Angus has been involved in developing and writing British and International Fire & Safety standards since the mid-1980s. The list of standards that he has participated in is impressive and includes BS5839-1, BS8629, EN54-18 and ISO7240-2. Angus utilises his extensive experience to provide an authoritative perspective on the key issues that affect the Fire & Security Industry today.
BS 5839-1 specifies two types of fire resistant cables for use with fire detection and fire alarm systems, standard and enhanced.
Standard grade fire resistant cables are intended for all normal risk fire systems and represents typically 90% of the market.
Enhanced cables are intended for buildings which are either not evacuated in the event of fire, such as hospitals, or where evacuation is anticipated to require an extended time. Such situations might relate to the height of the building, unsprinklered buildings over 30m high require enhanced cables, or where evacuation is delayed or part delayed to allow for investigation times or to compensate for restricted escape routes.
Details of the cables
Standard grade fire resistant cables, tested in accordance with BS EN 50200 with a survival time of 30 minutes, corresponding to class PH 30. These cables are used in most fire detection and fire alarm systems and are considered to be suitable for being able to support the operation of the fire detection system to the point where fire is detected. They are also considered likely to be able to survive in moderate fire conditions to support alarm functions. The cables are tested at 830oC.
Examples of standard grade fire cables is Prysmian FP200 gold or Draka Firetuf.
Enhanced fire resistance cables are tested to meet BS EN 50200 with a survival time of 120 minutes and a test temperature of 940oC, corresponding to class PH120. They are also tested for 120 minutes to BS 8483-2. These cables are required to be used when the cables must withstand fire for a prolonged period, which is anticipated in buildings over 30 metres high, or where there is delayed or multiphase alarm operation.
The Enhanced fire cable performance tests were originally designed around MICC cable, but other soft skinned cables are now available that meet the enhanced performance criteria, such as Prysmian FP Plus.
Historic cable types specified in BS 5839-1
Prior to the 2002 revision of BS 5839-1, standard, non-fire resistant, cables were used for the mains supply to the fire alarm system and these cables were also used for detection circuits.
Fire resistant cables were used for alarm circuits, or any other circuit that would have to operate for an extended period after fire was first detected.
The loop circuits of addressable systems were often wired in fire resistant cables.
Application specific guidance
The recommendations in BS 5839-1 give a simple choice for the type of cable used in the fire detection and fire alarm system, including the main supply cable from the dedicated terminals of the distribution board.
Standard fire resistant cables are considered appropriate for most fire systems, but enhanced cables should be used for unsprinklered buildings over 30m high above ground level, or for buildings that have a delayed or 4 or more stage evacuation programme.
BS 5839-1 clause 26.2 note 6 gives details of a sprinkler system considered to provide compensatory protection to the cables. The sprinkler system should comply with BS EN 12845. However, if this is taken into account with the use of standard fire resistant cable, care should be taken to ensure that means are in place to ensure that the sprinkler system will be active at all material times. If that were not the case, the cable type might need to be reconsidered.
The same cable type is used throughout the fire alarm system. There has been a case where an installer interpreted the recommendations of BS 5839-1 to mean that below 30m standard fire resistant cable could be used and enhanced was to be used above 30m. This interpretation is incorrect.
The whole fire alarm system should be wired in enhanced fire resistant cable. The reason behind the recommendations is that the drafting committee recognised that a specific section of cable might be subject to fire for an extended period, and if the integrity of the cable was required for correct operation of the system, then it would need to be enhanced fire resistant cable. It is impossible to predict where a fire would originate, therefore, the whole system requires enhanced cable.
However, if a part of the building, formed from a separate fire compartment, were to be provided with its own fire detection and fire alarm system, and where evacuation from this part of the building was immediate, in the event of fire within the compartment, then standard fire resisting cable could be used for this sub-system. An example of such a case might be a high rise block of flats, where each falt was provided with its own fire detection and fire alarm system, such as a BS 5839-6 grade a system.
BS 5839-1 shows a similar arrangement in figure 17, where a high rise building is provided with networked fire alarm systems, such that, in the case of the example shown, each sub-system operated on two floors. If it could be guaranteed that the area covered by the sub system would be evacuated immediately a fire occurred within its area, then standard grade cable could be used within the sub-system, but enhanced cable would be used for the network cables.
BS 5839-1 figure 17 also shows an example of using standard grade cable for the network where a diverse routing of the network cable is provided. This might, in practice, be difficult to guarantee that the network system integrity would be maintained for an adequate period of time, in the event of fire in an unsprinklered high rise building.
Got a question about BS 5839-1:2017? Need Fire Safety Compliance advice? Get in touch today!
For over 45 years, Fixfire® has been providing quality products, systems and services for Life & Property Protection. Whatever your requirement, please call our Compliance Team for expert advice and a refreshingly different approach.
Freephone 08000 891999
Following the recommendations of BS5839 Part 1 2017 (Fire Alarm British Standard), it is a mandatory requirement to have an up to date, clear and accurate Fire Alarm Zone Chart adjacent to your Fire Alarm Control Panel and any repeater panels you have in your premises.
The purpose of the Zone Chart is to assist persons responding to an alarm to quickly identify the specific location in the building and to help the Fire Brigade understand the building layout before they enter.
When the Fire Alarm System is installed, the building is divided into Fire Zones. Any Manual Call Point (Red Box) or Fire Detector that is fitted will trigger a particular zone when activated.
The Zone Chart shows the division of each zone area with a ‘You are Here’ arrow to identify the position of the Fire Alarm Panel. The view of the building should be orientated in relation to the Fire Alarm Panel position to minimise confusion.
What is involved in producing a Zone Chart?
- Hard copy
- Or preferably AutoCAD (dwg) format
You have a legal duty of care to dispose of waste legitimately and safely via a licensed waste carrier. Failure to do so can result in prosecution, even if you have outsourced the disposal to a third party.
The Fixfire® Extinguisher Recycling Process is your reassurance that any Fire Extinguishers we remove from your premises have been disposed of in a safe and legal manner. 97% of each processed Fire Extinguisher is recycled.
Our contracted Extinguisher Recycling Unit (ERU) is a dedicated facility offering a service for the safe processing and recycling/disposal of fire extinguishers. The facility operates closely with the local Water Authority and the Environment Agency to develop safe, efficient and environmentally friendly processes, ensuring that ISO14001 certification is upheld.
Got a question about Fire Extinguisher Disposal? Need Fire Safety Compliance advice? Get in touch today!
For over 45 years, Fixfire® has been providing quality products, systems and services for Life & Property Protection. Whatever your requirement, please call our Compliance Team for expert advice and a refreshingly different approach.
Freephone 08000 891999
False Fire Alarms remain a huge concern within the education sector- interrupting already carefully scheduled, planned and well-prepared lessons or even causing major disruption and distress to exams.
Clearly, these false alarms cause significant inconvenience and disruption to students, staff, and visitors. They compromise everyone’s safety in the school and present a significant risk to the local community since the Fire Brigade will prioritise the school over other emergency callouts.
Solutions you should consider:
The first and most straightforward way is to use anti-tamper products.
Fixfire® supplies a wide range of solutions designed to protect Fire Alarm Devices from inadvertent damage or deliberate misuse/vandalism.
Products include:
- Local plastic cover flaps which attach directly to manual call points.
- The stopper consists of a clear, tamperproof, tough polycarbonate cover, frame and spacer that retrofits over a break glass call point. When lifted to operate the break glass unit, its optional battery powered integral sounder emits a piercing 96dB (at 1m). Immediate attention is drawn to the area and a prankster will either run or be caught!
- A range of steel web stoppers designed to protect fire detectors and warning devices. They are constructed from heavy-duty galvanised steel rod which is plastic-coated for durability and external use.
- A range of polycarbonate enclosures are available for the protection of devices such as fire alarm control panels and associated control equipment. The enclosures combine tough rugged construction with stylish design and offer excellent protection with a key lock for authorised access.
We also provide anti-tamper devices for fire extinguishers and associated products.
KeyCall® is a patented anti-ligature Fire Alarm and Access Control call point. It is designed to use the same key as the doors, providing simple operation for staff whilst eliminating nuisance activations by service-users.
KeyCall® has been developed by Fixfire® specifically for approved applications where standard versions would be vulnerable to abuse.
It is one of the best solutions for SEN schools and it is also compatible with a wide range of Conventional and Addressable Fire Alarm Systems.
Got a question about False Fire Alarms? Need Fire Safety Compliance advice? Get in touch today!
For over 45 years, Fixfire® has been providing quality products, systems and services for Life & Property Protection. Whatever your requirement, please call our Compliance Team for expert advice and a refreshingly different approach.
Freephone 08000 891999
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