Saturday, May 4, 2013

Commissioning and maintenance of Fire Blankets

Commissioning and maintenance of Fire Blankets BS EN 1869 – Code of practice

1. Scope
This code of practice gives guidance on:

·       Regular inspection of a fire blanket

·       Regular maintenance of a fire blanket

·       Life of a fire blanket

·       Reasons to render a fire blanket unserviceable


2. Terms and Definitions

2.1. Container
The box, packet or cabinet (including closures) in which a fire blanket is normally housed.

2.2.
Fire Blanket
A fire blanket is a safety device designed to extinguish small incipient (starting) fires. It consists of a sheet of fire retardant material which is placed over a fire in order to smother it.

Small fire blankets, for use in kitchens and around the home, are usually made of either fibreglass or woven-nylon coated with silicone-based flame retardant and folded in to a quick-release container for ease of storage.

2.3.
Hand hold devices
Hand hold devices often made of woven material, securely attached to the blanket which can be seen and accessed from outside the container which allow the user to release the fire blanket from the container ready for deployment.

2.4.

Manufacturer’s instructions
Instructions written by the manufacturer to aid users deployment of the fire blanket.; including any instruction which aids the service provider to carry out maintenance of the blanket.

2.5.
Service provider
Person with the training and experience, with access to the relevant tools, equipment and information, manuals and knowledge of any special procedures recommended by the manufacturer of the fire blanket, to carry out the relevant maintenance procedures

2.6.
Responsible Person
Person or persons responsible for, or having effective control over, fire safety provisions adopted in or



appropriate to the premises or building or risk where an fire blanket is installed

NOTE For the purposes of this document, the term “responsible person” includes a nominated representative.


3. Process of Commissioning

The commissioning of a fire blanket should be carried out by a service provider as defined in 3.5. Upon removal from its packaging and transit protection, and immediately prior to placing in its designated place, the fire blanket should undergo this sequence of commissioning service actions:


4. Mounting

4.1.  Fire Blankets should be mounted so as to position the hand hold devices approximately 1.5 m from the floor.

4.2.  The positioning of kitchen furniture and/or equipment should not preclude access to the blanket.

5. Visual Inspection by the Responsible Person

5.1    The responsible person should carry out visual inspections of all fire blankets regularly. These visual inspections should be carried out at least monthly. When circumstances require, inspections should be carried out more frequently.

NOTE 1 Fire legislation in England & Wales, Scotland, Northern Ireland and its associated Guidance Notes suggest that good practice is to determine whether the fire blanket has been used and to check for damage on a weekly basis.

5.2    When carrying out these visual inspections, it should be ensured that:

5.3    each fire blanket is correctly located in the designated place;

5.4    each fire blanket is unobstructed and visible
5.5  the operating instructions of each fire blanket are clean and legible and face outwards;

5.6    each fire blanket container is not obviously damaged and that the hand hold devices are visible and undamaged

5.7    the tamper indicators of each fire blanket, where fitted, are not broken or missing.

5.8    The responsible person should record the results of these visual inspections and arrange for corrective action, where necessary, by a service provider. In the event of doubt the responsible person should arrange for a service provider to examine the fire blanket.

NOTE 2 Responsible persons have obligations under fire legislation in England & Wales, Scotland, Northern Ireland to use a service provider to maintain extinguishing equipment in an efficient state, in efficient working order and in good repair, where it is necessary to provide such equipment to safeguard employees in the event of fire.


6.    Basic service

6.1    The responsible person should ensure that basic service be carried out at 12 monthly intervals. The maintenance intervals given for basic service have for practical purposes a tolerance of ±1 month. Intervals should be taken from the date of installation or the last basic service. Intervals may be shortened, on the recommendation of the service provider where inspection reveals environmental and/or special hazards, or at the request of the responsible person.

6.2    The basic service of a fire blanket should be carried out by a service provider as defined in 2.4. The fire blanket should undergo this sequence of commissioning service actions: 



7. Labelling

7.1.  General

Any labelling that is applied to the fire blanket container should not obscure any marking required by BS EN 1869;

7.2    Maintenance label

7.2.1          The maintenance record should be indelibly marked on a durable label that is fixed firmly to the fire blanket container without obscuring any of the manufacturer’s markings and instructions. Where there is no more space on the maintenance label and a new label is fixed, the date of commissioning should be marked on the new label.

7.2.2          The following information should be given on the maintenance label:

7.2.3          type of action (commissioning or basic service)

7.2.4          name and postal address of the maintenance supplier;

7.2.5          a mark clearly identifying the service provider;

7.2.6          the date (year and month) of the action in a) above;

7.2.7          the date (year and month) of commissioning

This information should be readable without any special equipment.

Any additional information for the benefit of service providers may be shown in a more compact form, such as bar codes.

NOTE 3 The information on the maintenance label of each fire blanket may additionally be entered into a central record. In this way one aspect of the important information on fire prevention can be kept readily available.



8. Evaluation of fitness - Blankets which are to be condemned

Any fire blanket with a major defect or defects which make it unsafe for use should be immediately removed from its designated place, and marked “CONDEMNED” together with the reason for this assessment. The responsible person should be advised in the written report (see 9) that a permanent replacement is needed as soon as possible. Evaluation of whether the damage or wear to a fire blanket make it unsafe for use depends on the judgement of the service provider.


8.1.  Conditions indicating that a fire blanket is unsafe for use

Potentially the most serious hazard presented by a defective fire blanket is it’s inability to either (a) be deployed or (b) starve a fire of oxygen, allowing the fire to burn uncontrollably after deployment. These could be caused by any of the following conditions:

8.1.1          wear, contamination or damage to the fire blanket material.

8.1.2          wear or damage to the fire blanket hand hold devices;

8.1.3          serious damage to the container;

8.1.4          fire damage to the container or fire blanket;

8.1.5       age. Follow manufacturers instructions or if there are none then if more than 7 years from date of commissioning consider replacing the blanket.

8.2    Additional reasons for condemning a fire blanket include the following (unless rectified by the replacement of the appropriate components):

illegible marking or operating instructions;

instructions not in English;


9.    Provision of a written report

The service provider should advise the responsible person in a written report:

9.1    of any fire blankets that have been condemned or are missing;

9.2    of any permanent replacement fire blankets required to replace those reported in a);

9.3    of any additional fire blankets required to ensure that the level of cover at the premises is appropriate for the risks present;

9.4    that any replacement or additional fire blankets reported in b) or c) should be provided as soon as possible; and

9.5    of the responsible person’s obligation under fire legislation to provide an appropriate level of fire-fighting equipment at all times.


10. Maintenance documentation

A certificate of inspection should be issued in all cases.

      10.1   The certificate of inspection should include the following information:

10.2    the name, postal address and telephone number of the maintenance company;

10.3    the date of maintenance;

10.4    identification of the maintenance technician;

10.5   a list of all fire blankets included in the maintenance programme; including all nonconforming equipment, and recommendations for appropriate corrective action or reference to where this information can be found;

10.6    the signature of the responsible person, which should be obtained upon completion of the service visit and prior to the service technician leaving the premises, or a record of the reason why this is not possible (e.g. unmanned sites);

 11Permanent replacement of a Fire Blanket.

It is the duty of the responsible person to arrange for permanent replacement fire blankets to be put into place as soon as possible after inspection has shown that some fire blankets should be replaced. The service provider is responsible for bringing this duty to the responsible person’s attention in the written report.

Friday, April 5, 2013

How Should A Fire Alarm System Be Tested

How Should A Fire Alarm System Be Tested

We are often asked by customers "How Often Should A Fire Alarm System Be Tested?". The British Standard associated with fire alarm systems gives some recommendations as to when and how often a fire alarm system should be tested.
BS5839 recognises that although modern fire alarm systems incorporate a high degree of monitoring, so that faults are indicated at the control panel position, it is still necessary for a responsible person nominated by the user to ensure that fault indications at the panel are identified for appropriate action.  It is also impertitive for a regular test to be carried out to ensure that there has not been any major failure of the entire system, or significant part of the system.

How Often Should The User Test Their Fire Alarm System?
BS5839 recommends that the user / responsible person for the fire system tests their fire alarm system on a weekly basis.  The recommendations of the standard are as follows:-
  1. Every week, a manual call point should be operated during normal working hours.  It should be confirmed that the control equipment (fire alarm panel) is capable of processing a fire alarm signal and providing an output to fire alarm sounders installed on the system, and if applicable to ensure that the fire alarm signal is correctly received at any fire alarm receiving centre to which fire alarm signals are transmitted.  It is not necessary to confirm that all fire alarm sounder circuits operate correctly at this time of the test.
  2. The British Standard recommends that the weekly test carried out by the user should be carried out at approximately the same time each week.  Instructions to occupants should then be that they should report any instances of poor audibility of the fire alarm sounders.  In systems with staged alarms that incorporate an 'Alert' and 'Evacuate' alarm signal, the two signals should be operated, where praticable, sequentially in order they would occur at the time of a real fire event (i.e. 'Alert' and then 'Evacuate').
  3. In premises in which some employees only work during hours other than at which the fire alarm system is normally tested, an additional test(s) should be carried out at least once a month to ensure familiarity of these employees with the fire alarm system singal(s).
  4. A different manual call point on the system should be used at the time of every weekly test, so that all manual call points within the building are tested in rotation over a prolonged period.  There is no maximum limit for this period (e.g. in a system with 150 manual call points, the user will test each call point every 150 weeks). The result of the weekly test and identity of the manual call point should be recorded in the system log book.
  5. The duration for which any fire alarm signal is given at the time of the weekly test by the user should not normally exceed one minute, so that, in the event of a fire at the time of the weekly test, occupants will be warned by the prolonged operation of the fire alarm devices.
  6. Voice alarm systems should be tested weekly in accordance with the recommendations of BS5839-8.
Recommendations For Monthly Attention By The User Of The Fire Alarm System
Each month BS5839 makes the following recommendations upon the monthly attention on a fire alarm systems each month if applicable.
  1. If an automatically started emergency generator is used as part of the standby power supply of a fire alarm system, it should be started up once each month by simulation of failure of the normal power supply and operated on-load for at least one hour.  The test should be carried out in accordance with the instructions of the generator manufacturer, including instructions on the load that should be operated.  At the end of the test, the fuel tanks should be left filled, and the oil and coolant levels should be checked and topped up if necessary.
  2. If vented batteries are used as a standby power supply, a visual inspection of the batteries and their connections should be made to ensure that they are in good condiction.  Action should be taken to rectify any defect, including low electrolyte level.
Note:  Care should be taken to ensure that any person undertaking these monthly tasks is competent to do so safely and has the relevant technical knowledge and training.

Saturday, March 2, 2013

Install End of Line Resistance

Install End of Line Resistance
End of line resistors (EOLR) are resistors of a specified value that are used to terminate protective loops or zones.

The purpose of EOLR's is to allow the control panel to supervise the field wiring for open or short circuit conditions. How the alarm responds to each depends on the panel as well as system zone programming, but generally speaking, an alarm views an open circuit as a fault or alarm condition, and a short circuit as a trouble or alarm condition (if armed). The purpose of EOLR's is to allow the panel to differentiate between the two conditions by looking for a known resistance.

EOLR's should be installed at the last device on the loop, electrically speaking, and not inside the control, unless special conditions are met. The benefits of EOLR's on protective zones with all concealed wiring is commonly argued by professional installers, as well as EOLR's installed inside the control unit, negating their effectiveness, as well as disabling the EOLR feature and using NC (normally closed) loops for zone definitions. The use of EOLR's is recommended and is particularly important when the field wiring is subject to damage or compromise.
A fire EOLR should always be installed at the last device and never inside the control or across the zone defined as fire, as this is an inherent safety issue.

Some equipment supports Double End of Line Resistors (DEOLR) to further differentiate between conditions that may exist on the loop.

Saturday, February 2, 2013

Radio / Wireless Fire Alarm Systems Benefits

Radio / Wireless Fire Alarm Systems Benefits

Radio or Wireless Fire Alarm Systems first became available in the early 80’s.  In these days the early systems began to gain a poor reputation for reliability, mainly related to the radio transmissions and battery life of the devices.  However over time the technology involved in these 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 technology to create 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 Radio Fire Alarm Systems is that they reduce the needs to run cables 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.
Another huge benefit of radio / wireless fire alarm systems is the vastly reduced installation times.  As each device is battery powered and does not require a cable to connect it to the fire alarm system, a single device could be installed in a room in around 30 minutes.  A hard wired alternative system would in comparison take weeks or months to install, greatly increasing the installation time and the amount of disruption within the building.  In a hotel for example installing a ‘hard wired’ type system would take months to install.  It may be more cost effective to install a radio fire alarm system when the amount of ‘down-time’ is taken into account i.e. the hotel may lose much more revenue in shutting areas of the building while the installation of a fire alarm system is taking place.

Due to the flexibility and ease of installation, radio fire alarm systems are also being used as temporary systems.  Some building companies for example use radio fire alarm systems on sites where fire detection is required whilst building work is on going.  These systems can be installed as the building work commences and be used on the project until the project is finished.  The system can then be simply taken down ready to be used on their next project.  The benefit of flexibility can also seen when using radio fire alarm systems on projects with phased construction works.  The devices can be simply added and removed as work is on going without having to add and remove cables and therefore speeding up the construction process.

The increase in reliability of Radio Fire Alarm Systems is now a huge benefit.  Radio Fire Alarm Systems have now been allocated a dedicated communication frequency to use.  In the past one problem with radio fire alarm systems was that they were using similar communication frequencies to other services, such as the radio communication with taxi companies for example.  This lead to interference with the two systems and false alarms occurring.  However now with the new dedicated frequencies this can no longer happen and as a result the systems are much more reliable.  The reliability of radio fire alarm systems is also dependent on a successful radio survey being carried out by a person trained to carry out a radio fire alarm survey.  This is to ensure that the building is suitable for a radio fire alarm system and also to ascertain where the fire alarm panels and signal booster panels should be installed.

Advances in battery technology have enabled radio fire alarm systems to become easier to manage in terms of maintenance.  As the devices on a radio fire alarm system are all battery powered, there is no escaping the fact that these batteries will need to be changed.  However radio fire alarm manufacturers are embracing new battery technology to increase the battery life of their devices.  Many radio fire alarm system manufacturers are now using lithium batteries.  These batteries have a much greater life span than the batteries that were traditionally used and many radio fire alarm manufacturers are quoting life spans of up to 5 – 7 years for the batteries used within their system devices.

In conclusion radio fire alarm systems if correctly surveyed and installed offer huge advantages over traditional ‘hard-wired’ fire alarm systems.  Offering greater flexibility, reduced installation times and huge leaps forward in the reliability in the systems over the last 20 years.

Friday, January 4, 2013

Clean up after a Fire Extinguisher Discharge

How to clean up after a Fire Extinguisher Discharge ?
So you have managed to put out the small fire in your office or living room and rescued the day. Well done, your fire extinguisher and your bravery protected you from some potentially very expensive fire damage or worse! However, your powder extinguisher has caused a wintery landscape in the room and your mouth tastes of some sort of unhealthy childhood lolly. How do you clean up the mess? Here are some helpful hints.

Protective Equipment Required
Powder extinguisher
Dust mask, gloves, goggles. The chemicals in a powder fire extinguisher can be an irritant to lungs, eyes and throat.
Foam, Wet Chemical
Impermeable Gloves, goggles. The chemicals in foam fire extinguishers can be carcinogenic.

Cleaning Measures
Foam, Water additive, wet Chemical fire extinguishers
1.    Wear the protective equipment as listed above
2.    Soak up the foam or liquid from the wet chemical or water extinguisher with either paper towels or old towels that can be thrown away
3.    Wash the area thoroughly with water and use paper towels or an old towel to soak up any excess
4.    Place all towels into a plastic bag and seal before throwing it away into the usual waste bin
Powder fire extinguisher
1.    Wear the protective equipment as listed above
2.    Use a vacuum cleaner to clean up the powder residue, or a brush to sweep it away if you do not have a vacuum cleaner
3.    Place all the powder from the vacuum cleaner or that has been swept up into a plastic bag and seal it. Dispose of this bag in the usual waste bin
4.    Use a damp cloth to clean any residue of powder off furnishings, do not use copious amounts of water. There is a risk that any residue left may start to eat away at soft furnishings. Curtains should be washed if possible

Tips:-
1.    Remove fuel, oxygen or heat to eliminate the fire. If one of those 3 elements are missing. the chemical reaction to create fire cannot occur.
2.    Shake dry chemical extinguishers once a month to prevent the powder from settling or packing. Check the manufacturer's recommendations.
3.    Many local fire departments will happily demonstrate to you how to use a fire extinguisher. Call your local one to find out more. You will need to set up a time to do this. Many towns have monthly demonstrations.
4.    The US Fire Administration does not recommend the use of fire extinguishers by untrained persons. While this is only a recommendation and may be unrealistic sometimes, it is often easy enough to get training from your local fire department, so make the most of this opportunity to become "trained".
5.    Always have a household plan of escape in the event of fire, as well as working smoke alarms in place. A carbon monoxide detector can be useful also.
6.    Immediately replace the extinguisher if it needs recharging or is damaged in any way.
7.  Pressure test the extinguisher (a process called hydrostatic testing) after a number of years to ensure that the cylinder is safe to use. Find out from the owner's manual, the label, or the manufacturer when an extinguisher may need this type of testing.
8.    Fire extinguishers need to be regularly checked to ensure that:
9.    The extinguisher is not blocked by furniture, doorways, or anything that might limit access in an emergency.
10. The pressure is at the recommended level. Some extinguishers have gauges that indicate when the pressure is too high or too low.
11. All parts are operable and not damaged or restricted in any way. Make sure hoses and nozzles are free of insects or debris. There should not be any signs of damage or abuse, such as dents or rust, on the extinguisher.
12. The outside of the extinguisher is clean. Remove any oil or grease that might accumulate on the exterior.

Saturday, December 1, 2012

IONIZATION VS PHOTOELECTRIC

IONIZATION VS PHOTOELECTRIC
The two most commonly recognized smoke detection technologies are ionization smoke detection and photoelectric smoke detection.
Ionization smoke alarms are generally more responsive to flaming fires.
How they work: Ionization-type smoke alarms have a small amount of radioactive material between two electrically charged plates, which ionizes the air and causes current to flow between the plates. When smoke enters the chamber, it disrupts the flow of ions, thus reducing the flow of current and activating the alarm.
Photoelectric smoke alarms are generally more responsive to fires that begin with a long period of smoldering (called “smoldering fires”).
How they work: Photoelectric-type alarms aim a light source into a sensing chamber at an angle away from the sensor. Smoke enters the chamber, reflecting light onto the light sensor; triggering the alarm.

For each type of smoke alarm, the advantage it provides may be critical to life safety in some fire situations. Home fatal fires, day or night, include a large number of smoldering fires and a large number of flaming fires. You can not predict the type of fire you may have in your home or when it will occur. Any smoke alarm technology, to be acceptable, must perform acceptably for both types of fires in order to provide early warning of fire at all times of the day or night and whether you are asleep or awake.

The best evidence has always indicated that either type of smoke alarm will provide sufficient time for escape for most people for most fires of either smoldering or flaming type. However, research is ongoing, and standards are living documents. If at any time, research points to a different conclusion, then that will lead to proposals for changes in the NFPA standard or the closely related Underwriters Laboratories standard for testing and approving smoke alarms. Both organizations currently have task groups looking at smoke alarm performance in the current home environment.

Saturday, November 3, 2012

Digital Signage

Digital Signage Capacitive Touch Technology
With the development of science and technology, capacitive touch screen is known to the public. In the foreseeable future, it will replace resistive touch panel, and gradually catch up with Infrared Touch panel. Capacitive touch screen will dominant the market in the future, and mainly depends on its own merits as follows:

·         Capacitive touch screen generates signal only by touching instead of pressure.
·         In the production of capacitive touch screen, it doesn’t need calibration or just need one-time calibration, but resistive screen requires regular calibration.
·         Life span of the capacitive touch screen is much longer, because the capacitive touch screen parts no need movement.
·         Capacitive performs better than resistive touch on the optical loss and power consumption.

·         Capacitive touch screen is better in wearing resistance, long life, low maintenance costs compared with the resistive touch screen.

Friday, October 5, 2012

Fire alarm design category LD3 residential

Fire alarm design category LD3 residential
A Category LD3 fire alarm system is intended only to protect circulation areas that would be used as escape routes, by giving a warning if smoke is detected in these areas, so that occupants can escape before heat or smoke make this impossible. Therefore, the fire detection is positioned on the escape routes.

A Category LD3 fire alarm system cannot be expected, with any degree of reliability, to protect people who might be involved with the fire at ignition or in its early stages. This Category of fire system might not therefore prevent the death or serious injury of occupants in the room where the fire originates; it is intended only to ensure escape for those not immediately involved. If no fire detector is installed in the room in which fire starts, the time available for evacuation of other areas once fire is detected in the circulation area might be quite short. 
In a large family house adapted to provide accommodation for several households in separate self-contained units (a house in multiple occupation), a fire in one dwelling unit can be a hazard to occupants of other units. 

In this case, the fire detection and fire alarm system normally needs to extend across the boundaries between occupancies or be interconnected with systems in other occupancies. In practice, it is often appropriate for there to be a single integrated fire detection and fire alarm system that will alert all occupants before a fire in any dwelling threatens the communal escape routes, and that will provide early warning of any fire that starts in these escape routes. This objective is additional to that of enabling occupants of the dwelling in which fire starts to escape before their escape routes become impassable owing to heat or smoke.
In the case of purpose-built flats or sheltered housing, the degree of compartmentation between occupancies is normally sufficient to ensure that fire is contained in the dwelling of origin for a prolonged period. During this time, other occupants can remain in reasonable safety within their own dwellings. Accordingly, this part of BS 5839 does not provide recommendations for fire detection and fire alarm systems that incorporate detectors in the communal areas or ancillary accommodation (e.g. plant rooms) within purpose-built flats or sheltered housing. If, however, the provision of detection in these areas is considered desirable, it is essential to refer to the guidance contained in BS 5588-1, and it is appropriate that such fire detection and fire alarm systems comply with the recommendations of BS 5839-1.

BS 5839: Pt.6 covers the following domestic building types:
Bungalows
Multi-storey houses
Individual flats
Individual maisonettes
Mobile homes
Individual sheltered accommodation as well as their common parts
Houses in multiple occupation (HMOs)
Certain NHS housing in the community
Mansions 
Shared houses 
Houses divided into several self-contained single-family dwelling units

Not included are hostels, caravans, boats (other than permanently moored) and communal parts of blocks or flats or maisonettes.

BS 5839: Pt.6 is primarily concerned with saving lives and reducing injuries. However, it does contain within it recommendations for helping to reduce property damage too. Good fire safety practice and adherence to the Code can give the best possible early warning of fire and so reduce the financial impact as well as human suffering.

Mains Powered Smoke Alarms with Back-up Battery - Grade D

The problems outlined above can be overcome by using mains powered alarms that incorporate, within each alarm, a stand-by supply such as a primary or rechargeable battery. The alarms have to be interconnected either through wiring or radio-interlink. The mains power supply can come from a dedicated power supply directly from the fuse box or from the nearest permanently powered light fitting, as long as the smoke alarm heads can be removed without removing the base as well.

Grade D is required for new, owner-occupied buildings of up to three storeys, two storey rented properties and existing, owner-occupied buildings of more than two storeys. Very large storeys (>200m2) might require Grade B alarm system.

A question remains for landlords - can they be sure that their tenants are paying their electricity bills? Given that many tenants may have low incomes (in many local authorities, 70% or more of all tenants are on subsidised incomes), they may well experience periods of disconnection - and yet the landlord could well be liable if the alarm fails to sound because the tenant has not paid his or her bills! Unfair or not, as the law stands, it obviously makes good commercial sense to ensure that a reliable, ideally re-chargeable and sealed-in backup battery is in place.

The minimum back-up duration recommended is 72 hours, and the Code acknowledges that there could well be circumstances where a longer stand-by period is justified e.g. tenants' inability to pay their electricity bill.

Saturday, September 1, 2012

False Fire Alarms Five Lessons to Learn

False Fire Alarms: Five Lessons to Learn

Successful fire detection has helped to reduce the number of fire deaths. But fire detection and alarm systems (FDAS) are also responsible for a large number of false alarms – 293,100 were recorded in 2011/12 alone.
Estimated losses of around £1bn a year have been attributed to false alarms, due largely to the disruption and loss of productivity in businesses.
1. Smoke detectors and age of components
Optical smoke detectors were responsible for 74% of the live false alarms observed during study.
The majority of these were due to cooking, dust, aerosol and steam. Although 74% may seem high, this type of detector is probably the most common type installed in the field.
Stringent false alarm tests may be necessary to force manufacturers to develop more sophisticated smoke detectors with greater immunity to false alarms.
2. Manual call points (MCPs)
False alarms generated from the misuse or accidental operation of manual call points have been observed during a previous BRE study. It was found then that the use of protective covers could reduce false alarms by up to 17%.
False alarms resulted from physical impacts to the sides of the MCP, and other accidental activations as well as malicious (or even ‘good faith’) intent.
Here, false alarms could be reduced by installing covers that require a dual action: lifting the protective cover has to be followed by activating the MCP mechanism.
3. Sprinkler flow activation switches
A drop in water pressure from an activated sprinkler system can cause a signal to be sent to the fire alarm system.
These signals can be sent erroneously from sprinkler systems during servicing or when local changes occur, such as a drop in pressure in the water mains.
Due to the complexity of fire sprinkler systems, more research has to be done before detailed recommendations for reducing false alarms in this area can be made. However, the use of a suitable signaling time delay may in some cases be effective.
4. Procedures dealing with false alarms
Where there were procedures for dealing with fire alarm activations, in 88% of cases they did not address false alarms, and in 93% of cases fire alarm contractors had given no false alarm advice.
Clearly, this demonstrates a need for more training for the people responsible for writing procedures, and for a greater exchange of false alarm information.
Further research work could be used to provide valuable guidance on how to reduce false alarms to a much wider audience. Frequent meetings between stakeholders are recommended to support this.
5. Multi-sensor detectors
None of the false alarm observed came from multi-sensors. This finding is encouraging and suggests that multi-sensors do not cause many false alarms.
However, the BRE alarm specialist cautions, that there are many different types of devices, each with their own false alarm rejection criteria, which could produce a broad range of alarm responses.
Some multi-sensor detectors may be set up to respond to one fire phenomenon only (e.g. steam). This would mean that, though less prone to producing false alarms, they may also be less sensitive to detecting certain types of smoke.

Further research is required to support the use of multi-sensor detectors. The findings should then be used to inform codes of practice and building regulations.