Guidance Note Guide to the changes in BS

Transcription

1 Guidance Note

2 INTRODUCTION... 3 SCOPE... 4 THE CHANGES START ON THE FRONT PAGE NEW STYLE...5 NEW VERSION... 6 NEW TITLE... 7 NORMATIVE REFERENCES... 8 COINCIDENCE DETECTION... 9 COMPETENT PERSON RESPONSIBLE PERSON STAFF ALARM ADDRESSABLE SYSTEM RECOMMENDED FOR HIGH RISK PREMISES...13 ZONE PLAN VARIATIONS OMISSION OF DETECTORS IN L1 AND P1 SYSTEMS...17 FEATURES OF CIE CONVENTIONAL V NON ADDRESSABLE...19 REMOTE DETECTOR INDICATORS AUTOMATIC COMMUNICATION WITH THE FIRE AND RESCUE SERVICE...21 SOUND PRESSURE LEVELS AT THE BEDHEAD IN HOSPITALS AND RESIDENTIAL CARE PREMISES...22 FIRE ALARM WARNINGS FOR PEOPLE WITH IMPAIRED HEARING...23 DELAYED ALARMS GENERALLY DELAYED ALARMS IN RESIDENTIAL CARE HOMES...25 MOUNTING HEIGHT OF CALL POINTS VIDEO SMOKE DETECTION CEILING HEIGHTS ASPIRATING SMOKE DETECTION (ASD) SYSTEMS...29 OPTICAL BEAM SMOKE DETECTORS (OBSD)...31 MEASURES TO LIMIT FALSE ALARMS CONSIDERATIONS WHEN USING AND SELECTING POINT AND OPTICAL BEAM SMOKE DETECTORS [FALSE ALARMS] MAINTENANCE USER S RESPONSIBILITIES MAINS POWER SUPPLIES ISOLATION DEVICES MAINS SUPPLY WIRING WIRELESS SYSTEMS VISUAL ALARM DEVICES (VADS) WALL MOUNTED DETECTORS CARE HOMES V CARE PREMISES SOUND PRESSURE MEASURING INSTRUMENTS...44 HIS AND HERS CONFORMITY VERSUS COMPLIANCE FIRE DETECTION AND FIRE ALARM CIE GLOSSARY REFERENCES of 49

3 INTRODUCTION This is a short guide to some of the changes and the significance of some of the changes to BS that were introduced with the launch of the new edition in of 49

4 SCOPE The scope of this document is limited to identifying some of the more significant changes and does not attempt to go into every single change. Part of the purpose of this document is to highlight the impact of the changes; how they will affect the people involved in the provision and maintenance of systems and those who are ultimately responsible for purchasing and using them. There is an assumption in this document, that the reader is already familiar with the BS , the Code of Practice (CoP). However, it is worth pointing out that each part of the body of the CoP is split into two, the first part being the commentary the second the recommendations. The commentary provides a general overview of the topic in, approximately, plain English, while the recommendations give the specific rules which should be complied with. Compliance with the CoP is usually taken as conforming to the recommendations. The annexes are either informative and work like the commentary, or normative, which means they work like the recommendations and should be conformed to. 4 of 49

5 THE CHANGES START ON THE FRONT PAGE NEW STYLE The new version follows the current BSI house style. 5 of 49

6 NEW VERSION This is a new version, BS , not a revision (A3) however, the majority of the document is unchanged. BSI house rules prevent a CoP being amended more than twice. So even though it has not undergone the full in-depth review and, almost mandatory rewrite, it is, nonetheless, a new issue. Unlike most new CoPs there is no long phase in or coming into effect date. Instead, it replaced the old CoP on the date it was issued, 31 March The changes are not very extensive and are mostly concerned with a general tidy up of typographical errors and updating references. Many of the amendments are related to care homes, as a result of lessons learned from the Rose Park fire investigation. One substantive change results from experiments done at the BRE, partly funded by the FIA, into the effectiveness of optical beam smoke detectors (OBSD) and aspirating smoke detectors (ASD) in high spaces. The other, apparently, substantial change is for visual alarm devices (VADs). In essence, it is a new annex added at the end which explains the selection process for VADs conforming to BS EN Consequences Anyone issuing enquiries, tenders, quotes and the like, which specifically reference the 2008 version of the CoP, need not be too concerned, unless the system includes detection in high spaces or where stratification is likely to be a problem. 6 of 49

7 NEW TITLE Fire detection and fire alarm systems for buildings Part 1: Code of Practice for design, installation, commissioning and maintenance of systems in non-domestic premises 7 of 49

8 NORMATIVE REFERENCES Part 1 now refers to: BS 9999, Code of Practice for fire safety in the design, management and use of Buildings. This CoP defines the category of system depending on the risk profile of the building. However, in some cases the category indicated in the CoP may over or under prescribe for the actual building according to some commentators. BS EN 54-23:2010, Fire Detection And Fire Alarm Systems Part 23: Fire alarm devices Visual alarm devices. (See also Appendices.) Code of Practice for the design, installation, commissioning and maintenance of aspirating smoke detector (ASD) systems, Fire Industry Association, Issue 3 February of 49

9 COINCIDENCE DETECTION 3.9: A new definition has been added. 3.9 Coincidence Arrangement designed so that an output is obtained only when at least two independent input triggering signals are present at the same time Note: This is not to be mistaken for double knock, which is a colloquial term often used for an arrangement whereby an output is given only when two successive signals are received from the same device This definition aligns with BS Consequences Those who have been involved with FD&FA systems for a long time, particularly in connection with fire suppression systems, may find the description of double-knock contrary to their understanding. 9 of 49

10 COMPETENT PERSON 3.12: The following definition has a slight change Competent person Person with the relevant current training and experience, and with access to the requisite tools, equipment and information, and capable of carrying out a defined task Changing necessary training to relevant current training serves to underline the need for update and refresher training. Consequences You need to keep your training up-to-date. 10 of 49

11 RESPONSIBLE PERSON The definition of the responsible person, formerly clause 3.49, has been deleted. It was considered that the reader may be confused with the term used in English and Welsh fire legislation and which has a radically different meaning. Section 7, clause 47; the title has been changed from responsible person to the premises management. This section has been reworded to remove the term responsible person but the meaning of 47 remains largely unchanged. 48 Logbook, 48.2 a) has been amended to remove the term responsible person but otherwise the meaning of the sub-clause is unchanged. It is worth pointing out that the identity of the persons responsible for the FD&FA system should be recorded in the logbook, which is something that is often overlooked. Consequences Users should still appoint someone to be responsible for all matters concerning the FD&FA system, but they shouldn t call this person a responsible person. The identity of the person responsible for premises management should be recorded in the logbook. 11 of 49

12 STAFF ALARM The definition of staff alarm, clause 3.58, has been slightly amended to indicate that a staff alarm can be given prior to summoning the fire and rescue service (F&RS). 12 of 49

13 ADDRESSABLE SYSTEM RECOMMENDED FOR HIGH RISK PREMISES The title of clause 4 Need for a fire detection and fire alarm system and type of system is an extension of the old clause and refers to type of system. The commentary (4.1) now strongly hints that systems in high risk premises, such as nursing homes and hospitals, should be addressable to enable earlier location of the source of the alarm and, therefore, earlier intervention. This is expanded in the recommendation 4.2 c) which specifically says that where occupants of a building are going to need assistance from staff to evacuate, the system should be addressable. 13 of 49

14 ZONE PLAN Following the recommendations of the Rose Park enquiry, there have been a number of changes to the CoP. One of the problems faced by the staff was their inability to effectively locate the source of the alarm. One of these factors was that the zone plan wasn t clear which, in part, stemmed from disagreements between various parties as to whom was responsible for it. A definition of a zone plane has been inserted, clause Zone plan Diagrammatic representation of a building, showing specific topographic information and the division of the building into detection zones This effectively repeats the definition from e). In clause 6, exchange of information, the commentary 6.1 picks up this theme and says that responsibility for supplying the zone plan should be defined at an early stage of the planning of an installation. 6.2 c) recommends that the installer consults with the designer, the user or purchaser, the supplier of the system and consultants, and that during these consultations the topic of the provision of the zone plan should be settled. In Clause 23, control and Indicating equipment, there are no actual changes regarding CIE but there is emphasis on the provision of zone plans in the commentary clause 23.1, where a new paragraph has been added at the end. It starts with an anecdote about a real fire which, while it doesn t name the premises, was the Rose Park care home fire. In at least one multiple-fatality fire, it has been determined that some or all of the deaths could have been avoided if a diagrammatic representation of the premises (commonly described as a zone plan) had been provided in close proximity to the CIE. Accordingly, it is important to ensure that a suitable zone plan is provided adjacent to all CIE (including any repeat control and/or indicating equipment), unless the CJE incorporates a suitable display (eg an illuminated mimic diagram). The objective is to ensure that those responding to a fire alarm signal (including staff on the premises and firefighters) are given unambiguous information as to the location of a fire. In clause , the following recommendations apply to the facilities provided for visual indication of fire signals, following the last sub-clause e). There is a new note, note 3, which recommends that additional information be included on the zone plan and talks particularly about shopping centres, where occupier details might be helpful. It also makes the important point that this information should be kept up-to-date. Note 3: In some complex premises, eg shopping centres, additional information, such as occupier names, might be of value to those who are unfamiliar with the premises. This could be provided by a supplementary list that, for example, enables a unit number on a zone plan to be related to the occupier name, such as the name of a retailer in a shopping centre. Where such information is provided, it is important that it is kept up-to-date. In 42, acceptance, there is a new sub-clause inserted at 42.2 b) 4. This says that before accepting a system, the purchaser (or appropriate representative of the purchaser) should ensure that a suitable diagrammatic representation of the premises is provided close to all CIE, as recommended in e), which is, in short, a zone plan. 14 of 49

15 Consequences In new systems, a zone plan should be provided and as the user is likely to do this, it is down to the supplier of the system to supply it. The CoP effectively makes it the installer s responsibility to sort out the zone plan, but in many instances the installer is likely to be a specialist subcontractor for the supplier. The specialist would generally tend to have little or no contact with any of the others, which tends to move responsibility up and it becomes the supplier s problem. For existing systems, the service organisation is supposed to point out to the user if the zone plan is wrong or missing, but it is the user who is responsible for any corrections. This would usually mean that the service organisation would be asked to do it. 15 of 49

16 VARIATIONS There is a new clause e in 7.2 which recommends e) Major non-compliances (see 46.2) that are agreed variations should be clearly recorded in the logbook, so that they are readily available for future reference by maintenance companies and any other interested parties This is intended to ensure that anyone looking at the system is aware that any intended deviation from the CoP is a variation, rather than a mistake made by parties previously involved with the system. This is a bit of a relief for maintainers, as quite often the only bit of documentation that survives any time after the system is supplied, is the logbook. As the information should also be contained in the system documentation, the new maintenance organisation now has two chances to get their hands on it. Consequences For information to be included in the logbook, the supplier of the system would need to ensure that a logbook is supplied and partially completed at handover/acceptance. 16 of 49

17 OMISSION OF DETECTORS IN L1 AND P1 SYSTEMS Clause 8.2 f) describes Category L1 or P1 system, saying that automatic fire detectors should be installed in all rooms and areas of the building, but certain rooms or areas need not be protected if they are of low fire risk. It then lists some examples. However, it has long been a contention that these exceptions should also apply to other categories. A new note now makes this clear. Note 9: If detection can be excluded from any room or area in a Category L 1 system, it can also be excluded from such rooms or areas in a Category L2, L3 or L4 system. k) CIE should conform to BS EN Consequences Designers no longer have to worry that, having omitted detectors from what they consider low risk areas in L2 through L4 systems, they may have to justify what they have done. The CoP now provides the support. 17 of 49

18 FEATURES OF CIE In clause 11, system components, sub-clause k, note 1 has been added. k) CIE should conform to BS EN 54-2 Note 1: BS EN 54-2 contains optional performance characteristics which are not necessarily provided in all C/E, even if third -party certificated against BS EN It needs to be ensured that the C/E provided has appropriate facilities to enable compliance with all the recommendations of this British Standard. The note is intended to warn you that, just because the CIE is EN 54-2 compliant, it doesn t mean it will have all the features you require. Many features are not required by EN 54-2, but if they are provided, they must comply with EN There are several optional functions that are of concern to the UK market: Three controls are optional; coincidence detection, delays to outputs, disablement of addressable points and test condition. There are also four optional outputs; fire alarm devices (sounder outputs), fire alarm routing, fault alarm routing and extinguishing system outputs. For example, all life safety applications will require sounder outputs, but only those connected to an ARC would require a fire alarm routing output. Slightly off-topic but relevant; a general evacuate button is not a requirement of either BS EN 54-2 or BS However, BS does say that where phased evacuation is used, there should not be a general evacuate button. Consequences This means that if you are selecting CIE it should have EN 54-2 certification and approval, and that includes the options that are required. 18 of 49

19 CONVENTIONAL V NON ADDRESSABLE In , system integrity, d note 1 there was a typographical error in the 2008 version which has been corrected; the reference to conventional has been changed to non-addressable. Consequences While we still tend to refer to conventional systems, we should, since 2002, refer to nonaddressable systems. 19 of 49

20 REMOTE DETECTOR INDICATORS Nowhere in BS does it recommend using remote detector indicators (RDI). In the commentary 13.1, it says that in non-addressable systems RDIs are desirable in concealed locations and that they may not be necessary in addressable systems in the same situation. However, in there is a new note Note: Remote indicators might be required in a specification for areas such as inaccessible voids or locked rooms. See also 40.2 for the as-fitted drawing. which, quite rightly, suggests that the provision of RDI should be agreed with the client and identified in the specification. Consequences When estimating and quoting systems, remember that RDIs are not recommended in the CoP and have an impact on price. 20 of 49

21 AUTOMATIC COMMUNICATION WITH THE FIRE AND RESCUE SERVICE Following the recommendations of the Rose Park enquiry, there have been a number of changes to the CoP. One of the problems was the delay in summoning the F&RS. In clause 15, communication with the fire and rescue service, in 5.1, commentary, a sentence has been inserted: Automatic transmission of fire alarm signals is also necessary in the case of residential care premises. There are additional references in note 2 and note 3 of sub-clause e and f respectively, pointing out that automatic transmission is a requirement under Scottish Building Regulations. Note 2: In the case of shopping centres and hospitals, compliance with the Technical Handbooks (see scotland.gov.ukftopics/built -Environmentl Building!Building -standardslpublicationslpubtech) that support the Building (Scotland) Regulations 2004 (3] necessitate automatic transmission of fire alarm signals to an alarm receiving centre. Note 3: In the case of residential care premises, compliance with the Technical Handbooks (see http :llwww.scotland. gov.uk!topicslbuilt -EnvironmentlBuildingl Building -standardslpublicationslpubtech) that support the Building (Scotland) Regulations 2004 {3} necessitates automatic transmission of fire alarm signals to an alarm receiving centre. The note to 15.2 I) which recommends that alarm receiving centres should be third-party certificated has been extended to point out that the scope of the certification should include monitoring of fire signals, not just security. Note 4: Schemes exist for third-party certification of alarm receiving centres to BS However, transmission of fire alarm signals (as opposed to intruder alarm signals) is not always within the scope of the alarm receiving centre s certification; if reliance is placed on third-party certification, it needs to be confirmed that monitoring of fire alarm signals is within the scope of certification Consequences Purchasers and suppliers of a system for a shopping centre, hospital or care home need to be aware that provision of transmission equipment and a link to an alarm receiving centre, is a legal requirement in Scotland for new builds and, because installing a FD&FA system would be construed as a significant change to the building, it applies to existing buildings as well. Users and maintainers should ideally, ensure that the ARC is TPC for FD&FA system monitoring or at least claims compliance with BS 5979 for FD&FA monitoring. 21 of 49

22 SOUND PRESSURE LEVELS AT THE BEDHEAD IN HOSPITALS AND RESIDENTIAL CARE PREMISES The minimum sound pressure level (SPL) at the bedhead recommended in is 75dB (A). This is clearly unreasonable where the occupant of the bed is in no state to help themselves. Previously, the CoP implied that a lower SPL would have to be agreed among all interested parties. It didn t call this a variation but the description of the process was virtually that of a variation. In the new standard recommendations applicable to hospitals and residential care premises sub-clause b) has been shortened and the attendant note removed, so that the consultation and agreement of interested parties is no longer required. Consequences In hospitals and residential care premises, the designer can, where the intent is not to rouse the occupant of the bed from sleep, design to 65 or even 60dB(A), without the need for consultation or getting any of those pesky variations. It would, however, be prudent for the designer to establish which beds/bedrooms this applies to. It is also worth noting that HTM Part B (in England and Wales) and SHTM 82 (in Scotland) give further guidance on this but generally only apply to NHS premises. It is also worth noting that both of these codes are now downloadable from the internet FREE OF CHARGE. Go to and and search for them. 22 of 49

23 FIRE ALARM WARNINGS FOR PEOPLE WITH IMPAIRED HEARING Unofficially, there was a minor error with the previous edition of the CoP. Nowhere in the relevant section of the CoP did it refer to Annex C of the CoP, which describes the power supply requirements for tactile alarm devices. This error has been corrected in the new version by the addition of subclause e) where tactile devices are provided, control and transmission equipment should comply with the recommendations of Annex C. Similarly, , portable alarm devices sub-clause j) also requires power supplies to comply with Annex C. 23 of 49

24 DELAYED ALARMS GENERALLY Where the consequences of false alarms are severe or where frequent false alarms occur, it is common practice to delay the evacuation to give staff time to investigate and determine if the alarm is genuine. In this case, a staff alarm would be initiated on activation of a detector. This is described in clause 19, staged fire alarms, , recommendations applicable to staff alarms, what is now subclause c. However, it is apparent that heat detectors and sprinkler systems seldom give false alarms. Sub-clause c has been amended slightly now to include call points, heat detectors and sprinklers. It states that in these cases the general evacuate should not be delayed. Consequences All parties involved with a FD&FA system need to be aware that alarms initiated from heat detectors and sprinklers, as well as manual call points, should not be delayed. However, in some instances, where malicious activation might be a problem, delays on MCPs might be appropriate. 24 of 49

25 DELAYED ALARMS IN RESIDENTIAL CARE HOMES Following the recommendations of the Rose Park enquiry, there have been a number of changes to the CoP. At Rose Park there was a delay in calling the F&RS while the alarm was investigated. Clause 19 staged fire alarms, , recommendations applicable to staff alarms, a new sub-clause b) has been inserted. b) In residential care premises, a staff alarm should not incorporate any delay in summoning of the fire and rescue service when the fire alarm system operates, but there may be a delay in the general alarm signal, provided all staff are made aware of the fire alarm signal [see also 15.2 f)]. Consequences All involved with a FD&FA system in a care premises need to be aware that the F&RS should be called immediately on activation of a detection device, including a call point, even if there is a delayed or staff alarm procedure. 25 of 49

26 MOUNTING HEIGHT OF CALL POINTS The mounting height was 1.4m above finished floor level (AFFL) +/-200mm, so that gives you a range of 1.2 to 1.6m AFFL. However, accepted practice in buildings used by wheelchair users, is that the mounting height of switches and the like, was no greater than 1.2m AFFL. With millimetre accuracy you could just satisfy both requirements. Clause 20, manual call points, 20.2 h) note 6, has been amended to give a range of +/-300mm. So the mounting height can be between 1.1m and 1.7m AFFL. Consequences In most cases, positioning call points will not require any special considerations. If you, designers and installers, are told or have good reason to suspect that the building might be used by wheelchair users, you can mount the call points between 1.1m and 1.2m AFFL, knowing you would have satisfied the building regulations and the CoP, and without having to agree any variations. 26 of 49

27 VIDEO SMOKE DETECTION The final paragraph of , smoke detectors (which is a commentary) and which describes video smoke detection, has been expanded and slightly reworded. While there are no corresponding recommendations, it does indicate that this technology is now coming of age. 27 of 49

28 CEILING HEIGHTS The recommendations about ceiling heights have been simplified. Table 4 in the old CoP, which referred to greater ceiling heights for category P systems, where there was rapid attendance by the fire and rescue services (F&RS), has gone now only refers to Table 3. Table 3 has also been amended. The key differences relate to aspirating smoke detection (ASD) and optical beam smoke detectors (OBSD) which are dealt with below. 28 of 49

29 ASPIRATING SMOKE DETECTION (ASD) SYSTEMS The CoP has now adopted the terminology used in BS EN to describe high sensitivity, Class A ; enhanced sensitivity Class B ; and standard sensitivity Class C. In , choice of fire detection principle (which is a commentary), a new paragraph has been inserted below the list of applications where aspirating systems may be suitable. This new paragraph implies that, where ASD is used, only a specialist should be employed. Clause 21, types of fire detector and their selection, sub-clause 21.2e, is a list of detection types suitable for areas in which early detection of a smouldering fire is required. Not before time, ASD has been added to the list. In clause 22, spacing and siting of automatic fire detectors sub-clause 22.1, commentary, aspirating systems are referred to, alongside beam detectors as suitable detection types in tall spaces. Where it discusses stratification, it suggests that positioning sample holes at different levels might be employed. This is expanded on in 22.7, recommendations for the siting of aspirating smoke detection systems, where a new sub-clause c) has been inserted. c) Where an aspirating smoke detection system is used to protect spaces with high ceilings (>25 m) and there is a risk that the smoke could stratify before reaching the ceiling, sampling should be provided at multiple levels using drop-pipe arrangements at the wall and, where practical, within the main space. Table 3: Limits of ceiling height Detector type Heat detectors (BS EN 54-5) Class A1 Other Classes Point smoke detectors (BS EN 54-7) Carbon monoxide detectors (BS EN 54-26) Optical beam smoke detectors (BS EN 54-12) Normal sensitivity Enhanced sensitivity (alarm at 35% attenuation or less) Aspirating smoke detection systems (BS EN 54-20) General limit Class C with at least 5 holes Class C with at least 15 holes Class B with at least 15 holes Other fire detectors Column 1 Generally applicable Max ceiling height m (see Note 1) (see Note 2) Column 2 maximum ceiling for 10% of ceiling height area m As specified by the manufacturer see Note 1) (see Note 2) Note 1: The use of supplemental detection is recommended [see 22.5 d)] unless the risk (ie probability x consequence) of stratification is minimal. Note 2: The use of multilevel sampling is recommended [see 22.7 c)] unless the risk (ie probability x consequence) of stratification is minimal. 29 of 49

30 Combining the recommendations of 22.7 c) with note 2 of table 3, the implication is that in spaces between 25m and 40m tall, ASD should be used and sampling should be provided at multiple levels using drop-pipes arrangements at the walls and, preferably, within the main space as well. Alternatively, OBSD should be used. Also in clause 22.1, commentary, it discusses the stagnant boundary layer of air close to the ceiling surface, but suggests that aspirating systems are unaffected, permitting the use of flush mounted sample points. This is firmed up in 22.7 a) which has been amended to say that aspirating sample points do not have to comply with 22.3 d), which says the sensing element should be at least 25mm below the ceiling I), a new note 9 has been inserted, in effect recommending that aspirating systems should be used in racks over 8m high. In 22.3 and 22.7, the reader is told that further guidance can be found in the FIA Code of Practice for design, installation, commissioning and maintenance of aspirating smoke detector (ASD) systems. In 34, design process for limitation of false alarms, , recommendations for selection and siting of automatic fire detectors, a new clause has been inserted and is now sub-clause a). Essentially, it recommends using ASD in dusty and dirty areas, where other forms of detection might give rise to an unacceptable level of false alarms. It refers to the use of filters, but does contain the caveat that these would require cleaning or replacing to prevent blockage. a) In areas with high levels of dust and dirt which could contaminate detectors and/or lead to unwanted alarm, aspirating smoke detectors may be used which incorporate mechanical filtration of the air samples before they are analysed for the presence of smoke. It should be confirmed that the filters used for any such detectors are covered under the detectors approval to BS EN Furthermore, consideration should be given to the consequences of blocked filters to the detection capability of the system and a rigorous regular maintenance regime established if needed. Consequences Designers and installers should: Have specialist knowledge of ASD. Consider ASD for a much wider range of applications, as many will now conform to the CoP. Should consider ASD among other technologies, where the fire is likely to start as a smouldering fire. Be careful to select the appropriate class of ASD for the application. Use ASD or OBSD in spaces up to 40m high. In tall spaces, over 25m, where ASD is used, provide sample points at multiple levels, using droppipe arrangements at the wall and, where practical, within the main space, unless the purchaser has indicated that the risk of stratification is known to be low. In tall spaces over 25m, where OBSD is used at high level, supplementary detection should also be provided (angled beams or low level beams). Consider ASD in racks where storage racking is over 8m high. On ceilings use flush sample points, spigots/nozzles are not required. Use ASD in dusty and dirty areas, but these should be fitted with filters. Make good use of the FIA Code of Practice for (ASD) systems. 30 of 49

31 OPTICAL BEAM SMOKE DETECTORS (OBSD) 22, spacing and siting of automatic fire detectors, 22.1, commentary, there is a discussion about stratification and a passing mention of aiming an optical beam detector at an angle to the horizontal d) makes recommendations about beam type smoke detectors sited to provide supplementary detection where stratification is likely to occur. Following this is a new note, note 1, which says much the same thing and introduces a grammatical error in the last line. Note 1: An optical beam smoke detector may be installed at an angle from the horizontal, pointing down from the ceiling, in order to provide supplementary detection (ie in addition to beams located at or near the ceiling, as recommended in 22.3 d)} to detect of a stratified smoke layer within a high space. Table 3: Limits of ceiling height Detector type Heat detectors (BS EN 54-5) Class A1 Other Classes Point smoke detectors (BS EN 54-7) Carbon monoxide detectors (BS EN 54-26) Optical beam smoke detectors (BS EN 54-12) Normal sensitivity Enhanced sensitivity (alarm at 35% attenuation or less) Aspirating smoke detection systems (BS EN 54-20) General limit Class C with at least 5 holes Class C with at least 15 holes Class B with at least 15 holes Other fire detectors Column 1 Generally applicable Max ceiling height m (see Note 1) (see Note 2) Column 2 maximum ceiling for 10% of ceiling height area m (see Note 1) (43.0 (see Note 2) As specified by the manufacturer Note 1: The use of supplemental detection is recommended [see 22.5 d)] unless the risk (ie probability x consequence) of stratification is minimal. Note 2: The use of multilevel sampling is recommended [see 22.7 c)] unless the risk (ie probability x consequence) of stratification is minimal. The implication of Table 3, note 1, is that between 25m and 40m tall rooms, supplementary detection would be required and further combined with note 1 of 22.5 d), angled beams might be preferred. This makes sense, as the exact height of the stratification layer will not be known. By angling OBSD down through the area where the stratification layer might form, at least part of the beam will pass through the smoke and give an alarm. However, the CoP gives no advice on quantity, spacing, mounting height or the angle of the OBSDs. Consequences You can now use beams in much taller buildings than before but you must assume supplementary detection or angled OBSD will be required in spaces over 25m, unless you know for sure that there will be no stratification. Specialist knowledge would be required where angled beams are used; consult the manufacturers. 31 of 49

32 MEASURES TO LIMIT FALSE ALARMS 35, measures to limit false alarms, , recommendations for selection and siting of automatic fire detectors, has been significantly altered: A new sub-clause a) has been inserted, which recommends that ASD should be used in dusty and dirty areas. The ASD should be fitted with suitable filters and conform to BS EN It also emphasises suitable maintenance for such filters. Sub-clause h) was sub-clause g). The second sentence, which referred to Table 5 (now table 4) has been removed. The notes that followed have been moved and are now note 6 following the table 4 (was table 5). Sub-clause j), was clause h) has been amended. The first couple of sentences remain largely unchanged, except for removing the blanket term high sensitivity and replacing it with the contemporary terms high sensitivity (Class A) and enhanced sensitivity (Class B). The second part of the sub-clause has been removed and a new note, note 2, inserted. This indicates that class A and B ASD might be used to provide pre-alarm or may be used to give local/staff alarms in sensitive areas. j) Many aspirating smoke detection systems can operate at a level of sensitivity much higher than normal point type smoke detectors. Special consideration should be given to the potential for false alarms when a high sensitivity (Class A) or enhanced sensitivity (Class B) aspirating: smoke detection system is proposed, to ensure that an unacceptable rate of unwanted alarms is not likely to result. Note 2: Such systems are often used to provide signals intended to be managed as a pre -alarm warning (to indicate that an alarm condition is approaching) or as a very early warning (to alert staff of abnormal conditions that are worthy of investigation). Such signals might not be suitable (or intended) to be managed as an alarm signal that triggers alarm devices and evacuation of the building. In fact, such pre-alarm warnings or very early warning signals can be used to avoid false alarms and unnecessary evacuations. In some applications in which Class A and/or Class B aspirating smoke detection systems are used, a Class C (normal sensitivity) signal is provided which is managed as an alarm condition. 32 of 49

33 Table 4: Considerations when using and selecting point and optical beam smoke detectors Area Smoke detectors should never be installed Smoke detectors should be avoided if lf smoke detectors are installed they should not be of the type indicated possible Kitchens X Areas close to kitchens Ionisation chamber Rooms in which toasters are used X Ionisation chamber (Note 1) Rooms in which people smoke X (Note 2) Bathrooms and shower rooms X Areas in which steam occurs under X Optical normal operations Areas in which airborne dust occurs X (Note 3) Optical Dusty roof voids loft spaces and similar X (Note 3) Optical (Note 4) environments Areas in which large numbers of small insects (eg grain thrips) might enter Optical Areas in which t he sensing element of the detector will be exposed to high air velocities Areas in which there is high humidity likely to condense inside the detector Areas in which vehicle or other engine exhaust fumes occur Areas in which combustion gases may occur (eg certain boiler rooms) X X Ionisation chamber Optical Ionisation chamber Optical Ionisation chamber Optical beam Note 1: In confined spaces with poor ventilation, optical smoke detectors in close proximity to a toaster might give rise to false alarms, unless the detectors incorporate specific techniques for avoidance of false alarms. Note 2: Certain optical smoke detectors that incorporate specific techniques for avoidance of false alarms might be suitable for installation in rooms in which people smoke. Note 3: Regular cleaning or replacement of detectors might be necessary. Note 4: Certain optical smoke detectors incorporate measures to filter out false alarms in the event of dust ingress. Note 5: Optical detectors that are suitably designed to minimise unwanted alarms from insect ingress may be used in this application. Note 6: Table 4 does not apply in the following circumstances: a) Where it is considered necessary to install smoke detectors or smoke detectors of a type indicated as unsuitable, but filtering measures are incorporated (see ). b) Where, in a time-related system (see 3.6.1), the smoke detectors are disabled at times when the unsuitable environment exists. c) Where a multi -sensor smoke detector incorporates facilities to avoid unwanted alarms from the smoke sensor under environmental conditions in question. X X 33 of 49

34 CONSIDERATIONS WHEN USING AND SELECTING POINT AND OPTICAL BEAM SMOKE DETECTORS (FALSE ALARMS) Table 4 (was Table 5), considerations when using and selecting point and optical beam smoke detectors has been extensively altered and a lot of notes added There are two new entries; areas in which airborne dust occurs and dusty roof voids, loft spaces and similar environments. The entry areas in which the sensing element of the detector will be exposed to high air velocities now appears to rule out all forms of optical and ionisation type smoke detection, which presumably means only ASD or OBSD. If you argue that ASD and OBSD are forms of optical detector, it rules these out too, so no form of smoke detection would be applicable unless you class CO detectors as smoke detectors. This requires further clarification , filtering measures, , commentary, has been altered and now generally advocates delaying general evacuation to allow staff to investigate detector activations. It also advocates delaying summoning of the F&RS in all but care homes. This last point is now referenced in Recommendations d) note 1 and a new second sentence of f). e) has also been amended and makes it clear that at the end of the delay, that the F&RS should be called unless the alarm is confirmed as false. Consequences The changes to the table emphasises that those specifying and designing systems, need to consider the nature of the environments in which the detector is expected to function and the nature of any likely fire, to enable the appropriate detector to be selected, balancing the need for early detection against the need to minimise false alarms. Delayed alarms/staff alarms should now be considered as, almost, normal. Similarly in all but the highest risk premises (eg care homes) delaying the signal to the ARC should be considered, almost, normal. 34 of 49

35 MAINTENANCE It is a popular misconception in the fire safety industry and among many users, that part of the function of a service visit is to identify non-compliances with the current Code of Practice, and to verify that the system design was and remains, correct for the premises. BS has always indicated what is in the scope of the maintenance technician s actions, but it didn t indicate what was outside the scope. A new paragraph inserted at the end of 45 Inspection and servicing, 45.1, commentary, largely solves this. Routine servicing of a fire detection and fire alarm system does not constitute a fresh review of system design; it is a verification of the functionality and serviceability of the existing system. Accordingly, it will not necessarily be the case that non-compliances with Section 2 of this Standard will be identified at the time of routine servicing; in any case, the maintenance technician might not be aware as to whether an apparent non-compliance is, in fact, simply an agreed variation, particularly if the design certificate is not available. However, at their own prerogative, the maintenance organisation may point out aspects of non-compliance with Section 2. Nevertheless, any such advice provided to the user by the maintenance organisation cannot be regarded (by users, enforcing authorities or any other party) as an implication that the maintenance technician has identified, or has endeavoured to identify, all such areas of non-compliance, or that there has been any review of the original design. The section 2 referred to above is design considerations. In 45.3, recommendations for periodic inspection and test of the system, clause d) used to say: The standby battery should be disconnected and full load alarm should be simulated. This was a very simple test which proved very satisfactorily, that the power supply could support the system under the most arduous of conditions, without the help of the battery. This clause has been deleted and replaced by a new clause d) which says: The battery voltage should be measured with the mains on to check the steady state charge voltage and check it is within the manufacturer s recommendations. This however, assumes that there is an appropriate test within the manufacturer s maintenance manual, and that the service technician is in possession of it. The FIA would recommend carrying out both the old and the new recommendations as a simple safeguard. 45.4, recommendations for inspection and test of the system over a 12 month period, sub-clause o) used to say o): The cause and effect programme should be confirmed as being correct. It has been suggested that the intention was that the service technician should check that the programming had not been altered or deleted. However, many took this to mean a comprehensive test of the programming. In the new standard this sentence has been extended with the addition of by activating at least one cause and observing the operation of effects. This has simplified and clarified matters particularly where the C&E were quite complex. In 46.2, recommendations for special inspection on appointment of a new servicing organisation, subclause b) recommends that major areas of non-compliance with this standard should be documented and identified to the responsible person appointed by the user and then lists some examples including a new one, b) 10 the absence of a zone plan or other suitable diagrammatic representation of the premises (see e) , recommendation for inspection and test of the system following long periods of disconnection, was and is a one liner, which recommended that all the functions that would have been included over a 12 month period should be crammed into one service. But it has acquired a note which recommends that if there has been a major change of occupancy, the C&E should be 35 of 49

36 checked. Presumably this means more than that recommended as part of the 12 month service, and probably means that a review of the whole procedure would need to be done where this involves delays or phased evacuation. Consequences Maintenance technicians and maintenance organisations should bear in mind that they are not expected to be world authorities on system design; far from it. The change to the CoP gives you some protection from giving wrongful advice, but it would be better if you refrained from any comment other than known faults in the system, and any glaringly obvious non conformities. Maintainers; power supplies should be tested in compliance with the manufacturer s maintenance manual, if you can get your hands in it. While the new CoP does not recommend testing the power supply with the battery disconnected plus full alarm load anymore, the FIA would recommend doing this as simple safeguard. Maintainers; you do not have to do a comprehensive test of the C&E each year, just one aspect of it. But when taking over a new maintenance, you need to thoroughly check the C&E. At least once a year you should check that there is a suitable zone plan. 36 of 49

37 USER S RESPONSIBILITIES Section 7, clause 47; the title has been changed from responsible person to the premises management. There other changes related to the term responsible person which is discussed elsewhere in this document. An additional recommendation has been added, 47.2 j), which requires that the premises management ensure that the zone plan is kept up-to-date. Because F&RS across the UK have varying policies regarding automatic calls, a note has been added at the end of Note 2: It would be of value for the premises management to be aware of the policy of the relevant fire and rescue service with regard to response to calls from the premises and/or any ARC, in the event of operation of the fire detection and fire alarm system. Consequences The user should periodically check that the zone plan is current and correct. Where you, the user, have a link to an ARC you should also periodically check what the F&RS policy is in responding to automated calls. While the CoP doesn t say it, you would be well advised to record that you have done this in the logbook. 37 of 49

38 MAINS POWER SUPPLIES ISOLATION DEVICES The recommendations in respect of isolation devices in electrical supplies haven t changed. However, an additional explanatory note, note 2, has been added to 25 power supplies, 25.2, recommendations for mains power supplies. Note 2: The contractor responsible for supplying the 230V mains power supply needs to ensure that the particular device used does actually afford isolation. A number of switching devices do not meet the required isolation performance criteria. BS 7671:2008+A1.:2011, Table 53.4, details whether a particular device can actually be used for the purpose of isolation. An identically worded note, note 4, has been added to 29 electrical safety, 29.2, recommendations e) 25.2 h) which recommended that the isolator should in a position inaccessible to unauthorised persons or be protected against unauthorised operation by persons without a special tool, remains unchanged but the attendant note, note 4, which said: A special tool may, for example, be a key actuator (sometimes called secret key ) for a mains switch device, has been deleted. Consequences The installers should provide for double pole isolation of the mains supply to all parts of the system; the isolation facilities should be suitably sited, in the vicinity of the equipment served, for use by maintenance technicians without the need for access to remote parts of the building. It should be possible to lock the facilities in both the normal and isolate positions to prevent unauthorised use. A double pole concealed key switch, as commonly used for testing emergency lighting, would normally be suitable. 38 of 49

39 MAINS SUPPLY WIRING 25, power supplies, 25.2, recommendations for mains power supplies e) discuses power distribution in large premises and permits, in some circumstances, supplies to the FD&FA system to be taken from sub-distribution boards. A new note, note 4, has been added. The purpose of the new note is to permit the use of non-fire resisting cable between main distribution boards and the sub-distribution boards serving the FD&FA system. Note 4: It is recognized that in such an arrangement the recommendations of Clause 26 in respect of the fire resistance of the mains power supplies cables do not apply. However, taken at face value, the note seams to permit non-fire resisting cable all the way up to the FD&FA equipment. The last few paragraphs of 26, cables, wiring and other interconnections, 26.1, commentary, start by implying that final supplies to the FD&FA system should not be taken from RCDs and concluded with a statement implying that the supply should be surface run. These paragraphs were added to the A2 amendment in 2008, coinciding with the publication of BS 7671, but have now been deleted. We must presume that concerns over power interruptions from over-sensitive RCDs tripping out have proved unfounded and any normal breaker is now acceptable. Consequences Installers be aware: Final supplies from the distribution board to any part of the FD&FA system should be in fire resisting cable. Wiring between distribution boards does not have to be fire resisting. Final supplies may be run off RCDs and other protective device. Final supplies may be concealed in the fabric of the building or surface, run in exactly the same way as any other small power circuit apart from being in fire resisting cable. 39 of 49

40 WIRELESS SYSTEMS The opening of 27 radio-linked systems, 27.2, recommendations, has been subtly rewritten, making it clear that wireless devices which rely solely on battery power, should have two independent batteries, such that if one set (primary) should fail, a second would continue to support the device. A number of paragraphs in 27.2 have been deleted and the paragraphs renumbered. These paragraphs described the operation of the equipment and are no longer required, as BS EN covers this. Consequences Designers and installers should be aware that devices using just one battery set should not be used, even if they comply with BS EN of 49

41 VISUAL ALARM DEVICES (VADS) Where previously selecting VADs was a bit of a guessing game, it is now more of a science. Clause 17, visual alarm signals, sub-clause 17.2 e) said and still says: The intensity of output of visual alarm devices should be sufficient to attract attention, but not so high as to cause difficulty with vision due to glare. Previously, the system designer would have made a judgement as to the number and type of visual alarms required. However, note 3 has been added to the sub-clause and a whole new annex has been added to the CoP. BS EN 54-23:2010, Fire detection and fire alarm systems, fire alarm devices, visual alarm devices specifies the requirements, test methods and performance criteria for visual alarm devices used in fire alarm system. The new edition of the CoP calls for VADs to comply with BS EN BS EN requires the manufacturer to provide data on the product which the designer can use to determine the size and location of the VADs. The new CoP also calls the designer to use the methodology in the joint LPCB/FIA document CoP 0001, Code of Practice for visual alarm devices used for fire warning. Annex F contains all the information and data you need. In clause 11, system components, sub-clause m), has been inserted recommending visual alarm devices to comply with BS EN A new annex F has been inserted visual alarm device illumination characteristics. At first view this annex looks hideously complicated, but it isn t that bad. VADs are divided into three categories; C = ceiling mounted, W = wall mounted and O = the manufacturer provides the information. VADs with C and W categories have a numerical suffix x and y ; x being the maximum mounting height and y is the size of the area covered. In the case of category C VADs, y is the diameter of a circle, centred on the floor immediately below the VAD. In the case of category W VADs, y is the length of each side of a squire on the floor projecting out from the wall immediately below the VAD. The category and the numerical suffix, together, form the rating of the device. The tables F1 through F9 relate the size of the room (left hand column) to the maximum light level (top row). Thus if you know the room dimensions and the maximum light level, you can look up the rating of the VAD that you need. Consequences At the time the CoP was being drafted there weren t any VADs complying with the standard, so designers and installers may find that sourcing may be an issue in the short term. Also as the transition period for EN has been extended to 31 December 2013, products that do not comply with EN will still be available on the market until this date. The FIA has issued a guideline document on this issue, but basically where a VAD that is not approved to EN has been specified this must be explained and justified on a variation notice, so that all parties are agreed that it is suitable for the application. If you are a designer, you will have to be familiar with the tables and the method of determining the rating of devices and you ll have to get up-to-date data from your VAD manufacturer. 41 of 49