BS EN 54-5 for Class A1 or A2 detectors, unless the foreseeable maximum ambient temperature in the protected area is 40 °C or above, in which case a Class B-G detector should be used as appropriate.                                          c) Fire alarm point smoke detectors should conform to BS EN 54-7.
d) Fire detection in the form of flame detectors should conform to BS EN 54-10.
e) Fire detection in the form of optical beam smoke detectors should conform to BS EN 54-12.

f) Aspirating smoke detectors should conform to BS EN 54-20;
g) Wireless fire alarm Components and systems using radio links should conform to BS EN 54-25;
h) Multi-sensor, optical and heat detectors should conform to either:
1) BS ISO 7240-15;
2) BS EN 54-5 and BS EN 54-7; or
3) CEA 4021.
i) Multi-sensor, carbon monoxide and heat detectors should conform to BS ISO 7240-8.
j) Carbon monoxide fire detectors should, in the absence of any relevant British, European or
International Standard, be capable of detecting a fire within 60 s if the carbon monoxide concentration exceeds 60 ppm, and should have a fire sensitivity (in combination with any other sensors within the fire
detector) sufficient to pass TF5 of BS EN 54-7 where the detector is declared to be suitable for installation instead of a smoke detector, or TF2 and TF3 of BS EN 54-7 where the detector is declared
only to be suitable for detecting smouldering fires. Any restrictions in the use of the detectors declared
by the manufacturers should be taken into account in the system design.
k) Control and indicating equipment should conform to BS EN 54-2.
l) Audible fire alarm devices should conform to BS EN 54-3.
m) Power supply equipment should conform to BS EN 54-4.
n) Cables should conform to the recommendations of Clause 26.
o) Those functions of the system that are recommended in this part of BS 5839, for which the storage of
programs and data is necessary to control the fire detection and alarm system, should comply with the
additional design requirements for software controlled control and indicating equipment in BS EN 54-2.
p) Where a PC is used as a user interface, e.g. in networked systems, it should be considered as a supplementary interface and there should be control and indicating equipment conforming
to BS EN 54-2 mounted adjacent, as it is unlikely that a PC would meet the requirements of BS EN 54-2.
q) Radio paging transmitters and receivers should conform to the relevant British or harmonized
European Standards applicable.

Fire alarm system components

The reliability of the fire alarm system to perform its functions on demand will, to a significant degree, be governed by the reliability of individual components. In general, it is advisable that all components that form the fire alarm system, such as manual call
points, detectors, control and indicating equipment and fire alarm devices, comply with relevant British Standards, and have undergone type testing to these standards. It is advisable to use components
having certification under a recognized product certification scheme (comprising third-party certification of product conformity against a relevant standard, based on testing and continuing surveillance, together with assessment of the manufacturer’s quality assurance systems against BS EN ISO 9000).

Where there is no relevant British, European or International Standard, it is advisable that care is taken to ensure, as far as possible, that the components are fit for their purpose. Third-party approval against an
appropriate test standard may provide assurance of this.
Compliance of an individual component with a recognized standard does not necessarily ensure that it will operate satisfactorily in conjunction with another component that complies with the relevant standard for that component. It is essential that compatibility between components is taken into account by the designer of the fire alarm system.

London based, fire alarm company, Fire Systems Ltd, design fire alarms using equipment from different manufactures. For example, we will purchase our fire alarm panels from Kentec Electronics and our detection from Argus.

Fire alarm systems to comply with current legislation

It is important, that fire alarms comply.

Every business needs to consider fire safety. This is a requirement by law and it is not only, but a legal requirement to carry out a Fire Risk Assessment on your company premises, but also to ensure that your fire safety equipment is in full working order and up to date in order to comply with the current regulations.

From conventional to wireless fire alarm systems and remote monitoring, these kinds of fire systems are important in detecting the presence of fire if an unfortunate incident was to occur in your building. As someone who is responsible for the organisation, you need to understand that this is a key component of fire safety.

You will find that there are a number of fire alarm systems available on the market so you may wish to speak to a fire safety specialist, such as a fire alarm company fire systems ltd, in deciding which would be most suitable for your business premises and that best meets your requirements.

When you have identified the right fire alarm solution, whether this is an entry level model or highly complex fire system, you can then make a purchase and arrange for it to be installed.

If you are looking for help with your fire safety compliance, you should get in touch with a BAFE approved fire alarm company that will be able to assist you.

Fire alarm systems in explosive environments

The important items to consider, when installing fire alarm systems in explosive gas or dust atmospheres

10.1 Commentary
If it is necessary to install fire alarm equipment or wiring in areas where an explosive atmosphere could result from the presence of flammable gases, vapours or mists, or the presence of combustible dusts, special protection measures are essential to ensure that the potential for ignition of the atmosphere by the fire alarm equipment or wiring is minimized.

10.2 Recommendations
The following recommendations are applicable.
a) Any fire alarm system (or part of a fire system) protecting an area, or with cables passing through an area, in which there may be an explosive gas, vapour or mist atmosphere should comply with the requirements of BS EN 60079-14.

b) Any fire alarm system (or part of a fire system) protecting an area, or with cables passing through an area, in which
there may be an explosive dust atmosphere should comply with the requirements of BS EN 50281-1-2.

Actuation of other fire alarm systems or safety facilities cont.

Interfacing fire alarms together, or actuating other systems, is discussed in the section.

The following recommendations are applicable in the case of fire alarm systems intended to actuate other fire alarm systems or safety facilities (e.g. by triggering an automatic fire suppression system, closing fire resisting doors, shutting down an air handling system or grounding lifts).
a) The fire alarm system should comply with the recommendations of any applicable part of BS 7273 for fire suppression.
b) If no part of BS 7273 is applicable, any special requirements for system design should be identified in
the purchase specification or design proposals.

c) If operation of the fire alarm system during routine testing would have an undesirable effect on other
fire systems or equipment, means should be provided for disabling the automatic actuation of the fire suppression system or equipment. The facility for disablement, and the indication of disablement, should comply with BS EN 54-2.
d) The other equipment or systems should not draw power from the fire alarm system in the non-fire state, other than for indicators and interface devices (e.g. relays). The power consumption of any such
indicators and interface devices should be taken into account in the calculation of battery capacity(see 25.4).

Fire Alarm detector, using Air Sampling

 

Fire alarm detection using air Sampling is one of the most sensitive forms of fire detection currently available. By detecting smoke at an very early stage and taking appropriate remedial action the damage caused by fire and smoke can often be avoided.

Fire alarm maintenance, design and commission of these sensitive fire alarm detection systems is a specialist task and should only be untaken by a professional fire alarm company, such as Fire Systems Ltd.

Fire Systems Ltd, have been installing and maintaining Air Sampling Systems since 1992. Our staff have a great deal of experience in this field. We work with and install fire alarm systems from all the major manufacturers, by being independent and not tied to any one manufacturer, our advice is completely impartial

Air-sampling Smoke Detectors work by:

1. Continually drawing air into a pipe network attached to a detector unit.
2. Passing the air through a dual stage filter to remove dirt
3. Sending the clean air to a laser detection chamber for smoke detection.
4. Measuring the light scatter caused by any smoke
5. Processing the detector signal and presenting the smoke level graphically
6. Communicating the information to a fire alarm control panel, a software management system or a building management system.

Installing a fire alarm using Air-sampling smoke detectors provide the early warning of an imminent fire hazard. Why is this important? It buys time. Time to investigate a smoke alarm. Time to take action. Time to avoid the danger, damage and disruption caused by fire.

Another, advantage of using air sampling is with regards to the fire alarm maintenance, as the maintenance engineer does not have to test individual detector.

A fire alarm company such as fire systems ltd, is independent and have been installing fire alarm systems since 1992.

Conventional fire alarm

Fire Alarm Systems fall broadly in to two groups - Conventional fire alarm Systems or Analogue Addressable Systems.

A fire alarm maintenance is required for both types of systems.

'Conventional' Fire Alarm Systems, in their various forms, have been around for many years and have changed little in that time in terms of technology although design and reliability have improved significantly. However, Conventional fire alarm system are a well-proven technology protecting many hundreds of thousands of properties worldwide. A Conventional Fire Alarm System is often the natural choice for smaller systems or where budget constraints exist.

Incorporating the Multipoint detector with built-in sounder means the whole system cab be installed using only one pair of wires.

Using the Multipoint detector as part of the Twinflex 2-wire fire alarm system means that when a detector is wired in, a sounder is too - with no extra wiring. This greatly reduces the number of points that need to be installed and the time it takes to install them.

Fire Systems Ltd, offer the complete range of fire alarm maintenance packages.