The Rafiki Twinflex plus is a patented, 2 wire intelligent fire alarm system suitable for the majority of fire alarm installations. The Twinflex plus also has the option of the added feature of  ‘checkpoint’ alarm confirmation.

Checkpoint alarm confirmation drastically reduces the disruption and cost associated with false alarms, particularly during the settling-in-period following installation. Introduction of mandatory licensing of HMO’s of three stories or more was introduced in April 2006.

Licensing of HMO’s is mandatory for all local authorities and all buildings that are registered must comply, amongst other things, with fire regulations contained within BS5839 part 6, the main code of practice for installations within HMO’s and in some cases BS5839 Part 1 may also be applicable in communal areas.

False alarms are a huge problem in within these types of buildings and installers are constantly looking for an early warning fire alarm system without the disruption of false alarms.

There are over 485,000 false alarms attended by the Fire Services each year and hundreds of thousands more that are not recorded, sixty-five per-cent of which are attributed to equipment. In the main, detecting fire when no real fire is present, e.g. cooking fumes, steam etc. Even though these fire detectors are doing what they are designed to do they obviously can’t differentiate between a real fire and a false alarm, but the disruption caused and cost to the community is enormous. To tackle this problem Rafiki Protection has developed the Twinflex plus system incorporating ‘checkpoint’ alarm confirmation.

Extract from BS5839 Part 6 (Clause 12. Limitation of false alarms)

In some (usually larger) houses in multiple occupation, high levels of false alarms sometimes occur, simply as a result of the number different occupants, each of whom carry out activities, such as cooking, that can lead to false alarms. In such circumstances, occupiers have been known to compromise or even cause damage to, the fire detection and alarm system, or to ignore fire alarm signals. This makes it important to minimise, as far as practicable, the extent to which occupiers are disrupted by false alarms in other occupiers’ accommodation. This might, for example, be achieved by use of a mixed system (see 9.1.5)*. Alternatively, other measures might be adopted; for example, in the event of a fire signal in one dwelling unit, a short time delay might be incorporated for the occupier to investigate the cause and, if appropriate, reset the system before a fire alarm signal in other dwelling units.
* Mixed system BS5839 part 6 and BS5839 Part 1

Rafiki Checkpoint – Definition

Alarm selection, the main feature of the Rafiki Twinflex plus is the ability to set a pre-alarm in individual rooms or apartments but at the same time initiate full alarm should fire be detected in any communal area. This is made possible by a detector sounder ‘logical link’ feature. This is the first time that this feature has been made available on a conventional system and is beneficial where two stage alarms are required.

At the planning stage of installation fire zones are designated as ‘dwelling’ or ‘communal’. Detectors in dwelling zones (e.g. apartments, hotel rooms etc.) are enabled with the ‘logical link’ feature by way of a dil switch in the detector. This then allows the control panel to be, simply, programmed with a variable time alarm confirmation period (1-5 minutes at one minute increments). In the event of a fire being detected in a dwelling only the local (room) sounder will operate to alarm occupants of that particular dwelling.

The control panel will then carry out a number of checks over this period (which may be 2 minutes, for example ) to confirm the detector is still in alarm and is a genuine fire, not a false alarm generated by cooking fumes, steam etc. If at the end of this checking period the detector ceases to signal alarm the control panel will automatically reset the detector/sounder and the system will revert to its normal state.

If, however, at the end of the confirmation check the detector is still generating an alarm signal the control panel will instantly sound all alarms in the building for full evacuation. Detectors sensing fire, or, call point activation (in any zone) in communal areas instantly generate a full alarm throughout the building.

• The control panel meets all the requirements of EN54-2 and EN54-4:1997.
• The detector meets the requirements of EN54-5 and EN54-7 :2000.
• The sounder meets the requirements of EN54-3:2001.

NOTE: Twinflex Plus panels are configured to have ‘Dwelling’ or ‘Communal’ zones at the time of commissioning. Dwelling zones are then set with the ‘checking’ period – between 1 and 5 minutes. Rafiki advises that this panel should only be installed and configured by qualified fire alarm installers or equivalent personnel.

Using the Twinflex Plus system in an installation

At the planning stage, fire zones are designated as either ‘Dwelling’ or ‘Communal’. Multipoint detectors in the dwelling zones have the facility to use ‘checkpoint’ technology. By simply enabling the logical link dil switch in the detector. The ‘Checkpoint’ technology is the ability to select a checking period for individual detectors to confirm the smoke/heat detected as a genuine fire not an false alarm. This checking period can be selected between 1 – 5 minutes at commissioning stage after consultation with fire officers or other authorized bodies.

Communal Zone
Communal area, e.g. hall/stairway; kitchen; lounge. When a detector alarm is activated on this type of zone, the control panel enters the fire state and the alarms are activated immediately in all zones throughout the installation.

Single Dwelling per Zone (Zonal confirmation alarm) e.g. flats with more than one room

When a detector alarm is activated on this type of zone, all sounders on the zone are activated and then the control panel carries out the configured number of confirmation checks.If the detector alarm is confirmed, the control panel enters the fire state and the alarms are activated throughout the installation; if the detector alarm is rejected, the sounders on the zone are silenced, and the detector in alarm is reset.

Multiple Dwellings per Zone (Local confirmation alarm)
Dwellings requiring a single detector/sounder, e.g. hostel; hall of residence; hotel rooms; bedsits.

When a detector alarm is detected on this type of zone, the integral sounder in the detector that generated the alarm signal is activated and then the control panel carries out the configured number of confirmation checks. If the detector alarm is confirmed, the control panel enters the fire state and the alarms are activated throughout the installation; if the detector alarm is rejected, the sounder is silenced, and the detector reset.

Note: Activation of any manual call point will override alarm confirmation

Read more about the generally accepted guidelines by Rafiki, Aico, and other Fire Alarms manufacturers, (they are also commonly accepted for all the domestic, commercial and industrial properties in UK); the Rafiki advices for Fire Alarms, some of the guidelines provided by Rafiki(intelligent fire technology) – check out the Rafiki series of industrial/commercial fire alarm systems (like the Rafiki Twinflex), found at The Conventional and Analogue Fire Alarms. For more details about the fire alarms, visit the Fire-Detect website(see a list of articles about the fire alarms here and here).

• The responsible person is required under BS5839 to undertake certain tasks with respect to the testing and maintenance of the Fire Alarm System.
• The responsible person is also required to liaise with the building maintenance personnel to ensure that their work does not impair or otherwise affect the operation of the Fire Alarm System, and to ensure that a clear space is maintained in the vicinity of detectors, and call points (break glass units) remain unobstructed and conspicuous.

Routine Testing

• The responsible person should also ensure that the following routine testing is carried out. If there is a link to a remote monitoring centre it will be necessary to advise the centre prior to a test.
• On larger systems it may be necessary to isolate building services interfaces to avoid disruption to the occupants.
• In any case the panel should provide audible and visual indication that parts of the system are isolated. This may take the form of a light on the main control panel.

Daily testing
Check that the panel indicates normal operation and that any fault is recorded. Also check that the recorded faults have been dealt with.

Weekly testing
Every week, a different Manual Call Point should be operated to test the ability of the control equipment to receive a signal and sound the alarm. The results should be recorded in a log book.

Biannually (previously quarterly) testing
The system should be checked by a Fire Alarm service organisation. This may be the system installer or an approved maintenance company, and is normally arranged via a maintenance agreement which specifies the number of visits and the level of service. The agreement should also cover non-maintenance visits, eg. call outs to attend faults etc.

The standard specifies a number of maintenance tasks which include a visual inspection of the installation to ensure that there are no alterations or obstructions which could effect the operation of the system, and functional checks to confirm the operation of the system. Any defects should be recorded in the log book and reported to a responsible person. A certificate of testing should also be completed and given to the responsible person.

Annually testing

• Each device on the system should be tested for correct operation as before.
• Any defects should be recorded in the log book and reported to the responsible person.
• A certificate of testing should be completed and given to the responsible person.

Action by user following a fire

• Advise the servicing company to arrange for the system to be tested by them.
• A certificate of testing should be issued to confirm the system operation following the inspection and any remedial work that is necessary.

Action by the user after any false alarm

The user can assist the servicing company in the identification of false alarms by observing the following:

• Always make a note of all illuminated indicators and messages displayed at the control panel
• Try and identify the activated device, i.e. Do not reset the panel until the area of the incident has been inspected
• Record any other incidents occurring at the same time which could affect the system, e.g. Power supply failure, building works etc.
• The service organization will be more likely to trace the false alarm if the above information is available.

Action by the user following a fault

• When a fault is reported by the control panel, the user should note all illuminated LED’s and the circumstances at the time the fault occurred, and report to the servicing company.
• The service company will be able to advise if the system is still able to respond to a Fire Alarm or whether extra vigilance should be observed until the fault is rectified.
• Faults should, under no circumstances be left unreported.

These are the generally accepted guidelines by Rafiki, Aico, and other Fire Alarms manufacturers, and they are also commonly accepted for all the domestic, commercial and industrial properties in UK. It is also our recommendation to all our visitors and customers to mind these basic rules(which should also be printed/posted especially at the workplaces).  Read more about the Rafiki advices for Fire Alarms, some of the guidelines provided by Rafiki(intelligent fire technology) – check out the Rafiki series of industrial/commercial fire alarm systems (like the Rafiki Twinflex), found at The Conventional and Analogue Fire Alarms. For more details about the fire alarms, visit the Fire-Detect website(see a list of articles about the fire alarms here and here).

Rafiki Manual Call Points

• A ‘Manual Call Point’ is a device which enables personnel to raise an alarm in the event of a fire incident by pressing a frangible element to activate the alarm system.
• The Manual Call Points should be installed at a height of 1.2m above floor level at easily accessible, conspicious positions, on exit routes, at the entry floor landings of staircases and at all exits to the open air.
• The Manual Call Points should be spaced so that one may always be found within a maximum distance of 45m apart or 25m for disabled person.

Rafiki Automatic Detectors

When deciding on the type of detector to be used in any area it is important to remember that the detector has to discriminate between a genuine fire and the normal conditions existing therin, like the smoking and staff rooms, steam from ensuite bathrooms, kitchen fumes, vehicle and forklift truck fumes in warehouses, etc. Generally, all types of detectors should be sited on the ceiling at the highest point of the area to be covered. Detectors mounted at greater heights have a reduced efficiency and in these cases further advice should be sought.

Smoke Detectors – general info

In open spaces under flat horizontal ceilings, every point should lie within 7.5m of a smoke detector.
Smoke detection should be generally avoided in the following areas to avoid unwanted alarms.  They should  be protected by means of other detectors such as heat detectors.

• Contamination in dusty areas may cause unwanted alarms and reduce the life of the detector.
• Damp or humid conditions such as showers, bathrooms and external areas should be avoided as the water vapor may cause unwanted alarms and reduce the life of the detector.
• Detectors should never be used at low temperature where ice or condensation can affect detector sensitivity.
• Kitchens, garages, welding shops and boiler houses should generally be avoided.

Heat Detectors – general info

• In open spaces under flat horizontal ceilings, every point should lie within 5.3m of a heat detector.
• Heat detectors are designed to either detect a rapid rise in temperature or to operate at a fixed temperature.  Although they provide a slower response time than smoke detectors they do provide a method of protection for areas where smoke detectors cannot be used.
• Heat detectors should not be used for the protection of life or where extensive property loss may be expected.

Types of heat detectors

• ‘Rate of Rise’ Heat Detectors
  ‘Rate of Rise’ heat detectors respond to both rapid increases of temperature and to fixed top temperatue.
• ‘Fixed Temperature’ Heat Detectors
  Fixed temperature heat detectors are available with different temperature settings, and are normally installed in kitchens, boiler rooms, etc.

Detection In Apex Roofs

If the ceiling is pitched or sloping, smoke will tend to rise towards the highest point (apex) of the roof, therefore detection should be placed in the apex.  As the slope tends to reduce the delay before smoke or heat reaches the detectors, it is permissible to use a greater spacing between the detectors mounted there.
The spacing of the smoke detectors in the apex only, may be increased by 1% for every degree of slope of the ceiling up to a maximum of 25%.

Fire Alarm Sounders

• Fire Alarm Sounders should be installed throughout the building with an even distribution, to generally provide a minimum sound level of 65dB(A) or 5dB(A) above any background noise which is likely to persist for more than 30 seconds.
• Where the alarm may have to arouse sleeping persons e.g. Hotel bedrooms, nursing homes, etc, a minimum sound level of 75dB(A) is required, at the bed head with all the doors shut.
• All fire alarm sounders in a building should produce the same sound, distinct from any other audible warning devices in the building.
• Where fire alarm sounders are required in extremely noisy areas (e.g. machine shops), it may be necessary to install additional ‘Visual Indication Beacons’.

Cabling

The operation of a ‘Fire Alarm and Detection System’ depends on the cabling and connections between the components.  It is essential that connection between Manual Call Points and Detectors function correctly when they are operated. The cables within the system are required to function correctly for significant periods after being attacked by fire.  These include the power supply cables to the control panel, the detection circuits and the fire alarm sounder circuits.  Thus the cables chosen must be correctly rated to withstand these conditions.

This is the second part of the Rafiki advices for Fire Alarms(the first part is here), some of the guidelines provided by Rafiki(intelligent fire technology) – check out the Rafiki series of industrial/commercial fire alarm systems (like the Rafiki Twinflex), found at The Conventional and Analogue Fire Alarms. For more details about the fire alarms, visit the Fire-Detect website(see a list of articles about the fire alarms here and here).

A fire risk assessment should identify:

• Possible hazards;
• Sources of ignition;
• Persons at risk of fire;
• Means of escape;
• Fire detection and alarm systems;
• Fire fighting facilities;
• Routing procedure in the event of fire;
• Any difficulties with the above – and plans to put them right.

Fire Detection & Alarm Systems BS5839 – Risk Assessment

• The ‘Fire precautions (Workplace) Regulations’ require any business employing five or more persons to hold a written ‘Fire Risk Assessment’ and ‘Emergency Plan’.  This must be periodically reviewed.
• The local fire brigade can enforce compliance, and close any building that does not meet this act.
• In the event of a fire in a building without a written ‘Fire Risk Assessment’, those responsible may face fines and imprisonment, and/or private litigation.

The Law requires you to

• Complete a fire risk assessment for your work place (considering all employees, the public, disabled people and people with special needs).
• Identify and record any significant findings or persons at risk.
• Provide and maintain fire precautions.
• Provide information, instruction and training.
• Nominat e persons responsible to implement your emergency plan.
• Consult employees about the above nominations and your proposals to improve fire precautions.
• Inform other employees who may have work places in the building about any significant risks which may affect their safety and co-operate with them to reduce/control these risks.
• If you are not an employer, but control premises which contain more than one workplace, you are responsible for complying with fire regulations.
• You must establish a suitable means of contacting the emergency services.
• Your employees must co-operate to ensure the workplace is safe from fire and its effects.

Fire Risk Assessment – System Zoning Information

In order to aid identification of the source of a possible fire, the protected building should be divided into ‘zones’.  When deciding on a suitable zoning scheme for a building, consideration should be given to the size, any existing fire routines, escape routes, zone accessibility, and structural fire compartmentation.

The following guide lines should be observed:

• If the total floor area of the building is less than 300sqm then the building needs only one zone, regardless of the number of storeys.
  If the total floor area is greater than 300 sqm:
• The maximum area for a zone is 2000sqm.
• If a stairwell (or similar) extends beyond one floor it should be a separate zone.
• If a zone covers more than one fire compartment then the zone boundaries should follow the compartment boundaries.
• The search distance within the zone in order to ascertain the position of the fire should not exceed 60m.  Remember that the use of Remote Indicator lamps may help to reduce the distance traveled.
• If a building is divided between occupiers, zones must not be shared between them.

These are some of the guidelines provided by Rafiki(intelligent fire technology) – check out the Rafiki series of industrial/commercial fire alarm systems (like the Rafiki Twinflex), found at The Conventional and Analogue Fire Alarms. For more details about the fire alarms, visit the Fire-Detect website(see a list of articles about the fire alarms here and here).

The Multipoint Detector – Twinflex

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 wired in too – with no extra wiring, therefore greatly reducing the number of points that need to be installed and the time it takes to install them.

As the Multipoint offers 7 different modes of detection, the installation is made even simpler as this one device suits all applications. Whatever type of detection is required, for any part of the installation it can be selected by the flick of a switch at the time of commissioning. Any one of 3 different smoke modes, 2 fixed temperature heat modes, a rate of rise mode and a combination smoke or heat mode can be selected.

As the Twinflex Multipoint detector is available with or without a full specification 90 dB(A) sounder (for only a marginal cost difference) no extra devices need to be purchased when audible warning is required. (Meets audibility levels recommended in BS5839 Part 1:1988). Twinflex Manual Call Points can be run on the same pair of wires as detectors. Both detectors and Manual Call Points have a built in EOL switch so that any device may be set as the end of line monitor. The panel can also differentiate between a Manual Call Point and a Detector alarm.

If extra sound is required, or for areas that do not require detection, then the Twinflex Hatari sounder may be used on the same two wires, offering sound output of 100dB(A). It also has a built in EOL monitoring switch.

The panel can accommodate up to 32 devices per zone, has separate fault monitoring displays for each zone, and a one man walk test facility. Zones are configured without the need to use resistors or capacitors on unused zones.

The Rafiki TwinFlex – features

• Two wire installation – only one circuit per zone to connect detectors and sounders – installation savings can be as high as 40%
• Break glass identification. The panel has the ability to differentiate between call point or detector alarms.
• Built in end of line device. All devices, including detectors, manual call points and sounders have a built in end of line monitoring function. Simply flicking a switch within any device will enable end of line monitoring. No resistors or extra circuits are required.
• No base diode requirement.
• Seven modes of detection.
• System fully complies to BS and EN.
• 32 devices per zone.
• Easy to install – no need to worry about marking “in’s” and “out’s”.
• Available in 2, 4 & 8 zone panels.
• 72 hour standby.
• All panels have 1 auxiliary sounder circuit (500mA).
• 8 and 16 zone repeater panels available.
• Input & Output modules available for plant shutdown, door release, etc.
• Savings in cable costs.
• Savings in installation costs.
• Multipoint Detector/Sounder saves the cost of a sounder.

Rafiki Twinflex – Technical specifications

• Battery: 2/4 zone – 2 x 12v 2.1Ah, 8 zone – 2 x 12v 3.3Ah
• Panel Dimensions (WxHxD): 2/4 zone – 310 x 243 x 85 mm, 8 zone – 315 x 400 x 90 mm
• Panel Construction: 2/4 zone – fire retardant plastic, 8 zone – mild steel
• Mains Voltage: 230 volts AC +10% -15% 50Hz
• Operating Voltage: 24 volts DC

Buy online the Rafiki series of conventional fire alarms:

• Rafiki Twinflex Hatari Sounder, White sounder;
• Rafiki Twinflex Multipoint Combined Detector and Sounder;
• Rafiki Twinflex Manual Call Point with Sounder;
• 2 Zone Twinflex PLUS Fire Alarm Control Panel;
• 8 Zone Twinflex PLUS Fire Alarm Control Panel Rafiki;

at the Fire Alarms, Conventional and Analogue Fire Alarms section.